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Home My WebLink About20183741.tiffEXHIBIT INVENTORY CONTROL SHEET Case USR17-0072 - PIONEER LAND COMPANY, LLC, C/O NORTHERN COLORADO CONSTRUCTORS, INC. Tyler Exhibit Page # Submitted By T. 2-5 Nicole Cantrell U. V. 8-13 Jim Cantrell Description Surrounding Property Owner Petition (received 12/05/2018) 6-7 Nicole Cantrell Map of existing gravel pits (12/05/2018) Email correspondence between Mr. Cantrell and Anadarko (received 12/05/2018) Air Quality Control Commission (received W. 14-121 Brad Windell 12/05/2018) WRAP Fugitive Dust Handbook (received X. 122-365 Brad Windell 12/05/2018) Y. 366-383 Brad Windell Photos (received 12/05/2018) 2018-3741 GRAVEL PIT OPPOSITION PETITION USR 17-0072 OPPOSITION PETITION ON BEHALF OF THE WELD COUNTY COMMUNITY Petition Point of Contact: Cantrell Family iioi6 County Road 23, Fort Lupton, CO 80621 We the community surrounding the proposed gravel pit mining site east of and adjacent to CR 23; North of CR 22 1/2 wish to protect our region _ from the negative impacts the proposed gravel pit will have on our rural lives and our community. Gravel Mine Concerns: 1. Significant increase in truck traffic — Safety risks and environmental risks 2. Roadway safety at an already busy and dangerous intersection (CR 23 and CR 24) a. Increased traffic congestion at an already dangerous and busy intersection b. Increased road damage due to heavy load trucks c. Increased road hazards from large trucks not obeying posted speed signs and loose gravel being spread on roadways d. Air pollution concerns with trucks idling in front of residential housing while waiting to turn onto roadway 3. Dust pollution — Difficult to mitigate without constant water truck management 4. Noise pollution — Jake breaks, back up notifications, gravel mining operations will impact rural lifestyle 5. Environmental Concerns regarding water wells and surrounding water table, effect on wildlife habitat 6. Water tap does not exist on site to support planted trees acting as barriers, roadway watering and plumbing for onsite staff 7. Loss of property value — Long term impact on surrounding properties and water storage abilities to return site to a suitable state after mining operations 8. Roadway impact for construction and the movement of road 24 9. Long term plans for the movement of CR 24 to connect I25 to Highway 85 may impact this area again in the future? Currently there are 15 gravel mining sites within a 6 -mile radius. It is unclear that there is a need for additional mined sand, gravel and stone materials. In addition, there has been a significant increase in truck traffic on county roads that were not constructed to withstand this excess usage, weight and travel. New mining will add to already overburdened roadways. Most neighboring homeowners have multiple wells to provide water for their families and their properties. There is concern for changes in these wells and their operation due to gravel mining. There is a concern regarding changes in the water table due to mining operations. Dust particulate is difficult to mitigate and will be spread across the surrounding community and could impact public health. Water truck schedules are not established and may not meet the need of the community. Mining productions would be detrimental to the environment and to the many families that live nearby. We have grave concerns that if this plant opens there will be a loss of everyday liberties for all residents, which will cause a reduction in property values, and a reduction in the quality of life due to the issues noted. The amplified use of roads leading to increases in traffic, hazards, and degradation are long term issues that must be considered. Gravel Pit Opposition Petition - USR 17-0072 If the County Commissioners should decide to go against the communities wishes, which is to deny the gravel mining application, and the Commissioners approve the permit for USR 17-0072 - we request the following provisions be considered and included as part of gravel mining operation requirements set forth by the Weld County Board of Commissioners: Requests: 1 2 3 1. Installation of a traffic light at the newly constructed intersection of County Road 23 and County Road 24 to improve public safety and address traffic congestion concerns. 2. Establishment trigger points which would require action for any wells or ground water tables adversely affected by mining operations. 3. Determine a required water truck roadway maintenance plan including multiple roadway watering trips per day to reduce dust pollution. 4. Prohibition of lighting on the property which would cause additional light pollution. 5. The restriction of the usage of Jake breaks and back up beeping warnings on trucks entering the site, leaving and while on the property. 6. Additional barriers/tree considerations to improve the look of gravel mining operations and block the view of the pit for neighbors. PRINTED NAME HOME ADDRESS gy-rJ5zsJ C4€E4L1 SA Uri 4 j-eT X169.3 tt 3M-5 Cod n►ty KD 23 Thupa'\ co 6ce' /CY0// Cocvcty Roc( ‘23 LcApkkric/D a 1 i06gi c��,ty 6Ceak 23 00:9CocV -rdr± (.5,Ifori, 02) c(oGA /opt of. 2-y- rser Thitr tit -Div/ Go or001--/ �CSusi� 104\ YILLS L) 17 -1.h.) �v ci 1, a 1 6 l0r35 � A4 /-2 LcktxCrnudij Firs,C,,�}�,n, Co M*1011 7 6-bcrrN (�pIANT`7 lit �q�-hkeeuN Gav\v\oyN IoeJs ,2424 L, 4\ka) Co Penal \ti --\35 3 LLtricoiN CO %Oteck4 Gravel Pit Opposition Petition - USR 17-0072 SIGNATURE COMMENTS 2 J 1M\E ADDRESS �1 SIGNATURE COMMENTS yvtos" A -V -E Tier r ?am: •ttb-r-4 naki Pic( 29 y 694 y riy goad 29- ritere4, (O,j, Antonio 1;)c tam\ 23 C12. 11 .13,121 Cfr- aze �o v�%fa Co,� � ridn CA) Mt\ 4ut 17ti3 , /\ W P /rt naa�oE�inco C (2 2 7) izo3 CD 5d 6e eeo volQ See Wat 7"-Zcer 3 PRINTED NAME HOME ADDRESS SIGNATURE COMMENTS �3 (030 ed2-- r).3 m c NACL � t-l�E L a- FT', kmi N <= ° ; �0 6 z( ilitAsaggc'eve � : 24 Ptk Ave �L Co e0C, 01 tz. pi',;, Fizz, _. 0 ..7A-nel 4 ror--16" itia. ki>phet, c,:::--tA :2.1 LaAker4A 86.4 frn ttiquin 1 , i a+ LuLapitin CI i'-C V a i ((4% ci& 2.3 2� w, II/ Lcs:s <,•5 Fc,te_/- curs,,... co gu6,..4 7/1.`� J� /-1-Aa9vvie\ celiE 1�� Ma z8 � �'\�i- rho b 71 ,.v. 1 t 4 (50 rot, w p ton ( o Y'lii()\411/414 7 �kry v 1101L CAC. Q3 '' I ,• lk;l�_ cu. ft 1-N\AKohl Co Seal ScAmbf' s96.7 c/2. a 3 .. rt CO rog,, zP . Holt, etts 6 n plika 21 sl94 C2 2 i_\ s g it vr 1-)Lp+e-nr- CSO ..cSuctirk5 M kx) Se.,62- ( ert: , , 7 i��s6 C�u.ry�.p,as :t8,._ I% �\��i�n7��- 33,S?t �tp,1 �C.i �_��l(1niS k'L�jo, (c, c:a3� CS 4 , E MC -wt L L i�� Cc_17 sa 5-ratNJ Et4cTL10,&/ << 3 4t 3 z -ti ck *t--..3 r TC'ti>k,cc as U44 k -4171I il _ f Gravel Pit Opposition Petition - USR 17-0072 4 PRINTED NAME HOME ADDRESS SIGNATURE COMMENTS 36 -�( 1 il-c)c-ct- F o r -c LAi-settsAk 0 3 g.� CO La. W.C l2. at� i-esw-d/J___ 3,4i-e),..� me (1. 37 i‘(( L. /�� L / al !o9(a3 E,�ce. ter/'/i for+ Lc -10,‘ ed S2O-1 3s LANO(CE en-IlGf e_ io3z+ c 23 Cc pi- UtPnM1 &Ofl( 39 /C32.1 Fr WPThtJ, Co "Obit WO At --1--- �-� esoyfr3 etc. ?z 40 �� 4 AA) 6._ g. 6,-/ ter $4. rt t 2 , / (7ES F/4,04/ el, )?4°.2 7 . .__ 41 pAtNn C\00{, - IoHt3 Cet-5 Ple- 0014 Cb BoCoz4 42 43 }�iwl I V Chi: Ecent Cy/tit /�C%, 44 '?Zi4ck> 71, boDei,`/ co rk, 45 '1 j ��.1. �� Ql (Irk, ca. Co1-4 Lo 301o2( Pivn 46 47 48 49 Gravel Pit Opposition Petition - USR 17-0072 )2.2 L1984_Web_Mercator_Auxiliary_Sphere reld County Colorado 0 6,751.08 13,502.2 Feet This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. THIS MAP IS NOT TO BE USED FOR NAVIGATION Ex Si.��} � ra el Pits Rhin \N jI S Radius borders are Rd 30 1/2 to the North, Rd 4 1/2 to the South, Rd 91/2 to the West and Rd 35 to the East. 1 Bestway Pit — Rd 25 & Rd22 2 Pioneer Pit — Rd 25 & Rd 20 3 NCC Pit 1 -Rd 18 & Rd 25 NW Corner 4 Everist Pit — Rd 18 & Rd 25 NE Corner and S of Rd18 to Rd14 1/2 and from the Platte River to Rd 23 1/2 5. Brannen Pit — Hwy 52 & Hwy 85 6 Ft Lupton Pit — Hwy 52 & Rd 25 7 Chavers Mine -Hwy 85 & Rd 8 NW Corner 8 Aggregate Industries — Hwy 85 & Rd 6 SW Corner 9 NCC Perry Pit — Rd 6 and Platte River 10 River Bend Pit, Martin Marietta — Hwy 85 & Rd 6, NW & NE Corners 11.Brannen Pit —13600 Rd 8 12 Bestway Pit — Rd 24 & Rd 9 3/4 13 Everist Pit — 6254 Rd 26 14.Everist Pit -12248 Rd 15 15 Varra Pit — Hwy 66 & Rd 17, Hwy 66 to Rd 26 1/2 This message, including any attachments,is intended only for the use of the individual /s) to which it is addressed and may contain information that is privileged confidential Ann' other distribution, copying or disclosure is strictly prohibited If you are not the intended recipient or have received this message in error, please notify us immediately by reply e-mail and pennanently delete this message including any attachments, without reading it or making a copy. Thank you. -DISCUSSIONS AND COMMUNICATIONS REGARDING THIS MATTER CONSTITUTE MERELY PRELIMINARY NEGOTIATIONS BETWEEN THE PARTIES, DO NOT CONSIIIlTE AN OFFER HY ONE PARTY TO THE OTHER PARTY. AM) DO NOT CREATE IN ANY PARTY A POWER OF ACCEPTANCE" From: Cavanagh, Brett <Brett.Cavanagh c@i,anadarko.com> Sent: Thursday, October 11, 2018 10:46 AM To: Kim Ogle <kogle c@weldgov.com> Cc: Kemock, Joseph <Joseph.Kemock a,anadarko.com>; Cabral, Tony <Tony.Cabral@anadarko.com> Subject: USR17-0072 (Pioneer Land Co - Bennett Open Pit) Caution: This email originated from outside of Weld County Government. Do not click links or open attachments unless you recognize the sender and know the content is safe. Kim, We have quite a few pipelines, flowlines and wells in this area. Can we get a better understanding of their operations and how our assets will be protected. Thanks, USR 17-0072 NORTHERN COLORADO CONSTRUCTO BENNETT PIT LOCATED iN THE SW 1/4 OF THE SE 1/4 SECTION 1, AND NORTH 1/2 OF SECTION 12, T2N, Fi WELD COUNTY, COLORADO I I i I t I i a Ur MD UNTIE, DCAIR !LECTI4G 30' cc a11AVV. AGCTS1 *IQ C 0AS, wen ' Pamen ELECTRIC, CENTURvl BN MOIE, :ANTRAL MI MLR COUNTY WATER prima WATER, ie kt&2KNAt7AAKO GAS 0 cal et G } calve ► *pasl- i i i {St!' ROM- -UV( f AILS 2L, 1M . ma, iS. PC MI �:�-:...,r•-10, tfl'ty t+cwtk ELECTRIC ,Y OcTSEt PaMSN i_ e MIT.IWD HLUA VISM G 016 1114 -‘ de J: t hl A A — Brett A. Cavanagh, MBA— DJ Basin — Staff Landman r, rte! • Phone: 720.929.3296 *Cell: 970219.9343<W Jl6errA 1099 18th Street, Suite 1800, Denver CO 80202 • P.O. box 173779, Denver CO WORM Cal li I I I I 6e' 0-T_ 70 rr1Y• i M1 act( FIOM rnstio v LIME TO *+awG UITT i *re a-`- . •—vim.. �.. --.r . SIMMS 'Y• .. .... •! NORTH CELL 1410.13 tal a 16 WC. 1 text rr 1 • SOOTHtltl a- : "SAC AUALARKO GAS NM STE s.• - NS R ICA NM Sa>: MOO rr�TI*1% PON F /ie - Ii, r CENTURYUNK PHONE , UMTED PO to aecmC 0311 WRlllt,Z ACM 1 !'R3i'el*Tv in it wawa LUTE • snack r 3u man' air T6+ Mli71C UYd non Ina .nom, PPCPERn' t. 't ISN14C tall I ',EL GAS t4TURYUNtc !HONE dump POKER eattni)C coodse T 06. Sob la —0- -a— SD a a Maaal a a NS .� - ..r.- ...- _461S_ —� MEM tttta a al S to t! a man IIter PERtaff f0 BOLNDAAT • t*S7A'ICE an EaSTe.C This message, including any attachments,is intended only for the use of the individual(s) to which it is addressed and mtw contain information that is privileged/confidential Any other distribution, copying or disclosure is strictly prohibited if you are not the intended recipient or have received this message in error, please notify us immediately by reply e-mail and permanently delete this message including any attachments, without reading it or making a copy. Thank you. -DISCUSSIONS AND COMMUNICATIONS REGARDING THIS MATT ER CONSTITUTE MERELY PRELIMINARY NEGOTIATIONS BETh'EEN THE PARTIES. DO NOT CONSTITUTE AN OFER BY ONE PARTY TO THE anIER PARTY, AND IX) NOT CREATE IN ANY PARTY A POWER OF ACCEITANCE- COTE NO ON 112DON'T SET COLORADO Proposed energy setbacks would devastate Colorado's economy and put thousands of jobs like mine at risk. Learn more at www.protectcolorado.com Click here for Anadarko's Electronic Mail Disclaimer From: Cavanagh, Brett <Brett.Cavanagh©anadarko.com> To: c,orkfires@aol.com <corkfires@aol.com> Subject: FW: Home owner concern off 23 and 24 near firestone Date: Mon, Dec 3, 2018 8:55 am Please see below. Brett A. Cavanagh, MBA— DJ Basin — Staff Landman p • Phone: 720.929.3296 •Cell: 970.219.9343(W KerrMeGe! 1099 18th Street, Suite 1800, Denver CO 80202 • P.O. box 173779, Denver CO This message, including any anachment s,is intended only for the use of the individual(s) to which it is addressed and may contain information that is privileged/confidential. Any other distribution, copying or disclosure is strictly prohibited If you are not the intended recipient or have received this message in error. please notify us immediately by reply e-mail and permanently delete this message including any attachments, without reading it or making a copy. Thank Wit. "DISCUSSIONS AND COMMUNICATIONS REGARDING THIS MATTER CONSTITUTE MERELY PRELIMINARY NEGOTIATIONS BETWEEN THE PARTIES. DO NOT CONSTITUTE AN OFnK BY ONE PARTY TO THE OTHER PARTY, AND DO NOT CREATE IN ANY PARTY A POWER Of ACCEPTANCE' From: Keiser, Nathan Sent: Wednesday, November 28, 2018 5:09 PM To: Knowles, Elizabeth<Elizabeth.Knowles@anadarko.com>; Cavanagh, Brett <Brett.Cavanagh@anadarko.com>; Miller, Jesse [USIC] <Jesse.Miller@anadarko.com>; Marshall, Donald <Donald.Marshall@anadarko.com>; Ishida, Thomas <Thomas.Ishida@anadarko.com>; Price, Tom <Tom.Price@anadarko.com> Subject: RE: Home owner concern off 23 and 24 near firestone Elizabeth and Team, I know this road is classified as a collector so Weld will reserve an 80' ROW for any future expansions. Also, their 2035 Long Range Transportation plans contemplates improvements to the CR 24 and CR 23 intersection and shows this work being performed sometime between 2016-2025. It's never sure on whether this work will actually be done though, and I didn't see any reference to the widening of 23. I have a call into Weld County to confirm this though and will report back as soon as I know something. Thanks everyone for getting our team looped in. Nathan From: Knowles, Elizabeth Sent: Wednesday, November 28, 2018 4:33 PM To: Cavanagh, Brett <Brett.Cavanagh@anadarko.com>; Miller, Jesse [USIC] <Jesse.Miller@anadarko.com>; Marshall, Donald <Donald.Marshall@anadarko.com>; Ishida, Thomas <Thomas.Ishida@anadarko.com>; Price, Tom <Tom.Price@anadarko.com> Cc: Keiser, Nathan <Nathan.Keiser@anadarko.com> Subject: RE: Home owner concern off 23 and 24 near firestone Nathan, Could you please look into whether the County has any plans on expanding WCR 23? Thanks, Elizabeth From: Cavanagh, Brett Sent: Monday, November 26, 2018 7:25 AM To: Miller, Jesse [USIC] <Jesse.Miller@anadarko.com>; Marshall, Donald <Donald.Marshall@anadarko.com>; Ishida, Thomas <Thomas.Ishida@anadarko.com>; Price, Tom <Tom. Pri ce@anadarko. com> Cc: Keiser, Nathan <Nathan.Keiser@anadarko.com>; Knowles, Elizabeth <Elizabeth.Knowles@anadarko.com> Subject: RE: Home owner concern off 23 and 24 near firestone Jesse, Thank you for reaching out. I do not see anything in weld County, that shows WCR 23 is expanding. I assume ( not verified) that the bore is at least 10-15 feet under the current road_ 131102200009 131111000024 Does anyone know what the plans are? Thanks, CAN1RELL H OIVA D4W 1 311 01 000020 Brett A. Cavanagh, MBA— DJ Basin — Staff Landman er ,,�.,c-aa .�, • Phone: 720.929.3296 *Cell: 970.219.9343411 Kerr) Gene 1099 18`'I Street, Suite 1800, Denver CO 80202 • P.O. box 173779, Denver CO This message, including any anachments,is intended only for the use of the individual(s) to which it is addressed and may contain information dam is privileged/conf dential. Ant' other distribution, copying or disclosure is strictly prohibited. If ►ou are not the intended recipient or have received this message in error, please notify us immediately by reply e-mail and pernumently delete this message including any attachments, without reading it or making a copy. Thank you. "DISCUSSIONS AND COMMUNICATIONS REGARDINGTHIS MATTER CONSTrrUTE MERELY PRELIMINARY NEGOTIATIONS BETWEEN THE PARTIES, DO NOT CONSTITUTE AN OFFER BY ONE PARTY TO THE OTHER PARTY, AND DO NOT CREATE IN ANY PARTY A POWER OF ACCEPTANCE' From: Miller, Jesse [USIC] Sent: Tuesday, November 20, 2018 4:25 PM To: Marshall, Donald <Donald.Marshall@anadarko.com>; Cavanagh, Brett <Brett.Cavanagh c@i@anadarko.com>; Ishida, Thomas <Thomas.lshida c@anadarko.com>; Price, Tom <Tom.Price@anadarko.com> Subject: Home owner concern off 23 and 24 near firestone Hey all, I was scoping out a locate when a homeowner approached me and was expressing some concerns about an access road (going east from 24) that was previously build and where the dirt was either removed or packed in making a 3 line R.O.W. shallow. He also informed me that he would not be concerned but apparently this access road will be susceptible to high amounts of truck traffic due to a planned road expansion on 23.This R.O.W. is about 200 feet away from his house. I went ahead and informed him that I was unsure of the answers but told him I would figure out what could be done/learned for him. After reaching out to Don I was Given Brett's number who had me re -verify the depth of the lines — the water was around 5-6' deep, the gathering was about 3' deep, and the condensation was about 5' deep. I am going to be giving Brett's phone number to the homeowner and will also have the land owners number available at the bottom of this email, along with a latitude and longitude as well as a photo of the area from Imaps for reference. Homeowner (Howard): (970)396-6155 Lat/long: 40.1595746, -104.8479108 Please let me know if I missed something or if I am needed to do anything further to assist. Thanks and have a good one, Jesse Miller Anadarko Pipeline Locator (970)451-1883 nrrnitsu KELUIIU UTILITY SERVICES hk IRIAM 01 %IC DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Air Quality Control Commission REGULATION NO. 1 EMISSION CONTROL FOR PARTICULATE MATTER, SMOKE, CARBON MONOXIDE, AND SULFUR OXIDES 5 CCR 1001-3 Regulation Number 1 EPA test methods 1, 2, 3, 4, 5, 6, 6a, 6b, 6c, 8 and method 9 (40 CFR 60.275, Appendix A, Part 60) are hereby incorporated by reference by the Air Quality Control Commission and made a part of the Colorado Air Quality Control Commission Regulations. Materials incorporated by reference are those in existence as of the date of this regulation and do not include later amendments. The material incorporated by reference is available for public inspection during regular business hours at the Office of the Commission, located at 4300 Cherry Creek Drive South, Denver, Colorado 80246, or may be examined at any state publications depository library. Parties wishing to inspect these materials should contact the Technical Secretary of the Commission, located at the Office of the commission. Definitions ASTM American Society for Testing and Materials EPA United States Environmental Protection Agency Fugitive Emissions Emissions that cannot be reasonably collected and passed through a stack, chimney, vent or other equivalent opening. gr/dscf Grains per dry standard cubic foot Haul Roads Roads which are used for commercial, industrial or governmental hauling of materials and which the general public does not have a right to use. Intermittent Sources Those stationary sources of air pollution which do not operate on a continuous basis for a period of time sufficient to allow for opacity observations in accordance with EPA Method 9. PM Particulate Matter Roadways Roads, other than haul roads, used for motorized vehicular traffic. Welfare As used in these regulations, effects on public welfare include, but are not limited to, effects on soils, water, crops, vegetation, manmade materials, animals, wildlife, weather, visibility, and climate, damage to and deterioration of property, and hazards to transportation, as well as effects on economic values and on personal comfort and well being. Regulation Number 1 Emission Control Regulations for Particulate Matter, Smoke, Carbon Monoxide, and Sulfur Oxides for the State of Colorado. I. APPLICABILITY: REFERENCED FEDERAL REGULATIONS I.A. The provisions of this Regulation No. 1 are applicable to both new and existing sources and without regard to whether a source has been issued an emission permit. Except where specifically made applicable to attainment, attainment/maintenance or non -attainment areas, the requirements set forth herein apply statewide. (Areas designated as unclassifiable shall be treated as attainment). The provisions of this regulation apply to a source even though it may also be subject to other regulations of the commission; and in the event the requirements of this regulation conflict or are inconsistent with the requirements of any other regulation of the commission, the more stringent emission limitations shall apply except that a specific emission limitation for a particular source shall take precedence over a general emission limitation which is inconsistent. I.B. At several places in this regulation various federal regulations, performance standards, and procedures that have been previously published in the Federal Register and/or the Code of Federal Regulations have been incorporated by reference. This regulation provides appropriate citations to such materials and incorporates them as they are published. Amendments to such regulations, standards and procedures made after the effective date of this regulation are not incorporated herein. Copies of said materials may be obtained for a nominal copying fee from the Technical Secretary to the commission at the Air Quality Control Commission office at 4300 Cherry Creek Drive South, B-1, Denver, CO 80246. Copies are also available at the commission office for public inspection at no cost. II. SMOKE AND OPACITY II.A. Stationary Sources II.A.1. Except as provided in paragraphs 2 through 6 below, no owner or operator of a source should allow or cause the emission into the atmosphere of any air pollutant that is in excess of 20% opacity. This standard is based on 24 consecutive opacity readings taken at 15 -second intervals for six minutes. The approved reference test method for visible emissions measurement is EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)) in all subsections of Section II. A and B of this regulation. II.A.2. Intermittent Sources Except as provided in paragraphs 3 through 6 below, no owner or operator of an intermittent source shall allow or cause the emission into the atmosphere of any pollutant that is in excess of 20% opacity. If EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)), a continuous emissions monitor, or other credible method is used and 24 consecutive opacity readings taken at 15 -second intervals cannot be taken because such a source does not operate continuously for six minutes, the readings shall be taken at 15 -second intervals during periods of operation until 24 readings have been made or for a period of thirty minutes, whichever is sooner, and the source shall be deemed in violation if the average opacity of such readings exceed 20%. II.A.3. Pilot Plants and Experimental Operations No owner or operator of a process unit of a pilot plant or experimental operation shall emit or cause to be emitted into the atmosphere from any such process unit particulate matter for a period or periods aggregating more than six minutes in any sixty consecutive minutes which is in excess of 30% opacity. Except as otherwise provided in this paragraph this emission standard for pilot plants and experimental operations shall be applicable for a period not to exceed 180 -operating days cumulative total from the date operation of such a process unit commences; thereafter the 20% opacity limitation provided in Section II.A.1 or 2 of these regulations shall apply to emissions from such a process unit of a pilot plant or experimental operation. For the purpose of this Section II.A.3 "Operating Days" shall mean any calendar day during which the process unit is operated and air pollutants are emitted (without regard to the length of period of time operated or amount of pollutants emitted). For good cause shown, the division may extend the period of relaxed operation beyond 180 operating days for the operation of a process unit, but in no event to greater than 365 operating days without the concurrence of the commission. II.A.4. Fire Building, Cleaning of Fire Boxes, Soot Blowing, Start-up, Process Modification or Adjustment of Control Equipment Except as provided in Sections II.A.6, no owner or operator of a source shall allow or cause to be emitted into the atmosphere any air pollutant resulting from the building of a new fire, cleaning of fire boxes, soot blowing, start-up, any process modification, or adjustment or occasional cleaning of control equipment, which is in excess of 30% opacity for a period or periods aggregating more than six minutes in any sixty consecutive minutes. II.A.5. Smokeless Flare or Flares for the Combustion of Waste Gases No owner or operator of a smokeless flare or other flare for the combustion of waste gases shall allow or cause emissions into the atmosphere of any air pollutant which is in excess of 30% opacity for a period or periods aggregating more than six minutes in any sixty consecutive minutes. II.A.6. Exemptions The requirements of Section II.A.1 and 2 of this regulation shall not apply to the following sources or types of emissions: II.A.6.a. Emissions from fireplaces, fireplace inserts and stoves, provided such devices are burning only clean dry wood or wood products and are used for noncommercial or recreational purposes. II.A.6.b. Fugitive dust: As used in this Regulation No. 1, "fugitive dust" means airborne particulate matter, which is not a direct or proximate result of man's activities. II.A.6.c. Fugitive particulate emissions: As used in this Regulation No. 1, "fugitive particulate emissions" mean fugitive emissions of particulate matter that are the direct or proximate result of man's activities, (e.g., Materials left by man exposed to the wind or later acted upon by another force as the wind or automobile traffic, or particulate matter being thrown into the atmosphere by the operation of a bulldozer.) II.B. Diesel Powered Locomotives II.B.1. Except as provided in paragraph 2 below, no owner or operator shall emit or cause to be emitted into the atmosphere from any diesel -powered locomotive any air pollutant which is in excess of 20% opacity while being operated below 6,000 feet (mean sea level) and 30% opacity while being operated above 6,000 feet (mean sea level). II.B.2. Exceptions II.B.2.a. Emissions that exceed the opacity limits of Section II.B.1. as a result of a cold engine start-up, not to exceed thirty consecutive minutes and provided the locomotive is in a stationary position. II.B.2.b. Emissions for nonconsecutive periods of three minutes with an aggregate of not more than ten minutes in any consecutive sixty minutes when a locomotive engine is being tested, adjusted, rebuilt, or repaired in the maintenance yards. II.B.2.c. Emissions for periods of up to four minutes when a locomotive is accelerated after standing still. II.B.3. The owner or operator of any diesel -powered locomotive that has been cited for violation of Section II.B.1. of this regulation, but which is not available for compliance inspection shall submit to the division an affidavit attesting to those abatement measures which have been completed and shall state in that affidavit that the vehicles cited have achieved compliance with this regulation. II.C. Open Burning II.C.1. Except as provided in paragraph 2 below, no person shall burn or allow the burning of rubbish, wastepaper, wood or other flammable material on any open premises, or on any public street, alley, or other land adjacent to such premises, unless an open burning permit is first obtained from the division. In granting or denying such permits the division shall base its decision on the location and proximity of such burning to any building or other structure, the potential contribution of such burning to air pollution in the area, climactic conditions on the day or days of such burning, and compliance by the applicant for the permit with applicable fire protection and safety requirements of the local authority. The division may consider: (A) Whether there is any practical alternative method for the disposal of the material to by burn and (B) Whether burning will be conducted so as to minimize emissions. Methods for minimizing emissions may include, but are not necessarily limited to, the use of permitted incinerators or air curtain destructors, the use of clean auxiliary fuel, drying the material prior to ignition and separating out for alternative disposal: Rubber, tires, plastic, insulated wire, insulation, and other materials which produce more smoke than clean combustible materials. Sources subject to the open burning provisions in this regulation No. 1 may also be subject to state only Regulation No. 9. I I.C.1.a. Whether there is any practical alternative method for the disposal of the material to be burned. II.C.2. Sources Exempted from obtaining open burning permits II.C.2.a.The non-commercial burning of private household trash in PM attainment areas unless local ordinances or rules prohibit such burning. II.C.2.b. Fires used for non-commercial cooking of food for human beings or recreational purposes. II.C.2.c. Fires used for instructional or training purposes, except instructional or training wildland pile or broadcast fires larger than the de minimus thresholds of a low smoke impact burn pursuant to Appendix A of Regulation Number 9. II.C.2.c(1). Training or instructional fires must comply with all applicable federal, state and local laws including the demolition notification requirements in Regulation Number 8, Part B, section III.E.1. for intentional structural fires. II.C.2.d. Flares used to indicate some danger to the public. II.C.2.e.Agricultural open burning — The open burning of cover vegetation for the purpose of preparing the soil for crop production, weed control, and other agricultural cultivation purposes. The open burning of animal parts or carcasses is not included in the exemption. Except that, if the State Agricultural commission declares a public health emergency or a contagious or infectious disease outbreak that imperils the livestock of the state that requires the burning of diseased animal carcasses after providing telephone notice to the division and the relevant local health department office by leaving a voice mail message. All necessary safeguards shall be utilized during such non -permitted open burning to minimize any public health or welfare impacts. In addition, the owner or operator shall take steps to ensure that all surrounding and potentially impacted residents, businesses, schools and churches are notified prior to beginning the open burn. II.C.2.f. Noncommercial burning of trash in the unincorporated areas of counties of less than 25,000 population according to the latest federal census provided such open burning is subject to regulations of the board of county commissioners for such county adopted by resolution and such regulations include, among other things, permit provisions and prohibit any such burning that would result in the exceedence of any NAAQS. II.C.3. Nothing herein shall be construed as relieving any person conducting open burning from meeting the requirements of any applicable federal, state or local requirements concerning disposal of waste materials. II.D. Smoke and Obscurants for Military Training Exercises Emissions associated with the generation of smoke or obscurants on Fort Carson and Pinon Canyon maneuver site (hereafter, referred together as Fort Carson) by United States military forces, or allied forces in a combined training exercise with the United States, shall be exempt from the opacity limits specified in Regulation No. 1, sections II. and III. provided that all of the following conditions are met: II.D.1. All participants in the training shall follow all applicable Department of Defense training manuals and guidance regarding Department of Defense -approved smokes and obscurants. II.D.2. No off -property transport of visible emissions from any smoke or obscurants used on Fort Carson shall occur. III.D.3. Smoke or obscurants generation shall cease immediately in the event that any such visible emissions cross or has a reasonable probability of crossing the installation property boundary. II.D.4. The commander in charge of any training involving smoke or obscurants will ensure the following precautionary measures are implemented. II.D.4.a. When planning and conducting training, prevailing meteorological conditions will be analyzed, both before and on the day of training, to determine if they meet established training criteria for the use of smoke or obscurants and to allow compliance with the requirements of paragraph 3 above. If the meteorological conditions do not meet those criteria, then smoke or obscurants will not be employed. II.D.4.b. Prior to using smoke or obscurants, inspect and validate the training site and the training mission. II.D.4.c. Upon initiation of smoke or obscurant generation, observe the initial smoke or obscurant plume to verify that it conforms to established training criteria and to allow compliance with the requirements of paragraph 3 above. If the wind direction and speed is not favorable for the exercise, then the location will be adjusted or the smoke mission will be postponed or canceled. II.D.4.d. Post one or more trained smoke observers to provide direct observation of the smoke/obscurant plume at all times while smoke or obscurants are used during the training. Smoke observers will remain alert for visible smoke that has a reasonable probability of drifting across the installation property boundary, in which case the smoke observer shall have the authority to immediately halt smoke generation operations. The smoke observer(s) must maintain capability for immediate communication with the officer commanding the use of smoke or obscurants used in the training exercise. II.D.4.e. Units conducting training using smoke or obscurants on Fort Carson must perform necessary checks with Fort Carson range division to assure immediate communication capability, including capability to request or obtain meteorological updates. In the event of failure to maintain such capability, the training exercise will be halted. II.D.5. In the event visible emissions from smoke or obscurant use drift across the installation property boundary, Fort Carson shall implement necessary response measures to minimize impacts and shall inform the state as soon as possible, but no later than 24 hours or the next business day after the event. A written notice shall follow this notification within 48 hours to the state detailing the circumstances of the occurrence and stating whether additional measures will be adopted to prevent such visible emissions from drifting across the boundary in the future. II.D.6. Installation commander, Fort Carson, shall be responsible to ensure compliance with this section by all personnel employing smoke or obscurants at Fort Carson. III. PARTICULATE MATTER III.A. Fuel Burning Equipment III.A.1. No owner or operator shall cause or permit to be emitted into the atmosphere from any fuel -burning equipment, particulate matter in the flue gases which exceeds the following: III.A.1.a. 0.5 lbs. per 106 BTU heat input for fuel burning equipment of less than or equal to 1x106 BTU/hr total heat input design capacity. III.A.1.b. For fuel burning equipment with designed heat inputs greater than 1x106 BTU per hour, but less than or equal to 500x106 BTU per hour, the following equation will be used to determine the allowable particulate emission limitation. PE=0.5(FI)-o.26 Where: PE = Particulate Emission in Pounds per million BTU heat input. Fl = Fuel Input in Million BTU per hour. III.A.1.c. 0.1 lbs. per 106 BTU heat input for fuel burning equipment of greater than 500x106 BTU per hour or more. III.A.1.d. If two (2) or more fuel burning units connect to any opening, the maximum allowable emission rate shall be calculated on a lb/ hour basis as calculated from a weighted average of the individual allowable limits for each unit ducting to the common stack. III.A.2. Performance Tests Prior to granting of a final approval permit or amending a permit, when an emission source or control equipment is altered, or at any time when there is reason to believe that emission standards are being violated, the division may require the owner or operator of any fuel burning equipment to conduct performance tests, as measured by EPA Methods 1-4 and the front half of EPA Method 5 (40 CFR 60.275, Appendix A, Part 60), or other credible method approved by the division, to determine compliance with this subsection of this regulation. The particulate emission standards contained in this subsection do not include condensable particulate matter, or the back half emissions of EPA Method 5. III.B. Incinerators III.B.1. No owner or operator of an incinerator shall operate any incinerator without a permit from the division. III.B.2. Standard of Performance for all incinerators other than biomedical waste incinerators and air curtain destructors subject to 40 CFR 60. III.B.2.a. In areas designated as non -attainment or attainment/maintenance for particulate matter, no owner or operator of an incinerator shall cause or permit emissions of more than 0.10 grain of particulate matter per standard cubic foot. (Dry flue gas corrected to 12 percent carbon dioxide.) III.B.2.b. In areas designated as attainment for particulate matter, no owner or operator of an incinerator shall cause or permit emissions of more than 0.15 grain of particulate matter per standard cubic foot. (Dry Flue gas corrected to 12 percent carbon dioxide.) III.B.3. Performance Tests Prior to granting a final approval permit or amending a permit, when an emission source or control equipment is altered, or at any time when there is reason to believe that emission standards are being violated, the division may require the owner or operator of an incinerator to conduct performance test(s) in accordance with 40 CFR 60 Appendix A. III.B.4. Standard of Performance for Biomedical Waste Incinerators. The owner or operator of an existing incinerator used for the disposal of biomedical waste shall comply with Part B, Section V of Regulation No. 6. Standard of Performance For New Biomedical Waste Incinerators as follows: III.B.4.a. All incinerators, existing as of the effective date of Part B, Section V of Regulation No. 6, with a design rate of four hundred pounds per hour and greater must comply with the requirements of this regulation. III.B.4.b. All incinerators, existing as of the effective date of Part B, Section V of Regulation No. 6, with a design capacity of less than four hundred pounds per hour must comply with the requirements of this regulation as applicable; except incinerators with a design capacity of less than 200 pounds per hour shall be permitted and allowed to operate only so long as the units continue to meet the particulate and visible emission standards existing prior to the effective date of Part B, Section V of Regulation No.6, the manufacturer's design specifications and any other applicable safety standards. (The standards existing prior to the effective date of this regulation are: a) For sources existing prior to January 30, 1979: 20% opacity and 0.10 grains per dry standard cubic foot (gr/dscf) of PM for PM non -attainment areas and 0.15 gr/dscf of PM for PM attainment areas; b) 20% opacity and 0.10 gr/dscf of PM for sources constructed after January 30, 1979.) III.C. Manufacturing Processes III.C.1. Except as provided in paragraphs 2 of this subsection C., no owner or operator of a manufacturing process unit shall cause or permit emission of any particulate matter into the atmosphere during any consecutive sixty minute period which is in excess of the following. III.C.1.a. For process equipment having design rates of 30 tons per hour or less, the allowable emission rate shall be determined by the use of the equation: PE = 3.59(P)o.62 Where: PE = Particulate Emission in lbs. per hour P = Process weight rate in tons per hour III.C.1.b. For process equipment having design rates of greater than 30 tons per hour, the allowable emission rate shall be determined by use of the equation: PE = 17.31(P)° 16 Where: PE = Particulate Emission rate in lbs. per hour P = Process weight rate in tons per hour III.C.1.c. If two or more process units are connected to the same opening, the maximum allowable emission rate shall be computed by summing the allowable emissions for the units being operated. III.C.2. Exceptions Fugitive dust and fugitive particulate emissions as defined in Section II.A.6 of this Regulation. III.C.3. Performance Tests Prior to granting of a final approval permit or amending a permit, when an emission source or control equipment is altered, or at any time when there is reason to believe that emission standards are being violated, the division may require the owner or operator of any manufacturing process to conduct performance tests, as measured by EPA Methods 1-4 and the front half of EPA Method 5 (40 CFR 60.275, Appendix A, Part 60), or other credible method approved by the division, to determine compliance with this subsection of this regulation. The particulate emission standards contained in this subsection do not include condensable particulate matter, or the back half emissions of EPA Method 5 (40 CFR 60.275, Appendix A, Part 60). III.D. Fugitive Particulate Emissions III.D.1. General Requirements III.D.1.a. Existing Sources III.D.1.a.(i). Every owner or operator of a source or activity that is subject to this Section III.D. shall employ such control measures and operating procedures as are necessary to minimize fugitive particulate emissions into the atmosphere through the use of all available practical methods which are technologically feasible and economically reasonable and which reduce, prevent and control emissions so as to facilitate the achievement of the maximum practical degree of air purity in every portion of the State. III.D.1.a.(ii). In determining what control methods are available, practical, economically reasonable and technologically feasible, the following factors shall be considered: effects on the health, welfare (as defined in Section I.G. of the Common Provisions regulation), convenience, and comfort of the inhabitants of the State of Colorado; effects on the enjoyment and use of the scenic and natural resources of the State; the impact on normal operating procedures; altitude, topography, climate, and anticipated meteorological conditions (including wind and precipitation); soil conditions; the degree to which a type of emission to be controlled is significant; the continuous, intermittent, or seasonal nature of the emission, the economic, environmental, and energy impacts and other costs of compliance; the proximity of the source or activity to populated areas; and the nature, scope and duration of the source or activity. III.D.1.a.(iii). This Section III.D. shall be enforceable only through the procedures specified below in Section III.D.1.b. through III.D.1.e. III.D.1.b. New Sources Every owner or operator of a new source or activity that is subject to this Section III.D. and which is required to obtain an emission permit under Regulation No. 3 shall submit a fugitive particulate emission control plan meeting the requirements of this Section III.D. at such time as, and as part of, the required permit application. Such plan shall be approved or disapproved by the division in the course of acting to approve or disapprove the permit application and no emission permit shall be issued until a fugitive particulate emission control plan has been approved. III.D.1.c. Emission Limitation Guidelines for Submission of Control Plan. If the division determines that a source of activity which is subject to this Section III.D. (whether new or existing) is operating with emissions in excess of 20% opacity and such source is subject to the 20% emission limitation guideline; or if it determines that the source or activity which is subject to this Section III.D. is operating with visible emissions that are being transported off the property on which the source is located and such source is subject is to the no off property transport emission limitation guideline; or if it determines that any source or activity which is subject to this Section HI.D. is operating with emissions that create a nuisance; it shall require the owner or operator of that source or activity to submit a written plan to the division for the control of fugitive particulate emissions within the time period specified in Section III.D. Provided, however, that in the case of a source or activity which already has a control plan, the division shall review said control plan and if it determines the plan does not meet the requirements of this Section III.D. it shall require the submission of a revised control plan. (As used herein, "nuisance" shall mean the emission of fugitive particulates that constitutes a private or public nuisance as defined in common law, the essence of which is that such emissions are unreasonable interfering with another person's use and enjoyment of his property. Such interference must be "substantial" in its nature as measured by a standard that it would be of definite offensiveness, inconvenience, or annoyance to a normal person in the community.) [Cross Reference: Appendices A and B] III.D.1.d. III.D.1.d.(i). Control Plans With respect to operations or activities that have more than one source of fugitive particulate emissions, submissions of control plans or plan revisions pursuant to Section III.D. shall be required only with respect to those individual sources for which there does not exist a currently approvable control plan and which are not being operated in accordance with the requirements of this Section III.D., provided, however, that control plans required by Section III.D.1.b for new sources and activities shall contain provisions for control of fugitive particulate emissions from all significant sources of such emissions. III.D.1.d.(ii). Sources required to submit control plans for revisions to the division shall do so within sixty days of the date such plan or revision is requested; provided, however, that the division, in its discretion, may where appropriate establish a different time period for submittal, taking into consideration such factors as the duration of the operation of the source or activity, the significance and nature of the emissions, and the relative complexity of the operation and applicable control methods. III.D.1.d.(iii). Each control plan shall include all available practical methods which are technologically feasible and economically reasonable and which reduce, prevent and control fugitive particulate emissions from the source or activity into the atmosphere. For those materials, equipment, services or other resources (such as water for abatement and control purposes), which are likely to be scarce at any given time, an alternative control method must be included in the control plan. Any source required to submit a control plan may ask for a "control plan conference" with the division, and if so requested the division shall hold such a conference for the purpose of advising what types of control measures and/or operating procedures will meet the requirements of this section. [Cross Reference: Sections III.D.2.a. through III.D.2.k.] III.D.1.d.(iv). The division shall approve any plan submitted under this Section III.D. unless the division determines that the plan does not meet the requirements of Section III.D. If a control plan is not approvable in its entirety, the division shall approve those portions, which meet the requirements of this section and disapprove those portions, which fail to meet the requirements of this section. III.D.1.e. Enforcement III.D.1.e.(i). It shall be a violation of this regulation and the division may take enforcement action pursuant to C.R.S. 1973, 25-7-115, as amended, if the owner or operator: III.D.1.e.(ii).(A). Fails to submit a control plan (or revision of an existing plan) within sixty days (or other time period specified by the division) after being notified by the division that such submittal is required unless operation of such source is discontinued so as to permanently eliminate the cause of fugitive particulate emissions there from; or III.D.1.e.(ii).(B). Owns or operates a source or activity for which the division has disapproved a control plan or a revised control plan unless operation of such source is discontinued so as to permanently eliminate the cause of fugitive particulate emissions there from; or III.D.1.e.(ii).(C). Fails to comply with the provisions of an approved control plan. III.D.1.e.(iii). The 20% opacity, no off -property transport, and nuisance emission limitation guidelines of this Section III.D. are not enforceable standards and no person shall be cited for violation thereof pursuant to C.R.S. 1973, 25-7-115 as amended. III.D.2. Sources Subject to Section III.D. The control measures and operating procedures listed in Sections III.D.2.a. through III.D.2.k. are generally considered appropriate for the specific types of sources under which they are listed — at least as applied individually. Whether they remain appropriate when used in coil other measures and procedures, must be determined on a case -by -case basis. III.D.2.a. Roadways III.D.2.a.(i). Unpaved III.D.2.a.(i).(A). Applicability — Attainment and Non -attainment Areas III.D.2.a.(i).(B). General Requirement Any owner or operator responsible for construction or maintenance of any (existing or new) unpaved roadway which has vehicle traffic exceeding 200 vehicles per day in attainment areas or 150 vehicles per day in non -attainment areas (averaged over any consecutive 3 -day period) from which fugitive particulate emissions will be emitted shall be required to use all available, practical methods which are technologically feasible and economically reasonable in order to minimize emissions resulting from the use of such roadway in accordance with the requirements of Section III.D. of this regulation. III.D.2.a.(i).(C). Applicable Emission Limitation Guideline The nuisance emission limitation guideline shall apply to unpaved roadways. Abatement and control plans submitted for unpaved roadways shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.a.(i).(D). Control Measures and Operating Procedures Control measures or operations procedures to be employed may include but are not necessarily limited to, watering, chemical stabilization, road carpeting, paving, suggested speed restrictions and other methods or techniques approved by the division. III.D.2.a.(i).(E). If the division receives a complaint that any new or existing unpaved roadway is creating a nuisance, it may require persons owning or operating or maintaining such roadways to supply vehicle traffic count information by any reasonable available means for the purpose of determining if they have sufficient traffic to subject them to the requirements of this Section III.D. III.D.2.a.(ii). Paved III.D.2.a.(ii).(A). Applicability - Attainment and Non -attainment Areas III.D.2.a.(ii).(B). General Requirement Any person who through operations or activities repeatedly deposits materials which may create fugitive particulate emissions on a public or private paved roadway is required to submit a control and abatement plan upon request by the division which provides for the removal of such deposits and appropriate measures to prevent future deposits such that fugitive particulate emissions which may result are minimized; except that sand, salt or other materials may be dropped on snow or ice covered roadways for the purpose of safety and such deposits shall not be required to be removed on a more frequent basis than the community's normal street cleaning schedule except as otherwise provided in an applicable SIP provision. III.D.2.a.(ii).(C). Applicable Emission Limitation Guideline The nuisance emission limitation guideline shall apply to paved roadways. Abatement and control plans submitted for paved roadways shall be evaluated for compliance with the requirements of section III.D. of this regulation. III.D.2.a.(ii).(D). Control Measures and Operating Procedures Control measures or operational procedures to be employed may include but are not necessarily limited to, covering the loaded haul truck, washing or otherwise treating the exterior of the vehicle, limiting the size of the load and the vehicle speed, watering or treating the load with chemical suppressants, keeping the roadway access point free of materials that may be carried onto the roadway, removal of materials from the roadway and other methods or techniques approved by the division. III.D.2.b. Construction Activities III.D.2.b.(i). Applicability - Attainment and Non -attainment Areas III.D.2.b.(ii). General Requirement Any owner or operator engaged in clearing or leveling of land or owner or operator of land that has been cleared of greater than five acres in attainment areas or one (1) acre in non -attainment areas from which fugitive particulate emissions will be emitted shall be required to use all available and practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.b.(iii). Applicable Emission Limitation Guideline Both the 20% opacity and the no off -property transport emission limitation guidelines shall apply to construction activities; except that with respect to sources or activities associated with construction for which there are separate requirements set forth in this regulation, the emission limitation guidelines there specified as applicable to such sources and activities shall apply. Abatement and control plans submitted for construction activities shall be evaluated for compliance with the requirements of Section III.D. of this regulation. [Cross Reference: Subsections e. and f. of Section III.D.2. of this regulation.] III.D.2.b.(iv). Control Measures and Operating Procedures Control measures or operational procedures to be employed may include, but are not necessarily limited to, planting vegetation cover, providing synthetic cover, watering, chemical stabilization, furrows, compacting, minimizing disturbed area in the winter, wind breaks and other methods or technique. division. III.D.2.c. Storage and Handling of Materials III.D.2.c.(i). Applicability - Attainment and Non -attainment t III.D.2.c.(ii). General Requirement Any owner or operator or any new or existing materials storage am. ,,andling operation from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.c.(iii). Applicable Emission Limitation Guideline Both the 20% opacity and the no off -property transport emission limitation guidelines shall apply to storage and handling operations. Abatement and control plans submitted for storage and handling operations shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.c.(iv). Control Measures And Operating Procedures Control measures or operational procedures to be employed may include, but are not necessarily limited to, the use of enclosures, covers, stabilization, compacting, watering, limitation of fines and other methods or techniques approved by the division. III.D.2.d. Mining Activities III.D.2.d.(i). Applicability - Attainment and Non -attainment Areas III.D.2.d.(ii). General Requirements Any owner or operator of any new or existing mining operation from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.d.(iii). Applicable Emission Limitation Guideline Both the 20% opacity and the no off -property transport emission limitation guidelines shall apply to mining activities' except that with respect to sources or activities associated with mining for which there are separate requirements set forth in this regulation, the emission limitation guidelines there specified as applicable to such sources and activities shall apply. Abatement and control plans submitted for mining activities shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.(iv). Control Measures and Operating Procedures Control measures or operating procedures to be employed may include, but are not necessarily limited to: III.D.2.d.(iv).(A). watering or chemical stabilization of unpaved r, often as necessary to minimize re -entrainment of fugitive particulate matter from the road surface, or paving of road:. III.D.2.d.(iv).(B). prompt removal of coal, rock minerals, soil, and other dust -forming debris from paved roads and scraping and compaction of unpaved roads to stabilize the road surface as often as necessary to minimize re -entrainment of fugitive particulate matter from the road surface; III.D.2.d.(iv).(C). restricting the speed of vehicles in and around the mining operation; III.D.2.d.(iv).(D). revegetating, mulching, or otherwise stabilizing the surface of all areas adjoining roads that are a source of fugitive particulate emissions; III.D.2.d.(iv).(E). to the extent practicable restricting vehicular travel vehicles to established roads; III.D.2.d.(iv).(F). enclosing, covering, watering, or otherwise treating loaded haul trucks and railroad cars, or limiting size of load, to minimize loss of material to wind and spillage; III.D.2.d.(iv).(G).substitution of conveyor systems for haul trucks; III.D.2.d.(iv).(H). minimizing the area of disturbed land; III.D.2.d.(iv).(I). prompt revegetation of disturbed surface areas; III.D.2.d.(iv).(J). planting of special windbreak vegetation at critical points; III.D.2.d.(iv).(K). restricting the areas to be blasted at any one time; III.D.2.d.(iv).(L). reducing the period of time between initially disturbing the soil and revegetating or other surface stabilization; III.D.2.d.(iv).(M).control of fugitive particulate emissions from storage piles through use of enclosures, covers, or stabilization, minimizing the slope of the upwind face of the pile, confining as much pile activity as possible to the downwind side of the pile and other methods or techniques as approved by the division. [Cross Reference: Subsections a., b., c., e., f., g., and i. of Section III.D.2. of this regulation.] III.D.2.e. Haul Roads III.D.2.e.(i). Applicability - Attainment and Non -attainment Areas III.D.2.e.(ii). General Requirement Any owner or operator of any new or existing haul road which has vehicle traffic exceeding 40 haul vehicles or 200 total vehicles per day (averaged over any consecutive 3 -day period) from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.e.(iii). Applicable Emission Limitation Guideline The no off -property transport emission limitation guideline shall apply to on -site haul roads (i.e., those located on and abutted by the property owned or under control of the owner or operator of the haul road) and the nuisance guideline shall apply to off -site haul roads (i.e., those abutted on both sides by property not owned or under the control of the owner or operator of the haul road). Abatement and control plans submitted for haul roads shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.e.(iv). Control Measures and Operating Procedures Control measures and operational procedures to be employed may include, but are not necessarily limited to, the use of vehicular speed reduction, watering, chemical stabilization, road carpeting and other methods of techniques approved by the division. III.D.2.e.(v). The division may require persons owning or operating or maintaining any new or existing haul roads to supply vehicle traffic count information by any reasonable available means for the purpose of determining if they have sufficient traffic to subject them to the requirements of this Section III.D. III.D.2.f. Haul Trucks III.D.2.f.(i) Applicability - Attainment and Non -attainment Areas III.D.2.f.(ii). General Requirement Any owner or operator of any new or existing haul trucks from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.f.(iii). Applicable Emission Limitation Guideline The no off -property transport emission limitation guideline shall apply to haul trucks; except that when operating off the property of the owner or operator, the applicable guideline shall be no off -vehicle transport of visible emissions. Abatement and control plans submitted for haul trucks shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.f.(iv). Control Measures and Operating Procedures Control measures or operation procedures to be employed may include but are not necessarily limited to, covering the materials, washing or otherwise treating loaded haul trucks to remove materials from the exterior of the vehicle prior to transporting materials, limiting load size, wetting the load and other methods or techniques approved by the division. [Cross Reference: C.R.S. 1973, Section 42-4-1208] III.D.2.g. Tailings Piles and Ponds III.D.2.g.(i). III.D.2.g.(ii). Applicability - Attainment and Non -attainment Areas General Requirement Any owner or operator of any new or existing tailings piles and ponds from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.g.(iii). Applicable Emission Limitation Guideline Both the 20% opacity and the no off -property transport emission limitation guidelines shall apply to tailings piles and ponds. Abatement and control plans submitted for tailings piles and ponds shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.g.(iv). Control Measures and Operating Procedures Control measures or operational procedures to be employed may include, but are not necessarily limited to: II I.D.2.g.(iv).(A). watering and/or chemical stabilization, III.D.2.g.(iv).(B). synthetic and/or revegetative covers, III.D.2.g.(iv).(C). windbreaks, III.D.2.g.(iv).(D) minimizing the area of disturbed tailings, III.D.2.g.(iv).(E). restricting the speed of vehicles in and around the tailings operation, and/or, III.D.2.g.(iv).(F). other equivalent methods or techniques approved by the division. III.D.2.h. Demolition Activities III.D.2.h.(i). III.D.2.h.(ii) Applicability - Non -attainment Areas General Requirements Any owner or operator of any new demolition activities from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.h.(iii). Applicable Emission Limitation Guideline Only the no off -property transport emission limitation guideline shall apply to demolition activities. Abatement and control plans submitted for demolition activities shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.h.(iv). Control Measures and Operating Procedures Control measures or operational procedures to be employed may include, but are not limited to: III.D.2.h.(iv).(A). wetting down, including pre -watering of work surface, III.D.2.h.(iv).(B). removal of dirt and mud deposited on improved streets and roads, III.D.2.h.(iv).(C).wetting down, washing, or covering haulage equipment when necessary to minimize fugitive dust emissions during loading and transit. III.D.2.h.(v) Any demolition or renovation activity that has materials insulated or fireproofed with friable asbestos will also be subject to the provisions of the Air Quality Control commission's Regulation No. 8, Part B. III.D.2.i. Blasting Activities III.D.2.i.(i). III.D.2.i.(ii). Applicability - Attainment and Non -attainment Areas General Requirement Any owner or operator of any new or existing blasting activities from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section HI.D. of this regulation. III.D.2.i.(iii). Applicable Emission Limitation Guideline Only the no off -property transport emission limitation guideline shall apply to blasting activities. Abatement and control plans submitted for blasting activities shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.i.(iv). Control Measures and Operating Procedures Control measures or operational procedures to be employed may include, but are not limited to, the use of: III.D.2.i.(iv).(A). the removal of overburden prior to blasting, III.D.2.i.(iv).(B). watering down the blasted area as soon as practicable after blasting, III.D.2.j.(iv).(C). other equivalent methods or techniques approved by the division. III.D.2.j. Sandblasting Operations III.D.2.j.(i). Applicability - Attainment and Non -attainment Areas III.D.2.j.(ii). General Requirement Any owner or operator of any new or existing sandblasting activities from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section HI.D. of this regulation. III.D.2.j.(iii). Applicable Emission Limitation Guideline Only the 20% opacity emission limitation guideline shall apply to sandblasting operations. Abatement and control plans submitted for sandblasting operations shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.j.(iv). Control Measures and Operating Procedures Control measures and operating procedures to be employed may include, but are not limited to the use of enclosures with necessary dust collecting equipment, using wet sandblasting methods, and other methods or techniques approved by the division. III.D.2.k. Livestock Confinement Operations III.D.2.k.(i). III.D.2.k.(ii). Applicability - Attainment and Non -attainment Areas General Requirement Any owner or operator of any new or existing livestock confinement operations from which fugitive particulate emissions will be emitted shall be required to use all available practical methods which are technologically feasible and economically reasonable in order to minimize such emissions in accordance with the requirements of Section III.D. of this regulation. III.D.2.k.(iii). Applicable Emission Limitation Guideline Only the no off -property transport guideline shall apply to livestock confinement operations. Abatement and control plans submitted for livestock confinement operations shall be evaluated for compliance with the requirements of Section III.D. of this regulation. III.D.2.k.(iv). Control Measures and Operating Procedures Control measures or operating procedures to be employed may include, but are not limited to the use of sprinkler systems and/or other equivalent methods or techniques as approved by the division. IV. CONTINUOUS EMISSION MONITORING REQUIREMENTS FOR NEW OR EXISTING SOURCES IV.A. Sources which are required to install, calibrate, certify and maintain continuous ei monitoring (CEM) systems for opacity, and/or sulfur dioxide and/or carbon monoxic, Sections B, C, and D, of this Section IV and in Section VII.) shall have such equipm€ a location which in accord with sound engineering practice will provide for accurate op. sulfur dioxide, and/or carbon monoxide emission readings. The averaging times for then monitors shall correspond to the averaging times for the appropriate emission standard. IV.B. Fossil Fuel -fired Steam Generators IV.B.1. A continuous emission monitoring system for the measurement of opacity shall be installed, calibrated, maintained and operated by the owner or operator of any steam generator of a total rated capacity of or greater than 250 million BTU per hour heat input except where: IV.B.1.a. Gaseous fuel is the only fuel burned or, IV.B.1.b. Oil or a mixture of gas and oil are the only fuels burned and the source is able to comply with the applicable particulate matter and opacity regulation without utilization of particulate matter collection equipment, IV.B.1.c. The source demonstrates that a continuous monitoring system would not provide accurate determinations of the opacity of emissions (e.g., condensed, uncombined water vapor in the emissions would prevent accurate readings) and an alternative method of determining opacity approved by the division is employed. IV.B.2. Either a continuous emission monitoring system for the measurement of sulfur dioxide shall be installed, calibrated, maintained and operated or a division approved sampling plan shall be developed and implemented for determining the amount of sulfur in the fuel in order to calculate sulfur oxide emissions on any fossil fuel fired steam generator of a total rated capacity of or greater than 250 million BTU per hour heat input. IV.B.3. If an owner or operator is required to install a continuous monitoring system for sulfur oxides, a continuous monitoring system for measuring either oxygen or carbon dioxide is also required. IV.C. Sulfuric Acid Plant IV.C.1 The owner or operator of each sulfuric acid plant of or greater than 300 tons per day production capacity (the production capacity being expressed as 100 percent acid) shall install, calibrate, maintain and operate a continuous emission monitoring system for the measurement of sulfur dioxide for each sulfuric acid producing unit within such plant. IV.D. Fluid Bed Catalytic Cracking Unit at Petroleum Refineries IV.D.1. The owner or operator of each catalyst regenerator for fluid bed catalytic cracking units of or greater than 20,000 barrels per day fresh feed capacity shall install, calibrate. maintain and operate a continuous emission monitoring system for the measurement of opacity. IV.D.2. The owner or operator of each fluid bed catalytic cracking unit of 5,000 barrels per day or greater fresh feed capacity, located in a carbon monoxide (CO) non -attainment area shall install, calibrate, maintain, and operate a continuous emission monitoring system for the measurement of carbon monoxide. IV.D.3. Exemptions: IV.D.3.a. The owner or operator of a fluid bed catalytic cracking unit described in IV.D.2. may apply to the division for an exemption from continuous emission monitoring requirements listed in subsection IV.D.2. In order for an exemption to be granted, the following requirements must be met: IV.D.3.a.(i). The owner or operator of a source must conduct a flue gas emission test for carbon monoxide concentration. The test protocol must be approved at least 30 days in advance by the division and emissions during the test must not exceed 250 ppm by volume on a one hour average; and IV.D.3.a.(ii). Source owners or operators must establish a consistent relationship between carbon monoxide flue gas concentration and indicator parameter(s) such as flue gas oxygen content, or flue gas temperature, through a division approved test program; and IV.D.3.a.(iii). Source owners or operators must maintain records of CO indicator parameter(s), as described above, for a period of at least two years which shall be made available for division review upon request. IV.E. Performance Specifications The performance specifications used to determine the acceptability of monitoring equipment installed pursuant to Section IV.D.2. shall conform to those referenced in Appendix B of Part 60, Title 40, Code of Federal Regulations, or other specifications approved by the division. IV.F. Calibration of Equipment Owners or operators of all continuous monitoring systems subject to Section IV. of this regulation shall check the zero and span drift of the system at least once per day and at such other times as designated by the division, according to procedures approved by the division. The division may also make such determinations in order to assure proper quality assurance. IV.G. Notification and Recordkeeping The owner or operator of a facility required to install, maintain, and calibrate continuous monitoring equipment shall submit to the division within 30 days following the end of each calendar quarter, a report of excess emissions for all pollutants monitored for that quarter. This report shall consist of the following information and/or other reporting requirements as specified by the division. IV.G.1. The magnitude of excess emissions computed in accordance with division guidelines, any conversion factor(s) used, and the date and time of commencement and completion of each time period of excess emissions. IV.G.2. The nature and cause of the excess emissions, if known. IV.G.3. The date and time identifying each period of equipment malfunction and the nature of the system repairs or adjustments, if any, made to correct the malfunction. IV.G.4. A schedule of the calibration and maintenance of the continuous monitoring system. IV.G.5. Compliance with the reporting requirements of this Section IV.G. shall not relieve the owner or operator of the reporting requirements of Section II.E. of the Common Provisions Regulation concerning upset conditions and breakdowns. IV.H. A file of all data collected relating to the preceding two- year period shall be maintained by the owner or operator of an affected source. The format in which the required information is submitted shall be determined by the division. IV.I. The owner or operator of a facility utilizing fuel sampling as an alternative to continuous emission monitoring shall report fuel analysis data as specified in the sampling plan to the division within 30 days following the end of each calendar half in a format prescribed by the division. The purpose of such report shall be to disclose emissions that would exceed SO2 emission standards. V. EMISSION STANDARDS FOR EXISTING IRON AND STEEL PLANT OPERATIONS V.A. Electric Arc Furnaces V.A.1. Visible emissions from the gas -cleaning device or from uncaptured emissions escaping the Electric Arc Furnace shop, shall not exceed twenty percent (20%) opacity at any time. The approved reference test method for visible emissions measurement on which these standards are based is EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)). V.A.2. Emissions from the gas -cleaning device shall not exceed a mass emission rate of 0.00520 gr/dscf of filterable particulates maximum two-hour average, as measured by EPA Methods 1-4 and the front half of Method 5 (40 CFR 60.275, and Appendix A, Part 60), or by other credible method approved by the division. This particulate emissions standard does not include condensable emissions, or the back -half emissions of Method 5. V.B. Sources of particulate emissions at iron and steel plants not subject to specific emission limitations set forth in Section V shall comply with applicable emission limitations set forth elsewhere in this regulation. V.B.1. Smoke Emissions and Opacity Requirements [Cross-reference: Section II, subsections A.1., A.2 and A.6.i and A.6.iii] V.B.2. Particulate Emission Requirements [Cross-reference: Section III, subsection A.1, A.2, C.1 and C.3] V.C. A statement of the basis and purpose for the revisions to this Section adopted March 11, 1982 is hereby incorporated by reference, and a copy of the statement is available from the Air Quality Control commission office. VI. SULFUR DIOXIDE EMISSION REGULATIONS VI.A. Sources constructed or modified prior to August 11, 1977 shall be considered an existing source. All existing sources of sulfur dioxide emissions, except for sources listed in Section VII, shall comply with the following: VI.A.1. Averaging time - Unless otherwise specified in other sections of this regulation, the averaging time for all sulfur dioxide emissions standards shall be a three-hour rolling average. VI.A.2. If the sum of sulfur dioxide emission rates for all sources located on a contiguous site is less than three tons per day potential uncontrolled SO2 emissions, and if all federal and state ambient air quality standards are met no process based SO2 emission standard shall apply. VI.A.3. Existing sources of sulfur dioxide shall not emit sulfur dioxide in excess of the following process -specific limitations. (Heat input rates shall be the manufacturer's guaranteed maximum heat input rates). VI.A.3.a. Coal-fired operations including coal-fired steam generation: (These standards are also applicable to the use of coal -based by-product fuels.) VI.A.3.a.(i). Units with a heat input from coal or coal -based by-product fuels of less than 300 million BTU per hour: 1.8 pounds of sulfur dioxide per million BTU of heat input. VI.A.3.a.(ii). Units with a heat input from coal or coal -based by-product fuels equal to or greater than 300 million BTU per hour: 1.2 pounds of sulfur dioxide per million BTU of heat input. VI.A.3.b. Oil -fired Operations Including Oil -Fired Steam Generation VI.A.3.b.(i) Units with a heat input from oil of less than 300 million BTU per hour: 1.5 pounds of sulfur dioxide per million BTU of heating input. VI.A.3.b.(ii). Units with a heat input from oil equal to or greater than 300 million BTU per hour: 0.8 pounds of sulfur dioxide per million BTU of heating input. VI.A.3.c. Combustion Turbines VI.A.3.c.(i). Combustion Turbines with a heat input of less than 300 million BTU per hour: 1.2 pounds of sulfur dioxide per million BTU of heating input. VI.A.3.c.(ii) Combustion Turbines with a heat input equal to or greater than 300 million BTU per hour: 0.8 pounds of sulfur dioxide per million BTU of heating input. VI.A.3.d. Natural Gas Desulfurization Desulfurization Plants emitting more than five tons of sulfur dioxide per day: 2 pounds of sulfur dioxide per 1,000 cubic feet of (actual) delivered gas. VI.A.3.e. Petroleum Refining 0.7 pounds sulfur dioxide for the sum of all SO2 emissions from a given Refinery, per barrel of oil processed, per day. This emission limit shall be calculated over each 24 -hour period that commences at midnight. If the refinery does not operate for the entire 24 -hour period, the actual hours of operation shall be used as the averaging time. At no time shall the averaging time be greater than 24 hours. Refineries in operation on or before August 1, 1995, which are covered by this regulation, shall submit a plan for division approval no later than February 1, 1996. Sources constructed after August 1, 1995 shall submit a plan for division approval along with construction permit applications. The plan shall define how compliance with this limitation will be demonstrated. This plan shall address both how the SO2 value is calculated, i.e. mass balance, monitors, and how the barrels of oil processed value is derived, taking into account intermediate storage. The division shall not limit the determination of barrels processed per day to a 24 -hour period. The owner or operator of the affected source shall maintain all data used to show compliance with this emission standard for a period of two years for sources that are not subject to the operating permit program, and five years for sources that are subject to the operating permit program. This data shall be available for inspection by the division upon request. VI.A.3.f.Cement Manufacture Seven pounds of sulfur dioxide per ton of material (including fuel) processed. This emission limit shall be calculated over each 24 -hour period that commences at midnight. If the source does not operate for the entire 24 -hour period, the actual hours of operation shall be used as the averaging time. At no time shall the averaging time be greater than 24 hours. The owner or operator of the affected source shall maintain all data used to show compliance with this emission standard for a period of two years for sources not subject to the operating permit program and five years for sources subject to the operating permit program. This data shall be available for inspection by the division upon request. VI.A.3.g. Sources Not Specifically Listed Above Application of all available practical methods of control, which are technologically feasible and economically reasonable. This is to be determined by the division. VI.A.4. Recordkeeping and Reporting - All sources that have record keeping and reporting requirements shall comply with Sections IV.G. and IV.I of this regulation. VI.A.5. Data Retention - All sources that have recordkeeping and reporting requirements shall retain emission data for the preceding two-year period as referenced in Section IV.H. of this regulation or for a longer period if required under other applicable regulations. VI.B. All new sources of sulfur dioxide emissions shall comply with emission limitations as specifically provided by this subsection B. VI.B.1. For purposes of this Section VI.B. a new source is defined as a newly constructed or modified source of sulfur dioxide emissions that has not been issued an Emission Permit (in accord with Regulation No. 3 of this commission) prior to the August 11, 1977 effective date of this amended regulation. VI.B.2. The averaging time far all new source emissions standards for sulfur dioxide shall be three hours, and any three-hour rolling average of emission rates which exceeds these standards is a violation of this regulation. VI.B.3. The term "modification" is as defined in the Common Provisions Regulation, Section I.G. except that any source of sulfur dioxide subject to an emission standard which measures the sum of all sulfur dioxide emissions from a given facility shall not be considered "modified" for the purposes of this regulation unless the alteration may cause an increase in the sum of all sulfur dioxide emissions from such facility. VI.B.4. New sources of sulfur dioxide shall not emit or cause to be emitted sulfur dioxide in excess of the following process -specific limitations (Heat input rates shall be the manufacturer's guaranteed maximum heat input rates.) VI.B.4.a. All Coal -Fired Operations, Including Coal -Fired Steam Generators VI.B.4.a.(i). Units converted from other fuels to coal: 1.2 lbs. SO2/million BTU of coal heat input. VI.B.4.a.(ii). Units with a coal heat input of less than 250 million BTU per hour: 1.2 lbs. SO2/million BTU coal heat input. Vl.B.4.a.(iii). Units with a coal heat input of 250 million BTU per hour or greater: 0.4 lbs. SO2/million BTU coal heat input. VI.B.4.b. All Oil -fired Operations, Including Oil -Fired Steam Generation. VI.B.4.b.(i). Units with an oil heat input of less than 250 million BTU per hour: 0.8 pounds of sulfur dioxide per million BTU of oil heat input. VI.B.4.b.(ii). Units with an oil heat input of 250 million BTU per hour or greater: 0.3 lbs. SO2/million BTU of oil heat input. VI.B.4.c. Combustion Turbines VI.B.4.c.(i). Combustion Turbines with a heat input of less than 250 million BTU per hour: 0.8 pounds of sulfur dioxide per million BTU of heat input. VI.B.4.c.(ii). Combustion Turbines with heat input of 250 million BTU per hour or greater: 0.35 lbs. SO2/million BTU of heat input. IV.B.4.d. Natural Gas Desulfurization (As employed in this section, the term "delivered" means (a quantity of gas) delivered to the transmission pipeline). VI.B.4.d.(i). SO2: Desulfurization Plants emitting less than three tons per day of 2.0 lbs. SO2/1000 cubic feet of (actual) delivered natural gas. VI.B.4.d.(ii). Sources emitting three or more tons per day of SO2: 0.8 lbs. SO2/1000 cubic feet of (actual) delivered natural gas. VI.B.4.e. Petroleum Refining 0.3 lbs. sulfur dioxide, for the sum of all SO2 emissions from a given refinery per barrel of oil processed. (Averaged over a daily 24 -hour period, I.E. Midnight through 23:59.) VI.B.4.f. Production of Oil from Shale Production of oil from shale shall be subject to the emission limitations provided in Colorado Air Quality Control commission Regulation No. 6, Subpart B (Non-federal New Source Performance Standards (NSPS), Section IV.C.3.) VI.B.4.g. Refining of Oil Produced from Shale VI.B.4.g.(i). Refineries processing less than 1,000 barrels per day: No process emission standard. VI.B.4.g.(ii). Refineries processing 1,000 or more barrels per day: 0.3 lbs. sulfur dioxide, for the sum of all Sulfur dioxide emissions from a given refinery, per barrel of oil processed. VI.B.4.h. Sulfuric Acid Production 4.0 lbs. sulfur dioxide/ton of acid produced and 0.15 lbs. H2SO4 mist/ton of acid produced. VI.B.5. Any new source of sulfur dioxide not specifically regulated above shall: VI.B.5.a. dioxide, or Limit emissions to not more than two (2) tons per day of sulfur VI.B.5.b. Utilize best available control technology as determined by the division subject to review by the commission. VI.B.6. Recordkeeping and Reporting - All sources that have recordkeeping and reporting requirements shall comply with Sections IV.G. and IV.I of this regulation. V.l.B.7. Data Retention - All sources that have recordkeeping and reporting requirements shall retain emission data for the preceding two-year period as referenced in Section IV.H. of this regulation or for a longer period if required under other applicable regulations. V.1.B.8.A written statement of the basis and purpose of this new source emission control regulation, which includes a detailed analytical evaluation of the scientific and technical rationale justifying this regulation has been prepared and adopted by the commission on August 11, 1977. This written statement entitled, "Rationale for the Promulgation of a New Source Emission Control Regulation and Ambient Air Quality Standards for Sulfur Dioxide", is hereby incorporated in this regulation by reference, in accord with C.R.S. 1973, 24-4-103 as amended. VI.C. Fuel Sampling The division must approve all fuel sampling plans. The appropriate ASTM test methods or other equivalent method approved by the division shall be used for all fuel sampling plans. VI.D. Performance Tests Prior to granting of a final approval permit or amending a permit, when an emission source or control equipment is altered, or at any time when there is reason to believe that emission standards are being violated, the division may require the owner or operator of any facility subject to the emission standards under Section VI to conduct performance tests, as measured by EPA Methods 1-4 Methods 6, 6a, 6b, 6c and Method 8 (40 CFR 60.275, Appendix A, Part 60), or any other method which the division finds appropriate to determine compliance with this subsection of this regulation. VI.D.1. The owner or operator of an existing source of sulfur dioxide shall, upon request of the division, conduct performance test(s) and furnish the division a written report of the results of such performance test(s) to determine compliance with this regulation. VI.D.2. Performance test(s) shall be conducted and data reduced and recorded in accordance with the test methods and procedures specified above unless the division: VI.D.2.a. Approves the use of an alternative method the results of which the division has determined to be adequate for indicating whether a specific source is in compliance, or VI.D.2.b. Waives the requirement for performance test(s) because the owner or operator of a source has demonstrated by other means to the division's satisfaction that the affected facility is in compliance with the standard. Nothing in this paragraph C. shall be construed to abrogate the commission's or division's authority to require testing under Article 7 of Title 25, Colorado Revised Statute 1973, and regulations of the commission promulgated there under. VI.D.3. The owner or operator of an affected facility shall provide the division thirty days prior notice of the performance test to afford the division the opportunity to have an observer present. VI.E. Related Compounds Containing Sulfur in Oxidized States: VI.E.1. For the purposes of this regulation, all oxidized forms of sulfur (including, but not restricted to sulfur trioxide (SO3), trionyl chloride (SOCl2), and sulfuric acid mist (H2504)) shall be considered as sulfur dioxide. VI.E.2. Quantities of such oxidized sulfur compounds shall be converted on a molar basis to an equivalent quantity of sulfur dioxide. The total of all such quantities, (expressed in parts per million by volume sulfur -dioxide -equivalents of other oxidized forms) shall be interpreted as "parts per million by volume sulfur dioxide" as used in Section B. above. VI.F. Alternative Compliance Procedures VI.F.1. Any person may apply to the division Director for approval of an alternative: VI.F.1.a. Test method, VI.F.1.b. Method of control, VI.F.1.c. Compliance period, VI.F.1.d. Emission limit, or VI.F.1.e. Monitoring schedule. VI.F.2. The application shall include a demonstration that the proposed alternative produces: VI.F.1.a. An equal or greater air quality benefit than that required in this subsection VI, or VI.F.2.b. The alternative test method is equivalent to that required by these regulations. VI.F.3. The division Director shall obtain concurrence from EPA prior to approving an alternative. VII. EMISSION REGULATIONS FOR CERTAIN ELECTRIC GENERATING STATIONS OWNED AND OPERATED BY THE PUBLIC SERVICE COMPANY OF COLORADO VII.A. The electric generating stations owned and operated by the Public Service Company of Colorado listed below shall not emit or cause to be emitted nitrogen oxides (NOr) or sulfur dioxide (SO2) in excess of the following limits. The emission rates for NO, and SO2 are measured in terms of pounds of pollutant per million British Thermal Units of fuel fired in the unit (lb/mmBTU). VII.A.1. Cherokee Electric Generating Station, 6198 North Franklin Street, Denver, CO VII.A.1.a. NO, and SO2 limits: NO, (lb/mmBTU) SO2 (lb/mmBTU) Unit 1 - 1.1 Unit 2 - 1.1 Unit 3 0.60 1.1 Unit 4 0.45 1.1 The NO, limit will be calculated based on a 30 -day rolling average, and is effective November 1, 1994. The SO2 limit will be calculated as a three-hour rolling average, and is effective November 1, 1994. Public Service Company of Colorado shall install, certify and operate continuous emission monitoring equipment in accordance with 40 CFR Part 60.13, for measuring opacity, SO2, NOR, and either O2 or CO2 on Units 1, 2, 3 and 4. VII.A.b. Effective January 1, 2005, the NO, limit for Unit 1 shall be 0.60 lb/mm BTU, provided EPA approves the designation of the Denver area as a PM -10 attainment/maintenance area. Such limit shall be calculated based on a 30 -day rolling average. VII.A.c. Upon EPA approval of the designation of the Denver area as a PM -10 attainment/maintenance area, the SO2 emission rate from units 1 and 4 shall not exceed 0.88 lb/mm BTU, calculated separately for each unit, based on a 30 -day rolling average. Such emission limit shall apply seasonally from November 1 through Mardi 1. The additional SO2 limit set out in this subsection VII.A.1.c. shall not apply unless EPA repeals the incorporation of SO2 permit limits into the SIP at 40 CFR 52.320(c)(82)(i)(E). VII.A.2. Arapahoe Electric Generating Station, 2601 South Platte River Drive, Denver, CO VII.A.2.a. No, and SO2 limits: NO, (lb/mmBTU) SO2 (lb/mmBTU) Unit 1 - 1.1 Unit 2 - 1.1 Unit 3 - 1.1 Unit 4 0.60 1.1 +20% annual tonnage reduction The NO, limit will be calculated based on a 30 -day rolling average, and is effective November 1, 1994. - The SO2 limit will be calculated as a three-hour rolling average, and is effective January 1, 1995. - The 20% SO2 limit from Unit 4 shall be calculated on a calendar year, total annual tonnage basis. — Public Service Company of Colorado shall install, certify and operate continuous emission monitoring equipment in accordance with 40 CFR Part 60.13, for measuring opacity, SO2, NOR, and either O2 or CO2 on Units 1, 2, 3 and 4. VII.A.2.b. Upon EPA approval of the designation of the Denver area as a PM -10 attainment/maintenance area, the SO2 emission rate from unit 4 shall not exceed 0.88 lb/mm BTU, calculated on a 30 -day rolling average. Such emission limit shall apply seasonally from November 1 through March 1. VII.A.2.c. Retirement of units 1 and 2 VII.A.2.c.(i). Units 1 and 2 shall be permanently retired by January 1, 2003. This section VII.A.2.c. shall become effective upon EPA approval of the designation of the Denver area as a PM -10 attainment/maintenance area. VII.A.2.(ii). This section VII.A.2.c shall not be construed to prevent the construction or operation of a new source on the site of such units, provided any such new source complies with all laws and regulations applicable to new sources. VII.A.3. Valmont Electric Generating Station, 1800 North 63rd Street, Boulder, CO NO„ (lb/mmBTU) SO2 (lb/mmBTU) Unit 5 0.45 1.1 - The NO limit will be calculated based on a 30 -day rolling average, and is effective November 1, 1994. - The SO2 limit will be calculated as a three-hour rolling average, and is effective November 1, 1994. Public Service Company of Colorado shall install, certify and operate continuous emission monitoring equipment in accordance with 40 CFR Part 60.13, for measuring opacity, SO2, NOX, and either O2 or CO2 on Unit 5. VIII. RESTRICTIONS ON THE USE OF OIL AS A BACKUP FUEL VIII.A. Applicability The provisions of this section are applicable to all points at the following stationary sources in the Denver PM10 Attainment/Maintenance area that use oil as a backup fuel for natural gas, which is the primary process fuel: VIII.A.1.Public Service Company of Colorado, Zuni Electric Generating Station; VIII.A.2.Public Service Company of Colorado, Valmont Electric Generating Station; VIII.A.3.Public Service Company of Colorado, Delgany Steam Generating Station; VIII.A.4.University of Colorado Health Science Center (Fitzsimmons); and VIII.A.5.Trigen-Colorado Energy, Golden, CO. VIII.B. Requirements Beginning November 1, 1993, natural gas shall be the only fuel used from November 1 to March 1 of each year, except under the following circumstances: VIII.B.1.The supplier or transporter of natural gas imposes a curtailment or an interruption of service; Vlll.B.2.For necessary testing of equipment used to operate the unit on oil, testing of fuel and training of personnel; or Vlll.B.3. When an equipment malfunction at the facility makes it impossible or unsafe for the unit to operate on natural gas. VIII.C. Recordkeeping Each stationary source subject to these provisions shall maintain records for a period of two years, which include the following information: VIII.C.1.dates and number of hour's fuel oil are burned; VIII.C.2. percent sulfur analysis of the fuel oil that is burned; VIII.C.3. number of gallons burned each day; and VIII.C.4. reason(s) for the use of the fuel oil. VIII.D. Reporting Beginning April 1, 1994 and by April 1 of each year thereafter, each stationary source subject to these provisions shall submit to the division a report containing the information listed in Section VIII.C. VIII.E. Alternate Recordkeeping and Reporting Where the information required under subsections C and D above is otherwise made available to the division, for example in Air Pollution Emission Notice (APEN) reports submitted by the source or pursuant to operating permit requirements or analogous information is maintained by the source in a credible form approved by the division, the requirements of subsections C and D of this Section VIII are satisfied. IX. EMISSION REGULATIONS CONCERNING AREAS WHICH ARE NONATTAINMENT OR ATTAINMENT/MAINTENANCE FOR CARBON MONOXIDE - REFINERY FLUID BED CATALYTIC CRACKING UNITS: No later than nine months after the effective date of this revision (January 30, 1987) no source which has emitted 1,000 or more tons of carbon monoxide during any 12 month period, nor any source which can reasonably be expected to emit 1,000 or more tons of carbon monoxide during any future 12 -month period, shall emit any gas in which carbon monoxide constitutes 0.050% (500 ppm) or more of the volume of the gas, based on a one hour average. X. STATEMENTS OF BASIS AND PURPOSE Sections I through IV and minor revisions to Section VI (Adopted April 8, 1982) Regulation No. 1 sets forth emission limitations, equipment requirements, and work practices (abatement and control measures) intended to control the emissions of particulates, smokes and sulfur oxides from new and existing stationary sources. Control measures specified in this regulation are designed to limit emissions into the atmosphere and thereby minimize the ambient concentrations of particulates and sulfur oxides. The regulation is primarily aimed at control of particulates of 10 -micron size and smaller (i.e. "inhalable" particles). However, in recognition of the fact that larger particles - especially which may settle on roads, be ground into smaller sizes and later reintroduced into the atmosphere — larger size particles have also been controlled where control seemed appropriate. Section II.A.1 — Smoke and Opacity. The previous opacity regulations have made any exceedence of 20% opacity a violation. To conform to the method of opacity measurement used by the U.S. Environmental Protection Agency, the commission has switched to the 6 -minute averaging method of measuring opacity contained in EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)). The testimony presented by division representatives indicated investigators in the field have in effect been averaging opacity. The commission encourages the division to continue its practice of allowing non -agency personnel to attend smoke school and receive certification. Section II.A.2 — Intermittent Sources. The switch in methods of measuring opacity (see comments on Section II.A.1 above) made it necessary to devise a modified method to measure opacity from those sources, which do not operate continuously for at least six minutes. EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)) was amended to accommodate this situation. Section II.A.3 — Pilot Plants and Experimental Operations. The previous regulation excerpted pilot plants and experimental operations from its 20% opacity standard to the extent of allowing emissions of up to 40% opacity for no more than 3 minutes in any 60 -minute period (see previous Section II.A.2.b.). Because of the switch in methods of measuring opacity (i.e., now averaging for six minutes) this exception has been changed to now allow up to 30% opacity (as measured by EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)) for no more than 6 minutes in any 60 - minute period. This revised exception represents an equivalent relaxation. This relaxed opacity limitation applied only for 180 operating days, after which the 20% opacity limitation of Sections II.A.1 and 2 again applied. The regulation, however, provides that the division may extend the maximum 180 -day period on good cause shown. For clarification, the phase "operating day" has now been defined and the exception made applicable to "process units" of a pilot plant or experimental operation to more accurately reflect the commission's intent. Section II.A.4 — Fire Building, Cleaning of Fire Boxes, Soot Blowing, Start -Up, Process Malfunction or Adjustments of Control Equipment. On the same rationale that the limited exception for pilot plants was amended (see comments on II.A.3. above), the limited exceptions for these sources has also been changed from up to three minutes in a 60 - minute period at no more than 40% opacity to up to six minutes at 30% opacity (averaged). Section I I.A.5 — Smokeless Flares. Smokeless flares were not previously exempted in any way from the 20% opacity standard. The commission has now allowed a limited exception of up to six minutes in a 60 -minute period at 30% opacity (averaged) to reduce the burden of upset reporting on operations of smokeless flares. Section II.A.6. — Alfalfa Dehydrating Plants. This section remains the same as the previous Regulation No. 1 and requires compliance with 20% opacity by January 1, 1985. Section II.A.7 — Wigwam Burners. House Bill 1366 (1977) added Section 25-7-108(3)(e) to the Air Pollution Control Act of 1970. It provided: "that the provisions of any commission Regulation concerning Wigwam Burners shall not apply prior to July 1, 1982, to any such burner located within seventy-five air miles of the border of any state bordering on Colorado if the regulations concerning wigwam wood waste burners of the bordering state are less stringent that those of the commission. Said exemption shall not apply to wigwam wood waste burners located within a twenty mile radius of any city, town, or municipality having a population of fifty thousand persons as determined by the 1970 Federal Census." House Bill 1109 (1979) repealed the Air Pollution Control Act of 1970 including Section 25-7-108(3)(e). The Colorado Air Quality Control Act established by House Bill 1109 did not contain the above quoted exemption in the new Section 25-7-109(3)(e) which gave the authority to adopt emission regulations for Wigwam wood waste burners to the commission. The commission has therefore promulgated emission standards for new and existing wigwam burners in this Regulation No. 1. New wigwam burners are subject to 20% opacity at all times. Effective January 1, 1983, existing wigwam burners are subject to a 40% opacity ceiling (i.e., no emissions in excess of 40% are allowed) except for 1 hour of start-up (ignition of a new fire after a period of non -operation). Additionally, existing wigwam burners must submit a plan to control their emission by the same date. As was provided for in HB 1090 and HB 1109 (1979), the regulation recognizes exemption from state regulation for certain wigwam wood waste burners subject to county regulation. Section II.A.8. — Exemptions. As with the previous regulation, certain sources have been exempted from the opacity limitations in Sections II.A.1. and II.A.2. In some instances the exemptions are based on a determination that control of opacity is not economically reasonable or technically feasible (e.g., "fugitive dust" and noncommercial fireplaces burning clean wood); in others because the sources are subject to more appropriate emission limitations elsewhere in the regulation (e.g., iron and steel plants and "fugitive particulate emissions") the commission realizes that woodburning in fireplaces, fireplace inserts and stoves may cause severe air pollution problems and has appointed a committee to evaluate the problems and plans, if necessary, to recommend changes to the regulation regarding smoke sources when adequate data is developed. Definitions of "Fugitive Dust" and "Fugitive Particulate Emissions." In connection with its decisions on exemptions from Section II.A.1. and II.A.2. and for the purposes of Regulation No. 1 only, the commission has developed new definitions for "fugitive dust" (which is not subject to regulation) and "fugitive particulate emissions" (subject to the provisions of Section III.D.) to help distinguish between fugitive particulate pollution subjected to and exempted from regulation. Section II.B. — Diesel Powered Locomotives. This section has provisions for Diesel Powered Locomotives only and they are the same as the previous Regulation No. 1. Provisions for other motor vehicles have been deleted primarily because of the amendment of C.R.S. 1973, Section 18-13-110 in 1979. The previous restrictions on emissions from off - highway heavy duty diesel -powered vehicles was not carried forward to the current regulation because it was felt no significant reduction in emissions could be achieved in light of the exemption for such vehicles for nonconsecutive periods of 15 seconds (see former Section I.B.3.c-2). Section II.C. — Open Burning. This section was reorganized by the commission and contains few substantive changes. The exemption for burning in municipalities with less than 3,500 population has been replaced with an exemption created by HB1090 (1979) for the unincorporated areas of counties with less than 25,000 population where the Board of County commissioners has adopted regulations to control open burning. As was provided for in HB 1090 (1978), the regulation recognizes a limited exemption from state regulation for certain burning subject to county regulation. Section III.A. — Fuel Burning Equipment. This section has been reorganized and contains the same provisions as the previous Regulation No. 1 except that the performance test method has been changed from the American Society of Mechanical Engineer's Power Test Codes-PTC-27 dated 1957 entitled "Determining Dust Concentrations in A Gas Stream" to EPA Methods 1-4 and the front half of EPA Method 5 (40 C.F.R. 60.275, Appendix A, part 60). The change in test methods was made because of division testimony that the latter method is the more widely used and recognized test procedure. Sources subject to Section V (iron and steel plants) of this Regulation No. 1 are exempt from this section. Section III.B. — Incinerators. This section was changed only with respect to the performance test method. The new methods to be used are EPA Methods 1-4 and the front half of EPA Method 5 (C.F.R. 60.275, Appendix A, Part 60). The change in test methods was made because of division testimony that the latter method is the more widely used and recognized test procedure. Section III.C. — Manufacturing Processes. This section is a reorganization of the previous Regulation No. 1 and also contains provisions for existing alfalfa dehydration plants (also found in Air Quality Control commission Regulation No. 5). Specific exemptions for Section V and for fugitive particulate emissions have been included in this section. Section III.D.1 — (Fugitive Particulate Emissions) General Requirements. In its 1981 opinion in CF&I Steel Corporation v. Colorado Air Pollution Control commission (Case No. 77- 804), the Colorado Court of Appeals expressed reservations about appropriateness of applying an opacity test to non -point sources, stating it saw "a significant number or problems" attributable to the fact the test was developed for application to stack or point sources. Although the court's reservations were expressed in dicta and the commission has found that the opacity test can be applied to area sources (and the State Supreme Court has agreed to review the Court of Appeals decision), the commission nonetheless realizes that opacity readings may be made on point sources more readily than on certain "area sources". Accordingly, the new regulation has shifted the use of opacity (and off property transport) observations from an enforceable standard for area sources to a guideline in determining when the adequacy of applied control methods should be reviewed. The "general requirements" provisions of Section III.D. explain when control plans (or revisions to existing control plans) must be submitted and set forth the criteria for approvability of such plans. Under this new approach, enforcement action under C.R.S. 1973, 25-7-115 will be taken only when an owner or operator (a) fails to comply with the approved emission control plan for its source, (b) the source fails to submit a plan within the time prescribed for submittal, or (c) continues to operate after a control plan (or portion thereof) has been disapproved. A source will not, however, be deemed in violation if operation of such source is discontinued so as to permanently eliminate the cause of fugitive particulate emissions there from. Pursuant to C.R.S. 1973, 25-7-114(f) and 25-7-115(5), if a new source is denied a permit for failure to provide an adequate control plan or an existing source cited for operation in violation of the regulation, the owner/operator is afforded the opportunity to contest the division's action before the Air Quality Hearings Board. The lists of control and abatement measures contained in the regulation represent measures that are generally considered to be available, practical, economically reasonable and technically feasible. This determination is based on several factors, including the division's observation that the same measures contained in the previous version of the regulation generally were both effective in controlling emissions of particulates and sulfur oxides and affordable. With few exceptions, (e.g., road carpeting), no new measures have been added to the list of suggested control and abatement measures beyond those which were listed in Section 2.D.9. of the previous Regulation No. 1. To the extent cost data could be obtained from affected sources', or by the commission, or its staff, a cost -benefit analysis was done for controls of fugitive particulate emissions on the basis of dollar cost of control per ton of emissions reduced. The commission also considered, but did not quantify in dollars, other benefits to public health and welfare from controlling fugitive particulates such as aesthetics (e.g., elimination of visible plumes which obstruct views), elimination of "nuisance" conditions which frequently result in citizen complaints (e.g., dust from feedlots, construction activities and roadways), and possible adverse effects on certain industries — such as ski and tourist industries which benefit from clean air. The regulation requires employment of "all available practical methods that are technologically feasible and economically reasonable." This requirement does not necessarily mean a source must employ all control measures and practices listed. For example, it obviously would not be economically reasonable to employ paving, road carpeting, dust suppressants and watering to control fugitive particulate emissions from unpaved roadways. Although the commission has determined that the control and abatement measures listed in the regulation are generally economically reasonable for the types of sources to which they apply, it is recognized that in particular instances some of the listed measures are ineffective, redundant or otherwise inappropriate. On the other hand, there may be control measures or practices not listed in the regulation for a type of source which are available, practical, technologically feasible and By Order of August 7, 1981, the commission ordered its staff and the parties to the rulemaking proceeding to conduct an "informal discovery process" for the purpose, among others, of securing information on the cost to owners and operators of fugitive particulate emission sources of implementing the various control and abatement measures specified in the regulation. Discovery was to proceed in two phases of written inquiries and responses. The results of the process were disappointing. Some of the parties fully cooperated and submitted requested cost data including adequate information to substantiate the claimed costs. Despite receipt of written inquiries from commission staff, requests made to parties during the hearings for additional information, and the commission's follow-up letters to parties (dated November 6 and December 10, 1981) again requesting submittal of requested data; several parties failed to respond, others submitted unsubstantiated cost data, and others only partially responded. The commission therefore, proceeded on the assumption that control and abatement measures that have been successfully employed in the past, continue to represent available, practical, economically reasonable and technologically feasible methods of control unless substantive evidence to the contrary was received. The regulation therefore requires submission and evaluation of emission control plans on a source -by - source basis to allow the division to evaluate the plan for each source in light of its particular circumstances. At such time, the owner or operator and the division may determine that some of the listed measures are not appropriate as applied to a particular source or that others not listed are. This approach of a separate control plan for each source allows maximum flexibility in developing an enforceable control plan which represents an appropriate approach to control - in some instances more, in other instances less stringent than the listed controls. As control technology advances and other relevant circumstances change, it is expected that control methods meeting the requirements of Section III.D. will also change and that control plans previously appravable may have to be amended. Sections III.D.1.c. and d. (Amended October 28, 1982) Regulation No. 1, sections III.D.1.c. and d. were amended in response to the Attorney General's rule opinion of April 19, 1982 (disapproving, in part, section III.D. of Regulation No. 1 as adopted on April 8, 1982) and the objections of the Air Pollution Control division of the Colorado Department of Health that the regulation did not allow it to require fugitive particulate emission control plans in all appropriate situations. Evidence presented by the division at the hearing demonstrated that in many instances the emission limitation guidelines ("triggers") could be met by use of emission controls significantly less stringent than "all available practical methods of control that are technologically feasible and economically reasonable" (hereafter "all practical controls"). The attorney general's primary concern was that virtually identical sources could therefore be subjected to these differing "standards" — i.e., one required to apply "all practical controls"; the other only having to avoid exceeding a less stringent trigger with the division being unable to require a control plan. The division also testified that, in some instances, the 20% opacity and no -off -property -transport guidelines would be inadequate because use of those triggers to require submission of a control plan required an observation be made at the time the particulates were being emitted and also that the observations be made under specific circumstances. The division would therefore be unable to require a control plan, even though one may be appropriate, if an inspector did not actually observe the exceedence of the guideline or if all requirements for making the observation were not present (e.g., the winds exceeded 30 mph). First of all the regulation does not necessarily require that a division inspector personally observes emissions exceeding one of the triggers. The division may require a control plan provided there is adequate, reliable evidence that a trigger has been exceeded. The revisions to the regulation further address the problems the division has raised. The nuisance trigger (which was previously applicable only to unpaved roads and haul roads) has been made applicable to all regulated sources. This will allow the division to require a control plan from a source creating a nuisance even when an inspector is unable to use the 20% opacity or no off -property transport guideline (e.g., because of high winds). The language adopted is literally less comprehensive than that proposed in the rulemaking notice. The revised regulation, however, (a) at a minimum addresses those sources of fugitive particulate emissions where the need for specific control plans is clearest and (b) provides more concrete (less vague) guidance to persons subject to the regulation of what level of control is required absent a specific control plan. The commission expects that this will facilitate voluntary compliance by sources without plans. Although theoretically situations could still arise whereby similar sources are subjected to different standards, it is the determination of the commission that in practice, as revised, the regulation with its now broader nuisance trigger will subject virtually all significant sources of fugitive particulate emissions to the requirement of applying "all practical controls". In the event the regulation fails to achieve this intended objective, the regulation will be viewed as a "first step" towards its achievement and further revisions will be made. Nothing in the regulation is intended as, nor should it be construed as, prohibiting the division from conducting inspections as required by C.R.S. 1973, 25-7-115 — whether on an annual or other periodic basis, in response to complaints, or otherwise. Section III.D.2.a. — Roadways. This section provides a list of appropriate control measures for controlling dust from unpaved roadways. The commission initially had to determine which unpaved roadways warranted control based on the amount of fugitive particulate emissions resulting from their use. The amount of 25 tons per year (TPY) per mile was chosen as an appropriate figure based on the fact that 25 TPY is the figure in commission Regulation No. 3 deemed "significant" for the purpose of triggering the special non -attainment area permit requirements (e.g., offsets, LAER) for major modifications. Regulation No. 3, Section IV.D.2.b.(v). (Emissions of 25 TPY or more is also one of the triggering factors that would require a new emission permit application be subjected to public comment. Regulation No. 3, Section IV.C.1.) Using 25 TPY (per mile) as the point at which an unpaved road should be required to control emissions, it was calculated using representative figures for the other factors that unpaved roads with traffic counts of 150 vehicles in non -attainment areas and 200 vehicles in attainment areas would cause emissions requiring control. The commission included the traffic count of 150 vehicles per day (averaged over any consecutive 3 -day period) for unpaved roadways in non -attainment areas as a result of the calculated emissions from an average weight passenger car (2800 lbs.), traveling at a speed of 30 miles per hour, over a one mile stretch of unpaved road and with the assumption of 30% of those emissions remaining suspended. Using the following equations: EF= 5.9 (S) (V) EMISSIONS = S = silt content V = vehicle speed W = weight of vehicle 12 30 (w)o.8 (d) 3 365 .3{EF)x(Y) x 365 days/yr = 25 tons/yr. 2000 lbs /ton d = dry days per year EF = emission factor expressed in terms of lbs. per vehicle miles traveled Y = Vehicle miles traveled per day The higher traffic count in attainment areas can be accounted for by examining the difference in the factor "number of dry days per year" between attainment and non -attainment areas (215 and 285 respectively). (Because the non -attainment areas are basically all east of the mountains "dry day" figures for Colorado eastern plains were used for non -attainment areas; and north -central mountain figures were used for attainment areas.) In response to the Colorado Court of Appeals' decision in CF&I Steel Corporation vs. AQCC (cited above), the regulation no longer has separate sections concerning publicly owned and privately owned unpaved roadways. The provisions for control of emissions from unpaved roadways apply to all unpaved roadways and reference to ownership has been eliminated. There was discussion at the rulemaking hearing about whether dust emissions from unpaved roadways were inhalable and therefore presented a hazard to public health. It is the commission's conclusion that 65% of the emissions [expressed as a percentage of suspended particulate (i.e. less than 30 microns)] from unpaved roadways are less than 10 microns in size and less (improved emission factors for fugitive dust from western surface coal mining sources Vol. II) and that they therefore do warrant control for the protection of public health. Various persons, including local governments and the Colorado General Assembly, expressed concern about the cost of controlling emissions from unpaved roadways and urged that local officials are generally in a better position to determine and exercise appropriate control over roadways. Especially in light of the limited personnel resources of the division, the commission would therefore encourage the division to exercise its authority under C.R.S. 1973, Section 25-7-111(2)(f) in designating local agencies willing and able to enforce the regulation as agents of the division in concurrently enforcing this regulation — and especially with respect to air pollution problems which can be evaluated by such local agencies. Neither the 20% opacity nor the no off -property transport emission limitations guidelines seemed appropriate for application to unpaved roadways. To focus the limited personnel resources on the more serious problems a "nuisance" emission limitation guideline has been employed. Investigations will be initiated in response to citizen's complaints of nuisances created by excess emissions from unpaved roadways. Section III.D.2.b. — Construction Activities. Large percentages (54% from dozers, 49% from scrapers, 48% from graders, 67% from exposed areas) of the fugitive particulate emissions from construction activities are inhalable (Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources, Vol. II) and therefore need controls. Thus the commission has established a list of potential control measures for this activity. The smallest size of disturbed acreage requiring control in non -attainment areas was reduced from 5 acres to 1 acre in size in order that those smaller sources — determined to be significant source of emissions in non -attainment areas because of the great amount of construction activities occurring on smaller sites — could be controlled. The 5 acres remains as the size cutoff in attainment areas. Section III D.2.c. — Storage and Handling of Materials. The commission established a list of potential control measures for this activity for inclusion in a requested control plan. The percentage of inhalable particulates from storage and handling activities is presented in Improved Emission Factors for Fugitive Dust from Western Coal Mining Sources, Vol. II (listed as 30% loading, 49% dozer, 61% storage piles) are significant emissions and therefore the commission has concluded that such emissions should be controlled. Section III.D.2.d. — Mining Activities. A large percentage of fugitive particulate emissions from mining activities are inhalable. The information in Table 12-2 from Improved Emission Factors for Fugitive Dust from Western Coal Mining Sources, Vol. II, shows inhalable particulates for several mining related activities in a range of 30% — 67%. The commission has concluded that these are significant emissions and should therefore be controlled. Thus the commission has established the list of potential control measures for this activity for inclusion in a control plan. Underground mining activities are exempt from the provisions of Section III.D.2.d. However, if emissions from underground mining activities are vented to the atmosphere, they are subject to the opacity provisions of Section II.A.1. Section III.D.2.e — Haul Roads. The commission determined that a substantial amount of fugitive particulate emissions come from haul roads. For example, the percentage of inhalable particulates created by haul trucks traveling on such roads is listed as 52% in a table from Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources Vol., II. The commission has concluded that these emissions are significant and should be controlled. Thus, the commission established the list of potential control measures for this activity. The commission included a traffic count of 40 haul vehicles or 200 total vehicles per day (averaged over any consecutive 3 -day period) for haul roads as a result of the calculated emissions using the following formula: EF = SV 365-W N 60 365 4 S = silt content (if unknown assume 15%) V = vehicle speed in mph (average) W = mean annual number of days with .01 inches or more rainfall N = number of wheels on vehicle Assumptions: 40 mph (average speed) = V 6 wheels on vehicles = N 80 days (West Slope condition) = W EF = 15 x 40 365 — 80 6 = 11.7 lb/VMT 60 365 4 Emissions = .3 (EF) x "Y" x 365 Days /Yr 25 Tons/Year 2000 lb Per Ton E = 25 x 2000 .3(11.7)(365) EF = Emission factor expressed in terms of lbs. Per vehicle mile traveled "Y" = Vehicle miles traveled per day = 40 vehicle miles per day Recognizing that a haul road could have significant emissions even without hauling 40 haul vehicles per day because of other vehicular traffic, haul roads are subject to the regulation when their traffic count exceeds either 40 haul vehicles or 200 total vehicles per day (200 light weight vehicles representing emissions of 25 tons per year for unpaved roadways — see comments on Section III.D.2.a. above.) As with roadways and for the same reasons, a nuisance emission limitation guideline has been adopted as an inspection "trigger" for "off -site" haul roads. The no off -property transport emission limitation guideline applies to "on -site" haul roads. Section III.D.2.f. — Haul Trucks. A list of alternative control measures has been established by the commission for this activity for inclusion in a requested control plan. There were no emission factors for determining the emissions from the load of a loaded haul truck. Section III.D.2.g. — Tailings Piles and Ponds. The commission established the list of abatement and control measures for this activity for inclusion in any requested control plan. "exposed areas" are listed in a table as being 67% inhalable particulates. This is found in Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources, Vol. II. The commission concluded that these emissions are significant and therefore should be controlled. Section III.D.2.h — Demolition Activities. A significant amount of this activity does occur in the non -attainment areas and necessitates control. The commission established the list of control measures for this activity for inclusion in a control plan submittal. Cross-reference is made to the requirements of Regulation No. 8 regarding asbestos materials. Section III.D.2.i — Blasting Activities. The commission provided a list of potential control measures for inclusion in any requested control plan. The percentage of inhalable particulates from blasting is listed as 44% in a table from Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources, Vol. II. The commission concluded that these emissions are significant and should therefore be controlled. Section III.D.2.j. — Sandblasting Operations. The commission established a list of potential control measures for inclusion in any requested control plan. Section III.D.2.k — Livestock Confinement Operations. The commission established a list of potential control measures for inclusion in any requested control plan. These measures will provide an economic benefit to the operator of livestock confinement operations (i.e., there should be fewer incidents of dust pneumonia in livestock). Agriculture Activities: The commission determined that fugitive particulate emissions from agricultural activities (e.g., plowing, or dicing) cannot be controlled by methods that are economically reasonable and feasible - such as watering. The commission further determined that the great majority of emissions from agricultural activities were not from activities such as plowing, but from the action of the wind on exposed soil. The commission therefore reviewed the provisions of the Colorado Soil Erosion and Dust Blowing Act of 1954, C.R.S. 1973 Section 35-72-101, and determined that statute adequately addresses the problem of fugitive particulate emissions from agricultural activities. Agricultural activities are therefore not subject to the provisions of Section III.D. Agricultural activities have been specifically exempted from the open burning requirements of Section II.C. The exemption is viewed as an economic necessity to commercial agricultural operations. Section IV. - Continuous Emission Monitoring Requirements for Existing Sources. The commission has included Continuous Emission Monitoring Requirements for four types of sources: Fossil Fuel -Fired Steam Generators; Sulfuric Acid Plants; Fluid Bed Catalyst Regenerators at Petroleum Refineries. However, CEM units for the measurement of NOX emissions from existing sources of NOX were considered unnecessary as there is no NOX standard for existing sources. As a substitute to CEM an approved coal -sampling program to determine the sulfur content of the coal being fired in the steam generators may be employed. With such data, SO2 emissions can be calculated. Performance specifications, calibration requirements, notification and recordkeeping have been included for the evaluation of any such CEM system that is required by this section. This part meets and exceeds the requirements of 40 CFR, Part 51, Appendix P, Volume 40, No. 194 Fed. Req. 46247 (October 6, 1975). The commission has determined that continuous emission monitoring for carbon monoxide (CO) is necessary for fluidized -bed catalytic cracking unit regenerators at petroleum refineries. Continuous Emission Monitoring will ensure the emission standard is being met at these sources that are the largest CO emitters in the state. (March 20, 1986) Section V. - (Adopted March 11, 1982) See below. Section VI. - Sulfur Dioxide Emission Regulations: The commission made no substantive changes to the provisions of the previous Regulation No. 1. The commission revised the regulation to make existing sources subject to meeting specific emission standards when their emissions exceed three tons per day of sulfur dioxide rather than the previous five tons per day. The new level is to ensure that major sources of sulfur dioxide in Colorado are well controlled such that ambient impacts and potential air quality related value impacts are reduced. (March 20, 1986) Section IX. Emission Regulations Concerning Areas that are Non -attainment for C Carbon Monoxide Emission Regulation: The Denver Metro Area has a serious C; Pollution Problem. Air quality monitoring conducted in 1980 indicated that the De exceeded the standard by almost 58% (for the second worst case). Air quality m support of the 1982 State Implementation Plan (SIP) shows that the predicted rr CO in 1987 will still exceed the national Air Quality Standard by 25%. If Denver compliance by 1987 it faces possible economic sanctions or imposed measures, W..... carbon monoxide levels sufficiently so that the standard will be met. EPA reviewed Colorado's 1982 SIP submittal and expressed concern regarding the CO problem and the division's plans to deal with it. One strategy EPA has stated Colorado must employ is the requirement that all major stationary sources of CO (greater than 1,000 TPY) in non -attainment areas use "Reasonably Available Control Technology" (RACT) to reduce emissions. Though EPA has not specifically defined what RACT is for major CO sources, the commission herein defines RACT as any control device approved by the division that will reduce CO emissions to a level less than or equal to 0.050% of exhaust gases by volume. The only CO sources located in non -attainment areas of Colorado, which emit greater than 1,000 TPY are fluidized -bed catalytic cracking units (FCC) at Petroleum refineries. Uncontrolled emissions from these units can approach 10% (100,000 ppm). Control technology is readily available for use in FCC units. According to EPA publication AP -42, carbon monoxide boilers can reduce emissions to "negligible levels". Similarly, the use of combustion promoters can reduce CO emissions to less than 0.050%, according to the Encyclopedia of Chemical Technology. The requirement to apply RACT to carbon monoxide emission sources at refineries will reduce reported emissions, as used in the 1982 SIP Revision, from 125 tons per day to 11 tons per day, an improvement of about 91%. This will result in a 4% reduction in the Denver Metro CO inventory, thus demonstrating further progress towards attainment of the National Ambient Air Quality Standards. (March 20, 1986) APPENDIX A. Method of Measuring Opacity from Fugitive Particulate Emission Sources. Also in response to the referenced dicta in the Court of Appeal's CF&I decision, the commission has included a specified method for measuring opacity of fugitive particulate emissions from non -point sources. Although this may not be as precise as Method 9 (40 CFR. Part 60, Appendix A (July, 1992)) as applied to stacks since this is a guideline and not an enforceable standard the commission determined it to be quite adequate for these purposes. The method is a modified version of EPA Method 9 (40 CFR, Part 60, Appendix A (July, 1992)). Terminology was changed to reflect this method's applicability to fugitive particulate emission sources covered by Section III.D.A. of this regulation. Additional procedures are established for the positioning of the observer and the observing of emissions (at a point of release to the atmosphere). These procedures will become part of the training at "smoke schools" conducted by the Colorado Department of Health for certification of smoke and opacity observers. APPENDIX B. Method of Measurement of Off -Property Transport of Fugitive Particulate Emissions. The commission included this method of measurement of fugitive particulate emissions in order that the "Off -Property Transport" guideline is uniformly applied by observers. This method generally employs the same criteria for the positioning of an observer as the method of measurement of opacity in Section III.D.2. of this Regulation No. 1. This method will also be included in the "smoke school" training for the certification of smoke and opacity observers. a. Section V. (Adopted March 11, 1982) This rationale complies with the requirement of the Administrative Procedure Act, C.R.S. 1973, 24-4- 103(4) that the Air Quality Control commission (commission) prepare a statement of basis and purpose for these amendments. The statutory authority for these amendments is in the Air Quality Control Act at C.R.S. 1973. 25-7-102, 25-7-105, 25-7-106, and 25-7-109. The general purpose of the amendments was to require reasonably available control technology (RACT) be applied to particulate emission sources at existing iron and steel plants. The CF&l Steel Corporation (CF&I) and the U.S. Environmental Protection Agency (EPA) were the only parties to the rulemaking. The Air Pollution Control division (division) acted as staff for and advised the commission during the proceeding. The parties and the commission addressed two major areas of controversy: whether the use of clean water for coke quenching operations represents RACT and which methods of emission control for cast houses represents RACT. Coke quenching is considered by the commission to be a major source of particulate emissions from iron and steel plants and development of emission controls for coke quenching should be encouraged. As originally proposed, RACT for coke quenching would have required the use of water having no more than 700 mg/I of total dissolved solids (TDS). However, upon review of the rulemaking record, the commission has determined that it has insufficient information to adopt an emission control regulation for coke quenching. Therefore, the commission is requiring the submission of reports on the capabilities of wastewater treatment facilities, the generation rates of wastewater, the relationship between TDS levels in coke quench water and other variables, the particulate -removing efficiency of existing baffling systems, and the costs of installation of alternative baffling systems. Based on these reports and information relating to the effectiveness of powder activated carbon in wastewater treatment facilities, the effectiveness of baffling systems at other iron and steel plants, the relationship of TDS levels to particulate emissions, and other relevant information, the commission will reconsider the issue of RACT for coke quenching. The commission has determined that non -capture technology (for example, shrouding and suppression) constitutes RACT for cast house particulate emissions, except for emissions from the iron notch, ladle and spouts. Due to the developing and proprietary nature of such technology, the commission has adopted a general requirement for use of such technology that will permit iron and steel plants to determine its most cost and pollution control effective application at such plants. Iron and steel plants will be allowed a period of two years to develop, evaluate and apply a non -capture technology at one of its cast houses. It is not considered feasible to apply such technology in a lesser time period. Based on the experience with this initial application, the commission expects to develop a more specific standard for the use of such technology at additional cast houses. Because there is not a basis in the record for concluding that capture technology is cost effective or RACT, the commission has determined not to require such technology. b. Amended Sections V.A.5.c. and V.B.5.a. (Adopted: February 24, 1983). This rationale complies with the requirement of the Administrative Procedure Act, C.R.S. 1973, 24-4- 103(4) that the Air Quality Control commission (commission) prepare a statement of basis and purpose for these amendments. The statutory authority for these amendments are in the Air Quality Control Act at C.R.S. 1973, 25-7-102, 25-7-105, 25-7-106, and 25-7-109. The commission has determined that the effective dates for meeting the requirements for coke quenching and cast houses as described above in paragraph B should be postponed for the following reasons: (1) Due to economic conditions the coke plant and blast furnaces at the iron and steel plants are currently not in operation. The studies and control measures outlined in Section V were to be conducted and implemented while those sources were in operation (with the exception of a study outlining the costs of installing and operating existing quench towers with alternative baffling system(s)). (2) With regard to the study outlining the costs of installing and operating existing quench towers with alternative baffling systems, the commission determined that (due to the current economic conditions and reduced work force at iron and steel plants) a postponement until "normal rate of production" at coke plants is again reached would result in more useful data being submitted. In regard to quenching of coke the time period for submittal of reports shall be fifteen months from the time that production levels return to 128 ovens per day. With regard to cast houses, the time period for implementing controls shall be determined from the date of return to service of one blast furnace. Regarding the issue of reasonably available control technology ("RACT"), for the iron notch, the iron ladle and the iron spout required to be addressed by Section V.B.5., the commission adopts the division's and CF&I's agreement that RACT is not currently available in non -capture emission controls for the iron spout and the iron ladle. However, there is reason to believe that U.S. Steel Corporation will soon be publicly revealing its non -capture technology for iron and steel plants. The division should review the available technology, and if RACT exists, return to the commission with a recommendation for rulemaking. For these reasons, the commission believes that emissions from iron and steel plants will be controlled as expeditiously as practicable under these delayed schedules. c. Written statements of the basis and purpose for the various provisions in Section VI of this regulation were prepared and adopted by the commission at the times such provisions were adopted. These written statements were incorporated in this regulation by reference and in accord with C.R.S. 1973, 24-4-103 as amended. Copies are available at the office of the Air Quality Control commission. RATIONALE FOR THE PROMULGATION OF A NEW SOURCE EMISSION CONTROL REGULATION The Air Pollution Control commission of the State of Colorado has reviewed the oral testimony and documentary evidence submitted in the course of its rulemaking proceedings on proposed new ambient air standards for sulfur dioxide and new source emission standards for sulfur dioxide. The attached amendments to the existing Colorado ambient air quality standards for sulfur dioxide and the existing Regulation No. 1 of the Colorado Air Pollution Control commission are a result of study, analysis and technical evaluation by the commission and its staff and, in the judgment of the commission, represent those standards which will most effectively foster the welfare, convenience and comfort of Colorado residents in facilitating the enjoyment of nature, scenery, and other related resources of the State. In every respect, this commission's deliberations and determinations have been guided by the legislative declaration of the policy of the Colorado Air Pollution Control Act of 1970: to achieve the maximum practical degree of air purity in every portion of our State. New Source Emission Standards for Sulfur Dioxide It was evident throughout the course of public hearings and is obvious to the commission that the hazardous effects of sulfur dioxide are measured by its concentration in the ambient air. It is the quantity emitted per unit time that determines this ambient concentration rather than the concentration in any particular effluent stream. Emission rates are significant with respect to effects on the environment and on human population and vegetation, but ambient air concentrations are the primary consideration in terms of these effects and for that reason ambient air standards that are reasonably related to existing conditions in Colorado have been established. These new ambient standards and emission rates have been developed to reflect a consistent basis. The commission in the course of establishing these new sulfur dioxide standards has considered three general themes. (1) Best practical control technology must, in general, be employed. (2) For some industries the cost of such control technology might be prohibitive for certain small sources. Since the total emissions from such sources are not large and do not have a substantial effect on ambient concentrations, the commission has adopted emission standards which reflect economic considerations for small sources. (3) In response to overwhelming testimony from industry, from technical experts, and from the general public, the commission has acknowledged that emission standards should not be based on volumetric concentrations in the effluent stream but rather on the weight of sulfur dioxide emitted per energy input or unit of product as processed. Many witnesses representing industry and users of electrical power suggested that Colorado should adopt the EPA New Source Performance Standards (NSPS). The commission has considered this suggestion. However, it is the conclusion of the commission that EPA New Source Performance Standards are based on the use of high -sulfur coal as well as the application of best external control technology to the effluent gases. Given the availability of low -sulfur western coal for industrial usage in this state, it has been concluded that the application of best practical control technology should result in considerably lower emissions for Colorado sources than those specified in EPA New Source Performance Standards. Logically, the more stringent emissions standards are possible and desirable if low sulfur coal is employed. Testimony to support this conclusion was presented at the hearings. The commission has adopted certain features of the New Source Performance Standards: (1) The commission has established a two-hour averaging time for emission standards identical to that set forth in the NSPS. (2) The commission has recognized that small sources should not be subject to the substantial cost of external sulfur dioxide removal equipment, which is proportionately more costly for small industrial operations. The hazard to ambient air quality may be satisfactorily minimized in most instances by the use of low -sulfur fuels for these smaller sources. Where a distinction is made, the cut-off point for small sources is identical to that employed in the NSPS (250 million BTU per hour). Coal -Fired Operations Including Coal -Fired Steam Generation Take as a reference point the information supplied in the application for an emission permit for the proposed Pawnee 500 megawatt steam generating station. A heat input of 5,430 Million BTU per hour produces 500 megawatts of electrical power. The overall thermal efficiency is 31% and 10.9 million BTU per hour are required per megawatt of power. Some eastern high -sulfur coals have caloric values on the order of 12,000 BTU per pound and sulfur contents on the order of 2.5%. If it is assumed that 5% of the sulfur is retained in the ash, the emission rate of an operation using this coal would be 3.96 pounds of sulfur dioxide per million BTU. Compliance with the New Source Performance Standards of 1.2 pounds per million BTU would require a sulfur dioxide removal efficiency of 70%. It is the finding of this commission, based in part upon testimony from industrial and non -industrial sources, that control efficiencies on the order of 70% sulfur dioxide removal may be attained without undue financial burden on large new sources. This 70% removal efficiency may be taken as a measure of the application of best practical control technology. Testimony presented before the commission indicated that steam coal readily available for use in Colorado had a caloric content on the order of 8,000 BTU per pound and a sulfur content of 0.5%. Uncontrolled emissions from the use of such coal would be 1.19 pounds of sulfur dioxide per million BTU. The best practical control technology, operating at an efficiency of 70% would reduce the emission rate to 0.36 pounds of sulfur dioxide per million BTU. The commission, therefore, adopted an emission standard of 0.4 pounds of sulfur dioxide per million BTU. The required removal efficiencies are shown as a function of coal parameters in Table I. For smaller sources an emission limit was set identical to the NSPS large source values. This standard may be met by the use of high quality low -sulfur western coal. The maximum emission under this standard would be 3.6 tons of sulfur dioxide per day and could result in the production of 23 megawatts of electrical power. Table II contains some information regarding the quality of coal required to meet this standard. Of special concern to the commission was the problem of conversion of facilities from other fuels to coal. This issue was frequently raised in the testimony. It was clearly indicated that the cost of installing external sulfur dioxide control equipment would be prohibitive in terms of the necessary modifications to existing equipment: lack of space in which to install the control equipment was termed an almost insurmountable obstacle. The commission therefore concluded that the sulfur dioxide emissions standard for operations converted to coal -firing from the use of other fuels would be the NSPS; namely, 1.2 pounds of sulfur dioxide per million BTU. This standard can be met through the use of available high quality coal. The maximum emission from such a converted 100 -megawatt facility would be approximately 16 tons per day, or equivalent to the emissions from a 300 -megawatt installation operating at an emission rate of 0.4 pounds of sulfur dioxide per million BTU. The nature of the required coal quality is indicated in Table II. TABLE I REMOVAL EFFICIENCIES REQUIRED TO MEET AN EMISSION STANDARD OF 0.4 POUNDS PER MILLION BTU (Assumes 5% sulfur retention in ash) Caloric Content Efficiency Percent Sulfur (%) (BTU/Ib.) 8,000 9,000 10,000 11,000 0.4 0.5 0.6 0.8 0.9 0.5 0.6 0.8 1.0 0.6 0.7 0.9 1.1 0.6 0.7 0.9 1.1 TABLE II SULFUR DIOXIDE EMISSION FROM COAL Removal 58 66 72 79 81 62 69 76 81 65 70 77 81 62 67 74 79 (Assumes 5% sulfur retention in coal) BTU/pound 8,000 9,000 10,000 11,000 Maximum Sulfur Content to Meet Emission Standard of 1.2 pounds per million BTU 0.50% 0.57% 0.63% 0.69% Under certain circumstances the emission standards may be limiting; under other circumstances, the ambient air quality standards may govern the issuance of permits to new coal-fired sources. In any event, impact on ambient air quality is the ultimate concern and siting may thus become an important factor for new sources. Several Rocky Mountain States have adopted sulfur dioxide emission standards more restrictive than the Federal standards and in some cases, more restrictive than these Colorado Standards. Oil -Fired Operations Including Oil -Fired Steam Generation The New Source Performance Standards (NSPS) for oil -fired operations with a heat input greater than 250 million BTU per hour is 0.8 pounds of sulfur dioxide per million BTU. In line with the philosophy of higher emission rates per unit of energy input for small sources and in line with the adoption of NSPS for new coal-fired sources of less than 250 million BTU input per hour, the commission adopted an emission standard of 0.8 pounds of sulfur dioxide per million BTU for sources with a heat input less than 250 million BTU per hour. The required degree of oil quality is shown in Table III, and oil of the quality necessary to meet these standards is available. For larger oil -fired operations (greater than 250 million BTU per hour) the commission again decided to require best practical control technology. The standard adopted is calculated from the ration of the NSPS standards for coal and oil applied to the adopted 0.4 pounds per million BTU standard for coal-fired operations. The standard for large new oil -fired operations thus becomes 0.3 pounds of sulfur dioxide per million BTU. At present, there is little expectation that large new oil -fired facilities will be constructed. No industry provided testimony at the hearings regarding its intent to construct a large oil -fired facility in Colorado. TABLE III SULFUR DIOXIDE EMISSIONS FROM FUEL OIL Percent sulfur Pounds per million BTU 0.1 0.11 0.2 0.21 0.28* 0.30 0.4 0.42 0.6 0.42 TABLE III SULFUR DIOXIDE EMISSIONS FROM FUEL OIL Percent sulfur Pounds per million BTU 0.7 0.75 0.75** 0.80 0.9 0.95 1.0 1.05 * Maximum sulfur content required to meet standard of 0.3 lbs/million BTU ** Maximum sulfur content required to meet standard of 0.8 lbs/million BTU The standard of 0.8 pounds of sulfur dioxide per million BTU would be applied to emissions for facilities converted from other fuels to oil. The rationale follows that given above for coal-fired operations. Combustion Turbines These are used largely for peaking operations. There is little likelihood that natural gas will be used as a fuel for such sources in the near future. The major fuel will be oil for new sources and sources converted from natural gas use. The commission adopted the same standards for emissions from combustion turbines as for emissions from oil -fired operations. High quality distillate will be required. Little testimony was presented on this issue. Natural Gas Desulfurization Natural gas (primarily methane) is a clean and desirable fuel for household use. It is considerably more efficient for such use than electrical energy obtained from coal combustion. The conversion efficiency for the conversion of coal to electrical energy is on the order of 30%; the conversion of the chemical energy of natural gas to thermal energy is on the order of 80%. Much natural gas as it comes from the well is "sour"; i.e. contains significant and varying concentrations of hydrogen sulfide. This substance must be removed before the gas is put into the pipeline. For smaller sources, the waste hydrogen sulfide may be "flared" and converted into sulfur dioxide and emitted as such. For larger sources, the gas is desulfurized by means of a process which converts the hydrogen sulfide into elemental sulfur. Sulfur dioxide is emitted as a by-product in such a process. Control technology exists for reduction of all such sulfur dioxide emissions. The caloric content of natural gas is on the order of one million BTU per 1,000 cubic feet. Small coal-fired electrical generating facilities have been assigned an emission standard of 1.2 pounds per million BTU. Considering the greater efficiency of natural gas in its usage (by factor of 80/30) it is reasonable to adopt a higher emission rate per unit of energy for natural gas desulfurization. However, the stacks employed in such desulfurization are lower than those normally used in coal-fired generation operations and hence, contribute significantly to increased ambient levels. A balancing process for establishment of these emission standards has therefore become necessary. Application of highly efficient sulfur dioxide removal equipment may be prohibitively expensive for small sources. The commission has, after review of the short stack considerations, decided to adopt a break point between large and small sources of 3 tons of sulfur dioxide emissions per day. The applicable standard for such small sources is set at 2 pounds of sulfur dioxide per 1,000 cubic feet (one million BTU). This recognizes the greater thermal efficiency of natural gas while minimizing impact on ambient air quality. For larger sources, the emission standard of 0.8 pounds of sulfur dioxide per 1,000 cubic feet of gas delivered to the pipeline gives weight to the increased energy efficiency of natural gas, as compared to coal, for the generation of applicable power. (This standard is roughly twice that for coal-fired operation.) Suitable technology is available for control in such large sources. Again little testimony was presented at the hearings. Table IV contains some pertinent data with respect to natural gas desulfurization. TABLE IV NATURAL GAS DESULFURIZATION Vol. % CO2 Vol. % H2S 10 16 14 12 10 8 6 4 2 1 0.5 0 16 12 8 4 1 0.5 16 12 8 4 lbs. SO2/1,000 Cubic feet 38.6 32.9 27.5 22.3 17.4 12.8 8.3 4.1 % Removal (2.0 % Removal (0.8 lbs.) lbs.) 95 98 94 98 93 97 91 96 89 95 84 94 76 90 51 80 2.0 60 1.0 - 20 34.0 94 98 24.3 92 97 15.5 87 95 7.4 73 89 1.8 - 56 0.9 — 11 Permitted Production per day in Cubic Feet at Uncontrolled 3 tons of Sulfur Dioxide per day (Million cubic feet) 0.177 0.247 0.387 0.811 TABLE IV NATURAL GAS DESULFURIZATION Vol. % CO2 Vol. % H2S Petroleum Refining lbs. SO2/1,000 Cubic feet % Removal (2.0 % Removal (0.8 lbs.) lbs.) 1 3.334 0.5 6.666 The prediction and analysis of sulfur dioxide emissions from the refining of crude oil presents a complex problem. The sulfur content of the crude oil varies; the sulfur content of the various portions of refined products varies as does the mix of these products; the emissions are from several processes. The refineries now in operation in Colorado range in capacity from 6,000 to 35,000 barrels per day. The largest refinery processes crude oil with an average sulfur content of 0.9% and a range of about a factor of 2. This crude is considered "sour"; i.e. containing a significant concentration of elemental sulfur. Some sulfur dioxide escapes in this process as well as from other operations in the refining cycle. It is estimated that the total emissions from this refinery range from 10 to perhaps 15 tons per day. With a 35,000 barrel a day capacity the emission rate is thus 0.57 - 0.86 pounds of sulfur dioxide per barrel of oil processed. Little evidence was presented to the commission regarding technical aspects of new petroleum refining facilities. Further study by the commission and staff indicate that (1) emission standards should be set for the overall operation rather than on standards for the separate process units due to the complexity of this operation (2) that technology for new operations is available (tail -gas scrubbing) that would lower the emissions by at least a factor of three, and (3) such technology is economically feasible for new construction. The commission therefore adopted an emission standard of 0.3 pounds of sulfur dioxide per barrel of oil processed. Under this standard a 40,000 barrel a day plant would emit per day 6 tons of sulfur dioxide, equivalent to the emissions from a controlled 140 megawatt electrical generating facility. Production of Oil from Shale Due to the complexity of sulfur dioxide emission sources in a shale oil production facility, whether it involve surface retorting or "in situ" production, the commission adopted an emission standard which relates the permitted sulfur dioxide emission to the operation as a whole (in terms of quantity of oil produced). Some conflicting evidence was presented to the commission on this issue. The proposed Union Oil Plant would purportedly emit 6 tons of sulfur dioxide per day and produce 71,000 barrels a day; the emission rate would be 0.17 pounds of sulfur dioxide per barrel of oil produced. The proposed Colony surface retorting facility was described as emitting 3.9 tons per day with production of 43,000 barrels a day. The emission rate will be 0.18 pounds per barrel. Testimony from Standard Oil of Indiana projected an emission rate for a modified "in situ" process of close to a full pound of sulfur dioxide per barrel. This latter figure has, however, been significantly reduced, in the detailed development plan for this project, to 0.3 pounds of sulfur dioxide per barrel of oil. The "in situ" process may offer other significant advantages in environmental impact over surface retorting. It was the decision of the commission, therefore, to adopt an emission standard for large oil shale production facilities of 0.3 pounds of sulfur dioxide per barrel of oil produced. This standard is to be applied to the total of such emissions from the production facility. The commission anticipates the construction of small experimental units to test new methods for the production of oil from shale. The nature of sulfur dioxide emissions from such sources would not be precisely known, nor would the total emissions be large. The commission has therefore decided to exempt sources with a production rate less than 1,000 barrels a day from process emission standards. Under these standards, the emission rate for a 50,000 barrel a day operation would be 7.5 tons a day which is equivalent to the emissions from a controlled 130 megawatt electrical generating plant. Refining of Oil Produced from Shale It appears that the sulfur content of the shale oil delivered to the refineries will be on the order of one percent. This is similar to the oil now being processed in the Conoco refinery in Denver. The same argument would therefore apply here as was advanced for the refining of conventional crude oil. The emission standard for large operations is thus set at 0.3 pounds of sulfur dioxide per barrel of oil refined. Again the commission has decided to exempt small experimental operations from process standards. The cut-off has been set at 1,000 barrels per day. Taking an extreme point of view (all the sulfur is emitted as sulfur dioxide and none retained in the product) the daily emissions from a 1,000 barrel a day operation would be 2.8 tons of sulfur dioxide per day which is equivalent to the emissions from a controlled 50 megawatt electrical facility. Sulfuric Acid Production These are the EPA New Source Performance Standards and will require installation of control devices that are available. Any Sulfur Dioxide Source Not Specifically Regulated Above No evidence was introduced concerning such emissions. The commission is not aware of plans for construction of such sources or the nature of the sources. It is proposed, consistent with the general philosophy concerning small sources, to exempt sources with an emission rate of less than two tons per day (equivalent to the emissions from a controlled 36 megawatt installation) from process standards. For new large sources the application of best practical control technology will be required. Due to the unknown nature of these new sources, it is impossible to specify process emission rates, the nature of the control technology, and its efficiency. The Air Pollution Control division in its evaluation of the permit application is charged with determining whether best practical control technology will be utilized. The commission reserves the right to review such decisions. ADOPTED: AUGUST 11, 1977 COLORADO AIR POLLUTION CONTROL COMMISSION RATIONALE AND JUSTIFICATION FOR THE AMENDMENT OF AIR QUALITY CONTROL COMMISSION REGULATION NO. 1, SECTION IV, BY ADDING A NEW SUBSECTION D. On April 9, 1981 the Air Quality Control commission adopted an Amendment to Air Quality Control commission Regulation No. 1, Section IV. concerning Limitation on Emissions from Sinter Plant Windboxes at Existing Iron and Steel Plant Operations. Colorado's only existing sinter plants at iron and steel facilities are located at the CF&I plant in Pueblo, Colorado. The Pueblo area is currently designated by the U.S. Environmental Protection Agency (EPA) as non -attainment with respect to the National Ambient Air Quality Standards (NAAQS) for total suspended particulates. Section 172(b)(3) of the Federal Clean Air Act requires that State Implementation Plans for non - attainment areas require reduction of emissions from existing sources through adoption, at a minimum, of Reasonably Available Control Technology (RACT). EPA has proposed conditional approval of the Pueblo element of the Colorado State Implementation Plan in the December 12, 1980 Federal Register (45 Fed. Req. 81789). In that proposed rulemaking notice, EPA indicated that the Air Quality Control commission's existing emission limitations for various sources at existing iron and steel plants do not represent Reasonably Available Control Technology and proposed approval of the Pueblo element of the SIP on condition, among others, that the Air Quality Control commission emission control regulations for existing iron and steel plants be revised to represent RACT. In response to the requirement of section 172 of the Clean Air Act and EPA's proposed conditional approval of the Pueblo element of the SIP, the commission is conducting public hearings to review and revise as appropriate, emission control regulations for sources at existing iron and steel plants. Because of an existing compliance order issued by the Air Pollution Control division and affirmed by the Air Quality Hearings Board, requiring CF&I to bring its sinter plant into compliance with existing standards, the commission decided to conduct rule making with respect to sinter plants as early as possible. With respect to the interpretation of the numerical standard "0.03 gr/dscf", such standard is intended to be interpreted as an absolute standard such that any emissions in excess of 0.03 gr/dscf, no matter how minimal, shall constitute a violation. In other words, the commission is approving the Air Pollution Control division's past and continuing interpretation of numerical standards as if they were followed by an unlimited number of zeros. This interpretation by the Air Pollution Control division is approved on the understanding that the Air Pollution Control division would normally not initiate enforcement action for extremely minimal violations (e.g., 0.0301). The Air Quality Control commission determined that there was no legal basis for adoption as part of the regulation of an exemption for CF&I from enforcement of the applicable existing, less stringent emission limitation (.037 gr/dscf equivalent) while CF&I implements the new, more stringent 0.03 gr/dscf standard. The Air Quality Control commission acknowledges that the Air Pollution Control division, not the Air Quality Control commission, is charged by statute (C.R.S. 1973, 25-7-115) with enforcement of emission control regulations and trusts all relevant factors (including CF&I's efforts and success in complying with existing standards) will be considered by the Air Pollution Control division in exercising its enforcement authority. AIR QUALITY CONTROL COMMISSION ADOPTED: APRIL 9, 1981 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE Emergency Amendment to Regulation No. 1 Section III.D.1. (Fugitive Particulate Emissions) On April 8, 1982, the Air Quality Control commission adopted a new Regulation No. 1 which was scheduled to become effective May 30, 1982. On April 19, 1982, the Attorney General for the State of Colorado, in accordance with the provisions of C.R.S. 1973, 24-4-103(8)(b), issued an opinion as to the legality and constitutionality of the new regulation and disapproved in part Section III.D. of the regulation (concerning control of fugitive particulate emissions). Recognizing that the Attorney General's opinion raises a substantial question as to the validity of portions of Section III.D. of the regulation (and poses significant problems with respect to enforcement of said regulation; finding that having an enforceable regulation for the control of fugitive particulate emissions necessary to the preservation of the public health and welfare; and in order to avoid the circumstance of not having an enforceable regulation for the control of fugitive particulate emissions for any significant period of time [as would result if the normal rulemaking procedures were followed]); the Air Quality Control commission has determined adoption of amendment to Section III.D. of the Air Quality Control commission Regulation No. 1 is imperatively necessary for the preservation of the public health and welfare and that compliance with the normal rulemaking procedural requirements of C.R.S. 1973, 24-4- 103 would be contrary to the public interest. AIR QUALITY CONTROL COMMISSION ADOPTED: AUGUST 26, 1982 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE Revisions to Regulation Number 5 concerning Alfalfa Dehydration Plants "Regulation No. 5" and sections II.A.6 and III.C. of "Regulation No. 1" have previously exempted, until January 1, 1985, existing alfalfa dehydration plants from the 20 percent opacity standard otherwise applicable to sources of air pollution. In these amendments to "Regulation No. 5" and sections II.A.6. and III.C. of "Regulation No. 1" the commission has extended that exemption until January 1, 1987, in order to give the one existing alfalfa dehydration plant in Colorado an opportunity to come into compliance with the 20 percent standard. The commission expects compliance to be achieved by that date, and does not intend, through these amendments, to indicate that it will accept a permanent exemption from the 20 percent standard. ADOPTED: JANUARY 19, 1985 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE Regulations 1 and 5 concerning Alfalfa Dehydration Plant Drum Dryers The Air Quality Control Commission of the State of Colorado adopted the revisions to Regulations 1 and 5 described below on January 15, 1987. This Statement of Basis, Specific Statutory Authority and Purpose is required by Section 24-4-103, C.R.S.. The specific statutory authority for these changes is Sections 25-7-105, -106, and -110, C.R.S.. The Air Quality Control commission's Regulation 1 and the recently expired Regulation No. 5 provided that existing alfalfa -dehydrating plants must operate so as not to exceed 40% opacity. This extension was adopted in January of 1985 and extended this exemption (40% opacity limit) until January 1, 1987, at which time Regulation No. 5 terminated. Existing alfalfa dehydrators then fell under the provisions of Regulation No. 1. The effect of this is to require existing alfalfa dehydrators to meet 20% opacity limits; thus treating existing plants the same as new plants. Mr. Graves claims to be the only operator of an existing plant which is subject to these requirements. Mr. Graves has asked the commission to establish a 30% opacity as the standard for existing plants. In making this request, Mr. Graves has indicated he intends to install reasonably available control equipment as it is made known and to take other steps in revising his process in order to minimize emissions. ADOPTED: January 15, 1987 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revision to Regulation Number 1 adding a new Paragraph A.9. to Section II.A. Opacity Requirement Exemption The Pueblo Army Depot has made application for an air pollution emission permit to dispose of Pershing rocket motors in accordance with the Intermediate -Range Nuclear Forces Treaty, as ratified. From the test static firing of one Pershing rocket motor on May 31, 1988, the division has determined, by qualified observer, that the opacity of the plume from this activity would exceed the standard of 20% set forth in the Air Quality Control commission's Regulation No. 1. Therefore, the Pueblo Army Depot, in order to obtain a permit for the destruction of the remaining rocket motors, must obtain a waiver from the above opacity standard, or the permit will be denied. This waiver would be necessary due to the fact that there are no presently available methods to reduce opacity to compliance levels for this source. The commission takes this action pursuant to their regulatory authority in Section 25-7-109 CRS. The commission has adopted this rule in order to exempt the static firing of intermediate range and shorter range Pershing Missile systems from the opacity limits contained in Regulation No. 1, so long as such static firing results in emissions less than 250 tons per year of any one pollutant, adequate monitoring is conducted, and air pollutants are not emitted in dangerous quantities. Specific statutory authority for limiting the total emissions to 250 tons per year is provided by Section 25- 7-109 CRS. Specific statutory authority for the requirement that the source conduct air monitoring is provided by Section 26-7-106(6) CRS; authority for requiring the source to provide the division with the results of such monitoring is provided by 25-7-111(2) CRS; specific statutory authority for prohibiting potentially dangerous quantities of any air pollutant is provided by Section 26-7-109(3) CRS. COLORADO AIR QUALITY CONTROL COMMISSION ADOPTED: SEPTEMBER 15, 1988 EFFECTIVE: OCTOBER 30, 1988 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Sections VII and VIII This Statement of Basis, Specific Statutory Authority, and Purpose complies with the requirements of the Administrative Procedures Act, CRS 1973, Section 24-4-103 (4) for adopted or modified regulations. The Colorado Attorney General's Office had determined that any control strategy for a non -attainment area must be adopted as a State regulation in order for the control strategy to be enforceable by the State of Colorado. Sections 25-7-105 and -109 of the Colorado Air Pollution Prevention and Control Act provides the specific statutory authority to adopt the emission control regulations necessary to assure attainment and maintenance of the National Ambient Air Quality Standards. The purpose of the revised regulation is to reduce the allowable emission from the affected facilities in the Denver PM10 non -attainment area so that future attainment and maintenance of the PM10 National Ambient Air Quality Standard can be demonstrated. As committed in the Denver PM10 State Implementation Plan (SIP) Element, Regulation No. 1 is being revised to include the stationary source control measures adopted by the Colorado Air Quality Control commission on May 20, 1993. These revisions establish emission limits for PM10 precursors at Public Service Company's Cherokee, Arapahoe, and Valmont stations. These revisions also require that oil be restricted as a back-up fuel for natural gas at the following facilities: Public Service Company's Zuni, Valmont, and Delgany stations, Fitzsimmons Army Medical Center, US Department of Energy's Rocky Flats Plant, Gates Rubber company, and Coors Brewery (Golden, CO). ADOPTED: AUGUST 19, 1993 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revisions to Regulation No. 1, Section II.A.1, 4 and 10; Regulation No. 6, Part B, Section II.C.3.a (Regarding opacity limitations and sulfur dioxide averaging provisions for coal-fired electric utility boilers during periods of startup, shutdown and upset.) This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, section 24-4-103, C.R.S. and the Colorado Air Pollution Prevention and Control Act, sections 25-7-110 and 25-7-110.5, C.R.S. Basis Regulations 1 and 6 deal with opacity and sulfur dioxide emissions from various sources. This rule change addresses only coal-fired electric utility boilers. The Colorado Utilities Coalition ("CUC") requested that the commission modify the existing regulations to provide additional flexibility in meeting the opacity requirements and sulfur dioxide averaging, for coal-fired electric utility boilers during periods of start-up, shutdown, upset, process modification and adjustment of control equipment. Specific Statutory Authority The Colorado Air Pollution Prevention and Control Act, section 25-7-109(2), C.R.S., provides the authority for the commission to adopt and modify emissions control regulations pertaining to visible pollutants, particulates and sulfur oxides. Section 25-7-109(5) authorizes the commission to grant a rule change it feels is appropriate for periods of start-up, shutdown or malfunction or other conditions which justify temporary relief from controls. Section 25-7-105(1) provides the authority for the commission to make SIP revisions. Section 25-7-133(4)(a) provides the commission with the flexibility to determine what are necessary elements for the SIP. The commission's action is taken pursuant to authority granted and procedures set forth in sections 25-7-105, 25-7-109, and 25-7-110, C.R.S. Purpose The revisions to Regulation No. 1 and No. 6 are intended to provide a specific amount of flexibility related to compliance with opacity limitations and sulfur dioxide averaging provisions for coal-fired electric utility boilers during periods of startup, shutdown and upset. These revisions replace what is believed to be a problematic standard for these specific sources. CUC has demonstrated that there are instances during which these sources cannot comply with the 30% opacity limit and the SO2 emissions limit during start- ups and shutdowns. Although these sources may exceed the opacity limit, CUC has presented the commission with a study prepared by Radian Corporation, which concludes that removing the 30% opacity limit for these sources will not result in such an increase in emissions that Colorado will likely violate the National Ambient Air Quality Standards or other federal requirements. CUC proposed replacement of the 30% limit with a standard that more closely mimics the federal standard, and which these sources will have more certainty complying with, particularly for Title V compliance certification requirements. CUC also provided an ambient air analysis related to SO2 emissions which concluded that allowing a modification of SO2 limitations for the periods of startup, shutdown and malfunction would have no adverse impact on related federal requirements. The division agreed that some flexibility in complying with the 30% opacity limit was appropriate for these sources. The division also proposed replacing the 30% opacity limit. Action Taken The commission concludes that a rule change is appropriate for this category of sources and is removing the application of the 30% opacity limitation to these sources during periods of start -up, shutdown and upset. In addition, the commission agrees that a rule change is merited from the current treatment of SO2 emissions during periods of start-up, shutdown and malfunction. The commission also concludes that this rule can be made clearer and easier to implement through the changes adopted. The commission adopts language substantially similar to the federal New Source Performance Standard requirement that, during periods of startup, shutdown and malfunction, these sources, to the extent practicable, shall maintain and operate associated air pollution control equipment in a manner consistent with good air pollution control practice for minimizing emissions. In the commission's view, incorporating this standard will provide an important balance to the removal of the 30% limit. The federal New Source Performance Standard refers to "malfunctions", while the commission has adopted an upset provision. The commission finds that these two terms are substantially similar, with the exception that an upset must be properly reported to the division to be excused. In order to avoid confusion, the commission decided to use the term upset consistent with the Common Provisions Regulation. The division expressed concern that the "good practices" standard is subjective and requires substantially more resources to enforce than a numerical limit. In addition, without the 30% limit, opacity from these facilities could be at very high levels periods of time. The commission concurs and in this regulation adopts the division's proposed measures to limit the overall time during which a source may exceed the underlying 20% opacity restriction. Good Air Pollution Control Practices The revisions to Regulation No. 1 were developed by the Regional Air Quality Council and the Colorado Air Pollution Control division. Comments from the affected facilities, the Colorado Attorney General's Office and the US Environmental Protection Agency were utilized in further developing the regulation. The submittal of these revisions to the commission demonstrates the Commitment from industry, and local and state governments, and the citizens that they represent, to implement control measures and improve the air quality in the Denver area. The revised Regulation No. 1 will be submitted to the EPA as part of the Denver PM10 SIP Element. This regulation sets overall limits, by percentage of operating time, during which opacity may exceed 20% and SO2 emissions may exceed regulatory maximums. In the commission's view, this will allow more flexibility for the utilities without leaving them free of reasonable restriction. The percentages were determined based on a percentile of the exceedence times for all such sources within the state. Exceedence times were calculated based on the excess emissions reports submitted by each of the utilities over the last several years. These times included the periods of excess emissions due to the events listed in Regulation No. 1, section II.A.4 [fire building, cleaning of fire boxes, soot blowing, start-up, process modification and adjustment or occasional cleaning of control equipment], as well as shutdowns and upsets. Accordingly, the data upon which the commission based its adoption of the percentages used to define good air pollution control practices included all times during which a source exceeded the applicable opacity limitation. In turn, the percentages adopted as the definition of good air pollution control practices include all times during which a source exceeds the 20% opacity limitation. Thus, all periods of start-up, shutdown, upset, fire building, process modification and adjustment or occasional cleaning of control equipment will be counted against the unit's compliance with the percentages. This general rule does not apply in two circumstances. First, start-ups following planned maintenance outages which require significant changes at the facility are treated separately, because the commission concluded that these infrequent events posed particular difficulties for the utilities. It appears that the duration of these events cannot be reasonably predicted and they are not to be included in the calculation of the source's compliance percentages. However, in order to ensure accountability of these sources during planned outages, the commission is imposing requirements for advance notice to the division. Advance notice will ensure that these are, indeed, planned outages. The notice must include a plan for minimizing emissions and an estimate of the time during which controls will not be operable while the unit is in operation, both in order to prevent inordinate startups beyond reasonable limits. During start-ups, the source must still use good air pollution control practices. An additional definition of start-up is provided to add certainty for all concerned about the duration of these significant planned outage start-ups. In addition, the commission restricts the application of the planned maintenance outage exception to events requiring significant changes at the facility, such as replacement of major facility components or installation of new processes (e.g., installation of low NOx burners). This exception addresses changes from which the resulting impact on plant operations cannot accurately be predicted. The exception is not intended to allow exclusion of excess emissions resulting from routine maintenance outages, such as annual replacement of standard equipment, from calculation of the exceedence percentage time allowance. Second, opacity emissions which are not a result of the combustion of fuel in the steam -generating unit are excluded from the calculation of the compliance percentage. This approach is consistent with the federal New Source Performance Standard found at 40 CFR Part 60, Subpart D. The commission concludes that these emissions control measures are not intended to limit emissions from cleaning of fire boxes, soot blowing and other activities when a unit is off-line, i.e., when no fuel is being fed to the unit. In addition, there are technical concerns related to the ability of monitoring devices to operate accurately when the unit is off-line. The commission agrees that all of these sources can perform somewhat better and intends that the percentages will serve as an as an achievable measure of good air pollution control practices during these specific periods. This approach will also force poorer -performing facilities to improve their operations and maintenance practices and bring their exceedence levels down to one more consistent with that at other facilities. For baghouse-equipped boilers, a single percentage will suffice for the indefinite future. However, utility units using electrostatic precipitators to control particulate emissions present more complicated issues. Accordingly, the commission elected to provide an interim period of approximately three years during which these units will have a higher allowance percentage. The commission does not impose at this time a requirement for electrostatic precipitator -equipped facilities to achieve the same exceedence percentage time allowance as baghouses. However, the commission's ultimate goal is for ESP -equipped facilities to meet the same compliance standard as is today imposed on baghouses. The commission endorses the concept that the utilities conduct a study to evaluate operations and maintenance practices and equipment modifications at ESP -equipped facilities. The purpose for this study is to improve understanding of the operators, the division and the commission related to ESP operations and potential improvements. The results of this study are not intended for use as evidence that pre -study operations do not constitute good air pollution control practices. The commission did not agree with the CUC proposal for limitations on the duration of individual incidents of start-up and shutdown because this approach also is subjective and would require more resources to enforce. The Sierra Club proposal, although substantially similar to that presented by the division, would require enforcement with exceedence allowances calculated for each ESP -equipped facility. The commission is not convinced that the benefits of a more specific exceedence allowance justify the resources required to enforce these percentages. The allowance percentages will give both sources and the division a clear definition and reasonable limits to the concept of "good air pollution control practices." This definition limits sources from arguing that longer periods of exceedence are good practices. The definition is also intended to allow the division to investigate the source's practices and determine whether, in light of their compliance history, process and control equipment and operations and maintenance procedures, the source is using good practices. This treatment of good practices will in no way prevent the division from initiating an enforcement action if the division determines that a source is not using "good air pollution control practices," regardless of the amount of time the source has been in violation of the 20% opacity standard. The division may use any available information in order to evaluate whether the source is using good practices. Federal and State Statutory, and State Implementation Plan, Issues The commission is cognizant that section 193 of the federal Clean Air Act precludes revisions to the state implementation plan relating to non -attainment areas which do not provide equivalent or greater emissions reductions to the existing provisions of the plan. Even under this federal law, however, the commission is entitled to modify its plan to make it more cost-effective and to improve overall compliance and implementation. The commission concludes that the division's proposal does not represent a relaxation of the existing rule. The regulatory change removing application of the 30% opacity limit appears on first impression to relax requirements for these units. However, by limiting the overall time during which the units may exceed the 20% opacity limit, the commission believes this approach will result in at least the same levels of compliance with the opacity standard and will likely result in lower overall emissions. The commission is also aware that section 110 of the federal Clean Air Act imposes additional limitations on revisions to the state implementation plan. CUC presented information relating to the impact of its proposal on ambient air concentrations. The commission relied on this information, although it did not adopt the CUC proposal for defining and limiting "good air pollution practices." The commission concludes that the changes made in this rulemaking will not lead to increased emissions in amounts substantial enough to interfere with the state's programs to attain and maintain the NAAQS or any other federal requirements. The commission also has evaluated the proposal adopted pursuant to the standards of section 25-7- 105.1, C.R.S. This rule change and the compliance levels adopted today for these limited periods for coal-fired electric utility boilers clarify the federal narrative standard adopted, providing both the utilities and the division with greater levels of certainty. The levels also put a practical limit on excursions by these sources above the opacity and SO2 emissions limits and aid in ensuring that the NAAQS are attained or maintained and that no other applicable requirements are adversely affected. The commission has determined that continued enforcement of the Regulation No. 1 opacity provisions were relied on in development of the Denver PM10 element of the state implementation plan. The provisions deleted from Regulation No. 1 pertaining to electric power plants therefore must be replaced with substantially equivalent requirements. In the past, the division's enforcement discretion has been exercised to effectively allow 5% noncompliance by these sources. Substantial regulatory ambiguity in the opacity limitations applicable to startup and other periods also led to uncertainty and lower compliance levels. These revisions are substantially equivalent or better in their impact on emissions to the results of current law and practice because that past practice led to lower compliance than the anticipated compliance levels which will result from these changes. The commission finds that these modifications are necessary as parts of the state implementation plan. The commission also concludes that these revisions are not more stringent than federal requirements, considering the historical "5% policy" used by the division and EPA. Accordingly, the commission concludes that these changes should be forwarded to the General Assembly for review and then to EPA for inclusion in the state implementation plan. Finally, the commission adopts these rule changes subject to a delayed effective date insofar as the revisions apply to sources within the Denver PM10 non -attainment area. The Environmental Protection Agency has expressed concerns about the potential effect of this rule change on the pending approval of the PM10 element of the state implementation plan for the Denver non -attainment area. In order to ensure that the proposed approval of the PM10 element for the Denver non -attainment area is not endangered, the commission designates the effective date for these revisions as they apply to sources within this non -attainment area as the date on which EPA approves these changes as a revision to the state implementation plan. The commission has taken into consideration the items enumerated in section 25-7-109(1)(b), C.R.S. The commission also makes the following findings regarding the adoption of these rule changes: 1. The commission has considered, and has based its decision, on the reasonably available, validated, reviewed and sound scientific methodologies and information made available by the parties. 2. Where these revisions are not administrative in nature, the record supports the conclusion that the provisions adopted will result in a demonstrable reduction in air pollution. This reduction is accomplished because the overall exceedence levels of the facilities will be lowered under the proposal adopted. 3. The revisions selected maximize the air quality benefits of the emissions standards that apply. The revisions selected are the most cost-effective based on the documents submitted by the parties under section 25-7-110.5, and provide the regulated community with flexibility in meeting emissions limitations. Although the overall level of exceedences should be reduced under this rule change, operators of the units affected will have greater flexibility in start-up and shutdown of the facilities without incurring a violation. In addition, the greater levels of certainty provided by these changes will allow operators of affected facilities to more readily certify compliance with these applicable requirements under the Title V operating permit program. ADOPTED: DECEMBER 23, 1996 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revisions to Regulation No. 1, Section II The Fort Carson Army Installation has made application for an exemption to the opacity requirements in Regulation No. 1 during training exercises at Fort Carson and the Pinon Canon Maneuver Site that involve the generation of fog oil smoke and the use of other obscurants. Because the purpose in using obscurants is to train troops in situations of limited visibility, the opacity of the smoke generated is close to 100%, which exceeds the 20% standard in the Air Quality Control commissions Regulation No. 1. As Fort Carson's training relies, in part, on smoke and obscurant usage, the potential for base closure increases if an exemption is not granted. If closed, projected economic impact within a 50 -mile radius of the Installation is estimated at $621 million annually. The US Army and the division have used dispersion models to estimate the air quality impacts from fog oil generation. The impact levels for various averaging periods have been compared to National Ambient Air Quality Standards (NAAQS) for particulate matter and the National Research Council's (NRC) 1997 guideline values for fog oil exposure. The Colorado Department of Public Health and Environment's Disease Control and Epidemiology division has reviewed the toxicological data for fog oil and compared that data to the National Research Council (NRC) guideline values. Based on this review the division feels that under current operating practices fog oil generation is unlikely to cause a serious public health problem. The modeling analysis suggests that fog oil generation can cause impacts exceeding the NAAQS or NRC guideline values within 3 kilometers of the fog oil generators. Modeled impacts greater than the NAAQS or NRC guideline values may occur at distances of up to ten kilometers depending on the meteorological conditions and the configuration of the fog oil generators. For example, modeling suggests that fog oil generation at a usage rate of 1540 gallons of fog oil over a four-hour period could cause or contribute to a NAAQS exceedence at distances of up to ten kilometers if the plume is transported in the same direction for several hours. Typical U. S. Army fog oil generation requires mobile, as opposed to stationary, source operations. This might limit the potential for such extensive off -site impacts. The division has determined that impacts in ambient air should be below the NAAQS and NRC values if standard U. S. Army fog oil generator operations and the mitigation measures in the exemption are followed. These mitigation measures should also address concerns from the United States Environmental Protection Agency that this exemption might lead to a violation of the federal National Ambient Air Quality Standard for PM 2.5. The commission determines, pursuant to section 25-7-117, C.R.S., that the smoke generation for the training in question is purposefully intended to be at or near 100% opacity and therefore cannot occur in compliance with the 20% opacity limitation in Regulation No. 1. Accordingly, control techniques are not desirable for this emission of air pollutants. This proposed revision to the state implementation plan is consistent with the legislative policy set forth in section 25-7-102; and adoption of this limited exception is consistent with the requirements of section 110 of the federal act. Regarding this element, the commission concludes, based on the modeling information presented, that the generation of fog oil smoke will not cause or contribute to a NAAQS violation at the reservation boundary if the proponent operates in compliance with the limitations placed on this exemption. As additional toxicological data on fog oil is expected over the next few years, the Air Quality Control commission will revisit this exemption based on an evaluation of the Fort Leonard Wood fog oil study, but will not be limited to this report. This report should evaluate the Fort Carson fog oil exemption in Air Quality Control commission's Regulation No. 1 with regard to the protection of the public health in Colorado. The commission takes this action pursuant to their regulatory authority in section 25-7-109 and section 25-7-117. Findings This limited exception to the opacity restriction in Regulation No. 1 is not intended to reduce air pollution; accordingly, the commission makes no findings pursuant to section 25-7-110.8, C.R.S. Pursuant to section 25-7-133(3), C.R.S., the commission concludes that this limited exemption is not required by federal law nor is it more stringent than federal law. ADOPTED: JULY 17, 1998 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revisions to Regulation No. 1, Section VII, concerning emission limits for electric generating stations The April 19, 2001 amendments to Regulation No. 1, section VII were adopted to support the redesignation of the Denver metropolitan area to an attainment area for particulate matter. The rule amendments codify emission limitations and shut down requirements for the purpose of incorporating such limitations and requirements into the federally enforceable SIP. Basis and Purpose One of the emission limitations used to show maintenance of the NAAQS (the 20% SO2 limit for the Public Service Company of Colorado Cherokee facility) was previously found only in a state permit; it was not in a regulation. (Public Service Company is now doing business as Xcel Energy.) In 1997 EPA incorporated the permit for the Cherokee facility, together with the permits for several other stationary sources, into the SIP by reference. The EPA asserts that such incorporation is necessary to the extent the State relies on emission limits in the permits to demonstrate attainment of the PM -10 NAAQS. The incorporation of the permits into the SIP means that any revision to such permits must go through the extensive SIP revision process. The maintenance demonstration also relies on NOx limitations at the plant. NOx emissions are already subject to federal regulations that achieve the same result, albeit with a different averaging time and calculation method. EPA, however, has asserted that the limitation must be expressed as a short-term limit incorporated into the SIP. The division disagrees with EPA's interpretation of federal law, but does not believe that the circumstances warrant challenging EPA's position. Public Service Company has consented to the inclusion of certain SO2 and NOx emission limitations (calculated on a rolling thirty -day average basis) in the regulation and the SIP in order to resolve the matter with EPA. EPA has indicated that these limitations are adequate to resolve its concerns and, with them as a substitute, will agree that the Cherokee and all other permits may be removed from the SIP. Therefore, all permit limits and conditions contained in permits for the following facilities are specifically removed from the SIP: Trigen-Colorado Energy; Public Service Company; Purina Mills; Electron Corporation; Ultramar Diamond Shamrock; Conoco Refinery; Rocky Mountain Bottle; and Robinson Brick. A SIP revision shall not be required to modify permit limits and conditions for these facilities. Any increases in emission limits contained in Regulation No. 1 that are also incorporated into the SIP would require a SIP revision. For these reasons, the commission has determined that it is appropriate to include the requirements in the SIP and the regulation. Public Service Company has asked, and the commission agrees, that these new emission limitations should not become effective unless and until EPA approves the SIP. In 1998, the commission approved a voluntary emission reduction agreement between Public Service Company and the division pursuant to C.R.S. §25-7-1201 et seq. Under that agreement as amended, Public Service Company agreed, among other things, that it would permanently shutdown and retire Arapahoe Units 1 and 2 on January 1, 2003. This retirement of these two units was also used to show maintenance of the NAAQS. Despite the fact that the retirement is an enforceable commitment of the company under state law, EPA objected to the assumption that Arapahoe Units 1 and 2 will shutdown in 2003. The EPA asserts that the maintenance plan must include a federally enforceable provision mandating the closures. Again, the division disagrees with the EPA's position and believes that it may properly rely upon the provisions of the voluntary agreement to demonstrate maintenance of the standard. However, again in order to resolve the disagreement with the EPA, the Public Service Company consented to the inclusion of the shutdown requirements in the State regulations and the federally enforceable SIP. In the voluntary agreement, the retirement of Arapahoe Units 1 and 2 does not forbid Public Service Company (or some other person) from reusing the Arapahoe 1 and 2 plant site or equipment, provided that such reuse is subject to new source permitting requirements. The Company, as is its right under C.R.S. §25-7-1203(6), consented to the EPA's desire to include the retirement in the SIP only if the SIP and the state regulations recognize that such reuse is allowed subject to the new source permitting requirements. Therefore, the commission has determined that language in the proposed regulation allowing for such reuse is necessary and appropriate. This language will allow PSCO or some other party to use the Arapahoe Unit 1 or 2 equipment or plant site for the construction and operation of a new source, provided that, depending on its level of emissions, the new source obtains the applicable minor or major source permit. The Company also asked that the regulatory SIP provision should not apply if EPA disapproves the maintenance plan and redesignation request. Therefore, the regulation expressly states that it will take effect upon EPA approval of the redesignation request. This provision in the regulation is not to be construed to mean that approval of redesignation request is required in order for the voluntary agreement between the State and the Public Service Company to take effect. The regulation is not intended to supercede or modify the agreement. The agreement shall be effective whether or not the regulation takes effect. The commission adopted the regulation in order to satisfy EPA's demand to incorporate the shutdown requirement in the SIP, without incorporating the entire agreement into the SIP. Only the provisions applicable to the Arapahoe 1 and 2 retirement described in the regulation have been incorporated into the SIP. Statutory Authority Specific statutory authority to redesignate areas to attainment is provided in section 25-7-107, C.R.S. (1999). The authority to adopt the regulations necessary to maintain the NAAQS is set out at section 25- 7-105(1)(a)(l). C.R.S. The authority to control particulate emissions is set out in section 25-7-109(2)(b), C.R.S. Findings pursuant to section 25-7-110.8 Section 25-7-110.8 requires the commission to make specific findings concerning any regulation intended to reduce air pollution. The April 2001 amendments to Regulation No. 1 put into regulation pre-existing requirements. Although the regulations change the averaging time for SO2 and NOx limitations, and thus appear to make the existing requirements more stringent, the units were already in compliance with the revised standards based on the shorter averaging times. Thus, some of the determinations required by section 25-7-110.8 are irrelevant. To address the remaining, applicable requirements of 25-7-110.8, the commission determines that: (1) all validated, reviewed and sound scientific methodologies and information made available by interested parties has been considered; and (2) the amendments adopted represent the most cost-effective option. ADOPTED: APRIL 19, 2001 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revisions to Regulation No. 1: Sections II.A. 1-10; II.B.3., II.C.2.d.; Sections III.A.1.d., A.3.; III.B.4.a. & b.; III.C.2-4; Section IV.I.; Section V; Section VI.A.f.; Section VI.B.2. and VI.B.4.(iv); VI.C.1.; Sections VII.A.1, A.2. & A.3.; Sections VIII.A. & E. This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, section 24-4-103, C.R.S., and the Colorado Air Pollution Prevention and Control Act, sections 25-7-110 and 25-7-110.5, C.R.S. ("the Act"). Specific Statutory Authority The Act, section 25-7-109, C.R.S., provides the commission the authority to adopt and revise rules and regulations that are consistent with state policy regarding air pollution and with federal recommendations and requirements. Basis Regulation No. 1 deals with opacity, particulate, and sulfur dioxide emissions from various sources. This rule revises the title of the regulation, deletes obsolete parts of this regulation and conforms the regulation to the "Credible Evidence" rule adopted by the commission on April 19, 2001 (refer to Common Provisions Regulation, section 11.1.). The rule also deletes section II.A.10. and related provisions concerning good air pollution practices for coal-fired utility boilers. Finally, the rule revises the methodology and calculation for emissions from multiple fuel burning units ducted through a common stack in section III.A.1.d. Purpose In April 2001, the commission adopted the "Credible Evidence" rule into its Common Provisions Regulation, section 11.1. That rule allows for the use of any credible evidence for the purpose of submitting Title V compliance certifications or establishing whether a source has violated or is in violation of any emissions standard contained in any regulation that has been submitted to the U.S. Environmental Protection Agency. The revisions to Regulation No. 1 remove conflicting language from Regulation No. 1, and clarify that the EPA Method 9 is the approved visible emissions reference test method for the credible evidence rule. The opacity requirements in Regulation No. 1 were adopted based on the use of Method 9 for determining compliance with such requirements. This action also clarifies that, for purposes of compliance determinations, the particulate emissions standards found in Regulation No. 1 do not include the condensable or "back half portion of the emissions train. In 1992, section 25-7-109(8), C.R.S., was added to the Act to prohibit the regulation of most agricultural activities. In some circumstances, however, agricultural open burning may be subjected to commission regulation (section 25-7-123, C.R.S.). In order to address the confusion regarding open burning of animal parts and carcasses, the rule now expressly states that the open burning of animal parts and carcasses is not exempt from permit requirements. A special allowance to conduct open burning activities without a permit is provided where the State Agricultural commission declares a public health emergency or a contagious or infectious outbreak of a disease that imperils livestock and diseased carcasses must be destroyed on weekends or holidays. In this case, voice mail messages must be left with the division and any local health department, and adequate notice must be provided to neighboring residences, schools, and businesses prior to burning. This allows the division to promptly respond to complaints about smoke from these activities and provides an opportunity for the neighboring community to take steps to minimize smoke exposure, e.g., close windows and schedule indoor activities. Certain provisions that regulate "grandfathered" sources that do not exist in Colorado, such as wigwam burners, static firing of Pershing missiles at the Pueblo Army Depot. and standards for iron and steel plant operations, are removed. Rocky Mountain Steel Mills is the only iron and steel plant in Colorado, and only those provisions that are relevant to this operation have been retained. Provisions regulating coke ovens at steel mills, blast ovens, basic oxygen furnaces, and sinter plants have been removed as obsolete. Section II.A.10, and related provisions found in II.A.4. and VI.B., concerning emissions from coal-fired utility boilers, is removed. These provisions were added in 1996, and have never been approved by the U.S. EPA. However, the commission reaffirms the findings in the Statement of Basis, Specific Statutory Authority and Purpose associated with the 1996 rulemaking. There are technical concerns related to the ability of continuous opacity monitors to obtain accurate readings during periods when the boilers, fans and process equipment at coal-fired electric utility plants are off. As an alternative approach, the commission has proposed adoption of Affirmative Defense Provisions to be added to the Common Provisions Regulation to recognize the issues related to periods of excess emissions during startup and shutdown conditions of coal-fired utility boilers and other sources. Consequently, leaving these provisions in Regulation No. 1 renders coal-fired utility boilers subject to federal opacity requirements and conflicting and confusing state -only requirements. The commission wishes to remove such conflict and confusion. The rule revises section III.A.1.d. to more accurately calculate emissions from multiple fuel burning units ducting to a common stack (because it is not possible to sum the pounds per 106 British thermal units, as is currently reflected in the regulation). Regarding the approval of alternative performance test methods in sections III.A.2. and III.C.3., the commission intends that the existing practice of the division in consulting with the owner or operator of a source regarding appropriate alternative test methods will continue. Those consultations should include discussions why the reference method or other alternative methods are inappropriate. The commission recognizes that the division must approve any alternative test method but that the owner or operator of a source may appeal that determination to the commission. In section VII.,A.1., A.2. and A.3., the Public Service Compliance date of January 1, 1995 has been deleted as obsolete. In addition, emissions limitations are placed on the Valmont Electric Generating Station in Boulder, Colorado, Units 1, 2, 3, and 4. In reality, Valmont only has a Unit 5, and thus revisions are made to reflect this reality. In section VIII, fuel restrictions are placed on specified sources. The regulation is revised to reflect a name change of a source and to revise the example of a reporting tool referenced in this section. The Regulation No. 1 revisions adopted by the Air Quality Control commission as described above will be submitted to the EPA as part of the State Implementation Plan. COLORADO AIR QUALITY CONTROL COMMISSION ADOPTED: AUGUST 16, 2001 APPENDIX A Method for Measuring Opacity from Fugitive Particulate Emission Sources a. Principle and Applicability (I) Principle. The opacity of emissions from fugitive particul determined visually by a qualified observer. (ii) Applicability. This method is applicable for the determi emissions from fugitive particulate emission sources an.. for visually determining opacity of emissions; provided, however, Li, — shall not be used when wind velocities exceed 30 m.p.h. as determined by records from the nearest official station of the U.S. Weather Service, by interpretation of surface weather maps by a qualified meteorologist, or by use of one or more anemometers at the site. The division shall use anemometers where practicable. b. Procedures. The observer qualified in accordance with Section c. of this method shall use the following procedures for visually determining the opacity of emissions: (i) Position. The qualified observer shall stand at a distance sufficient to provide a clear view of the emissions with the sun oriented in the 140° sector to his back. Consistent with maintaining the above requirement, the observer shall, as much as possible, make his observations from a position such that his line of vision is approximately perpendicular to the plume direction. The observer's line of sight should not include more than one plume at a time. Where the plumes from more than one source have been combined such that it is not possible to observe the emissions from a subject source alone this method shall not be applied to the "combined plume" to determine the opacity of emissions from any of the contributing sources. Emissions from rock or mineral drilling, crushing, conveying, screening, and storing are evaluated in the following manner: (A) Drilling. Emissions from drilling operations are evaluated at the point at which they are released from the drilling device or from the drill hole. (B) Crushing. Emissions included at this evaluation point are released as material is discharged from the primary and secondary crushing machines. Observations are performed on the same elevation as the discharge if possible. (C) Conveying. Visible emissions are evaluated as material is discharged at conveyer belt transfer points and loading points. Evaluation shall occur at the same elevation as the discharge if possible. (D) Screening. Visible emissions are evaluated as material is discharged from the screen into the chutes. The observer shall obtain an observation point as close to the same elevation of the screens as possible. (E) Storage. Observations are performed at ground level. (F) In operations involving rock or mineral drilling, moisture content of the material plays an important part in type and quantity of visible emissions. Therefore, any moisture in the feedstock or addition of moisture to the process should be noted on the field data sheet. (G) Emissions from all other sources of fugitive particulate emissions subject to this regulation shall be evaluated in a manner consistent with the above procedures. (ii) Field Records. The observer shall record the name of the plant, emission location, type facility, observers name and affiliation, and the date on a field data sheet. The time, estimated distance to the emission location, approximate wind direction, estimated wind speed, description of the sky condition (presence and color of clouds), and plume background are recorded on a field data sheet at the time opacity readings are initiated and completed. (iii) Observations. Opacity observations shall be made at the point of greatest opacity in the plume and with a background of contrasting color. The observer shall not look continuously at the plume, but instead shall observe the plume momentarily at 15 -second intervals. The observer shall record the approximate distance from the emission outlet to the point in the plume at which the observations are made. (iv) Recording Observations. Opacity observations shall be recorded to the nearest 5 percent at 15 -second intervals on an observational record sheet. A minimum of 24 observations shall be recorded. Each momentary observation recorded shall be deemed to represent the average opacity of emissions for a 15 -second period. (v) Data Reduction. Opacity shall be determined as an average of 24 consecutive observations recorded at 15 -second intervals. Divide the observations recorded on the record sheet into sets of 24 consecutive observations. A set is composed of any 24 consecutive observations. Sets need not be consecutive in time and in no case shall two sets overlap. For each set of 24 observations, calculate the average by summing the opacity of the 24 observations and dividing this sum by 24. If an applicable standard specifies an averaging time requiring more or less than 24 observations, calculate the average for all observations made during the specified time period. Record the average opacity on a record sheet. c. Qualifications and Testing (i) Certification requirements. To receive certification as a qualified observer, a candidate must be tested and demonstrate the ability to assign opacity readings in 5 percent increments to 25 different black plumes and 25 different white plumes, with an error not to exceed 15 percent opacity on any one reading and an average error not to exceed 7.5 percent opacity in each category. Candidates shall be tested according to the procedures described in paragraph c. (ii). Smoke generators used pursuant to this paragraph shall be equipped with a smoke meter which meets the requirements of paragraph c.(iii). The certification shall be valid for a period of six months, at which time the qualification procedure must be repeated by the observer in order to retain certification. (ii) Certification Procedure. The certification test consists of showing the candidate a complete run of 50 plumes - 25 black plumes and 25 white plumes - produced by a smoke generator. Plumes within each set of 25 black and 25 white runs shall be presented in random order. The candidate assigns an opacity value to each plume and records his observation on a suitable form. At the completion of each run of 50 readings, the score of the candidate is determined. If a candidate fails to qualify, the complete run of 50 readings must be repeated in any retest. The smoke test may be administered as part of a smoke school or training program, and may be preceded by training or familiarization runs of the smoke generator during which candidates are shown black and white plumes of known opacity. (iii) Smoke Generator Specifications. Any smoke generator used for the purposes of paragraph c. (ii) shall be equipped with a smoke meter installed to measure opacity across the diameter of the smoke generator stack. The smoke meter output shall display in stack opacity based upon a path length equal to the stack exit diameter, on a full 0 to 100 percent chart recorder scale. The smoke meter optional design and performance shall meet the specifications shown in Table 1. The smoke meter shall be calibrated as prescribed in paragraph c. (iii)(A) prior to the conduct of each smoke reading test. At the completion of each test, the zero and span drift shall be checked and if the drift exceeds 1 percent opacity, the condition shall be corrected prior to conducting any subsequent test runs. The smoke meter shall be demonstrated, at the time of installation, to meet the specifications listed in Table 1. This demonstration shall be repeated following any subsequent repair or replacement of the photocell or associated electronic circuitry including the chart recorder or output meter, or every 6 months, whichever occurs first. Calibration. The smoke meter is calibrated after allowing a minimum of 30 minutes warm- up by alternately producing simulated opacity of 0 percent and 100 percent. When stable responses at 0 percent or 100 percent is noted, the smoke meter is adjusted to produce an output of 0 percent or 100 percent, as appropriate. This calibration shall be repeated until stable 0 percent or 100 percent readings are produced without adjustment. Simulated 0 percent and 100 percent opacity values may be produced by alternately switching the power to the light source on and off while the smoke generator is not producing smoke. Table 1 Smoke Meter Design and Performance Specifications a. b. c. d. e. f. 9. Parameter Light Source Spectral Response of Photocell Angle of View Angle of Projection Angle Calibration Error Zero and Span Response Time Specification Incandescent lamp operated at nominal rate voltage Photopic (daylight spectral response of the human eye - reference d(iii)) 15° maximum total angle 15° maximum total 3% opacity, maximum 1% opacity, maximum Five seconds B. Smoke Meter Evaluation. The smoke meter design and performance are to be evaluated as follows: (1) Light Source. Verify from manufacturer's data and from voltage measurements made at the lamp, as installed, that the lamp is operated within 6 percent of the nominal rated voltage. (2) Spectral Response of Photocell. Verify from manufacturer's data that the photocell has a photopic response; i.e., the spectral sensitivity of the cell shall closely approximate this standard spectral -luminosity curve for photopic vision that is referenced in (b) of Table 1. (3) Angle of View. Check construction geometry to ensure that the total angle of view of the smoke plume, as seen by the photocell, does not exceed 15°. The total angle of view may be calculated from: ?=2 tan d/2L where ?=total angle of view; d=the sum of the photocell diameter + the diameter of the limiting aperture; and L=the distance from the photocell to the limiting aperture. The limiting aperture is the point in the path between the photocell and the smoke plume where the angle of view is most restricted. In smoke generator smoke meters this is normally an orifice plate. (4) Angle of Projection. Check construction geometry to ensure that the total angle of projection of the lamp on the smoke plume does not exceed 15°. The total angle of projection may be calculated from: ?=2 tan -1 d/2L, where ?=total angle of projection; d=the sum of the length of the lamp filament and the diameter of the limiting aperture; and L=the distance from the lamp to the limiting aperture. (5) (6) (7) References (I) (ii) (iii) Calibration Error. Using neutral -density filters of known opacity, check the error between the actual response and the theoretical linear response of the smoke meter. This check is accomplished by first calibrating the smoke meter according to (1) and then inserting a series of three neutral -density filters of nominal opacity of 20, 50, and 75 percent in the smoke meter path length. Filters calibrated within 2 percent shall be used. Care should be taken when inserting the filters to prevent stray light from affecting the meter. Make a total of five nonconsecutive readings for each filter. The maximum error on any one reading shall be 3 percent opacity. Zero and Span Drift. Determine the zero and span drift by calibrating and operating the smoke generator in a normal manner over a 1 -hour period. The drift is measured by checking the zero and span at the end of this period. Response Time. Determine the response time by producing the series of five simulated 0 percent and 100 percent opacity values and observing the time required to reach stable response. Opacity values of 0 percent and 100 percent may be simulated by alternately switching the power to the light source off and on while the smoke generator is not operating. Air Pollution Control District Rules and Regulations, Los Angeles County Air Pollution Control District, Regulation IV Prohibitions, Rule 50. Wefsburd, Melving L., Field Operations and Enforcement Manual for Air, U.S. Environmental Protection Agency, Research Triangle Park, N.C., APTD-1100, August 1972, pp. 4.1-4.36. Condon, E. U., and Oldshaw, H., Handbook of Physics, McGraw Hill Co., N.Y., N.Y. 1958, Table 3.1, p. 6-52. (iv) EPA Visible Emission Inspection Procedures, August 1975. APPENDIX B Method of Measurement of Off -Property Transport of Fugitive Particulate Emissions a. Applicability. This method is applicable for the determination of the off -property transport of fugitive particulate emissions sources covered by Section III.D.2 of this regulation; provided, however, this method shall not be used when wind velocities exceed 30 m.p.h. as determined by records from the nearest official station of the U.S. Weather Service, by interpretation of surface weather maps by a qualified meteorologist, or by use of one or more anemometers at the site. The division shall use anemometers where practicable. b. Procedure (i) Position. The observer shall stand at a distance sufficient to provide a clear view of the emissions with the sun oriented in the 140° sector to his back. The observer shall position himself off said property so as to be able to sight along a line which does not cross the property of emission origination. Consistent with maintaining the above requirements, the observer shall, to the extent possible, make his observations from a position such that his line of vision is approximately perpendicular to the plume direction. (ii) Field Records. The observer shall record the name of the plant, emission location, type facility, observer's name and affiliation, and the date on a field data sheet. The time, estimated distance and the emission location, approximate wind direction, estimated wind speed, description of the sky condition (presence and color of clouds), and plume background are recorded on a field data sheet at the time readings are initiated and completed. (iii) Observations. Observations shall be made in accordance with the provisions of this Appendix B sighting along a line which does not cross the property of emission origination and two such observations of fugitive particulate emissions transported off the property of at least 15 seconds in duration [within 24 hours] must be made and must be separated by at least fifteen (15) minutes. STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revisions to Colorado Air Quality Control commission Regulation No. 1 January 17, 2002 This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, section 24-4-103, C.R.S. and the Colorado Air Pollution Prevention and Control Act, sections 25-7-110 and 25-7-110.5 and implements parts of sections 25-7- 106(7) and (8), 25-7-114.7 and 25-7-123, C.R.S. Basis These rule revisions implement the provisions of Senate Bill 01-214 and relocate, update and reorganize existing provisions of Regulation No. 1 relating to open burning into Regulation No. 9. Regulation No. 9 deals solely with open burning activities. This new regulation contains permitting, monitoring, reporting and fee provisions, as well as requirements particular to significant users of prescribed fire. Specific Statutory Authority The Colorado Air Pollution Prevention and Control Act, sections 25-7-109(2)(e) and 25-7-123, C.R.S., provides the authority for the commission to adopt and modify a program including emissions control regulations to control burning activities. Sections 25-7-106(7) and 25-7-106(8), 25-7-114.7(2)(a)(III) and 25-7-123, C.R.S., set forth specific requirements relating to activities by significant users of prescribed fire, including open burning activities by federal land managers. The commission's action is taken pursuant to procedures set forth in sections 25-7-105, 25-7-110 and 25-7-110.5, C.R.S. Purpose Open Burning The focus of SB 01-214 is on open burning activities by significant users of prescribed fire. Addressing open burning issues is necessary in order to address emissions from natural and prescribed fires. The Grand Canyon Visibility Transport commission identified these fires as having enough episodic impact on visibility at class I areas to overwhelm progress made through other emission control measures. The commission views reduction of visibility impairment from fires as an important component in achieving federal and state visibility goals. This regulation should ensure that users of prescribed fire consider air pollution impacts in making determinations whether, and under what conditions, to use fire for grassland or forest management. Permitting The regulation continues the existing prohibition on open burning absent a permit from the division or a local agency. The exemptions from this requirement also remain largely the same. In particular, agricultural open burning activity does not require a permit. The regulation specifies factors that the division must consider in deciding whether, and under what conditions, to issue a burning permit. These factors differ depending on the type of permit applicable to the proposed activity. General open burning permits are the basic permits for most burning activities. General permits require that an applicant use best smoke management techniques to reduce or eliminate smoke impacts on the health and welfare of the public. Although the regulation includes a partial listing of methods to minimize fire emissions and smoke impacts, the commission intends that the division will exercise its discretion to achieve the goals of this regulation without imposing unreasonable conditions. General open burning may be delegated by the division to local counties. The next category of fire addressed by this regulation is planned ignition fires, which are a subset of prescribed fires for grassland and forestland management. The commission decided to establish an emissions and smoke de minimus threshold below which a permit applicant must only obtain a general open burning permit. For fires that will exceed that threshold, applicants intending to initiate a fire must obtain a permit for a planned ignition fire. Permits for this type of fire must address additional concerns beyond those applicable to general open burning activities. The commission listed factors for division consideration in determining whether, and under what conditions, to issue a permit. This list is not exclusive and the division may incorporate in permits additional conditions if it finds them necessary to minimize the impacts of fire on visibility and on public health and welfare. These factors focus on identifying and minimizing impacts to smoke -sensitive receptors. In addition, planned ignition permit conditions should ensure that the permittee will take appropriate action to ensure that the fire remains within the terms of the permit or is managed so as to return it within those terms, or that the permittee will suppress the fire if compliance with permit terms cannot otherwise be achieved. Unplanned ignition fire permits offer persons a mechanism to use fire for grassland or forest management even though the precise time and location of a particular prescribed fire cannot be anticipated. These permits generally will apply to larger parcels of land, in some portion of which unplanned ignition may occur. The purpose of this permit type is to determine before ignition the conditions under which the fire may be used for resource benefit. As with planned ignition fires, permit conditions should ensure that the permittee will take appropriate action to ensure that the fire remains within the terms of the permit or is managed so as to return it within those terms, or that the permittee will suppress the fire if compliance with permit terms cannot otherwise be achieved. This regulation focuses on fires that a person intends to use for a beneficial purpose, such as grassland or forest management. The commission distinguished between those fires and wildfires. Wildfires are beyond the scope of this regulation and no permitting requirements apply to a land manager within whose jurisdiction a wildfire occurs. The commission also concluded that a public comment opportunity should be available regarding fires with a high smoke risk. The commission intends that a high smoke risk rating be equivalent to a rating of 41 or greater from the draft Smoke Risk Rating Worksheet prepared by the division in conjunction with some users of prescribed fire and attached to this Statement of Basis and Purpose as Attachment A. The commission recognizes that the division and users of prescribed fire may find it appropriate to revise the smoke risk rating methodology in the future. If this is done, the commission intends that what constitutes a high smoke risk burn will consider at least the same factors as in Attachment A, and the point at which a fire becomes a high smoke risk should be equivalent to a rating of 41 on Attachment A. The division will determine which fires have a high smoke risk through consideration of the factors reflected in Attachment A. If, after considering these factors, the division concludes that the fire has a high smoke risk, it will allow the public thirty days in which to submit comments regarding whether a permit should be issued and what conditions are appropriate for inclusion in the permit. For planned ignition prescribed fires, the notice will include information about location of the fire, expected burn dates, expected duration of the fire, potential emissions, and potential air quality and visibility impacts at smoke sensitive receptors. The commission intends that the division either add appropriate conditions or combine permits to prevent circumvention of the public comment requirement, should a permit applicant submit separate applications that may have the effect of dividing burns that are more appropriately considered together. This comment opportunity is subject to the commission's Procedural Rules and includes the rights to a public comment hearing provided in those Rules. The comment opportunity does not include a right to an adjudicatory hearing to appeal issuance of a permit, as only the permit applicant may request such a hearing. Persons would still have recourse to seek judicial review of permits pursuant to the Administrative Procedures Act. Significant users of prescribed fire Senate Bill 01-214 imposes on significant users of prescribed fire additional requirements to ensure that that those users consider air quality impacts in making decisions about when, and under what conditions, they will use fire for grassland or forest management. Senate Bill 01-214 defined a significant user of prescribed fire as a person or agency that collectively manages or owns more than 10,000 acres of land and that uses prescribed fire. The commission enlarged on the part of this definition dealing with use of prescribed fire by establishing a minimum activity level based on PM,o emissions during a calendar year. The commission concludes that users of prescribed fire at levels below this threshold do not have significant enough an impact on visibility and air quality to justify their inclusion in this part of the smoke management program. This provision will focus the regulatory requirements and the resources of the division and others on the prescribed fires with the greatest potential impact on visibility and human health and welfare. The commission did not establish a de minimus threshold for other open burns, as even small fires intended to dispose of trash, rubbish and similar materials may have disproportionate impacts on local air quality. The regulation imposes additional duties on significant users of prescribed fire, consistent with specific requirements in SB 01-214. Section 25-7-106(8)(b), C.R.S., requires that significant users submit planning documents to the commission for comment and recommendations. This section also anticipates a hearing on the plans to allow public input. This public hearing requirement is similar to public hearing options applicable to major stationary source permitting. Public input on regulatory compliance and permits for major sources is important to public confidence in air pollution control efforts, particularly for long-term planning documents. The commission will hold public hearings to review the planning documents and may make comments and recommendations regarding the plans. Open burning permits for general, planned and unplanned ignition fires can only be issued to significant users of prescribed fire if the permit is consistent with the comments and recommendations of the commission. The commission intends that, wherever possible, the division will issue a permit with appropriate conditions in order to meet this requirement, rather than denying the permit altogether. This approach recognizes the value of prescribed fire in grassland and forestland management, but ensures that the air quality goals of SB 01-214 and this regulation are adequately protected. The commission defined planning documents and tailored the applicable regulatory requirements to focus submittals and commission review on the process used by a significant user of prescribed fire, rather than on the results of that process in a specific instance. The commission does not intend to challenge land use decisions made by the land manager. The purpose of the commission comments and recommendations will be to ensure that the land manager adequately considers air quality impacts when making decisions whether, and under what conditions, to use prescribed fire. The commission planning document review will focus on how a significant user of prescribed fire will meet the state air quality protection standard expressed in section 25-7-106(7)(e), C.R.S. Planning documents should summarize the decision process by which the land manager identifies and selects among alternative treatment methods for fuel reduction. The documents should provide a specific description relevant to accomplishment of the state air quality goal expressed in § 25-7-106(7)(e), C.R.S. This requirement will focus the land manager decision -making process on the goals of Senate Bill 01-214. The commission recognizes that planning documents will vary in their level of detail and sophistication in describing decision mechanisms used by land managers, particularly during the initial set of commission reviews. commission comments and recommendations may extend to beneficial changes in planning documents as well as improvements in the land manager planning process related to consideration of the state air quality goal. Specific permit conditions may be excluded from a permit if a federal land manager asserts that a federal statute specifically prohibits the compliance with the condition. In adopting this regulation, the commission made no evaluation whether any particular federal statute or permit condition may justify exclusion of a permit condition. Nevertheless, section 118 of the federal Clean Air Act, 42 U.S.C. §7418, subjects federal agencies engaging in activities resulting, or which may result, in discharge of air pollutants to state requirements on control and abatement of air pollution "in the same manner, and to the same extent as any nongovernmental entity." This waiver of federal sovereign immunity allows states to subject federal agencies to any substantive, procedural, permitting, fee or any other requirement. The Colorado General Assembly enacted §25-7-106(7), C.R.S., pursuant to §118 and directed that this subsection be construed to exercise the full extent of the state's authority regarding pollution from federal facilities. The commission intends these revisions to comport with §118 and to exercise the state's authority to its full extent. The division should consider this intent in deciding whether a federal statute specifically prohibits imposition of a particular permit condition. The rule also establishes a means for dealing with outdated plans or documents. The commission chose to view a plan as being outdated upon expiration of the period for which the plan itself states it is applicable, up to ten years. The commission may make comments or recommendations in the review process that urge a shorter applicable period than anticipated in the planning document. Any such comments will recognize applicable constraints on preparation of updated documents, such as the provisions of the National Environmental Policy Act. The regulation establishes a means for dealing with lands acquired by a significant user of prescribed fire after the commission reviews an initial or later version of a planning document. The commission concluded that requiring changes and further review of planning documents whenever a significant user acquires land would unduly increase the burdens of the review process on the commission, the division and the land managers. In general, the commission anticipates addressing planning documents for these lands at the next regular review, so long as the acquired lands will be managed in largely the same way as those already addressed by the commission. Where there will be a substantial difference in management of the acquired lands, the commission concluded that the land manager must submit planning documents to address the anticipated management. Fees and Monitoring Senate Bill 01-214 directed the commission to include within its smoke management program provisions for fees necessary to pay for administration of the program. Since the General Assembly granted the direct authority to develop a fee program for the smoke management program, the commission is not required to utilize the fee mechanism applicable to traditional stationary sources. The commission chose to apportion the cost of administering the program among users of prescribed fire rather than relying on traditional emissions fees. In part, this conclusion was due to the unique characteristics of this emission source category including highly variable emissions from one year to the next. Therefore, the commission concluded that the traditional emission fee approach would result in substantially greater administrative burdens for both the division and for users of prescribed fire. The methodology adopted combines the proportion of the total number of permits and total PM10 emissions of a particular user to determine the appropriate fraction of the program cost payable by that user. This approach will provide an equitable distribution of the costs of administering the common elements of the program. The commission intends that fees paid by stationary sources will not be used to pay any portion of the smoke management program costs. The total administrative cost of $129,646.45 at the outset is specified in an appendix to the regulation and the commission intends that any change to it or the distribution methodology occur only through a properly noticed public rule -making hearing before the commission. To that end, the cost is included in the regulation as the regulatory "fee." The division cost for program administration will be recalculated annually and reported to the commission each August. If the total cumulative dollar difference between the cost reflected in the regulation and the division's annual calculation exceeds five percent, the division will seek a fee change through a commission rulemaking. The "total cumulative dollar difference" between the regulatory fee and the annual cost will be calculated considering personnel and indirect and operating costs associated with the program, and the cumulative dollar difference from the previous year. This calculation will be performed substantially in accordance with the Colorado Smoke Management Program Cost and Fee Calculation Template (Attachment B). The commission also intends that the actual revenue collected be reported annually. If collections are consistently below projections, the division shall seek an appropriate fee adjustment consistent with the shortfall in revenue. In addition, the commission imposed a fee pursuant to section 25-7-114.7(2)(A)(III), C.R.S., to cover the direct and indirect costs of evaluating planning documents submitted to the commission. In order to reduce the administrative burden on the division and permittees, both the evaluation fees and the administration fee will be billed annually. The rule revisions adopted address the procedural mechanisms for accomplishing the mandatory requirements of Senate Bill 01-214. The general structure of the smoke management program has been established by statute. The commission's rule implements that legislative prescription; the revisions adopted set a de minimus level for significant users of prescribed fire, establish a fee mechanism and delineate the specifics of the program anticipated by the statute. The commission concludes that these rule revisions are adopted to implement prescriptive state statutory requirements, where the commission is allowed no significant policy -making options, for the purposes of § 25-7-110.5, C.R.S. The commission also concludes it has no discretion under state law to adopt alternative rules that differ significantly from these revisions, for the purposes of § 25-7-110.8(1), C.R.S. Accordingly, the commission did not include in the record some of the portions of the rulemaking prerequisites addressed in § 25-7-110.5, C.R.S., and did not make specific determinations regarding the factors listed in § 25-7-110.8(1), C.R.S. The commission took into consideration the appropriate items enumerated in section 25-7-109(1)(b), C.R.S. COLORADO AIR QUALITY CONTROL COMMISSION ADOPTED: JANUARY 17, 2002 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revision to Regulation No. 1: Section VIII.A This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, § 24-4-103, C.R.S., and the Colorado Air Pollution Prevention and Control Act, §§ 25-7-110 and 25-7-110.5, C.R.S ("the Act"). Specific Statutory Authority Section 25-7-107, C.R.S., provides the commission authority to review the current classification of any attainment, non -attainment, or unclassifiable area within the State. In addition, § 25-7-109, C.R.S., provides the commission authority to adopt, promulgate, modify and/or repeal emission control regulations that require the use of air pollution controls, including those regulations pertaining to particulates [§ 25-7-109(2)(b), C.R.S.]. Basis and Purpose Regulation No. 1 deals with opacity, particulate, and sulfur dioxide emissions from various sources. This amendment to Regulation No. 1 revises Section VIII.A, wherein a clerical error, which inadvertently materialized subsequent to the adoption of unrelated revisions to Regulation No. 1 during the August 2001 hearing, misrepresents the Denver area's PM -10 attainment/maintenance status. Section VIII.A erroneously referred to the Denver PM -10 non -attainment area, even though the area has been redesignated to "attainment/maintenance" for PM -10 (50 CFR 81.306). The EPA noted the discrepancy and asked the State to fix it when it approved the Denver PM -10 maintenance plan in September 2002 (40 CFR 52.320(c)(95)(i)(I)). This revision remedies the error. ADOPTED: JUNE 19, 2003 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revision to Regulation No. 1, Particulate Matter, Smoke, Carbon Monoxide and Sulfur Oxides This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, § 24-4-103, C.R.S., and the Colorado Air Pollution Prevention and Control Act, §§ 25-7-110 and 25-7-110.5, C.R.S ("the Act"). Specific Statutory Authority Section 25-7-109, C.R.S., provides the Commission authority to adopt, promulgate, modify and/or repeal emission control regulations that require the use of air pollution controls. [§ 25-7-109(1)(a), C.R.S.]. Basis and Purpose Regulation No. 1 generally sets forth emission limitations, equipment requirements, and work practices (abatement and control measures) intended to control the emissions of particulates, smokes, and sulfur oxides from new and existing stationary sources. This revision to Regulation No. 1 is intended to address Ft. Carson's need to use obscurants during training and to respond to EPA's August 8, 2001 letter regarding Regulation No. 1.Ft. Carson Obscurant usage The Commission adopted Regulation No. 1, Section D.C. on July 17, 1998, to allow soldiers to train with smoke or obscurants on Fort Carson, while requiring that visible emissions from these sources not cross the Installation boundary. This was accomplished by limiting the generation of smoke and obscurants to training areas at least three kilometers away from the Installation boundary. Section II.A of the regulation sets a general standard prohibiting emission into the atmosphere of any air pollutant that is in excess of 20% opacity. In recognition that smoke and obscurant generation in training by the United States Army purposefully intends to be at or near 100% opacity, Section II.C was added to Regulation No. 1 in 1998. Section II.C allowed the use of military smokes and obscurants at Fort Carson and the Pinon Canyon Maneuver Site (PCMS) (both of which will be referred to as Fort Carson or the Installation in this document), subject to specified limitations and conditions. Since the 1998 adoption, Ft. Carson has documented that the three -kilometer restriction placed essential training areas, such as drop zones for airborne operations, an urban war -fighting training complex, and a Combined Arms Live Fire Exercise Range, off limits for smoke or obscurant training. Consequently, by reducing the amount of available training area, the size and scope of training maneuvers were constrained, which diminished how realistic these battlefield environments were for the soldiers. Due to world events since 1998, and more particularly since September 11, 2001, the training demand at Fort Carson expanded considerably and will likely remain at a high level for the foreseeable future, placing even higher demand on limited training areas and threatening an inability to train soldiers to standard in a timely manner. The 1998 version of the regulation also restricted the types of smoke and obscurants, which did not provide realistic training for soldiers who would normally use other types of materials during combat situations. Therefore, the Commission has approved an amendment to the regulation to permit the use of more training acreage on Fort Carson for smoke or obscurants, as well as to allow the use of current or new Department of Defense- approved materials that create obscurant effects. Such changes to the regulation will allow the flexible and realistic military training that the Army requires to responsively address lessons learned from actual missions. Specifically, the amendment includes the following changes: • It replaces the specific reference to fog oil with a general reference to smoke or obscurants. This allows the use of other materials and devices that may be used only after an authorized Department of Defense official has approved them; • It cites more accurately that the training manuals and guidance for using smoke and obscurants are Department of Defense documents, not solely those from Fort Carson; • It removes the daily fog oil limitations. The relationship of those limitations to protecting the national ambient air quality standards appears nonexistent. In contrast, the additional specific controls on Fort Carson's use of smoke and obscurants imposed by the amended regulation provide a clear basis for compliance with the basic requirement of Section II.C, i.e., no transport of emissions from smoke or obscurants off Fort Carson; • Similarly, the revision replaces the three -kilometer buffer zone, the scientific basis for which has been called into question, with more realistic, yet still effective, planning and operating procedures that are equally or more likely to prevent visible emissions from crossing the Installation boundary; and • It imposes on Fort Carson specific, required measures to be executed before and during smoke and obscurant training. These measures will preclude commencement of such training under unsatisfactory conditions and stop such training if conditions unexpectedly deteriorate. In large part, imposition of these measures recognizes the fact that the duty of the Commission to protect the quality of Colorado's air is at one with the goal of the Army to provide effective, realistic training. For the Commission, smoke and obscurant use must be closely controlled to avoid off - Fort Carson transport. For the Army, training must replicate combat conditions. Under those conditions, use of smoke and obscurants must likewise be carefully controlled. If a plume travels too quickly or in unexpected directions, it will be ineffective at best, counter -productive at worst. To complement the specific operational requirements in the amended regulation, Fort Carson will revise its internal training regulations to incorporate those requirements. Thus, violations of the requirements of the regulation will be subject to military disciplinary or adverse administrative action as well as compliance actions under Colorado and federal law. Based on discussion between Ft. Carson, the Colorado Department of Public Health and Environment, Air Pollution Control Division, and the Environmental Protection Agency, the Commission believes that the NAAQS are protected if no visible emissions cross the Installation boundary. The Commission has concluded that the more comprehensive and practical control measures in the amended regulation provide as great or greater assurances that off -Installation transport will not occur as compared to the limitations and conditions in the 1998 version. Thus, the amended regulation comports with section 110(l) of the federal Clean Air Act. EPA August 2001 letter EPA's August 2001 letter raised several issues concerning Regulation No. 1. Some of EPA's issues concern changes contained in 1996 and 2001 SIP revisions that are currently pending before EPA. Other EPA comments related to provisions of the regulation that are already approved into the SIP. The Commission not only amends Regulation No. 1, it also hereby amends the SIP and withdraws some portions of the previous SIP submittal as appropriate to respond to EPA's comments. The reasons for such changes are described here. The scope of the SIP revision is set out below in the section entitled "Revisions to the Colorado State Implementation Plan". Section III. Particulate Matter EPA concern: In a recent review of a Colorado operating permit, we ran into confusion regarding the applicability of each subsection of Reg. 1, III.C.1. The problem stems from whether the categorization of a source as either above or below 30 tons per hour process weight rate is based upon the actual process weight rate at a given time for the unit, or based upon the maximum or design process weight rate for that unit. The Division indicated that, while it interprets the regulation to read as the former, it is considering a revision to the design rate interpretation. It would be appropriate and timely for the Division to include this change now with the extensive Reg. 1 updates it is making. The Division would be required to provide reasoning that shows that the change does not relax the SIP requirements. The Commission agrees and has changed the section to read design rate. The division currently uses design rate for this purpose so this change only clarifies the current practice. Section VI. Sulfur Dioxide A.1 EPA Concern: This part seems to indicate that the emission limit averaging time for sources using fuel sampling will be the frequency of the fuel sampling specified in the fuel sampling plan submitted pursuant to section IV.B.2. We have two concerns with this requirement. First, the averaging time of the emission limit should not vary based on the frequency of fuel sampling. Among other things, the fuel -sampling plan should describe the test method used to sample the fuel as well as the frequency at which the fuel should be sampled. The frequency of sampling should depend on whether or not the sulfur in the fuel is expected to remain constant. If it is not constant, it should be sampled more frequently than if it does remain constant. The amount of sulfur in the fuel will be considered a constant until the fuel is re sampled. If, for example, a fuel is sampled once/day, that measured concentration of sulfur in the fuel will be assumed to remain constant for all time periods of the day. Compliance with the emission limit is then based on the concentration of sulfur in the fuel and the feed rate of the fuel to the source. Second, section IV.B.2 applies only to fossil fuel fired stem generators greater then 250 mm BTU/hour heat input, whereas the SO2 emission limits in the section apply to different types of sources including sources less than 250 mm BTU/hr heat input. Referencing Section IV.B.2 limits section VI.A.1. The Commission agrees that the fuel sampling needs to be tied to the likelihood of the sulfur content in the fuel changing. The sampling should be scheduled so that changes in the fuel sulfur are monitored. A.3.f EPA Concern: The end of the first paragraph in Part f — Cement Manufacture- discusses "new sources" We question why this paragraph mentions new sources since section VI.A applies to "existing sources"? Additionally, section VI.B, which applies to new sources, does not contain emission limits for Cement Manufacture, Did you intend the Emission limits for existing Cement Manufacture to apply to new sources? New cement manufacturing plants will be covered by NSR permits that will include more stringent SO2 emissions limitations than are set out in Regulation No. 1. Therefore, the Commission is removing the reference to new cement manufacturing plants in section VI.A.3.f as unnecessary and redundant. A & B.1 EPA Concern: These sections are written to make it seem that an existing permitted source (i.e. permitted before August 11, 1977) which makes a modification would not be required to meet either sections VI.A or VI.B. Section VI.A only applies to sources constructed or modified prior to August 11, 1977. Section VI.B does not apply to sources, which constructed or modified and have not been issued a permit prior to August 11, 1977. Usually regulations are written so that existing sources which modify have to meet more stringent requirements, in this case Section VI.B. Is it your intent that existing permitted sources (i.e., permitted before August 11, 1977) which make modifications should not be subject to either section VI.A or VI.B? The Commission does not believe that there is an issue here. Section VI.A covers sources constructed or modified prior to August 11, 1977. Section VI.B covers new sources defined as newly constructed or modified which have not been issued an Emission Permit prior to August 11, 1977. Thus a source permitted before August 11, 1977 which made a modification would continue to be subject to Section VI.A. While EPA is correct that this does not subject the source to an increased stringency, the source would be subject to the regulation. B.4 EPA Concern: Comments here are on Parts e and g pertaining to emission limit relaxation. The existing SIP -approved rules limit SO2 emissions to 0.3 lbs/day. The State has revised the daily limit to 0.7 lbs/day. We view this as a relaxation to the SIP. Section 110(I) of the Act provides that we cannot approve a revision to a SIP if the revision would interfere with any applicable requirement concerning attainment and reasonable further progress, or any other applicable requirement of the Act. Section 110(1) applies to both attainment and unclassifiable areas, as well as non -attainment areas. The revisions may be a relaxation of existing requirements at sources that impact PM -10 non -attainment areas. As a result, the revisions may aggravate ambient air quality problems in the non -attainment area. The State should submit an analysis indicating whether the relaxation in the emissions limit will impact the non -attainment area. Also, the state should evaluate whether or not the emission limit relaxation would cause or contribute to a violation of the SO2 increments. Finally, the State should investigate whether section 193 of the Act would apply to the relaxed emission limitations. To the extent section 193 does apply, the SIP revision would have to provide equivalent or greater emission reductions to offset any emissions increases. Second, we do not understand why the rules indicate that "the Division shall not limit the determination of barrels processed per day to 24 hour period." What is the purpose of this sentence? This sentence is also found in section VI.A.3.g.ii The division attempted to model compliance with the new standard and found violations of the NAAQS. The Commission agrees that the previous language should be reinstated to protect the NAAQS, because the modeling did not support the relaxation of the standard. Such changes merely amend the state regulation to match the language already contained in the SIP and, therefore, need not be submitted to EPA as a SIP revision. Accordingly, the Commission is withdrawing the previously submitted language currently pending before EPA as a SIP revision. B.5 EPA Concern: The state deleted this section, which limited emissions of any new source not specifically regulated by the rule to 2 tons per day of SO2 and to utilize BACT. The same concerns we have in our comment in Section B.4.e and g above also apply here. The Commission had previously deleted this language because there is similar language in Regulation No. 6, Section III.D. However, Regulation No. 6, Section III.D is not part of Colorado's SIP. Therefore the Commission will reinstate the language in Regulation No. 1 and delete the state -only language in Regulation No. 6 in a future rule making. Other changes The division is also addressing several clean up and clarifying changes. The open burning provisions of Section II.C are being reinstated in the regulation. Section II.C was removed when the division created Regulation No. 9, Open Burning, Prescribed Fire, And Permitting. The Commission never intended that Regulation No. 9 become part of the SIP, so to maintain the integrity of the SIP the Commission is reinstating the open burning provisions in Regulation No. 1. The Commission is removing the Gates and Rocky Flats boilers from Section VIII.A because these boilers no longer exist or operate. REVISIONS TO THE COLORADO STATE IMPLEMENTATION PLAN The AQCC hereby revises and updates the SIP to reflect the July 21, 2005 amendments to Regulation No. 1. Most of Regulation No. 1 is already in the SIP. Accordingly, only the revisions to the provisions listed below adopted on July 21, 2005 are SIP revisions. For the convenience of EPA, and because the Commission simultaneous made non -substantive numbering changes throughout Regulation No. 1, a copy of Regulation No. 1, as adopted on July 21, 2005, is attached as Appendix A in its entirety. Appendix A shall not be construed to be a SIP revision for any provision that has already been incorporated into the SIP in its current form, except that EPA may adjust the numbering scheme in the SIP to reflect the new numbering scheme. Only the following provisions are submitted as SIP revisions: The unnumbered introductory paragraph that is the first paragraph of page 4 of Appendix A. Section I.A Section II.A.1 Section II.A.3 Sections II.C Section II.D Section III.B.2.a Section III.B.3 Section III.C.1 Section II.C.1.a Section II.C.1.b Section IV.D.2 Section IV.A.1 Section IV.A.3.f Section VI.A.5 Section VI.B.7 Section VI.B.5 Section VI.D.2.b Section VIII.A.5 Section VIII.A.6 Section IX. In addition to submitting the revisions to the twenty-one sections of Regulation No. 1 listed above, the Commission also retracts all previously submitted revisions to sections VI.B.4.e. and VI.B.4.g.(ii). On July 21, 2005 the Commission revised these two sections of Regulation No. 1 to match these two provisions as already incorporated into SIP verbatim. Thus, the versions of these two sections previously submitted as SIP revisions no longer match the state regulation and are hereby retracted as SIP revisions. Since the versions of sections VI.B.4.e and VI.B.g.(ii) adopted on July 21, 2005 match the provisions already approved into the SIP, it is not necessary to resubmit them as SIP revisions. In effect, the Commission has merely made conforming changes to the state rule to conform to the approved SIP. ADOPTED: JULY 21, 2005 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revision to Regulation No. 1 This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, § 24-4-103, C.R.S., and the Colorado Air Pollution Prevention and Control Act, §§ 25-7-110 and 25-7-110.5, C.R.S ("the Act"). Specific Statutory Authority The Colorado Air Pollution Prevention and Control Act, section 25-7-109, C.R.S., provides the commission the authority to adopt and revise rules and regulations that are consistent with state policy regarding air pollution and with federal recommendations and requirements. Basis and Purpose The U.S. Environmental Protection Agency (EPA) promulgated a New Source Performance Standard for Commercial and Industrial Solid Waste Incinerators (CISWI) at 40 CFR Part 60, Subpart CCCC on December 1, 2000. The Commission incorporated the new standard by reference into Regulation No. 6, Part A in February 2002. At that time, there were no sources in Colorado subject to Subpart CCCC. In September 2005 a new unit subject to Subpart CCCC commenced construction, which raised an issue regarding performance -testing requirements for that unit. Subpart CCCC of 40 CFR Part 60 applies to air curtain destructors that combust wood or yard wastes at a commercial or industrial facility. Subpart CCCC includes performance -testing requirements for such units. The Commission's Common Provisions regulation defines air curtain destructors subject to 40 CFR Part 60 as incinerators, which also subjects them to grain loading standards and performance testing requirements under Regulation No. 1, Section III.B. It is not feasible, however, to conduct performance testing on air curtain destructors for grain loading emissions as specified in Section III.B. due to their lack of a stack. In order to ensure that appropriate and reasonable emission standards and performance testing requirements are applied to air curtain incinerators, the Commission has adopted revisions to Regulation No. 1, Section III.B. clarifying that air curtain incinerators subject to 40 CFR Part 60 are not subject to Section III.B. Further, these revisions will include any typographical and grammatical errors throughout the regulation. ADOPTED: SEPTEMBER 21, 2006 COLORADO AIR QUALITY CONTROL COMMISSION STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE Revision to Regulation No. 1 This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements of the Colorado Administrative Procedures Act, section 24-4-103, C.R.S., and the Colorado Air Pollution Prevention and Control Act, sections 25-7-110 and 25-7-110.5, C.R.S. Statutory Authority The Air Quality Control Commission is authorized to adopt these revisions to Regulation Number 9 and Regulation No. 1 pursuant to C.R.S. §§ 25-7-106(7), (8) (2001) and 25-7-123(1) (2001). Basis and Purpose Prescribed Fire Regulation by Counties Current regulations provide that the Division issues permits for a prescribed fire. This revision clarifies that the Division, as well as local agencies that have been designated agents of the Division, may issue wildland fire permits. The revision also exempts such permits issued by delegated local agencies from State fees. The Division retains oversight of the program should a local agency fail to administer the program as per Regulation No. 9. The Division is authorized to delegate open burn regulation to local agencies under C.R.S. § 25-7- 111(2)(f). The Division may designate local agencies as agents of the state to administer powers and duties such as open burn regulation. Limited delegations are good policy because local governments are closest to the challenges of conducting such burning. They can work more closely and consistently with a larger number of local landowners to ensure timely inspection of proposed projects, more effective compliance assistance, and more effective smoke monitoring. This revision is necessary to avoid any confusion among land managers regarding which agency issues burn permits. Over the past thirty years, the Division has designated agencies from twelve counties as agents of the Division for the purpose of administering general open burn permitting. However, the general open burn program is limited to de minimus wildland fuel piles (as defined in Regulation 9 Appendix A). The pine beetle epidemic has changed the needs of all stakeholders. Certain Colorado counties are facing a critical need for tools to use in the management or disposal of dead timber after forests have been devastated by the pine beetle epidemic. The spread of the epidemic has been exponential, creating huge volumes of trees and woody debris to dispose of responsibly. The United States Forest Service estimates that 50-60% of the mature lodge pole trees in Summit County are dead or dying. The numbers climb to 80-90% in Grand County. Eagle County is also heavily impacted. The risk of catastrophic wildfire has increased by these large stands of diseased or dead trees. While no one approach will solve all the problems associated with dealing with the huge volume of trees to be disposed of, responsible burning is one option. Recently local county agencies and landowners in these areas have contacted the Division regarding the burning of piles of logged trees under local permitting. The Division has been collaborating with local counties affected by the mountain pine beetle epidemic to evaluate the prospect of delegating the prescribed fire program to willing and able county agencies. It now makes sense to designate local agencies to permit larger pile burns than possible under a general open burning permit. The Division believes that in the face of the pine beetle kill challenge, if local agencies are properly staffed and prepared to assume the responsibilities of permitting, it is appropriate to consider developing a written delegation agreement. Thus, the Division is now working on a delegation for the prescribed fire program to local agencies. Training and Instructional Fires Wildland fuel burns that have a training or instructional component but are large enough to constitute prescribed fires will now be subject to Regulation 9 permitting requirements. Prescribed fires are burns large enough to be over the de minimus low smoke risk threshold in Regulation 9, Appendix A. This change will require the permittees to insure that the smoke is managed responsibly and that public health is considered. Open burns causing de minimus smoke emissions that are used for training purposes are still exempt from permitting requirements. Prior to this revision, Regulations 1 and 9 exempted all training and instructional fires from permitting by the Division. However, this exemption does not reflect the realities of wildfire suppression training. Few, if any, burns are used exclusively for wildland fire suppression training. These burns accomplish several objectives in addition to training, such as habitat improvement, weed control, and wildfire fuel control. Most prescribed fires are used for training to some degree. Prior to this revision, these fires would arguably be entitled to an exemption. Prescribed fires are, by definition, large with significant emissions that can impact residents in the vicinity of the fire. If the Division were to grant an exemption for every prescribed burn that involves training, few prescribed fires would be permitted. Without a permit, the Division cannot ensure that the land manager is implementing the controls that are necessary to protect public health and safety. Wildland fire instructors usually consider applying for and obtaining a planned ignition fire permit from the Division as part of the training exercise. This revision reflects that burn permits are necessary for burns that exceed the de minimus smoke emissions threshold and the industry practice of requesting a permit. The Division is aware of instances where structures were ignited under the training exemption yet did not receive a Demolition Notice from the Division prior to ignition to assure they were free from asbestos. This revision does not require permitting for structural fire fighting training, though it does include a cross reference to Regulation Number 8, Part B, Section III.E.1. concerning the possible need for a Demolition Notice to assure the structure is free of asbestos before the structure is burned. Further, these revisions will include any topographical and grammatical errors throughout the regulation. ADOPTED: JUNE 21, 2007 COLORADO AIR QUALITY CONTROL COMMISSION Colorado Noise Related Statutes 8-3-108 IIIC What are unfair labor practices "Peaceable picketing" means simply, tranquil conduct, conduct devoid of noise or tumult, the absence of a quarrelsome demeanor, a course of conduct that does not violate or disturb the public peace. 8-3-109 What are not unfair labor practices However, picketing must be "peaceful", and "peaceful picketing" means simply, tranquil conduct, conduct devoid of noise or tumult, the absence of a quarrelsome demeanor, a course of conduct that does not violate or disturb the public peace. As a necessary corollary, boisterous conduct, the use of vile language, bellicose demeanor, threats, violence, coercion, intimidation, shouting and interference with the use of premises or impeding a public highway, as by mass picketing, which is the use of a large number of pickets, is not peaceable picketing, but is illegal picketing. 12-47-301 Licensing in general Denial of a license because of speculative reasons such as possible vandalism, noise, or disturbances, where it is obvious that these factors alone and not the required factors were the basis for the denial, is without legal justification. 18-9-106 Disorderly conduct c) Makes unreasonable noise in a public place or near a private residence that he has no right to occupy; or 24-65.1-202 Criteria for administration of areas of state interest (a) Areas around airports shall be administered so as to: (I) Encourage land use patterns for housing and other local government needs that will separate uncontrollable noise sources from residential and other noise -sensitive areas; and 25-12-101 Legislative declaration The general assembly finds and declares that noise is a major source of environmental pollution which represents a threat to the serenity and quality of life in the state of Colorado. Excess noise often has an adverse physiological and psychological effect on human beings, thus contributing to an economic loss to the community. Accordingly, it is the policy of the general assembly to establish statewide standards for noise level limits for various time periods and areas. Noise in excess of the limits provided in this article constitutes a public nuisance. 25-12-102 Definitions As used in this article, unless the context otherwise requires (1) "Commercial zone" means: (a) An area where offices, clinics, and the facilities needed to serve them are located; (b) An area with local shopping and service establishments located within walking distances of the residents served; (c) A tourist -oriented area where hotels, motels, and gasoline stations are located; 1 (d) A large integrated regional shopping center; (e) A business strip along a main street containing offices, retail businesses, and commercial enterprises; (f) A central business district; or (g) A commercially dominated area with multiple -unit dwellings. (2) "db(A)" means sound levels in decibels measured on the "A" scale of a standard sound level meter having characteristics defined by the American national standards institute, publication Si. 4 - 1971. (3) "Decibel" is a unit used to express the magnitude of a change in sound level. The difference in decibels between two sound pressure levels is twenty times the common logarithm of their ratio. In sound pressure measurements sound levels are defined as twenty times the common logarithm of the ratio of that sound pressure level to a reference level of 2 x 10-5 N/m2 (Newton's/meter squared). As an example of the effect of the formula, a three -decibel change is a one hundred percent increase or decrease in the sound level, and a ten -decibel change is a one thousand percent increase or decrease in the sound level (4) (a) "Industrial zone" means an area in which noise restrictions on industry are necessary to protect the value of adjacent properties for other economic activity but shall not include agricultural, horticultural, or floricultural operations (b) Nothing in paragraph (a) of this subsection (4), as amended by House Bill 05-1180, as enacted at the first regular session of the sixty-fifth general assembly, shall be construed as changing the property tax classification of property owned by a horticultural or floricultural operation. (5) "Light industrial and commercial zone" means: (a) An area containing clean and quiet research laboratories; (b) An area containing light industrial activities which are clean and quiet; (c) An area containing warehousing; or (d) An area in which other activities are conducted where the general environment is free from concentrated industrial activity (5.2) "Motorcycle" means a self-propelled vehicle with not more than three wheels in contact with the ground that is designed primarily for use on the public highways (5.4) "Motor vehicle" means a self-propelled vehicle with at least four wheels in contact with the ground that is designed primarily for use on the public highways (5.6) "Off -highway vehicle" means a self-propelled vehicle with wheels or tracks in contact with the ground that is designed primarily for use off the public highways. "Off -highway vehicle" shall not include the following (a) Military vehicles; (b) Golf carts; (c) Snowmobiles (d) Vehicles designed and used to carry persons with disabilities; and (e) Vehicles designed and used specifically for agricultural, logging,firefighting, or mining purposes. (6) "Residential zone" means an area of single-family or multifamily dwellings where businesses may or may not be conducted in such dwellings. The zone includes areas where multiple -unit dwellings, high-rise apartment districts, and redevelopment districts are located. A residential zone may include areas containing accommodations for transients such as motels and hotels and 2 Residential: residential areas with limited office development, but it may not include retail shopping facilities. "Residential zone" includes hospitals, nursing homes, and similar institutional facilities (7) "SAE J1287" means the J1287 stationary sound test or any successor test published by SAE international or any successor organization (8) "SAE J2567" means the J2567 stationary sound test or any successor test published by SAE international or any successor organization (9) "Snowmobile" means a self-propelled vehicle primarily designed or altered for travel on snow or ice when supported in part by skis, belts, or cleats and designed primarily for use off the public highways. "Snowmobile" shall not include machinery used strictly for the grooming of snowmobile trails or ski slopes 25-12-103 Maximum permissible noise levels (1) Every activity to which this article is applicable shall be conducted in a manner so that any noise produced is not objectionable due to intermittence, beat frequency, or shrillness. Sound levels of noise radiating from a property line at a distance of twenty-five feet or more therefrom in excess of the db(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance: Maximum Sound Level dB(A) 7 am to 7 pm 55 7pmto7am 50 Commercial :. 60 55 Light Industrial ndustnal 70 80 65 75 (2) In the hours between 7:00 a.m. and the next 7:00 p.m., the noise levels permitted in subsection (1) of this section may be increased by ten db(A) for a period of not to exceed fifteen minutes in any one -hour period. (3) Periodic, impulsive, or shrill noises shall be considered a public nuisance when such noises are at a sound level of five db(A) less than those listed in subsection (1) of this section. (4) This article is not intended to apply to the operation of aircraft or to other activities which are subject to federal law with respect to noise control. (5) Construction projects shall be subject to the maximum permissible noise levels specified for industrial zones for the period within which construction is to be completed pursuant to any applicable construction permit issued by proper authority or, if no time limitation is imposed, for a reasonable period of time for completion of project. (6) All railroad rights -of -way shall be considered as industrial zones for the purposes of this article, and the operation of trains shall be subject to the maximum permissible noise levels specified for such zone. (7) This article is not applicable to the use of property for purposes of conducting speed or endurance events involving motor or other vehicles, but such exception is effective only during the specific period of time within which such use of the property is authorized by the political subdivision or governmental agency having lawful jurisdiction to authorize such use. (8) For the purposes of this article, measurements with sound level meters shall be made when the wind velocity at the time and place of such measurement is not more than five miles per hour. 3 (9) In all sound level measurements, consideration shall be given to the effect of the ambient noise level created by the encompassing noise of the environment from all sources at the time and place of such sound level measurement. (10) This article is not applicable to the use of property for the purpose of manufacturing, maintaining, or grooming machine -made snow. This subsection (10) shall not be construed to preempt or limit the authority of any political subdivision having jurisdiction to regulate noise abatement. (11) This article is not applicable to the use of property by this state, any political subdivision of this state, or any other entity not organized for profit, including, but not limited to, nonprofit corporations, or any of their lessees, licensees, or permittees, for the purpose of promoting, producing, or holding cultural, entertainment, athletic, or patriotic events, including, but not limited to, concerts, music festivals, and fireworks displays. This subsection (11) shall not be construed to preempt or limit the authority of any political subdivision having jurisdiction to regulate noise abatement. (12) (a) Notwithstanding subsection (1) of this section, the public utilities commission may determine, while reviewing utility applications for certificates of public convenience and necessity for electric transmission facilities, whether projected noise levels for electric transmission facilities are reasonable. Such determination shall take into account concerns raised by participants in the commission proceeding and the alternatives available to a utility to meet the need for electric transmission facilities. When applying, the utility shall provide notice of its application to all municipalities and counties where the proposed electric transmission facilities will be located. The public utilities commission shall afford the public an opportunity to participate in all proceedings in which permissible noise levels are established according to the "Public Utilities Law", articles 1 to 7 of title 40, C.R.S. (b) Because of the statewide need for reliable electric service and the public benefit provided by electric transmission facilities, notwithstanding any other provision of law, no municipality or county may adopt an ordinance or resolution setting noise standards for electric transmission facilities that are more restrictive than this subsection (12). The owner or operator of an electric transmission facility shall not be liable in a civil action based upon noise emitted by electric transmission facilities that comply with this subsection (12). (c) For the purposes of this section: (I) "Electric transmission facility" means a power line or other facility that transmits electrical current and operates at a voltage level greater than or equal to 44 kilovolts. (II) "Rights -of -way for electric transmission facilities" means all property rights and interests obtained by the owner or operator of an electric transmission facility for the purpose of constructing, maintaining, or operating the electric transmission facility. 25-12-104 Action to abate Whenever there is reason to believe that a nuisance exists, as defined in section 25-12-103, any county or resident of the state may maintain an action in equity in the district court of the judicial district in which the alleged nuisance exists to abate and prevent such nuisance and to perpetually enjoin the person conducting or maintaining the same and the owner, lessee, or agent of the building or place in or upon which such nuisance exists from directly or indirectly maintaining or permitting such nuisance. Notwithstanding any other provision of this section, a county shall not maintain an action pursuant to this section if the alleged nuisance involves a 4 mining operation or the development, extraction, or transportation of construction materials, as those terms are defined in section 34-32.5-103, C.R.S., a commercial activity, the commercial use of property, avalanche control activities, a farming or ranching activity, an activity of a utility, or a mining or oil and gas operation. When proceedings by injunction are instituted, such proceedings shall be conducted under the Colorado rules of civil procedure. The court may stay the effect of any order issued under this section for such time as is reasonably necessary for the compliance with the provisions of this article 25-12-105 Violation for injunction - penalty Any violation or disobedience of any injunction or order expressly provided for by section 25- 12-104 shall be punished as a contempt of court by a fine of not less than one hundred dollars nor more than two thousand dollars. Each day in which an individual is in violation of the injunction established by the court shall constitute a separate offense. The court shall give consideration in any such case to the practical difficulties involved with respect to effecting compliance with the requirements of any order issued by the court. 25-12-106 Noise restrictions — sale of new vehicles (1) Except for such vehicles as are designed exclusively for racing purposes, no person shall sell or offer for sale a new motor vehicle that produces a maximum noise exceeding the following noise limits, at a distance of fifty feet from the center of the lane of travel, under test procedures established by the department of revenue: (a) Any motorcycle manufactured on or after July 1, 1971, and before January 1, 197388 dB(A); (b) Any motorcycle manufactured on or after January 1, 1973 86 dB(A); (c) Any motor vehicle with a gross vehicle weight rating of six thousand pounds or more manufactured on or after July 1, 1971, and before January 1, 1973 88 dB(A); (d) Any motor vehicle with a gross vehicle weight rating of six thousand pounds or more manufactured on or after January 1, 1973 86 dB(A); (e) Any other motor vehicle manufactured on or after January 1, 1968, and before January 1, 1973 86 dB(A); (f) Any other motor vehicle manufactured after January 1, 1973 84 db(A); (g) Deleted (2) Test procedures for compliance with this section shall be established by the department, taking into consideration the test procedures of the society of automotive engineers. (3) Any person selling or offering for sale a motor vehicle or other vehicle in violation of this section is guilty of a misdemeanor and, upon conviction thereof, shall be punished by a fine of not less than fifty dollars nor more than three hundred dollars 25-12-107 Powers of local authorities (1) Counties or municipalities may adopt resolutions or ordinances prohibiting the operation of motor vehicles within their respective jurisdictions that produce noise in excess of the sound levels in decibels, measured on the "A" scale on a standard sound level meter having characteristics established by the American national standards institute, publication S1.4 - 1971, and measured at a distance of fifty feet from the center of the lane of travel and within the speed limits specified in this section: 5 a) Any motor vehicle with a manufacturer's gross vehicle weight rating of six thousand pounds or more, any combination of vehicles towed by such motor vehicle, and any motorcycle other than a low - power scooter: 88 dB(A) 90 dB(A) Speed limit of more than 35 mph but less than 55 mph efore January. !, ;1973 After January 1, 1973 86 dB(A) 90 dB(A) (2) The governing board shall adopt resolutions establishing any test procedures deemed necessary. (3) This section applies to the total noise from a vehicle or combination of vehicles. (4) For the purpose of this section, a truck, truck tractor, or bus that is not equipped with an identification plate or marking bearing the manufacturer's name and manufacturer's gross vehicle weight rating shall be considered as having a manufacturer's gross vehicle weight rating of six thousand pounds or more if the unladen weight is more than five thousand pounds 25-12-108 Preemption Except as provided in sections 25-12-103 (12) and 25-12-110, this article shall not be construed to preempt or limit the authority of any municipality or county to adopt standards that are no less restrictive than the provisions of this article. 25-12-109 Exception — sport shooting ranges — legislative declaration — definitions (1) The general assembly hereby fmds, determines, and declares that the imposition of inconsistent, outdated, and unnecessary noise restrictions on qualifying sport shooting ranges that meet specific, designated qualifications work to the detriment of the public health, welfare, and morale as well as to the detriment of the economic well-being of the state. The general assembly further fmds, determines, and declares that a need exists for statewide uniformity with respect to exempting qualifying shooting ranges from the enforcement of laws, ordinances, rules, and orders regulating noise. As the gain associated with having a uniform statewide exemption for qualifying sport shooting ranges outweighs any gains associated with enforcing noise regulations against such ranges, the general assembly further declares that the provisions of this section, as enacted, are a matter of statewide concern and preempt any provisions of any law, ordinance, rule, or order to the contrary. (2) As used in this section, unless the context otherwise requires (a) "Local government" means any county, city, city and county, town, or any governmental entity, board, council, or committee operating under the authority of any county, city, city and county, or town. (b) "Local government official" means any elected, appointed, or employed individual or group of individuals acting on behalf of or exercising the authority of any local government. (c) "Person" means an individual, proprietorship, partnership, corporation, club, or other legal entity. (d) "Qualifying sport shooting range" or "qualifying range" means any public or private establishment, whether operating for profit or not for profit, that operates an area for the discharge or other use of firearms or other equipment for silhouette, skeet, trap, black powder, target, self-defense, recreational or competitive shooting, or professional training. 6 (3) Notwithstanding any other law or municipal or county ordinance, rule, or order regulating noise to the contrary (a) A local governmental official may not commence a civil action nor seek a criminal penalty against a qualifying sport shooting range or its owners or operators on the grounds of noise emanating from such range that results from the normal operation or use of the qualifying shooting range except upon a written complaint from a resident of the jurisdiction in which the range is located. The complaint shall state the name and address of the complainant, how long the complainant has resided at the address indicated, the times and dates on which the alleged excessive noise occurred, and such other information as the local government may require. The local government shall not proceed to seek a criminal penalty or pursue a civil action against a qualifying sport shooting range on the basis of such a noise complaint if the complainant established residence within the jurisdiction after January 1, 1985 (b) No person may bring any suit in law or equity or any other claim for relief against a qualifying sport shooting range located in the vicinity of the person's property or against the owners or operators of such range on the grounds of noise emanating from the range if (I) The qualifying range was established before the person acquired the property; (II) The qualifying range complies with all laws, ordinances, rules, or orders regulating noise that applied to the range and its operation at the time of its construction or initial operation. (III) No law, ordinance, rule, or order regulating noise applied to the qualifying range at the time of its construction or initial operation. 25-12-110 Off highway vehicles (1) An off -highway vehicle operated within the state shall not emit more than the following level of sound when measured using SAE J1287 (a) If manufactured before January 1, 1998 99 db(A); (b) If manufactured on or after January 1, 1998 96 db(A). (2) A snowmobile shall not emit more than the following level of sound when measured using SAE J2567: (a) If manufactured on or after July 1, 1972, and before July 2, 1975 90 db(A); (b) If manufactured on or after July 2, 1975 88 db(A). (3) (a) A person shall not sell or offer to sell a new off -highway vehicle that emits a level of sound in excess of that prohibited by subsection (1) of this section unless the off -highway vehicle complies with federal noise emission standards. A person shall not sell or offer to sell a new snowmobile that emits a level of sound in excess of that prohibited by subsection (2) of this section unless the snowmobile complies with federal noise emission standards. (b) For the purposes of this section, a "new" snowmobile or off -highway vehicle means a snowmobile or off -highway vehicle that has not been transferred on a manufacturer's statement of origin and for which an ownership registration card has not been submitted by the original owner to the manufacturer. (4) This section shall not apply to the following (a) A vehicle designed or modified for and used in closed-circuit, off -highway vehicle competition facilities. 7 (b) An off -highway vehicle used in an emergency to search for or rescue a person; and c) An off -highway vehicle while in use for agricultural purposes. (5) A person who violates this section commits a class 2 petty offense and, upon conviction thereof, shall be punished by a fore of not more than one hundred dollars (6) No municipality or county may adopt an ordinance or resolution setting noise standards for off -highway vehicles or snowmobiles that are more restrictive than this section. (7) (a) Nothing in this section shall be construed to modify the authority granted in section 25- 12-103 (b) Nothing in this section shall be construed to authorize the test to produce a less restrictive standard than the J1287 stationary sound test or the J2567 stationary sound test published by SAE international or any successor organization. (8) The following shall be an affirmative defense to a violation under this section if the off - highway vehicle or snowmobile: (a) Was manufactured before January 1, 2005; (b) Complied with federal and state law when purchased; (c) Has not been modified from the manufacturer's original equipment specifications or to exceed the sound limits imposed by subsection (1) or (2) of this section; and (d) Does not have a malfunctioning exhaust system. 29-1-1203 Applicability to other local laws This part 12 shall not be construed to affect the enactment or enforcement of laws generally regulating traffic, parking, excessive noise, or other adverse conditions affecting the health, welfare, and safety of citizens of a local government. 29-20-105.6 Notification to military installations by local governments of land use change — legislative declaration — definitions (1) The general assembly hereby fords, determines, and declares that it is desirable for local governments in the state to cooperate with military installations located within the state in order to encourage compatible land use, help prevent incompatible urban encroachment upon military installations, and facilitate the continued presence of major military installations within the state (2) - (3) (4) Upon submission of the information required to be provided pursuant to subsection (3) of this section, the military installation shall have fourteen business days within which to review the information and submit comments to the local government on the impact the proposed changes may have on the mission of the military installation. Such comments may include: (a) If the military installation has an airfield, whether the proposed changes will be compatible with the safety and noise standards contained in the air installation compatible use zone recommended by United States department of defense instruction 4165.57 for that airfield; (b) Whether the proposed changes are compatible with the installation environmental noise management program of the military installation; 5) — (6) 8 30-11-104 County buildings — acquisition of land or buildings by eminent domain authorized (1) (a) Each county, at its own expense, shall provide a suitable courthouse, a sufficient jail, and other necessary county buildings and keep them in repair. (b) For any penal institution that begins operations on or after August 30, 1999, that is operated by or under contract with a county, the county may establish standards relating to space requirements, furnishing requirements, required special use areas or special management housing, and environmental condition requirements, including but not limited to standards pertaining to light, ventilation, temperature, and noise level. If a county does not adopt standards pursuant to this paragraph (b), the penal institution operated by or under contract with the county shall be subject to the standards adopted by the department of public health and environment pursuant to section 25-1.5-101 (1) (i), C.R.S. In establishing such standards, the county is strongly encouraged to consult with national associations that specialize in policies relating to correctional institutions 30-15-401 General regulations (1) In addition to those powers granted by sections 30-11-101 and 30-11-107 and by parts 1, 2, and 3 of this article, the board of county commissioners has the power to adopt ordinances for control or licensing of those matters of purely local concern which are described in the following enumerated powers: (a) — (1) (m) (I) In addition to the authority given counties in article 12 of title 25, C.R.S., to enact ordinances which regulate noise on public and private property except as provided in subparagraph (II) of this paragraph (m); prohibit the operation of any vehicle that is not equipped with a muffler in constant operation and is not properly maintained to prevent an increase in the noise emitted by the vehicle above the noise emitted when the muffler was originally installed; and prohibit the operation of any vehicle having a muffler that has been equipped or modified with a cutoff and bypass or any similar device or modification. For the purposes of this paragraph (m), "vehicle" shall have the same meaning as that set forth in section 42-1-102 (112), C.R.S (II) Ordinances enacted to regulate noise on public and private property pursuant to subparagraph (I) of this paragraph (m) shall not apply to: (A) Property used for purposes which are exempt, pursuant to section 25-12- 103, C.R.S., from noise abatement; and (B) Property used for: Manufacturing, industrial, or commercial business purposes; public utilities regulated pursuant to title 40, C.R.S.; and oil and gas production subject to the provisions of article 60 of title 34, C.R.S. 33-13-108 Prohibited vessel operations (1) (a) No person shall operate or give permission for the operation of a vessel: (II) Which emits noise in excess of the permissible level established in standards promulgated by the board in accordance with article 4 of title 24, C.R.S 9 42-1-302 Legislative declaration (1) The general assembly hereby finds and declares that: (a) — (b) (c) Long -duration idling of truck engines annually consumes over one billion gallons of diesel fuel and annually emits eleven million tons of carbon dioxide, two hundred thousand tons of oxides of nitrogen, and five thousand tons of particulate matter into the air. Idling can increase engine maintenance costs, shorten engine life, adversely affect driver well-being, and create elevated noise levels 42-4-213 Audible and visual signals on emergency vehicles (1) Except as otherwise provided in this section or in section 42-4-222 in the case of volunteer fire vehicles and volunteer ambulances, every authorized emergency vehicle shall, in addition to any other equipment and distinctive markings required by this article, be equipped as a minimum with a siren and a horn. Such devices shall be capable of emitting a sound audible under normal conditions from a distance of not less than five hundred feet 42-4-224 Horns or warning devices (1) Every motor vehicle, when operated upon a highway, shall be equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than two hundred feet, but no horn or other warning device shall emit an unreasonably loud or harsh sound, except as provided in section 42-4-213 (1) in the case of authorized emergency vehicles or as provided in section 42-4-222. The driver of a motor vehicle, when reasonably necessary to ensure safe operation, shall give audible warning with the horn but shall not otherwise use such horn when upon a highway (2) No vehicle shall be equipped with nor shall any person use upon a vehicle any audible device except as otherwise permitted in this section. It is permissible but not required that any vehicle be equipped with a theft alarm signal device which is so arranged that it cannot be used by the driver as a warning signal unless the alarm device is a required part of the vehicle. Nothing in this section is meant to preclude the use of audible warning devices that are activated when the vehicle is backing. Any authorized emergency vehicle may be equipped with an audible signal device under section 42-4-213 (1), but such device shall not be used except when such vehicle is operated in response to an emergency call or in the actual pursuit of a suspected violator of the law or for other special purposes, including, but not limited to, funerals, parades, and the escorting of dignitaries. Such device shall not be used for such special purposes unless the circumstances would not lead a reasonable person to believe that such vehicle is responding to an actual emergency. (3) No bicycle, electrical assisted bicycle, or low -power scooter shall be equipped with nor shall any person use upon such vehicle a siren or whistle. 42-4-225 Mufflers — prevention of noise (1) Every motor vehicle subject to registration and operated on a highway shall at all times be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and no such muffler or exhaust system shall be equipped with a cut- off, bypass, or similar device. No person shall modify the exhaust system of a motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle above that 10 emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all of the requirements of this section. (1.5) Any commercial vehicle, as defined in section 42-4-235 (1) (a), subject to registration and operated on a highway, that is equipped with an engine compression brake device is required to have a muffler (2) A muffler is a device consisting of a series of chamber or baffle plates or other mechanical design for the purpose of receiving exhaust gas from an internal combustion engine and effective in reducing noise (3) Any person who violates subsection (1) of this section commits a class B traffic infraction. Any person who violates subsection (1.5) of this section shall, upon conviction, be punished by a fine of five hundred dollars. Fifty percent of any fine for a violation of subsection (1.5) of this section occurring within the corporate limits of a city or town, or within the unincorporated area of a county, shall be transmitted to the treasurer or chief financial officer of said city, town, or county, and the remaining fifty percent shall be transmitted to the state treasurer, credited to the highway users tax fund, and allocated and expended as specified in section 43-4-205 (5.5) (a), C.R.S. (4) This section shall not apply to electric motor vehicles. 11 Weld County Right to Farm Statement Weld County is one of the most productive agricultural counties in the United States, typically ranking in the top ten counties in the country in total market value of agricultural products sold. The rural areas of Weld County may be open and spacious, but they are intensively used for agriculture. Persons moving into a rural area must recognize and accept there are drawbacks, including conflicts with long-standing agricultural practices and a lower level of services than in town. Along with the drawbacks come the incentives which attract urban dwellers to relocate to rural areas: open views, spaciousness, wildlife, lack of city noise and congestion, and the rural atmosphere and way of life. Without neighboring farms, those features which attract urban dwellers to rural Weld County would quickly be gone forever. Agricultural users of the land should not be expected to change their long-established agricultural practices to accommodate the intrusions of urban users into a rural area. Well -run agricultural activities will generate off -site impacts, including noise from tractors and equipment; slow -moving farm vehicles on rural roads; dust from animal pens, field work, harvest and gravel roads; odor from animal confinement, silage and manure; smoke from ditch burning; flies and mosquitoes; hunting and trapping activities; shooting sports, legal hazing of nuisance wildlife; and the use of pesticides and fertilizers in the fields, including the use of aerial spraying. It is common practice for agricultural producers to utilize an accumulation of agricultural machinery and supplies to assist in their agricultural operations. A concentration of miscellaneous agricultural materials often produces a visual disparity between rural and urban areas of the County. Section 35-3.5-102, C.R.S., provides that an agricultural operation shall not be found to be a public or private nuisance if the agricultural operation alleged to be a nuisance employs methods or practices that are commonly or reasonably associated with agricultural production. Water has been, and continues to be, the lifeline for the agricultural Community. It is unrealistic to assume that ditches and reservoirs may simply be moved "out of the way" of residential development. When moving to the County, property owners and residents must realize they cannot take water from irrigation ditches, lakes or other structures, unless they have an adjudicated right to the water. Weld County covers a land area of approximately four thousand (4,000) square miles in size (twice the size of the State of Delaware) with more than three thousand seven hundred (3,700) miles of state and County roads outside of municipalities. The sheer magnitude of the area to be served stretches available resources. Law enforcement is based on responses to complaints more than on patrols of the County, and the distances which must be traveled may delay all emergency responses, including law enforcement, ambulance and fire. Fire protection is usually provided by volunteers who must leave their jobs and families to respond to emergencies. County gravel roads, no matter how often they are bladed, will not provide the same kind of surface expected from a paved road. Snow removal priorities mean that roads from subdivisions to arterials may not be cleared for several days after a major snowstorm. Services in rural areas, in many cases, will not be equivalent to municipal services. Rural dwellers must, by necessity, be more self-sufficient than urban dwellers. People are exposed to different hazards in the County than in an urban or suburban setting. Farm equipment and oil field equipment, ponds and irrigation ditches, electrical power for pumps and center pivot operations, high-speed traffic, sand burs, puncture vines, territorial farm dogs and livestock and open burning present real threats. Controlling children's activities is important, not only for their safety, but also for the protection of the farmer's livelihood. (Weld. County Code Ordinance 2002-6; Weld County Code Ordinance 2008-13) 2/22/2017 General Facts and Concepts about Ground Water Sustainabilitv of Ground -Water Resources —Circular 1186 GENERAL FACTS AND CONCEPTS ABOUT GROUND WATER The following review of some basic facts and concepts about ground water serves as background for the discussion of ground -water sustainability. • Ground water occurs almost everywhere beneath the land surface. The widespread occurrence of potable ground water is the reason that it is used as a source of water supply by about one-half the population of the United States, including almost all of the population that is served by domestic water -supply systems. • Natural sources of freshwater that become ground water are (1) areal recharge from precipitation that percolates through the unsaturated zone to the water table (Figure 4) and (2) losses of water from streams and other bodies of surface water such as lakes and wetlands. Areal recharge ranges from a tiny fraction to about one-half of average annual precipitation. Because areal recharge occurs over broad areas,even small average rates of recharge (for example, a few inches per year) represent significant volumes of inflow to ground water. Streams and other surface -water bodies may either gain water from ground water or lose (recharge) water to ground water. Streams commonly are a significant source of recharge to ground water downstream from mountain fronts and steep hillslopes in arid and semiarid areas and in karst terrains (areas underlain by limestone and other soluble rocks). https://pubs.usgs.gov/circ/circ1186/html/gem facts.html 1/7 2/22/2017 General Facts and Concepts about Ground Water spralon Figure 4. The unsaturated zone, capillary fringe, water table, and saturated zone. Water beneath the land surface occurs in two principal zones, the unsaturated zone and the saturated zone. In the unsaturated zone, the spaces between particle grains and the cracks in rocks contain both air and water. Although a considerable amount of water can be present in the unsaturated zone, this water cannot be pumped by wells because capillary forces hold it too tightly. In contrast to the unsaturated zone, the voids in the saturated zone are completely filled with water. The approximate upper surface of the saturated zone is referred to as the water table. Water in the saturated zone below the water table is referred to as ground water. Below the water table, the water pressure is high enough to allow water to enter a well as the water level in the well is lowered by pumping, thus permitting ground water to be withdrawn for use. Between the unsaturated zone and the water table is a transition zone, the capillary fringe. In this zone, the voids are saturated or almost saturated with water that is held in place by capillary forces. • The top of the subsurface ground -water body, the water table, is a surface, generally below the land surface, that fluctuates seasonally and from year to year in response to changes in recharge from precipitation and surface -water bodies. On a regional scale, the configuration of the water table commonly is a subdued replica of the land -surface topography. The depth to the water table varies. In some settings, it can be at or near the land surface; for example, near bodies of surface water in humid climates. In other settings, the depth to the water table can be hundreds of feet below land surface. • Ground water commonly is an important source of surface water. The contribution of ground water to total streamflow varies widely among streams, but hydrologists estimate the average contribution is somewhere between 40 and 50 percent in small and medium-sized https://pubs.usgs.gov/circ/circ1186/html/gen facts.htm I 2/7 2/22/2017 General Facts and Concepts about Ground Water streams. Extrapolation of these numbers to large rivers is not straightforward; however, the ground -water contribution to all streamflow in the United States may be as large as 40 percent. Ground water also is a major source of water to lakes and wetlands. • Ground water serves as a large subsurface water reservoir. Of all the freshwater that exists, about 75 percent is estimated to be stored in polar ice and glaciers and about 25 percent is estimated to be stored as ground water. Freshwater stored in rivers, lakes, and as soil moisture amounts to less than 1 percent of the world's freshwater. The reservoir aspect of some large ground -water systems can be a key factor in the development of these systems. A large ratio of total ground -water storage either to ground -water withdrawals by pumping or to natural discharge is one of the potentially useful characteristics of a ground -water system and enables water supplies to be maintained through long periods of drought. On the other hand, high ground -water use in areas of little recharge sometimes causes widespread declines in ground -water levels and a significant decrease in storage in the ground -water reservoir. • Velocities of ground -water flow generally are low and are orders of magnitude less than velocities of streamflow. The movement of ground water normally occurs as slow seepage through the pore spaces between particles of unconsolidated earth materials or through networks of fractures and solution openings in consolidated rocks. A velocity of 1 foot per day or greater is a high rate of movement for ground water, and ground -water velocities can be as low as 1 foot per year or 1 foot per decade. In contrast, velocities of streamflow generally are measured in feet per second. A velocity of 1 foot per second equals about 16 miles per day. The low velocities of ground- water flow can have important implications, particularly in relation to the movement of contaminants. • Under natural conditions, ground water moves along flow paths from areas of recharge to areas of discharge at springs or along streams, lakes, and wetlands. Discharge also occurs as seepage to bays or the ocean in coastal areas, and as transpiration by plants whose roots extend to near the water table. The three-dimensional body of earth material saturated with moving ground water that extends from areas of recharge to areas of discharge is referred to as a ground -water -flow system (Figure 5). EXPLANATION .t11M.3J liul, htst;F. Nigh hydraulic -conductivity aquifer hydra Lift -conductivity confining unit Very low hydraulic -conductivity bedrock Direction of ground: -water flow https://pubs.usgs.gov/circ/circ1186/html/gen facts.htm I 3/7 2/22/2017 General Facts and Concepts about Ground Water Figure 5. A local scale ground -water -flow system. In this local scale ground -water -flow system,inflow of water from areal recharge occurs at the water table. Outflow of water occurs as (1), discharge to the atmosphere as ground -water evapotranspiration (transpiration by vegetation rooted at or near the water table or direct evaporation from the water table when it is at or close to the land surface) and (2) discharge of ground water directly through the streambed. Short, shallow flow paths originate at the water table near the stream. As distance from the stream increases, flow paths to the stream are longer and deeper. For long-term average conditions, inflow to this natural ground -water system must equal outflow. • The areal extent of ground -water -flow systems varies from a few square miles or less to tens of thousands of square miles. The length of ground -water -flow paths ranges from a few feet to tens, and sometimes hundreds, of miles. A deep ground -water -flow system with long flow paths between areas of recharge and discharge may be overlain by, and in hydraulic connection with, several shallow, more local, flow systems (Figure 6). Thus, the definition of a ground -water -flow system is to some extent subjective and depends in part on the scale of a study. Unsafumled zone Water fable Surfacwalor body EY:PLANATIONJ High ilrydrauli-ccnduciivity aquifer trydraulic•coradtar;tivil; cnrrlisri it rnaif V�ty' 10.151lr)�cif u�-c�ir"rlucl€u11y b rcIs K Di ree':1ran cf groom d -water flow Local gro'.mli ww'alor sulssyslam Stibtegimal yrsund,Wal6r autiSyStant fl o o ral grr and -water suba ratem, https://pubs.usgs.gov/circ/circ1186/html/gen facts.html 4/7 2/22/2017 General Facts and Concepts about Ground Water Figure 6. A regional ground -water -flow system that comprises subsystems at different scales and a complex hydrogeologic framework. (Modified from Sun, 1986.) Significant features of this depiction of part of a regional ground -water -flow system include (1) local ground -water subsystems in the upper water -table aquifer that discharge to the nearest surface -water bodies (lakes or streams) and are separated by ground -water divides beneath topographically high areas; (2) a subregional ground -water subsystem in the water -table aquifer in which flow paths originating at the water table do not discharge into the nearest surface - water body but into a more distant one; and (3) a deep, regional ground -water -flow subsystem that lies beneath the water -table subsystems and is hydraulically connected to them. The hydrogeologic framework of the flow system exhibits a complicated spatial arrangement of high hydraulic -conductivity aquifer units and low hydraulic -conductivity confining units. The horizontal scale of the figure could range from tens to hundreds of miles. • The age (time since recharge) of ground water varies in different parts of ground -water -flow systems. The age of ground water increases steadily along a particular flow path through the ground -water -flow system from an area of recharge to an area of discharge. In shallow, local -scale flow systems, ages of ground water at areas of discharge can vary from less than a day to a few hundred years. In deep, regional flow systems with long flow paths (tens of miles), ages of ground water may reach thousands or tens of thousands of years. • Surface and subsurface earth materials are highly variable in their degree of particle consolidation, the size of particles, the size and shape of pore or open spaces between particles and between cracks in consolidated rocks, and in the mineral and chemical composition of the particles. Ground water occurs both in loosely aggregated and unconsolidated materials, such as sand and gravel, and in consolidated rocks, such as sandstone, limestone, granite, and basalt. • Earth materials vary widely in their ability to transmit and store ground water. The ability of earth materials to transmit ground water (quantified as hydraulic conductivity) varies by orders of magnitude and is determined by the size, shape, interconnectedness, and volume of spaces between solids in the different types of materials. For example, the interconnected pore spaces in sand and gravel are larger than those in finer grained sediments, and the hydraulic conductivity of sand and gravel is larger than the hydraulic conductivity of the finer grained materials. The ability of earth materials to store ground water also varies among different types of materials. For example, the volume of water stored in cracks and fractures per unit volume of granite is much smaller than the volume stored per unit volume in the intergranular spaces between particles of sand and gravel. • Wells are the principal direct window to study the subsurface environment. Not only are wells used to pump ground water for many purposes, they also provide essential information about conditions in the subsurface. For example, wells (1) allow direct measurement of water levels in the well, (2) allow sampling of ground water for chemical analysis, (3) provide access for a large array of physical measurements in the borehole (borehole geophysical logging) that give indirect information on the properties of the fluids and earth materials in the neighborhood of the well, and (4) allow hydraulic testing (aquifer tests) of the earth materials in the neighborhood of the well to determine local values of their transmitting and storage properties. In addition, earth materials can be sampled directly at any depth during the drilling of the well. • Pumping ground water from a well always causes (1) a decline in ground -water levels (heads; see Figure 7) at and near the well, and (2) a diversion to the pumping well of ground water that was moving slowly to its natural, possibly distant, area of discharge. Pumping of a single well typically has a local effect on the ground -water -flow system. Pumping of many wells (sometimes hundreds or thousands of wells) in large areas can have regionally significant effects on ground -water systems. https://pubs.usgs.gov/circ/circ1186/html/gem facts.htm I 5/7 2/22/2017 General Facts and Concepts about Ground Water E' R 4th 40 Figure 7. The concept of "hydraulic head"or'head"ata point in an aquifer. Consider the elevations above sea level at points A and Bin an unconfined aquifer and C in a confined aquifer. Now consider the addition of wells with short screened intervals at these three points. The vertical distance from the water level in each well to sea level is a measure of hydraulic head or head, referenced to a common datum at each point A, B, and C, respectively. Thus, head ata point in an aquifer is the sum of(a) the elevation of the point above a common datum, usually sea level, and (b) the height above the point of a column of static water in a well that is screened at the point. When we discuss declines or rises in ground -water levels in a particular aquifer in this report, we are referring to changes in head or water levels in wells that are screened or have an open interval in that aquifer. BOX A • Ground -water heads respond to pumping to markedly different degrees in unconfined and confined aquifers. Pumping the same quantity of water from wells in confined and in unconfined aquifers initially results in much larger declines in heads over much larger areas for the confined aquifers (see Box A). This is because less water is available from storage in confined aquifers compared to unconfined aquifers. At a later time, as the amount of water derived from storage decreases and the system approaches equilibrium, the response of the system no longer depends upon being confined or unconfined. The amount of head decline at equilibrium is a function of the transmitting properties of the aquifers and confining units, discharge rate of the well, and distance to ground -water -system boundaries. Many aquifers, such as the upper part of the deep flow subsystem shown in Figure 6, exhibit a response to pumping that is intermediate between a completely confined and a completely unconfined aquifer system. https://pubs.usgs.gov/circ/circ1186/html/gen facts.html 6/7 2/22/2017 General Facts and Concepts about Ground Water Back to Contents Back to Introduction Next --Box A https://pubs.usgs.gov/circ/circ1186/html/gen facts.html 7/7 Zack Williams Account Manager c: (303) 515-1735 zwilliamsO!pnncipleenergyseI ccs.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation.' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20'h St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control.com www. drillingnoisecontrol. com Zack Williams Account Manager c: (303) 515=1735 zvilliams@pnncipleenergyservices.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford,TX 76088 (855) 86 NOISE or (855) 866-6473 4689 W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. 1-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control.com www.drillingnoiseconttol.com Zack Williams Account Manager c:(303)515-1735 euilliannstdprincipleencrgryservices.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation"' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20`h St. Unit C2. Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control.com www.drillingnoisecontrol.com • Zack Williams Account Manager c:(303)515=1735 znilliams(aprincipleenergysery ces.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation'' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. . Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control AA(lIi l Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www. en vironmental-noise-control.com www.drillingnoisecontrol.com ZackWilliams Account Manager c: (303) 515-1735 zwilliams@pnncipleenergyservices.com IPLE ENERGY SERVICES Well Keep it Quiet Oilfield Noise Mitigation' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689 W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmen tal-noise-control.com www.drillingnoisecontrol.com Zack Williams Account Manager c:(303)515-1735 zwilliamsLiilpnncipleenergyservices.com IPLE ENERGY SERVICES We'll Keep It Quiet Oilfield Noise Mitigation' • Drilling • Completions • Production Behrens &_Associates, Inc. Environmental Noise Control IJ North American Headquarters 201 West Ranch Ct. . Weatherford,TX 76088 (855) 86 NOISE or (855) 866-6473 4689 W. 20'h St. Unit C2 • Greeley. CO 80634 Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control. com www.drillingnoisecontrol.com Zack Williams Account Manager c: (303)515=1735 zwilliams@piincipleenergyservices.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation' • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control V Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmen tal-noise-control.com www.drillingnoisecontrol.com Zack Williams Account Manager c:(303)515=1735 zwilliams a!principleenergyscrviccs.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation'" • Drilling • Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control.com www.drillingnoisecontrol.com Zack Williams Account Manager c:(3031515-1735 zwilliams aprincipleenergyservices.com IPLE ENERGY SERVICES We'll Keep it Quiet Oilfield Noise Mitigation"' • Drilling Completions • Production North American Headquarters 201 West Ranch Ct. • Weatherford, TX 76088 (855) 86 NOISE or (855) 866-6473 4689W. 20th St. Unit C2 • Greeley. CO 80634 Behrens & Associates, Inc. Environmental Noise Control Andrew Truitt Rocky Mountains Area Acoustical Engineer 9536 E. I-25 Frontage Road, Longmont CO 80504 Office: 970-535-9000 • Fax: 970-549-0700 • Cell: 205-454-4742 atruitt@baenc.com www.environmental-noise-control.com www.drillingnoisecontrol.com WRAP Fugitive Dust Handbook Prepared for: Western Governors' Association 1515 Cleveland Place, Suite 200 Denver, Colorado 80202 Prepared by: Countess Environmental 4001 Whitesail Circle Westlake Village, CA 91361 (WGA Contract No. 30204-111) September 7, 2006 TABLE OF CONTENTS Preface Executive S Chapter 1. Chapter 2. Chapter 3. Chapter 4. Chapter 5. Chapter 6. Chapter 7. Chapter 8. Chapter 9. Chapter 10. Chapter 11 Chapter 12 Chapter 13 Chapter 14 Glossary Appendix A. Appendix B. Appendix C. Appendix D. ummary Introduction Agricultural Tilling Construction and Demolition Materials Handling Paved Roads Unpaved Roads Agricultural Wind Erosion Open Area Wind Erosion Storage Pile Wind Erosion Agricultural Harvesting Mineral Products Industry Abrasive Blasting Livestock Husbandry Miscellaneous Minor Fugitive Dust Sources Emission Quantification Techniques Estimated Costs of Fugitive Dust Control Measures Methodology for Calculating Cost -Effectiveness of Fugitive Dust Control Measures Fugitive PM10 Management Plan PREFACE In 2004 the Western Regional Air Partnership's (WRAP) Dust Emissions Joint Forum (DEJF) selected Countess Environmental to prepare a fugitive dust handbook and an associated website (www.wrapair.org/forums/dejf/fdh) for accessing the information contained in the handbook. The material presented in the original handbook released on November 15, 2004 addressed the estimation of uncontrolled fugitive dust emissions and emission reductions achieved by demonstrated control techniques for eight major fugitive dust source categories. In 2006 WRAP hired Countess Environmental to update the handbook. The updates included revising each chapter in the handbook to reflect the new PM2.5/PM10 ratios developed for WRAP by the Midwest Research Institute (MRI) in 2005, addressing four additional major fugitive dust source categories as well as several minor source categories, and updating the existing chapters. The material in this handbook focuses on fugitive dust emissions "at the source" and does not evaluate factors related to the transport and impact of emissions on downwind locations where ambient air monitoring occurs. The methods for estimation of dust emissions rely primarily on AP -42 with additional references to alternative methods adopted by state and local control agencies in the WRAP region. With regard to emission factor correction parameters, source extent/activity levels, control efficiencies for demonstrated control techniques, and emission reductions by natural mitigation and add-on control measures, sources of data are identified and default values are provided in tables throughout the handbook. Graphs, charts, and tables are provided throughout the handbook to assist the end user. The handbook: (a) compiles technical and policy evaluations for the benefit of WRAP members, stakeholders, and other interested parties when addressing specific air quality issues and when developing regional haze implementation plans; (b) incorporates available information from both the public (federal, state and local air quality agencies) and private sectors (e.g., reports addressing options to reduce fugitive dust emissions in areas of the country classified as nonattainment for PM10); and (c) serves as a comprehensive reference resource tool of currently available technical information on emission estimation methodologies and control measures for the following twelve fugitive dust source categories: agricultural tilling, agricultural harvesting, construction and demolition, materials handling, paved roads, unpaved roads, mineral products industry, abrasive blasting, livestock husbandry, and windblown dust emissions from agricultural fields, material storage piles, and exposed open areas. This handbook is not intended to suggest any preferred method to be used by stakeholders in preparation of SIPs and/or Conformity analyses but rather to outline the most commonly adopted methodologies currently used in the US. The information contained in this handbook has been derived from a variety of sources each with its own accuracy and use limitations. Because many formulae and factors incorporate default values that have been derived for average US conditions, area specific factors should be used whenever they are available. Additionally, the 1 input terms (commonly referred to as "correction factors") used in any given emission factor equation presented in this handbook were obtained using a specific test methodology and are designed to give an estimate of the emission from a specific activity or source under specific conditions. As a result the emission estimate must be used appropriately in any downstream application such as dispersion modeling of primary PM emissions. It is important to note that EPA's criteria for exceedances, violations, and model calibration and validation are based on ambient data from the National Ambient Air Monitoring Sites. It should be further noted that estimates of the relative contribution of fugitive dust to ambient PM concentrations based on chemical analysis of exposed filters are usually much lower than that based on emission inventory estimates, in some cases by a factor of 4. Part of this discrepancy between ambient measurements and emission estimates is due to the near source deposition losses of freshly generated fugitive dust emissions. It is not an objective of this handbook to resolve this modeling discrepancy issue. It is the role of modelers to incorporate deposition losses into their dispersion models and to account for the formation of secondary PM, which in many areas of the country are responsible for an overwhelming contribution to exceedances of the federal PM NAAQS. Applicability to Tribes The Regional Haze Rule explicitly recognizes the authority of tribes to implement the provisions of the Rule, in accordance with principles of Federal Indian law, and as provided by the Clean Air Act §301(d) and the Tribal Authority Rule (TAR) (40 CFR §§49.1— .11). Those provisions create the following framework: 1. Absent special circumstances, reservation lands are not subject to state jurisdiction. 2. Federally recognized tribes may apply for and receive delegation of federal authority to implement CAA programs, including visibility regulation, or "reasonably severable" elements of such programs (40 CFR §§49.3, 49.7). The mechanism for this delegation is a Tribal Implementation Plan (TIP). A reasonably severable element is one that is not integrally related to program elements that are not included in the plan submittal, and is consistent with applicable statutory and regulatory requirements. 3. The Regional Haze Rule expressly provides that tribal visibility programs are "not dependent on the strategies selected by the state or states in which the tribe is located" (64. Fed. Reg. 35756), and that the authority to implement §309 TIPs extends to all tribes within the GCVTC region (40 CFR §51.309(d)(12). 4. The EPA has indicated that under the TAR tribes are not required to submit §309 TIPs by the end of 2003; rather they may choose to opt -in to §309 programs at a later date (67 Fed. Reg. 30439). 5. Where a tribe does not seek delegation through a TIP, EPA, as necessary and appropriate, will promulgate a Federal Implementation Plan (FIP) within reasonable timeframes to protect air quality in Indian country (40 CFR §49.11). EPA is committed to consulting with tribes on a 2 government -to -government basis in developing tribe -specific or generally applicable TIPs where necessary (see, e.g., 63 Fed. Reg.7263-64). It is our hope that the findings and recommendations of this handbook will prove useful to tribes, whether they choose to submit full or partial 308 or 309 TIPs, or work with EPA to develop FIPs. We realize that the amount of modification necessary will vary considerably from tribe to tribe and we have striven to ensure that all references to tribes in the document are consistent with principles of tribal sovereignty and autonomy as reflected in the above framework. Any inconsistency with this framework is strictly inadvertent and not an attempt to impose requirements on tribes which are not present under existing law. Tribes, along with states and federal agencies, are full partners in the WRAP, having equal representation on the WRAP Board as states. Whether Board members or not, it must be remembered that all tribes are governments, as distinguished from the "stakeholders" (private interest) which participate on Forums and Committees but are not eligible for the Board. Despite this equality of representation on the Board, tribes are very differently situated than states. There are over four hundred federally recognized tribes in the WRAP region, including Alaska. The sheer number of tribes makes full participation impossible. Moreover, many tribes are faced with pressing environmental, economic, and social issues, and do not have the resources to participate in an effort such as the WRAP, however important its goals may be. These factors necessarily limit the level of tribal input into and endorsement of WRAP products. The tribal participants in the WRAP, including Board members, Forum and Committee members and co-chairs, make their best effort to ensure that WRAP products are in the best interest of the tribes, the environment, and the public. One interest is to ensure that WRAP policies, as implemented by states and tribes, will not constrain the future options of tribes who are not involved in the WRAP. With these considerations and limitations in mind, the tribal participants have joined the state, federal, and private stakeholder interests in approving this handbook as a consensus document. 3 EXECUTIVE SUMMARY This fugitive dust handbook addresses the estimation of uncontrolled fugitive dust emissions and emission reductions achieved by demonstrated control techniques for twelve major and several minor fugitive dust source categories. The handbook focuses on fugitive dust emissions "at the source" and does not evaluate factors related to the transport and impact of emissions on downwind locations where ambient air monitoring occurs. The methods for estimating emissions draw (a) from established methods published by the USEPA, specifically AP -42: Compilation of Air Pollutant Emission Factors that are available from the Internet (www.epa.gov/ttn/chief/ap42), and (b) from alternate methods adopted by state and local air control agencies in the WRAP region such as the California Air Resources Board (www.arb.ca.gov/ei/areasrc/areameth.htm), Clark County, Nevada (www.co.clark.nv.us/air_quality), and Maricopa County, Arizona (www.maricopa.gov/envsvc/air). Sources of data are identified and default values for emission factor correction parameters, source extent/activity levels, control efficiencies, and emission reductions by natural mitigation and add-on control measures are provided in tables throughout the handbook. The handbook has several distinct features that give it a major advantage over the use of AP -42 or other resource documents. The handbook is a comprehensive document that contains all the necessary information to develop control strategies for major sources of fugitive dust. These features include: (a) extensive documentation of emission estimation methods adopted by both federal and state agencies as well as methods in the "developmental" stage; (b) detailed discussion of demonstrated control measures; (c) lists of published control efficiencies for a large number of fugitive dust control measures; (d) example regulatory formats adopted by state and local agencies in the WRAP region; (e) compliance tools to assure that the regulations are being followed; and (f) a detailed methodology for calculating the cost-effectiveness of different fugitive dust control measures, plus sample calculations for control measure cost-effectiveness for each fugitive dust source category. The handbook and associated website (www.wrapair.org/forums/dejf/fdh) are intended to: (a) support technical and policy evaluations by WRAP members, stakeholders, and other interested parties when addressing specific air quality issues and when developing regional haze implementation plans; (b) incorporate available information from both the public and private sectors that address options to reduce fugitive dust emissions in areas of the country classified as nonattainment for PMI0; and 1 (c) provide a comprehensive resource on emission estimation methodologies and control measures for the following twelve fugitive dust source categories: agricultural tilling, agricultural harvesting, construction and demolition, materials handling, paved roads, unpaved roads, minerals products industry, abrasive blasting, livestock husbandry, and windblown dust emissions from agricultural fields, material storage piles, and exposed open areas. The handbook contains separate, stand-alone chapters for each of the twelve major fugitive dust source categories identified above. Because the chapters are meant to stand alone, there is some redundancy between chapters. Each chapter contains a discussion of characterization of the source emissions, established emissions estimation methodologies, demonstrated control techniques, regulatory formats, compliance tools, a sample control measure cost-effectiveness calculation, and references. A separate chapter addressing several minor fugitive dust source categories and several appendices are also included in the handbook. Appendix A contains a discussion of test methods used to quantify fugitive dust emission rates. Appendix B contains cost information for demonstrated control measures. Appendix C contains a step -wise method to calculate the cost- effectiveness of different fugitive dust control measures. Appendix D contains a brief discussion of fugitive PM10 management plans and record keeping requirements mandated by one of the air quality districts within the WRAP region. A list of fugitive dust control measures that have been implemented by jurisdictions designated by the USEPA as nonattainment for federal PM10 standards is presented in the table below. The published PM10 control efficiencies for different fugitive dust control measures vary over relatively large ranges as reflected in the table. The user of the handbook is cautioned to review the assumptions included in the original publications (i.e., references identified in each chapter of the handbook) before selecting a specific PM10 control efficiency for a given control measure. It should be noted that Midwest Research Institute (MRI) found no significant differences in the measured control efficiencies for the PM2.5 and PM10 size fractions of unpaved road emissions based on repeated field measurements of uncontrolled and controlled emissions. Thus, without actual published PM2.5 control efficiencies, the user may wish to utilize the published PM10 values for both size fractions. Many control cost-effectiveness estimates were reviewed in preparation of this handbook. Some of these estimates contain assumptions that are difficult to substantiate and often appear unrealistic. Depending on which assumptions are used, the control cost- effectiveness estimates can vary by one to two orders of magnitude. Thus, rather than presenting existing cost-effectiveness estimates, the handbook presents a detailed methodology to calculate the cost-effectiveness of different fugitive dust control measures. This methodology is presented in Appendix C. The handbook user is advised to calculate the cost-effectiveness values for different fugitive dust control options based on current cost data and caveats that are applicable to the particular situation. 2 Fugitive Dust Control Measures Applicable for the WRAP Region Source Category Control Measure Published PMIO Control Efficiency Agricultural Tilling Reduce tilling during high winds 1 — 5% Roughen surface 15 — 64% Modify equipment 50% Employ sequential cropping 50% Increase soil moisture 90% Use other conservation management practices 25 - 100% Agricultural Harvesting Limited activity during high winds 5 — 70% Modify equipment 50% Night farming 10% New techniques for drying fruit 25 —60% Construction/Demolition Water unpaved surfaces 10 — 74% Limit on -site vehicle speed to 15 mph 57% Apply dust suppressant to unpaved areas 84% Prohibit activities during high winds 98% Materials Handling Implement wet suppression 50 — 90% Erect 3 -sided enclosure around storage piles 75% Cover storage pile with a tarp during high winds 90% Paved Roads Sweep streets 4 — 26% Minimize trackout 40 — 80% Remove deposits on road ASAP > 90% Unpaved Roads Limit vehicle speed to 25 mph 44% Apply water 10 — 74% Apply dust suppressant 84% Pave the surface >90% Mineral Products Industry Cyclone or muliclone 68 —79% Wet scrubber 78 —98% Fabric filter 99 — 99.8% Electrostatic precipitator 90 — 99.5% Abrasive Blasting Water spray 50 — 93% Fabric filter > 95% Livestock Husbandry Daily watering of corrals and pens > 10% Add wood chips or mulch to working pens > 10% Wind Erosion (agricultural, open area, and storage piles) Plant trees or shrubs as a windbreak 25% Create cross -wind ridges 24 — 93% Erect artificial wind barriers 4 — 88% Apply dust suppressant or gravel 84% Revegetate; apply cover crop 90% Water exposed area before high winds 90% 3 Chapter 1. Introduction 1.1 Background 1-1 1.2 Purpose of the Handbook 1-2 1.3 Dust Definition and Categorization Scheme 1-2 1.4 Factors Affecting Dust Emissions 1-5 1.5 Use of Satellite Imagery to Inventory Erodible Vacant Land 1-8 1.6 Emission Calculation Procedure 1-8 1.7 Emission Factors 1-10 1.8 Emission Control Options 1-11 1.9 Document Organization 1-13 1.10 References 1-14 This chapter describes the purpose for the preparation of this fugitive dust handbook; presents a summary of WRAP's fugitive dust definition and dust emissions categorization scheme; provides a brief overview/primer on fugitive dust that includes a summary of factors affecting dust emissions, an overview of emission calculation procedures (including a discussion of emission factors), and a discussion of options for controlling emissions; and summarizes the organizational structure of the handbook. This handbook does not address particulate emissions from wildfires or prescribed fires that are discussed in Section 13.1 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). For more information on particulate emissions from fires, the reader is directed to the WRAP's Fire Emissions Joint Forum at www.wrapair.org/forums/fejf. 1.1 Background Most of the more than 70 areas of the United States that have been unable to attain the national ambient -air quality standards (NAAQS) for PM10 (particles smaller than 10 µm in aerodynamic diameter) are in western states with significant emission contributions from fugitive dust sources. Fugitive dust sources may be separated into two broad categories: process sources and open dust sources. Process sources of fugitive emissions are those associated with industrial operations such as rock crushing that alter the characteristics of a feed material. Open dust sources are those that generate non -ducted emissions of solid particles by the forces of wind or machinery acting on exposed material. Open dust sources include industrial sources of particulate emissions associated with the open transport, storage, and transfer of raw, intermediate, and waste aggregate materials, and nonindustrial sources such as unpaved roads and parking lots, paved streets and highways, heavy construction activities, and agricultural tilling. On a nationwide basis, fugitive dust consists mostly of soil and other crustal materials. However, fugitive dust may also be emitted from powdered or aggregate materials that have been placed in open storage piles or deposited on the ground or roadway surfaces by spillage or vehicle trackout. Dust emissions from paved roadways contain tire and break wear particles in addition to resuspended road surface dust composed mostly of crustal geological material. Generic categories of open dust sources include: Agricultural Tilling and Harvesting Construction and Demolition (Buildings, Roads) Materials Handling Paved Travel Surfaces Unpaved Travel Surfaces Minerals Products Industry (Metallic Ores, Non-metallic Ores, Coal) Abrasive Blasting Livestock Husbandry (Dairies, Cattle Feedlots) Wind Erosion of Exposed Areas (Agricultural Fields, Open Areas, Storage Piles) 1.2 Purpose of the Handbook In early 2004 the Western Regional Air Partnership's (WRAP) Dust Emissions Joint Forum (DEJF) selected the Countess Environmental project team composed of senior scientists/consultants from Countess Environmental and Midwest Research Institute to prepare a fugitive dust handbook and a website (www.wrapair.org/forums/dejf/fdh) for accessing the information contained in the handbook. The handbook and website are intended to: (a) be used for technical and policy evaluations by WRAP members, stakeholders, and other interested parties when addressing specific air quality issues and when developing regional haze implementation plans; (b) incorporate available information from both the public and private sectors that address options to reduce fugitive dust emissions in areas of the country classified as nonattainment for PM10; and (c) serve as a comprehensive reference resource tool that will provide technical information on emission estimation methodologies and control measures for all of the major and several minor fugitive dust source categories. The material presented in the original handbook released on November 15, 2004 addressed the estimation of uncontrolled fugitive dust emissions and emission reductions achieved by demonstrated control techniques for eight major fugitive dust source categories. In 2006 WRAP hired Countess Environmental to update the handbook. The updates included revising each chapter in the handbook to reflect the new PM2.5/PM 10 ratios developed for WRAP by the Midwest Research Institute (MRI) in 2005, addressing four additional major fugitive dust source categories as well as several minor source categories, and updating the existing chapters. 1.3 Dust Definition and Categorization Scheme The WRAP Dust Emissions Joint Forum (DEJF) adopted a definition of dust and fugitive dust on October 21, 2004 that included developing criteria for separating anthropogenic dust from dust of natural origin.' Dust was defined as particulate matter which is or can be suspended into the atmosphere as a result of mechanical, explosive, or windblown suspension of geologic, organic, synthetic, or dissolved solids, and does not include non -geologic particulate matter emitted directly by internal and external combustion processes. Fugitive dust was defined as dust that could not reasonably pass through a stack, chimney, vent, or other functionally equivalent opening. The purpose of these definitions is to provide consistency when using the terms dust, fugitive dust, anthropogenic dust, and natural dust in the context of the federal regional haze rule. The distinction between anthropogenic dust and natural dust is made to: (a) clarify how the WRAP defines dust, its sources, and causes; (b) provide an operational definition for use in receptor- and emissions -based source apportionment techniques; and (c) identify and prioritize sources of dust which are most appropriate to control for purposes of improving visibility in Class I areas. 1-2 Natural and anthropogenic dust will often be indistinguishable and may occur simultaneously. For example, natural, barren areas will emit some dust during high wind events, but will emit more when the surface is disturbed by human activities. Hence, the dust from a disturbed, naturally barren area on a given day could be part natural and part anthropogenic. Any mitigation of dust for regional haze control would likely be focused on those anthropogenic sources which are most likely to contribute to visibility impairment in Class 1 areas and which are technically feasible and cost-effective to control. Sources that are already controlled or partially controlled may be technically infeasible or not cost-effective to control further. According to the WRAP's definition of dust, anthropogenic emissions do not include any emissions that would occur if the surface were not disturbed or altered beyond a natural range. Such emissions should be subtracted, if practicable, from the total dust emissions to determine the precise anthropogenic emission quantity. Examples of anthropogenic and natural dust categories in accordance with the WRAP's dust definition are provided in Tables 1-1 and 1-2. All mechanically suspended dust from human activities is classified as anthropogenic emissions, and windblown dust from lands not disturbed or altered by humans beyond a natural range is classified as natural emissions. For emissions from other sources, the emissions may be categorized as either anthropogenic or natural, depending on whether the mechanically -suspended emissions are due to indigenous or non -indigenous animals, and whether the windblown emissions are from surfaces disturbed by humans beyond a natural range or from surfaces which have not been disturbed by humans beyond a natural range. Table 1-1. WRAP Fugitive Dust Categorization Scheme for Mechanically Generated Dust Mechanically- and explosively -suspended solids and dissolved solids from activities including but not limited to: • Agriculture • Construction, mining, and demolition • Material handling, processing, and transport • Vehicular movement on paved and unpaved surfaces • Animal movement on surfaces which have been disturbed or altered by humans beyond a natural range • Animal movement on undisturbed or unaltered surfaces by a number of animals which is greater than native populations • Cooling towers • Movement of a number of indigenous animals on surfaces which have not been disturbed or altered by humans beyond a natural range • Natural landslides, rockslides, and avalanches • Solids and dissolved solids emitted by volcanoes, geysers, waterfalls, rapids, and other types of splashing • Extraterrestrial material and impacts 1-3 Table 1-2. WRAP Fugitive Dust Categorization Scheme for Windblown Dust Solids and dissolved solids entrained by wind passing Solids and dissolved solids entrained by wind over surfaces that have been disturbed or altered by passing over surfaces that have not been humans beyond a natural range. Such surfaces may disturbed or altered by humans beyond a natural include, but are not limited to: range. Such surfaces may include, but are not • Undeveloped lands limited to: • Construction and mining sites • Naturally -dry river and lake beds • Material storage piles, landfills, and vacant lots • Barren lands, sand dunes, and exposed rock • Agricultural crop, range, and forest lands • Natural water bodies (e.g., sea spray) • Roadways and parking lots Non-agricultural grass, range, and forest • Artificially -exposed beds of natural lakes and lands rivers Areas burned by natural fires (as defined by • Exposed beds of artificial water bodies the WRAP Policy for Categorizing Fire • Areas burned by anthropogenic fires (as defined Emissions) which have yet to be by the WRAP Policy for Categorizing Fire revegetated or stabilized Emissions) which have yet to be revegetated or stabilized Wind-blown particulate matter from sources created by natural events over 12 months ago, similar to EPA's natural events policy The WRAP's original dust characterization scheme broke down fugitive dust emissions into five categories ranging from 100% anthropogenic emissions (i.e., all mechanically -suspended dust from human activities except animal movement) to 100% natural emissions (i.e., windblown dust from lands not disturbed or altered by humans beyond a natural range), with three categories between these two extremes representing a mixture of anthropogenic and natural emissions. Environ developed an alternative dust characterization scheme for WRAP in 2005 that broke down fugitive dust emissions into three categories based on activity rather than a description of spatial location since very different dust sources may spatially co -exist at the same site.2 Environ's three categories are: Category 1: Category 2: Category 3: Purely anthropogenic sources (e.g., construction, mining, wind erosion and vehicle traffic on paved and unpaved roads, agricultural tilling and harvesting, wind erosion of agricultural fields, particle emissions from cooling towers). Purely natural sources (e.g., volcanic ash emissions, wind erosion of unstable soil following landslides, mineral particle emissions from wave action/sea spray). Natural sources that may be anthropogenically influenced (e.g., wind erosion and mechanical suspension of soil due to animal movement [both native and non-native], wind erosion of bare areas on natural lands [undisturbed versus previously disturbed], wind erosion of sediment from dried ephemeral water bodies [natural or anthropogenic]). 1-4 1.4 Factors Affecting Dust Emissions 1.3.1 Mechanically Generated Dust Mechanically generated emissions from open dust sources exhibit a high degree of variability from one site to another, and emissions at any one site tend to fluctuate widely. The site characteristics that cause these variations may be grouped into (a) properties of the exposed surface material from which the dust originates, and (b) measures of energy expended by machinery interacting with the surface. These site characteristics are discussed below. Surface Material Texture and Moisture. The dry -particle size distribution of the exposed soil or surface material determines its susceptibility to mechanical entrainment. The upper size limit for particles that can become suspended has been estimated at 75 µm in aerodynamic diameter.3 Conveniently, 75 µm in physical diameter is also the smallest particle size for which size analysis by dry sieving is practical.4 Particles passing a 200 -mesh screen on dry sieving are termed "silt". Note that for fugitive dust particles, the physical diameter and aerodynamic diameter are roughly equivalent because of the offsetting effects of higher density and irregular shape. Dust emissions are known to be strongly dependent on the moisture level of the mechanically disturbed material.3 Water acts as a dust suppressant by forming cohesive moisture films among the discrete grains of surface material. In turn, the moisture level depends on the moisture added by natural precipitation, the moisture removed by evaporation, and moisture movement beneath the surface. The evaporation rate depends on the degree of air movement over the surface, material texture and mineralogy, and the degree of compaction or crusting. The moisture -holding capacity of the air is also important, and it correlates strongly with the surface temperature. Vehicle traffic intensifies the drying process primarily by increasing air movement over the surface. Mechanical Equipment Characteristics. In addition to the material properties discussed above, it is clear that the physical and mechanical characteristics of materials handling and transport equipment also affect dust emission levels. For example, visual observation suggests (and field studies have confirmed) that vehicle emissions per unit of unpaved road length increase with increasing vehicle speed.3 For traffic on unpaved roads, studies have also shown positive correlations between emissions and (a) vehicle weight and (b) number of wheels per vehicle.5 Similarly, dust emissions from materials - handling operations have been found to increase with increasing wind speed and drop distance. 1.3.2 Wind Generated Dust Wind -generated emissions from open dust sources also exhibit a high degree of variability from one site to another, and emissions at any one site tend to fluctuate widely. The site characteristics that cause these variations may be grouped into (a) properties of the exposed surface material from which the dust originates, and 1-5 (b) measures of energy expended by wind interacting with the erodible surface. These site characteristics are discussed below. Surface Material Texture and Moisture. As in the case of mechanical entrainment, the dry -particle size distribution of the exposed soil or surface material determines its susceptibility to wind erosion. Wind forces move soil particles by three transport modes: saltation, surface creep, and suspension. Saltation describes particles, ranging in diameter from about 75 to 500 gm, that are readily lifted from the surface and jump or bounce within a layer close to the air -surface interface. Particles transported by surface creep range in diameter from about 500 to 1,000 gm. These large particles move very close to the ground, propelled by wind stress and by the impact of small particles transported by saltation. Particles smaller than about 75 gm in diameter move by suspension and tend to follow air currents. As stated above, the upper size limit of silt particles (75 gm in physical diameter) is roughly the smallest particle size for which size analysis by dry sieving is practical. The threshold wind speed for the onset of saltation, which drives the wind erosion process, is also dependent on soil texture, with 100-150 gm particles having the lowest threshold speed. Saltation provides energy for the release of particles in the PM 10 size range that typically are bound by surface forces to larger clusters. Dust emissions from wind erosion are known to be strongly dependent on the moisture level of the erodible material.6 The mechanism of moisture mitigation is the same as that described above for mechanical entrainment. Nonerodible Elements. Nonerodible elements, such as clumps of grass or stones (larger than about 1 cm in diameter) on the surface, consume part of the shear stress of the wind which otherwise would be transferred to erodible soil. Surfaces impregnated with a large density of nonerodible elements behave as having a "limited reservoir" of erodible particles, even if the material protected by nonerodible elements is itself highly erodible. Wind -generated emissions from such surfaces decay sharply with time, as the particle reservoir is depleted. Surfaces covered by unbroken grass are virtually nonerodible. Crust Formation. Following the wetting of a soil or other surface material, fine particles will move to form a surface crust. The surface crust acts to hold in soil moisture and resist erosion. The degree of protection that is afforded by a soil crust to the underlying soil may be measured by the modulus of rupture (roughly a measure of the hardness of the crust) and thickness of the crust. Exposed soil that lacks a surface crust (e.g., a disturbed soil or a very sandy soil) is much more susceptible to wind erosion. Frequency of Mechanical Disturbance. Emissions generated by wind erosion are also dependent on the frequency of disturbance of the erodible surface. A disturbance is defined as an action that results in the exposure of fresh surface material. This would occur whenever a layer of aggregate material is either added to or removed from the surface. The disturbance of an exposed area may also result from the turning of surface material to a depth exceeding the size of the largest material present. Each time that a surface is disturbed, its erosion potential is increased by destroying the mitigative effects of crusts, vegetation, and friable nonerodible elements, and by exposing new surface fines. 1-6 Wind Speed. Under high wind conditions that trigger wind erosion by exceeding the threshold velocity, the wind speed profile near the erodible surface is found to follow a logarithmic distribution:6 u* u(z) = In ? (z>zo) 0.4 zo where: u = wind speed (cm/s) u* = friction velocity (cm/s) z = height above test surface (cm) z° = roughness height (cm) 0.4 = von Karman's constant (dimensionless) (1) The friction velocity (u*) is a measure of wind shear stress on the erodible surface, as determined from the slope of the logarithmic velocity profile. The roughness height (z0) is a measure of the roughness of the exposed surface as determined from the y - intercept of the velocity profile (i.e., the height at which the wind speed is zero) on a logarithmic -linear graph. Agricultural scientists have established that total soil loss by continuous wind erosion of highly erodible fields is dependent roughly on the cube of wind speed above the threshold velocity.6 More recent work has shown that the loss of particles in suspension mode follows a similar dependence. Soils protected by nonerodible elements or crusts exhibit a weaker dependence of suspended particulate emissions on wind speed.9 Wind Gusts. Although mean atmospheric wind speeds may not be sufficient to initiate wind erosion from a particular "limited -reservoir" surface, wind gusts may quickly deplete a substantial portion of its erosion potential. In addition, because the erosion potential (mass of particles constituting the "limited reservoir") increases with increasing wind speed above the threshold velocity, estimated emissions should be related to the gusts of highest magnitude. The current meteorological variable which appropriately reflects the magnitude of wind gusts is the fastest 2 -minute wind speed from the "First Order Summary of the Day," published by the U.S. Weather Service for first order meteorological stations.]° The quantity represents the wind speed corresponding to the largest linear passage of wind movement during a 2 -minute period. Two minutes is approximately the same duration as the half-life of the erosion process (i.e., the time required to remove one-half the erodible particles on the surface). It should be noted that instantaneous peak wind speeds can significantly exceed the fastest 2 - minute wind speed. Because the threshold wind speed must be exceeded to trigger the possibility of substantial wind erosion, the dependence of erosion potential on wind speed cannot be represented by any simple linear function. For this reason, the use of an average wind speed to calculate an average emission rate is inappropriate. Wind Accessibility. If the erodible material lies on an exposed area with little penetration into the surface wind layer, then the material is uniformly accessible to the wind. If this is not the case, it is necessary to divide the erodible area into subareas representing different degrees of exposure to wind. For example, the results of physical modeling show that the frontal face of an elevated materials storage pile is exposed to 1-7 surface wind speeds of the same order as the approach wind speed upwind of the pile at a height matching the top of the pile;1' on the other hand, the leeward face of the pile is exposed to much lower wind speeds. 1.5 Use of Satellite Imagery to Inventory Erodible Vacant Land Windblown dust from arid soils in the West contributes to exceedances of national air quality standards for inhalable particulate matter. This problem is intensifying because of increasing land disturbance associated with rapid population growth in areas such as the Las Vegas Valley. The rates of fine particle emissions from open areas are strongly dependent on the type and frequency of land disturbance that destroys the mitigative stabilization effects of natural crusting and vegetation. Satellite imagery has been shown to be a useful tool in tracking land disturbances (source activity levels) and the resultant degree of soil vulnerability to high wind events. This method has recently been used to develop an inventory of native desert, disturbed vacant land, stabilized vacant land and private unpaved roads in the Las Vegas Valley.12 Wind tunnel studies have shown that each of these land categories have distinctly different potentials for wind -generated dust emissions. For example, native desert is essentially non -erodible because of the high stability of the undisturbed soil surface. Conversely, disturbed vacant land such as active grading areas at construction sites has the highest erodibility among the inventoried land categories. In this study funded by Clark County, Nevada, multi -spectral satellite imagery was used to inventory vacant land and private unpaved roads throughout the Las Vegas Valley. Landsat TM imagery was found to be appropriate for classifying surface areas as a measure of activity level. Although Landsat TM imagery has much lower spatial resolution (30 meter pixel size) than commercial satellite imagery (10 times smaller pixel size), it has higher spectral resolution (an additional two IR wavelength bands) and costs only about 1 percent of the cost of commercial satellite imagery. In the surface classification process, it was found useful to define additional land categories that could be profiled with the satellite imagery, as follows: barren/shadow (areas with steep slopes); concrete; urban vegetation (golf courses and irrigated parks); natural drainage (rocky surfaces); and urban structures (rooftops, asphalt surfaces, etc.). Ground-truthing test sites were used to develop and verify the applicability of distinctive multi -spectral reflectance patterns for each land category. A classification error matrix showed that the method has an 89 percent reliability for this application. This method can be applied at regular intervals to track the effect of land development on emissions from open areas. 1.6 Emission Calculation Procedure A calculation of the estimated emission rate for a given source requires data on source extent, uncontrolled emission factor, and control efficiency. The mathematical expression for this calculation is given as follows: R=SEe(1 -c) (2) 1-8 where: R = estimated mass emission rate in the specified particle size range SE = source extent e = uncontrolled emission factor in the specified particle size range (i.e., mass of uncontrolled emissions per unit of source extent) c = fractional efficiency of control The source extent (activity level) is the appropriate measure of source size or the level of activity that is used to scale the uncontrolled emission factor to the particular source in question. For process sources of fugitive particulate emissions, the source extent is usually the production rate (i.e., the mass of product per unit time). Similarly, the source extent of an open dust source entailing a batch or continuous drop operation is the rate of mass throughput. For other categories of open dust sources, the source extent is related to the area of the exposed surface that is disturbed by either wind or mechanical forces. In the case of wind erosion, the source extent is simply the area of erodible surface. For emissions generated by mechanical disturbance, the source extent is also the surface area (or volume) of the material from which the emissions emanate. For vehicle travel, the disturbed surface area is the travel length times the average daily traffic (ADT) count, with each vehicle having a disturbance width equal to the width of a travel lane. If an anthropogenic control measure (e.g., treating the surface with a chemical binder which forms an artificial crust) is applied to the source, the uncontrolled emission factor in Equation 2 must be multiplied by an additional term to reflect the resulting fractional control. In broad terms, anthropogenic control measures can be considered as either continuous or periodic, as the following examples illustrate: Continuous controls Periodic controls Wet suppression at conveyor transfer points Watering or chemical treatment of unpaved roads Enclosures/wind fences around storage piles Sweeping of paved travel surfaces Continuous vegetation of exposed areas Chemical stabilization of exposed areas The major difference between the two types of controls is related to the time dependency of performance. For continuous controls, the efficiency of the control measure is essentially constant with respect to time. On the other hand, the efficiency associated with periodic controls tends to decrease (decay) with time after application until the next application, at which time the cycle repeats but often with some residual effects from the previous application. In order to quantify the performance of a specific periodic control, two measures of control efficiency are required. The first is "instantaneous" control efficiency and is defined by: c(t)_/l e(t)\x100 e„ 1-9 (3) where: c(t) = instantaneous control efficiency (percent) eu(t) = instantaneous emission factor for the controlled source e„ = uncontrolled emission factor t = time after control application The other important measure of periodic control performance is average efficiency, defined as: T C(T) = T Jc(t)dt 0 where: c(t) = instantaneous control efficiency at time t after application (percent) T = time period over which the average control efficiency is referenced The average control efficiency is needed to estimate the emission reductions due to periodic applications. 1.7 Emission Factors (4) Early in the USEPA field testing program to develop emission factors for fugitive dust sources, it became evident that uncontrolled emissions within a single generic source category may vary over two or more orders of magnitude as a result of variations in source conditions (equipment characteristics, material properties, and climatic parameters). Therefore, it would not be feasible to represent an entire generic source category in terms of a single -valued emission factor, as traditionally used by the USEPA to describe average emissions from a narrowly defined ducted source operation. In other words, it would take a large matrix of single -valued factors to adequately represent an entire generic fugitive dust source category. In order to account for emissions variability, therefore, the approach was taken that fugitive dust emission factors be constructed as mathematical equations for sources grouped by the dust generation mechanisms. The emission factor equation for each source category would contain multiplicative correction parameter terms that explain much of the variance in observed emission factor values on the basis of variances in specific source parameters. Such factors would be applicable to a wide range of source conditions, limited only by the extent of experimental verification. For example, the use of the silt content as a measure of the dust generation potential of a material acted on by the forces of wind or machinery proved to be an important step in extending the applicability of the emission factor equations to a wide variety of aggregate materials of industrial importance. A compendium of predictive emission factor equations for fugitive dust sources is maintained on a CD-ROM by the U.S. EPA.13 These emission factor equations are also published in Volume I of the U.S. EPA's Compilation of Air Pollutant Emission Factors commonly referred to as AP -42.14 A set of particle size multipliers for adjusting the calculated emission factors to specific particle size fractions is provided with each equation. The ratios of PM2.5 to PMI0 0 for fugitive dust sources published in Section 13 of AP -42 typically range from 0.10 to 0.20. 1-10 Example: Vehicle Traffic on Unpaved Roads. For the purpose of estimating uncontrolled emissions, the U.S. EPA emission factor equation applicable to vehicle traffic on publicly accessible unpaved roads takes source characteristics into consideration: E = [ 1.8 (s/12)1 8 (S/30)°' / (M/0.5)°2] - C (5) where: E = PM10 emission factor (1bNMT) s = surface material silt content (%) S = mean vehicle speed (mph) M = surface material moisture content (%) C = emission factor for 1980's vehicle fleet exhaust, plus break/tire wear The denominators in each of the multiplicative terms of the equation constitute normalizing default values, in case no site -specific correction parameter data are available. The default moisture content represents dry (worst -case) road conditions. Extrapolation to annual average uncontrolled emission estimates (including natural mitigation) is accomplished by assuming that emissions are occurring at the estimated rate on days without measurable precipitation and, conversely, are absent on days with measurable precipitation. 1.8 Emission Control Options Typically, there are several options for the control of fugitive particulate emissions from any given source. This is clear from Equation 2 used to calculate the emission rate. Because the uncontrolled emission rate is the product of the source extent and the uncontrolled emission factor, a reduction in either of these two variables produces a proportional reduction in the uncontrolled emission rate. In the case of open sources, the reduction in the uncontrolled emission factor may be achieved by adjusted "work practices". The degree of the reduction of the uncontrolled emission factor can be estimated from the known dependence of the factor on source conditions that are subject to alteration. For open dust sources, this information is embodied in the predictive emission factor equations for fugitive dust sources as presented in Section 13 of AP -42. The reduction of source extent and the incorporation of adjusted work practices that reduce the amount of exposed dust -producing material are preventive measures for the control of fugitive dust emissions. Add-on controls can also be applied to reduce emissions by reducing the amount (areal extent) of dust -producing material, other than by cleanup operations. For example, the elimination of mud/dirt carryout onto paved roads at construction and demolition sites is a cost-effective preventive measure. On the other hand, mitigative measures involve the periodic removal of dust -producing material. Examples of mitigative measures include: cleanup of spillage on travel surfaces (paved and unpaved) and cleanup of material spillage at conveyor transfer points. Mitigative measures tend to be less favorable from a cost-effectiveness standpoint. Periodically applied control techniques for open dust sources begin to decay in efficiency almost immediately after implementation. The most extreme example of this is the watering of unpaved roads, where the efficiency decays from nearly 100% to 0% in a matter of hours. On the other hand, the effects of chemical dust suppressants applied to unpaved roads may last for several months. Consequently, to describe the performance of most intermittent control techniques for open dust sources, the "time -weighted average" control efficiency must be reported along with the time period over which the value applies. For continuous control systems (e.g., wet suppression for continuous drop materials transfer), a single control efficiency is usually appropriate. Table 1-3 lists fugitive dust control measures that have been judged to be generally cost-effective for application to metropolitan areas unable to meet PM10 standards. The most highly developed performance models available apply to application of chemical suppressants on unpaved roads. These models relate the expected instantaneous control efficiency to the application parameters (application intensity and dilution ratio) and to the number of vehicle passes (rather than time) following the application. More details on available dust control measure performance and cost are presented in two MRI documents.'5' 16 Table 1-3. Controls for Fugitive Dust Sources Source category Control action Agricultural Tilling and Harvesting, Livestock Husbandry Conservation management practices Construction/Demolition Paving permanent roads early in project Covering haul trucks Access apron construction and cleaning Watering of graveled travel surfaces Abrasive Blasting, Materials Handling, Mineral Products Industry Wet suppression Paved Roads Water flushing/sweeping Improvements in sanding/salting applications and materials Covering haul trucks Prevention of trackout Curb installation Shoulder stabilization Unpaved Roads Paving Chemical stabilization Surface improvement (e.g., gravel) Vehicle speed reduction Wind Erosion (agricultural, open area, and storage pile) Revegetation Limitation of off -road vehicle traffic 1-12 1.9 Document Organization The handbook contains separate, stand-alone chapters for each fugitive dust source category with chapters arranged in the following order: Chapter 2: Agricultural Tilling Chapter 3: Construction and Demolition Chapter 4: Materials Handling Chapter 5: Paved Roads Chapter 6: Unpaved Roads Chapter 7: Agricultural Wind Erosion Chapter 8: Open Area Wind Erosion Chapter 9: Storage Pile Wind Erosion Chapter 10: Agricultural Harvesting Chapter 11: Mineral Products Industry Chapter 12: Abrasive Blasting Chapter 13: Livestock Husbandry Chapter 14: Miscellaneous Minor Fugitive Dust Sources Each chapter contains the following subsections: (a) Characterization of Source Emissions (b) Emissions Estimation: Primary Methodology (generally from AP -42) (c) Emissions Estimation: Alternate Methodology (if available; e.g., CARB) (d) Demonstrated Control Techniques (e) Regulatory Formats (f) Compliance Tools (g) Sample Cost -Effectiveness Calculation (h) References A glossary and a series of Appendices are included in the handbook. Appendix A contains a discussion of two basic test methods used to quantify fugitive dust emission rates, namely: (a) The upwind -downwind method that involves the measurement of upwind and downwind particulate concentrations, utilizing ground -based samplers under known meteorological conditions, followed by a calculation of the source strength (mass emission rate) with atmospheric dispersion equations; and (b) The exposure -profiling method that involves simultaneous, multipoint measurements of particulate concentration and wind speed over the effective cross section of the plume, followed by a calculation of the net particulate mass flux through integration of the plume profiles. Appendix B contains cost information for demonstrated control measures. Appendix C contains a step -wise methodology to calculate the cost-effectiveness of different fugitive dust control measures. Appendix D contains a brief discussion of fugitive PM10 management plans and record keeping requirements mandated by one of the air quality districts within the WRAP region. 1-13 In compiling information regarding control cost-effectiveness estimates (i.e., $ per ton of PM 10 reduction) of different control options for the fugitive dust handbook, we discovered that many of the estimates provided in contractor reports prepared for air quality agencies for PM 10 SIPs contain either hard to substantiate assumptions or unrealistic assumptions. Depending on what assumptions are used, the control cost- effectiveness estimates can range over one to two orders of magnitude. Consequently, the end user of the handbook would get a distorted view if we published these estimates. Rather than presenting these published cost-effectiveness estimates, we have prepared a detailed methodology containing the steps to calculate cost-effectiveness that is included in Appendix C. We recommend that the handbook user calculate the cost-effectiveness values for different fugitive dust control options based on current cost data and assumptions that are applicable for their particular situation. 1.10 References 1. WRAP, 2004. Definitions of Dust, Western Regional Air Partnership, October 21. 2. Environ, 2005. Feasibility Analysis of the Implementation of WRAP 's Dust Definition, final report to the Western Governors' Association, May 9. 3. Cowherd, C. Jr., Axetell, K. Jr., Maxwell, C.M., Jutze, G.A., 1974. Development of Emission Factors for Fugitive Dust Sources, EPA -450/3-74/037. 4. ASTM, 1984. American Society of Testing and Materials, Standard Method for Sieve Analysis of Fine and Coarse Aggregates, Method C-136, 84a. 5. Cowherd, C. Jr., Bohn, R., Cuscino, T. Jr., 1979. Iron and Steel Plant Open Source Fugitive Emission Evaluation, EPA -600/2-79/1 03. 6. Woodruff, N.P. Siddoway, F.H., 1965. A Wind Erosion Equation, Soil Sci. Soc. Am. Proc. 29(5): 602-8. 7. Cowherd, C. Jr., Muleski, G.E., Englehart, P.J., Gillette, D.A., 1985. Rapid Assessment of Exposure to Particulate Emissions from Surface Contamination Sites, EPA/600/8-85/002. 8. Gillette, D.A., 1978. A Wind Tunnel Simulation of the Erosion of the Soil, Atmos. Environ., 12: 1735-43. 9. Cowherd, C. Jr., 1988. A Refined Scheme for Calculation of Wind Generated PM Emissions from Storage Piles, in Proceedings: APCA/EPA Conference on PMJ0.: Implementation of Standards. 10. NEDS, 1992. Local Climatological Data: Annual and Monthly Summaries, National Environmental Data Service, National Climatic Center, Asheville, NC. 11. Billings-Stunder, B.J. and Arya, S.P.S., 1988. Windbreak Effectiveness for Storage Pile Fugitive Dust Control: A Wind Tunnel Study, J. APCA 38: 135-43. 1-14 12. MRI, 2005. Remote Sensing Imagery for an Inventory of Vacant Land Soil Stability and Unpaved Private Roads, final report prepared for Clark County, Nevada, December. 13. U.S. EPA, 2005. Air CHIEF CD-ROM, Version 12, Research Triangle Park, NC. 14. USEPA, 2006. Compilation of Air Pollutant Emission Factors, Volume I: Stationary and Area Sources, Research Triangle Park, NC. 15. Cowherd, C. Jr., Muleski, G.E., Kinsey, J.S., 1988. Control of Open Fugitive Dust Sources, EPA 450/3-88-008. 16. Cowherd, C. Jr., 1991. Best Available Control Measures (BA CM) for Fugitive Dust Sources. Revised Draft Guidance Document. 1-15 Chapter 2. Agricultural Tilling 2.1 Characterization of Source Emissions 2-1 2.2 Emission Estimation: Primary Methodology 2-1 2.3 Demonstrated Control Techniques 2-3 2.4 Regulatory Formats 2-5 2.5 Compliance Tools 2-6 2.6 Sample Cost -Effectiveness Calculation 2-6 2.7 References 2-8 2.1 Characterization of Source Emissions The agricultural tilling source category includes estimates of the airborne soil particulate emissions produced during the preparation of agricultural lands for planting and after harvest activities. Operations included in this methodology are discing, shaping, chiseling, leveling, and other mechanical operations used to prepare the soil. Dust emissions are produced by the mechanical disturbance of the soil by the implement used and the tractor pulling it. Soil preparation activities tend to be performed in the early spring and fall months. Particulate emissions from land preparation are computed by multiplying a crop specific emission factor by an activity factor. The crop specific emission factors are calculated using operation specific (i.e., discing or chiseling) emission factors which are combined with the number of operations provided in the crop calendars. The activity factor is based on the harvested acreage of each crop for each county in the state. In addition, acre -passes are computed, which are the number of passes per acre that are typically needed to prepare a field for planting a particular crop. The particulate dust emissions produced by agricultural land preparation operations are estimated by combining the crop acreage and the operation specific emission factor. The current version of AP -42 (i.e., the 5th edition) does not address agricultural tilling even though an earlier edition (i.e., the 4th edition) included a PM10 emission factor equation for this fugitive dust source category expressed as follows: EF= 1.01 s .6 where, EF is the PM10 emission factor (lb/acre-pass) and s is the silt content of surface soil (%). Thus, the methodology adopted by the California Air Resources Board (CARB) is presented below as the primary emissions estimation methodology in lieu of an official EPA methodology for this fugitive dust source category. 2.2 Emission Estimation: Primary Methodology1"5 This section was adapted from Section 7.4 of CARB's Emission Inventory Methodology. Section 7.4 was last updated in January 2003. The particulate dust emissions from agricultural land preparation are estimated for each crop in each county using the following equation. Emissionscrop = Emission Factorcrop x Acrescrop Then the crop emissions for each county are summed to produce the county and statewide PM10 and PM2.5 emission estimates. The remainder of this section discusses each component of the above equation. Acres. The acreage data used for estimating land preparation emissions are based on the state summary of crop acreage harvested. The acreage data are subdivided by county and crop type for the entire state, and are compiled from individual county agricultural commissioner reports. 2-1 Crop Calendars and Acre -Passes. Acre -passes (the total number of passes typically performed to prepare land for planting during a year) are used in computing crop specific emission factors for land preparation. These land preparation operations may occur following harvest or closer to planting, and can include discing, tilling, land leveling, and other operations. Each crop is different in the type of soil operations performed and when they occur. For the crops that are not explicitly updated, an updated crop profile from a similar crop can be used. For updating acre -pass data, it is also useful to collect specific information on when agricultural operations occur. Using these data, it is possible to create detailed temporal profiles that help to indicate when PM emissions from land preparations may be highest. Emission Factor. The operation specific PM10 emission factors used to estimate the crop specific emission factor for agricultural land preparations were initially extracted from a University of California Davis report.4 After discussions with regulators, researchers, and industry representatives, the emission factors were adjusted based on a combination of scientific applicability, general experience, and observations. Five emission factors were developed by UC Davis using 1995 to 1998 test data measured in cotton and wheat fields in California. The operations tested included root cutting, discing, ripping and subsoiling, land planing and floating, and weeding, which produced emission factors that are summarized in Table 2-1 below. CARB has recently proposed adopting a PM2.5/PM10 ratio for fugitive dust from agricultural tilling and related land preparation activities of 0.15 based on the analysis conducted by MRI on behalf of WRAP 5, 6 Table 2-1. Land Preparation Emission Factors Land preparation operations Emission factor (lbs PM10/acre-pass) Root cutting 0.3 Discing, Tilling, Chiseling 1.2 Ripping, Subsoiling 4.6 Land Planing & Floating 12.5 Weeding 0.8 There are more than thirty different land preparation operations commonly used. With five emission factors available, the other operations can be assigned "best -fit" factors based on similar potential emission levels. The assignment of emission factors for operations are based on the expertise and experience of regulators, researchers, and industry representatives. For each crop, the emission factor is the sum of the acre -pass weighted emission factors for each land preparation operation. Assumptions and Limitations. The CARB methodology is subject to the following assumptions and limitations: 1. The land preparation emission factors for discing, tilling, etc., are assumed to produce the same level of emissions, regardless of the crop type. 2. The land preparation emission factors do not change geographically for counties. 2-2 3. A limited number of emission factors are assigned to all land preparation activities. 4. Crop calendar data collected for test area (i.e., San Joaquin) crops and practices were extrapolated to the same crops in the remainder of the state. Existing crop profiles were used for the small percentage of crops in which update information was not collected. 5. In addition to the activities provided in the crop calendars, it is also assumed that field and row crop acreage receive a land -planing pass once every five years. Temporal Activity. Temporal activity for agricultural tilling (and other land preparation activities) is derived by summing, for each county, the monthly emissions from all crops. For each crop, the monthly emissions are calculated based on its monthly crop calendar profile, which reflects the percentage of activities that occurs in that month. An example of the monthly activity profile for almonds, cotton, and wine grapes is shown below in Table 2-2. Because the mix of crops varies by county, composite temporal profiles combining all of the other county crops vary by county. An example of a composite land preparation profile by month for Fresno County, showing the combined temporal profile for all of the land preparation activities in the county, is shown in Table 2-3. Table 2-2. Monthly Activity Profile of Selected Crops Crops JAN FEB MAR APR MAY JUN JULY AUG SEP OCT NOV DEC Almonds 0 0 0 0 0 0 0 0 0 0 50 50 Cotton 0 9 9 0 0 0 0 0 0 0 41 41 Grapes -wine 0 0 0 4 16 16 12 12 12 28 0 0 Table 2-3. County Land Preparation Profile Composite County JAN FEB MAR APR MAY JUN JULY AUG SEP OCT NOV DEC Fresno 3 6 6 2 2 1 3 4 2 12 30 29 2.3 Demonstrated Control Techniques The emission potential of agricultural land preparation operations, including soil tilling, is affected by the soil management and cropping systems that are in place. Table 2-4 presents a summary of demonstrated control measures and the associated PM10 control efficiencies. It is readily observed that reported control efficiencies for many of the control measures are highly variable. This may reflect differences in the operations as well as the test methods used to determine control efficiencies. A list of control measures for agricultural tilling operations is available from the California Air Pollution Control Officers' Association's (CAPCOA) agricultural clearinghouse website (http://capcoa.org/ag_clearinghouse.htm). The list of control measures for land preparation activities for field and orchard crops include: ceasing activities under very windy conditions, combining operations to reduce the number of passes, application of chemicals through an irrigation system, fallowing land, use cover crops and/or mulch/crop residue to reduce wind erosion of soil, operating at night when moisture levels are higher and winds tend to be lighter, precision farming with a GPS system to 2-3 reduce overlap of passes, roughening the soil or establishing ridges perpendicular to the prevailing wind direction, and using wind barriers. Table 2-4. Control Efficiencies for Control Measures for Agricultural Tilling7" PM10 control Control measure efficiency References/Comments Equipment 50% MRI, 1981. Control efficiency is for electrostatically charged modification fine -mist water spray. Limited activity during a high -wind event Reduced tillage system (Conservation Tilling) 1 - 5% SCAQMD, 1997. Control efficiency assumes no tilling when wind speed exceeds 25 mph. 35 - 50% Coates, 1994. This study identified total PM10 emissions generated for five different cotton tillage systems, including conventional tilling. Four of the systems combine several tillage operations (e.g., shredding, discing, mulching). 60% MRI, 1981. Control efficiency is for a minimum tillage technique that confines farm equipment and vehicle traffic to specific areas (for cotton and tomatoes). 25 - 100% MRI, 1981; U.S. EPA, 1992. Control efficiency is for application of herbicide that reduces need for cultivation (i.e., 25% for barley, alfalfa, and wheat; 100% for cotton, corn, tomatoes, and lettuce). 30% MRI, 1981; U.S. EPA, 1992. Control efficiency is for laser - directed land plane that reduces the amount of land planing. 50% MRI, 1981; U.S. EPA, 1992. Control efficiency is for using "punch" planter instead of harrowing (for cotton, corn, and lettuce). 50% MRI, 1981. Control efficiency is for using "plug" planting that places plants more exactly and eliminates the need for thinning (for tomatoes, only). 50% MRI, 1981; U.S. EPA, 1992. Control efficiency is for aerial seeding which produces less dust than ground planting (for alfalfa and wheat). 91 - 99% Grantz, et al. 1998. Control efficiency is for revegetation of fallow agricultural lands by direct seeding. Tillage based on 90% MRI, 1981; U.S. EPA, 1992. Control efficiency is for sprinkler soil moisture irrigation as a fugitive dust control measure. Also, sprinkler irrigation could reduce the need for extensive land planing associated with surface irrigation. Sequential 50% MRI, 1981. Control efficiency is for double cropping corn. cropping Surface 15 - 64% Grantz et al, 1998. Control efficiency is for increasing roughening surface roughness using rocks and soil aggregates. 2-4 2.4 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. However, most air quality districts currently exempt agricultural operations from controlling fugitive dust. Air quality districts that regulate fugitive dust emissions from agricultural operations include Clark County, NV and several districts in California such as the Imperial County APCD, the San Joaquin Valley APCD and the South Coast AQMD. Imperial County APCD's Rule 806 prohibits fugitive dust emissions from farming activities for farms over 40 acres. The San Joaquin Valley APCD and the South Coast AQMD prohibit fugitive dust emissions for the larger farms defined as farms with areas where the combined disturbed surface area within one continuous property line and not separated by a paved public road is greater than 10 acres. The San Joaquin Valley APCD's Rule 4550 (Conservation Management Practices, CMPs) requires farmers with 100 acres or more of contiguous or adjacent farmland to implement and document a biennial CMP plan to reduce fugitive dust emissions from on - farm sources, such as unpaved roads and equipment yards, during land preparation and harvesting activities. The District's rule requires farmers to implement a separate CMP for each crop for the following source categories: land preparation and cultivation, harvesting, unpaved roads, unpaved equipment yards, and other cultural practices. Example regulatory formats downloaded from the Internet are presented in Table 2-5. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • San Joaquin Valley APCD, CA: valleyair.org/SJV_main.asp • South Coast AQMD, CA: aqmd.gov/rules • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/aq CAPCOA's agricultural clearinghouse website (capcoa.org/ag_clearinghouse.htm) provides links to rules of different air quality agencies within California that regulate fugitive dust emissions from agricultural operations. Table 2-5. Example Regulatory Format for Agricultural Tilling Control measure Agency Any person engaged in agricultural operations shall take all reasonable precautions to abate fugitive dust from becoming airborne from such activities. Clark County Reg. 41 7/10/04 Limit visible dust emissions to 20% opacity by pre- watering, phasing of work, applying water during active operations SJVAPCD Rule 8021 11/15/2001 Implement one of following during inactivity: restricting vehicle access or applying water or chemical stabilizers SJVAPCD Rule 8021 11/15/2001 Use mowing or cutting instead discing and maintain at least 3" stubble above soil (Also requires pre- application of watering if discing for weed abatement) SCAQMD Rule 403 12/11/1998 Cease activities when wind speeds are greater than 25 mph SCAQMD Rule 403.1 4/02/04 2-5 2.5 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (l) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations (e.g., observation of visible dust plume). An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Compliance tools applicable to agricultural tilling are summarized in Table 2-6. Table 2-6. Compliance Tools for Agricultural Tillin Record keeping Site inspection/monitoring Maintain daily records to document the specific dust control options taken; maintain such records for a period of not less than three years; and make such records available to the Executive Officer upon request. Observation of dust plumes during periods of agricultural tilling; observation of dust plume opacity (visible emissions) exceeding a standard; observation of high winds (e.g., >25 mph). 2.6 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for agricultural tilling. A sample cost-effectiveness calculation is presented below for a specific control measure (conservation tilling) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PMI0 0 and PM2.5. In selecting the most advantageous control measure for agricultural tilling, the same procedure is used to evaluate each candidate control measure (utilizing the control 2-6 measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Agricultural Tilling Step 1. Determine source activity and control application parameters. Field size (acres) Frequency of operations per year Control Measure Control application/frequency Control Efficiency 320 4 Conservation tilling Reduce 4 passes to 3 passes 25% The field size and frequency of operations are assumed values, for illustrative purposes. Conservation tilling has been chosen as the applied control measure. The control application/frequency and control efficiency are values determined from the proportional reduction in tilling frequency. Step 2. Obtain PM10 Emission Factor. The PM10 emission factor for agricultural tilling dust is 1.2 (lb/acre-pass).12 Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor, EF, (given in Step 2) is multiplied by the field size and the frequency of operations (both under activity data) and then divided by 2,000 lbs to compute the annual PM10 emissions in tons per year, as follows: Annual PM10 emissions = (EF x Field Size x Frequency of Ops) / 2,000 Annual PM10 emissions = (1.2 x 320 x 4) / 2,000 = 0.768 tons Annual PM2.5 emissions = (PM2.5/PM10) x PM10 emissions CARB proposed PM2.5/PM10 ratio for agricultural operations5 = 0.15 Annual PM2.5 emissions = (0.15 x 0.768 tons) = 0.115 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). For this example, we have selected conservation tilling as our control measure. Based on a control efficiency estimate of 25%, the annual controlled PM emissions are calculated to be: Annual Controlled PM10 emissions = (0.768 tons) x (1 — 0.25) = 0.576 tons Annual Controlled PM2.5 emissions = (0.115 tons) x (1 — 0.25) = 0.086 tons Step 5. Determine Annual Cost to Control PM Emissions. In this example, eliminating one tilling pass actually reduces the annual tilling costs. The annual cost savings of this control measure is calculated by multiplying the number of acres by the tilling cost per acre. The cost of tilling is assigned a value of $10 per acre (WSU, 199813). Thus, the annual cost savings from eliminating one tilling pass is estimated to be: 320 x 10 = $3,200. 2-7 Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annual cost (in this case annual cost savings) by the emissions reduction (i.e., uncontrolled emissions minus uncontrolled emissions), as follows: Cost-effectiveness = Annual Costs Savings / (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = -$3,200 / (0.687 — 0.576) = -$16,667/ton Cost-effectiveness for PM2.5 emissions = —$3,200 / (0.115 — 0.086) = —$111,111/ton [Note: The negative cost-effectiveness values indicate a net cost savings for this control measure.] 2.7 References 1. Flocchini, R. G., James, T. A., et al., 2001. Sources and Sinks of PM10 in the San Joaquin Valley, Interim Report for U.S. Department of Agriculture. 2. California Agricultural Statistics Service, 2002. 2000 acreage extracted from agricultural commissioner's reports, Sacramento, CA, December. 3. Gaffney, P. H., Yu, H., 2002. Agricultural Harvest: Geologic Particulate Matter Emission Estimates, Background Document prepared by the California Air Resources Board, December. 4. Cassel, T., 2002. Evaluation ofARB application of UCD emission factors, prepared for San Joaquin Valley Ag Tech Committee, July 12. 5. CARB, 2006. Private communication between Patrick Gaffney and Richard Countess, Tom Pace and Chat Cowherd, July 6. 6. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 7. Coates, W., 1994. Cotton Tillage/Quantification of Particulate Emissions, Final Report prepared for Arizona Department of Environmental Quality Air Assessment Division by the University of Arizona Tucson. 8. Grantz, D.A., Vaughn, D.L., R.J., Kim, B., VanCuren, T., Campbell, D., 1998. California Agriculture, Vol. 52, Number 4, Pages 8-13, July -August. 9. MRI, 1981. The Role of Agricultural Practices in Fugitive Dust Emissions, Draft Final Report prepared for California Air Resources Board by Midwest Research Institute, Project No. 4809-L, April 17. 10. SCAQMD, 1997. Air Quality Management Plan, Appendix IV -A: Stationary and Mobile Source Control Measures, CM#97BCM-04, South Coast AQMD, Diamond Bar, CA, February. 2-8 11. U.S. EPA, 1992. Fugitive Dust Background Document and Technical Information Document for Best Available Control Measures. U.S. EPA, Research Triangle Park, NC, September. 12. CARB, 2003. Emission Inventory Procedural Manual Volume III: Methods for Assessing Area Source Emissions, California Air Resources Board, Sacramento, CA, November. 13. WSU, 1998. Farming with the Wind, Washington State University College of Agriculture and Home Economics Miscellaneous Publication N.MISCO208, December. 2-9 Chapter 3. Construction and Demolition 3.1 Characterization of Source Emissions 3-1 3.2 Emissions Estimation: Primary Methodology 3-2 3.3 Emission Estimation: Alternate Methodology for Building Construction 3-8 3.4 Emission Estimation: Alternate Methodology for Road Construction 3-10 3.5 Supplemental Emission Factors 3-13 3.6 Demonstrated Control Techniques 3-13 3.7 Regulatory Formats 3-17 3.8 Compliance Tools 3-17 3.9 Sample Cost -Effectiveness Calculation 3-20 3.10 References 3-22 3.1 Characterization of Source Emissions Heavy construction is a source of dust emissions that may have a substantial temporary impact on local air quality. Building and road construction are two examples of construction activities with high emissions potential. Emissions during the construction of a building or road can be associated with land clearing, drilling and blasting, ground excavation, cut and fill operations (i.e., earth moving), and construction of a particular building or road. Dust emissions often vary substantially from day to day, depending on the level of activity, the specific operations, and the prevailing meteorological conditions. A large portion of the emissions results from construction vehicle traffic over temporary roads at the construction site. The temporary nature of construction differentiates it from other fugitive dust sources as to estimation and control of emissions. Construction consists of a series of different operations, each with its own duration and potential for dust generation. In other words, emissions from any single construction site can be expected (1) to have a definable beginning and an end, and (2) to vary substantially over different phases of the construction process. This is in contrast to most other fugitive dust sources where emissions are either relatively steady or follow a discernable annual cycle. Furthermore, there is often a need to estimate areawide construction emissions without regard to the actual plans of any individual construction project. For these reasons, methods by which either areawide or site -specific emissions may be estimated are presented below. The quantity of dust emissions from construction operations is proportional to the area of land being worked and to the level of construction activity. By analogy to the parameter dependence observed for other similar fugitive dust sources, one can expect emissions from construction operations to be positively correlated with the silt content of the soil (i.e., particles smaller than 75 micrometers [gm] in diameter), as well as with the speed and weight of the construction vehicle, and to be negatively correlated with the soil moisture content. Table 3-1 displays the dust sources involved with construction. In addition to the on - site activities shown in Table 3-1, substantial emissions are possible because of material tracked out from the site and deposited on adjacent paved streets. Because all traffic passing the site (i.e., not just that associated with the construction) can resuspend the deposited material, this "secondary" source of emissions may be far more important than all the dust sources located within the construction site. Furthermore, this secondary source will be present during all construction operations. Persons developing construction site emission estimates must consider the potential for increased adjacent emissions from off -site paved roadways (see Chapter 5). High wind events also can lead to emissions from cleared land and material stockpiles. Chapters 8 and 9 present estimation methodologies that can be used for such sources at construction sites. 3-1 Table 3-1. Emission Sources for Construction Operations Construction phase Dust -generating activities I. Demolition and debris removal 1. Demolition of buildings or other (natural) obstacles such as trees, boulders, etc. a. Mechanical dismemberment ("headache ball") of existing structures b. Implosion of existing structures c. Drilling and blasting of soil d. General land clearing 2. Loading of debris into trucks 3. Truck transport of debris 4. Truck unloading of debris II. Site Preparation (earth moving) 1. Bulldozing 2. Scrapers unloading topsoil 3. Scrapers in travel 4. Scrapers removing topsoil 5. Loading of excavated material into trucks 6. Truck dumping of fill material, road base, or other materials 7. Compacting 8. Motor grading Ill. General Construction 1. Vehicular Traffic 2. Portable plants a. Crushing b. Screening c. Material transfers 3. Other operations 3.2 Emissions Estimation: Primary Methodology -6 This section was adapted from: Estimating Particulate Matter Emissions from Construction Operations, report prepared for USEPA by Midwest Research Institute dated September 15, 1999.1 Note that AP -42 Section 13.2.3, "Heavy Construction Operations," was not adopted for the primary emission estimation methodology because it relies on a single -valued emission factor for TSP of 1.2 tons/acre-month based on only one set of field tests.2 3.2.1 PM Emissions from Construction Construction emissions can be estimated when two basic construction parameters are known: the acres of land disturbed by the construction activity, and the duration of the activity. A general emission factor for all types of construction activity is 0.11 tons PM10/acre-month and is based on a 1996 BACM study conducted by Midwest Research (MRI) Institute for the California South Coast Air Quality Management District (SCAQMD).3 The single composite factor of 0.11 tons PM 10/acre-month assumes that all construction activity produces the same amount of dust on a per acre basis. In other words, the amount of dust produced is not dependent on the type of construction but merely on the area of land being disturbed by the construction activity. A second 3-2 assumption is that land affected by construction activity does not involve large-scale cut and fill operations. Factors for the conversion of dollars spent on construction to acreage disturbed, along with the estimates for the duration of construction activity, were originally developed by MRI in 1974.4 Separate emission factors segregated by type of construction activity provide better estimates ofPM10 emissions that are more accurate estimate than are obtained using a general emission factor. The factors from the 1996 MRI BACM study3 are summarized in Table 3-2. Specific emission factors and activity levels for residential, nonresidential, and road construction activities are described below. Table 3-2. Recommended PM10 Emission Factors for Construction Onerationsl Basis for emission factor Recommended PM10 emission factor Level 1 Only area and duration known 0.11 ton/acre-month (average conditions) 0.42 ton/acre-month (worst -case conditions)a Level 2 Amount of earth moving known, in addition to total project area and duration 0.011 ton/acre-month for general construction (for each month of construction activity) plus 0.059 ton/1,000 cubic yards for on -site cut/fillb 0.22 ton/1,000 cubic yards for off -site cut/fillb Level 3 More detailed information available on duration of earth moving and other material movement 0.13 lb/acre-work hr for general construction plus 49 lb/scraper-hr for on -site haulagec 94 lb/hr for off -site haulages Level 4 Detailed information on number of units and travel distances available 0.13 lb/acre-work hr for general construction plus 0.21 lb/ton-mile for on -site haulage 0.62 lb/ton-mile for off -site haulagec a Worst -case refers to construction sites with active large-scale earth moving operations. b These values are based on assumptions that one scraper can move 70,000 cubic yards of earth in one month and one truck can move 35,000 cubic yards of material in one month. If the on-site/off-site fraction is not known, assume 100% on -site. If the number of scrapers in use is not knows, MRI recommends that a default value of 4 be used. In addition, if the actual capacity of earth moving units is known, the user is directed to use the following emission rates in units of lb/scraper-hour for different capacity scrapers: 19 for 10 yd3 scraper, 45 for 20 yd3 scraper, 49 for 30 yd3 scraper, and 84 for 45 yd3 scraper. s Factor for use with over -the -road trucks. If "off -highway" or "haul" trucks are used, haulage should be considered "on -site." 3.2.2 Residential Construction Residential construction emissions can be calculated for three basic types of residential construction: • Single-family houses • Two-family houses • Apartment buildings 3-3 Housing construction emissions are calculated using an emission factor of 0.032 tons PM 10/acre-month. Also required are: the number of housing units created, a units -to - acres conversion factor, and the duration of construction activity. The formula for calculating emissions from residential construction is: Emissions = (0.032 tons PM10/acre-month) B x f x m where, B = the number of houses constructed f = building to acres conversion factor m = the duration of construction activity in months Following the California methodology, residential construction acreage is based on the number of housing units constructed rather than the dollar value of construction. An alternative methodology is recommended for residential construction in areas in which basements are constructed or the amount of dirt moved at a residential construction site is known. The F.W. Dodge reports (www. fwdodge.com/newdodgenews.asp) give the total square footage of homes for both single-family and two-family homes. These values can be used to estimate the volume in cubic yards of dirt moved. Multiplying the total square footage of the homes by an average basement depth of 8 ft, and adding 10% additional volume to account for peripheral dirt removed for footings, space around the footings, and other backfilled areas adjacent to the basement, produces an estimate of the total volume in cubic yards of earth moved during residential construction. The information needed to determine activity levels of residential construction may be based either on the dollar value of construction or the number of housing units constructed. Construction costs vary throughout the United States. The average home cost can vary from the low to upper $100,000s depending on where the home is located in the United States. Because residential construction characteristics do not show as much variance as the cost does, the number of units constructed is a better indicator of activity level. The amount of land impacted by residential construction is determined to be about the same on a per house basis. The number of housing units for the three types of residential construction (single family, two-family, and apartments) for a county or state are available from the F.W. Dodge's "Dodge Local Construction Potentials Bulletin." A single-family house is estimated to occupy 1/4 acre. The "building to acres" conversion factor for a single-family house was determined by finding the area of the base of a home and estimating the area of land affected by grading and other construction activities beyond the "footprint" of the house. The average home is around 2,000 sq. ft. Using a conversion factor of 1/4 acre/house indicates that five times the base of the house is affected by the construction of the home. The "building to acres" conversion factor for two-family housing was found to be 1/3 acre per building. The 1/3 acre was derived from the average square footage of a two-family home (approximately 3,500 sq. ft.) and the land affected beyond the base of the house, about 4 times the base for two-family residences. 3-4 For comparison purposes, residential construction emission factor calculations are calculated below for BACM Level 1 and Level 2 scenarios. The PM10 construction emission factor for one single-family home is based on typical parameters for a single- family home: • area of land disturbed 1/4 acre • area of home 2,000 sq. ft. • duration 6 months • basement depth 8 ft. • moisture level 6% • silt content 8% The BACM Level 1 emission calculation is estimated as follows: 0.032 tons PM10/acre-month x 1/4 acre x 6 months = 0.048 tons PM10 = 96 lb PM10 The BACM Level 2 emission calculation is estimated as follows: Cubic yards of dirt moved = 2,000 ft2 x 8 ft. x 110% = 17,600 ft3 = 652 yd3 PM10 = (0.011 tons/acre-month x 1/4 acre x 6 months) + (0.059 tons/1000 yd3 dirt x 652 yd3 dirt) = 0.016 tons + 0.038 tons = 0.0545 tons PM10 = 109 lb PM10 The emission factor recommended for the construction of apartment buildings is 0.11 tons PM10/acre-month because apartment construction does not normally involve a large amount of cut -and -fill operations. Apartment buildings vary in size, number of units, square footage per unit, floors, and many other characteristics. Because of these variations and the fact that most apartment buildings occupy a variable amount of space, a "dollars -to -acres" conversion is recommended for apartment building construction rather than a "building -to -acres" conversion factor. An estimate of 1.5 acres/$106 (in 2004 dollar value) is recommended to determine the acres of land disturbed by the construction of apartments. This "dollars -to -acres" conversion factor is based on updating previous conversion factors developed by MRI4' 5 using cost of living adjustment factors. 3.2.3 Nonresidential Construction Nonresidential construction includes building construction (commercial, industrial, institutional, governmental) and also public works. The emissions produced from the construction of nonresidential buildings are calculated using the dollar value of the construction. The formula for calculating the emissions from nonresidential construction is: PM 10 Emissions = (0.19 tons PM 10/acre-month) x $ x f x m where, $ = dollars spent on nonresidential construction in millions f = dollars to acres conversion factor m = duration of construction activity in months 3-5 The emission factor of 0.19 tons PM 10/acre-month was developed by MRI in 1999 using a method similar to a procedure originated by Clark County, Nevada and the emission factors recommended in the 1996 MRI BACM Report.3 A quarter of all nonresidential construction is assumed to involve active earthmoving in which the recommended emission factor is 0.42 tons PM10/acre-month. The 0.19 tons PM10/acre- month was calculated by taking 1/4 of the heavy emission factor, (0.42 tons PM 10/acre- month) plus 3/4 of the general emission factor (0.11 tons/acre-month). The 1/4:3/4 apportionment is based on a detailed analysis of a Phoenix airport construction where specific unit operations had been investigated for PM10 emissions.6 The proposed emission factor of 0.19 tons/acre-month for nonresidential building construction resulted in a total uncontrolled PM10 emissions estimate that was within 25% of that based on a detailed unit operation emissions inventory using detailed engineering plans and "unit - operation" emission factors. Extensive earthmoving activities will produce higher amounts of PM10 emissions than the average construction project. Thus, a worst -case BACM "heavy construction emission factor" of 0.42 tons PM10/acre-month should provide a better emissions estimate for areas in which a significant amount of earth is disturbed. The dollar amount spent on nonresidential construction is available from the U.S. Census Bureau (www.census.gov/prod/www/abs/cons-hou), and the Dodge Construction Potentials Bulletin (www. fwdodge.com/newdodgenews.asp). Census data are delineated by SIC Code, whereas the Potentials Bulletin divides activity by the types of building being constructed rather than by SIC Code. It is estimated that for every million dollars spent on construction (in 2004 dollars), 1.5 acres of land are impacted. The "dollars to acres" conversion factor reflects the current dollar value using the Price and Cost Indices for Construction that are available from the Statistical Abstract of the United States, published yearly. The estimate for the duration of nonresidential construction is 11 months. 3.2.4 Road Construction Road construction emissions are highly correlated with the amount of earthmoving that occurs at a site. Almost all roadway construction involves extensive earthmoving and heavy construction vehicle travel, causing emissions to be higher than found for other construction projects. The PM10 emissions produced by road construction are calculated using the BACM recommended emission factor for heavy construction' and the miles of new roadway constructed. The formula used for calculating roadway construction emissions is: PM l 0 Emissions = (0.42 tons PM10/acre-month) x Mx f x d where, M = miles of new roadway constructed f = miles to acres conversion factors d = duration of roadway construction activity in months 3-6 The BACM worst case scenario emission factor of 0.42 tons/acre-month is used to account for the large amount of dirt moved during the construction of roadways. Since most road construction consists of grading and leveling the land, the higher emission factor more accurately reflects the high level of cut and fill activity that occurs at road construction sites. The miles of new roadway constructed are available at the state level from the Highway Statistics book published yearly by the Federal Highway Administration (FHWA; www.fhwa.dot.gov/ohim/hs97/hm50.pdf) and the Bureau of Census Statistical Abstract of the United States. The miles of new roadway constructed can be found by determining the change in the miles of roadway from the previous year to the current year. The amount of roadway constructed is apportioned from the state to the county level using housing start data that is a good indicator of the need for new roads. The conversion of miles of roadway constructed to the acres of land disturbed is based on a method developed by the California Air Resources Board. This calculation is performed by estimating the overall width of the roadway, then multiplying the width by a mile to determine the acres affected by one mile of roadway construction. The California "miles to acres disturbed" conversion factors are available for freeway, highway and city/county roads. In the Highway Statistics book, roadways are divided into separate functional classes. MRI developed a "miles -to -acres" conversion factor in 19991 according to the roadway types found in the "Public Road Length, Miles by Functional System" table of the annual Highway Statistics. The functional classes are divided into four groups. Group 1 includes Interstates and Other Principal Arterial roads and is estimated to occupy 15.2 acres/mile. Group 2 includes Other Freeways and Expressways (Urban) and Minor Arterial Roads and is estimated at 12.7 acres/mile. Group 3 has Major Collectors (Rural) and Collectors (Urban) and a conversion factor of 9.8 acres/mile. Minor Collectors (Rural) and Local roads are included in Group 4 and converted at 7.9 acres/mile. Table 3-3 shows the data used to calculate the acres per mile of road constructed. Table 3-3. Conversion of Road Miles to Acres Disturbed Group 1 Group 2 Group 3 Group 4 Lane Width (feet) Number of Lanes Average Shoulder Width (feet) Number of Shoulders Roadway Width` (feet) Area affected beyond road width Width Affected (feet) Acres Affected per Mile of New Roadway 12 12 12 12 5 5 3 2 10 10 10 8 4 2 2 2 100 80 56 40 25 25 25 25 125 105 81 65 15.2 12.7 9.8 7.9 Roadway Width= (Lane Width x # of Lanes) + (Shoulder Width x # of Shoulders). The amount of new roadway constructed is available on a yearly basis and the duration of the construction activity is determined to be 12 months. The duration accounts for the amount of land affected during that time period and also reflects the fact that construction of roads normally lasts longer than a year. The duration of construction of a new roadway is estimated at 12 to 18 months. 3-7 3.3 Emission Estimation: Alternate Methodology for Building Construction This section was adapted from Section 7.7 of CARB's Emission Inventory Methodology. Section 7.7 was last updated in September 2002. The building construction dust source category provides estimates of the fugitive dust particulate matter caused by construction activities associated with building residential, commercial, industrial, institutional, or governmental structures. The emissions result predominantly from site preparation work, which may include scraping, grading, loading, digging, compacting, light -duty vehicle travel, and other operations. Dust emissions from construction operations are computed by using a PM10 emission factor developed by MRI during 1996.3 The emission factor is based on observations of construction operations in California and Las Vegas. Activity data for construction is expressed in terms of acre -months of construction. Acre -months are based on estimates of the acres disturbed for residential construction, and project valuation for other non- residential construction. 3.3.1 Emission Estimation Methodology Emission Factor. The PM10 emission factor used for estimating geologic dust emissions from building construction activities is based on work performed by MRI3 under contract to the PM10 Best Available Control Measure (BACM) working group. For most parts of the state, the emission factor used is 0.11 tons PM10/acre-month of activity. This emission factor is based on MRI's observation of the types, quantity, and duration of operations at eight construction sites (three in Las Vegas and five in California). The bulk of the operations observed were site preparation -related activities. The observed activity data were then combined with operation -specific emission factors provided in AP -422 to produce site emissions estimates. These site estimates were then combined to produce the overall average emission factor of 0.11 tons PM10/acre-month. The PM2.5/PM10 ratio for fugitive dust from construction and demolition activities is 0.1 based on the analysis conducted by MRI on behalf of WRAP.7 The construction emission factor is assumed to include the effects of typical control measures such as routine watering. A dust control effectiveness of 50% is assumed from these measures, which is based on the estimated control effectiveness of watering.8 Therefore, if this emission factor is used for construction activities where watering is not used, it should be doubled to more accurately reflect the actual emissions. The MRI document3 lists their average emission factor values as uncontrolled. However, it can be argued that the activities observed and the emission estimates do include the residual effects of control. All of the test sites observed were actual operations that used controls as part of their standard industry practice in California and Las Ve- if in some cases watering was not performed during MRI's actual site decreases in emissions from the watering controls and raising the included in the MRI estimates. 3-8 The 1996 MRI report3 also includes an emission factor for worst -case emissions of 0.42 tons PM10/acre-month. This emission factor is appropriate for large-scale construction operations, which involve substantial earthmoving operations. The South Coast Air Quality Management District (SCAQMD) estimated that 25% of their construction projects involve these types of operations. For the remainder of the state, such detailed information is not readily available, so the average emission factor of 0.11 tons PMl 0/acre-month is used by CARB for these other areas of California.. Activity Data. For the purpose of estimating emissions, it is assumed that the fugitive dust emissions are related to the acreage affected by construction. Because regionwide estimates of the acreage under construction may not be directly available, other construction activity data can be used to derive acreage estimates. Activity data are estimated separately for residential construction and the other types of construction (commercial, industrial, institutional, and governmental). For residential construction, the number of new housing units estimated by the California Department of Finance9 are used to estimate acreage disturbed. It is estimated that single family houses are built on 1/7 of an acre in heavily populated counties, and 1/5 of an acre in less populated counties.1a12 It is also estimated that multiple living units such as apartments occupy 1/20 of an acre per living unit. For all of these residential construction activities, a project duration of 6 months is assumed.10 Applying these factors to the reported number of new units in each county results in an estimate of acre - months of construction. This estimate of acre -months of construction combined with the construction emission factor is used to estimate residential construction particulate emissions. For commercial, industrial, and institutional building construction, construction acreage is based on project valuations. Project valuations for additions and alterations are not included. According to the Construction Industry Research Board,13 most additions and alterations would be modifications within the existing structure and normally would not include the use of large earthmoving equipment. Most horizontal additions would usually be issued a new building permit. The valuations are 3.7, 4.0 and 4.4 acres per million dollars of valuation for the respective construction types listed.12 Valuations were corrected from 1999 values to 1977 values using the Annual Average Consumer Price Index (CPI -U -RS) provided by the U.S. Census Bureau.14 The Census Bureau uses the Bureau of Labor Statistics' experimental Consumer Price Index (CPI -U -RS) for 1977 through 2000.1' Valuations were corrected from 1999 values to 1977 values because the acres per dollar valuation values are based on 1977 valuations. For example, the CPI -U - RS for 1999 is 244.1 and the CPI -U -RS for 1977 is 100.0. The ratio of 1977 to 1999 dollars is 100.0/244.1 or 0.41. Inflation from 1999 to 2004 is estimated to be 12%. Thus, updating the 1977 valuation results to 2004 dollars produces a ratio of 1977 to 2004 dollars of 0.41/1.12 or 0.37. CARB assumes that each acre is under construction for 11 months for each project type.10 3-9 3.3.2 Assumptions and Limitations 1. The current methodology assumes that all construction operations in all parts of the state emit the same levels of PM 10 on a per acre basis. 2. It is assumed that watering techniques are used statewide, reducing emissions by 50% and making it valid to apply the MRI emission factor without correction. 3. The methodology assumes that valuation is proportional to acreage disturbed, even for high-rise type building construction. 4. The methodology assumes that construction dust emissions are directly proportional to the number of acres disturbed during construction. 5. The estimates of acreage disturbed are limited in their accuracy. New housing units and project valuations do not provide direct estimates of actual acreage disturbed by construction operations in each county. 6. The methodology assumes that the Consumer Price Index (CPI -U -RS) provides an accurate estimate of 1977 and current values. 3.3.3 Temporal Activity The temporal activity is assumed to occur five days a week between the hours of 8:00 AM and 4:00 PM. The table below shows the percentage of construction activity that is estimated to occur during each month. The monthly activity increases during the spring and summer months. Some districts may use a different profile that has a larger peak during the summer months. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 6.4 6.4 8.3 9.2 9.2 9.2 9.2 9.2 9.2 8.3 8.3 7.3 3.4 Emission Estimation: Alternate Methodology for Road Construction This section was adapted from Section 7.8 of CARB's Emission Inventory Methodology. Section 7.8 was last updated in August 1997. The road construction dust source category provides estimates of the fugitive dust particulate matter due to construction activities while building roads. The emissions result from site preparation work that may include scraping, grading, loading, digging, compacting, light -duty vehicle travel, and other operations. Dust emissions from road construction operations are computed by using a PM10 emission factor developed by MRI.3 The emission factor is based on observations of construction operations in California and Las Vegas. Activity data for road construction is expressed in terms of acre -months of construction. Acre -months are based on estimates of the acres disturbed for road construction. The acres disturbed are computed based on: estimates of the annual difference in road mileage; estimates of road width (to compute acres disturbed); and an assumption of 18 months as the typical project duration. 3-10 3.4.1 Emissions Estimation Methodology Emission Factor. The PM10 emission factor used for estimating geologic dust emissions from road construction activities is based on work performed by MRI under contract to the PM10 Best Available Control Measure working group.3 For most parts of the State, the emission factor used is 0.11 tons PM10/acre-month of activity. This emission factor is based on MRI's observation of the types, quantity, and duration of operations at eight construction sites (three in Las Vegas, and five in California). The bulk of the operations observed were site preparation related activities. The observed activity data were then combined with operation specific emission factors provided in U.S. EPA's AP -42 (5th Edition)2 document to produce site emissions estimates. These site estimates were then combined to produce the overall average emission factor of 0.11 tons PM10/acre-month. The PM2.5/PM10 ratio for fugitive dust from construction and demolition activities is 0.1 based on the analysis conducted by MRI on behalf of WRAP.? The construction emission factor is assumed to include the effects of routine dust suppression measures such as watering. A dust control effectiveness of 50% is assumed from these measures, which is based on the estimated control effectiveness of watering.8 Therefore, if this emission factor is used for road construction activities where watering is not used, it should be doubled to more accurately reflect the actual emissions. The MRI document3 lists their average emission factor values as uncontrolled. However, it can be argued that the activities do include the effects of controls. All of the test sites were actual operations that used watering controls, even if in some cases they were not used during the actual site visits. It is believed that the residual effects of controls are reflected in the MRI emission estimates. The MRI report3 also includes an emission factor for worst -case construction emissions of 0.42 tons of PM10/acre-month. This emission factor is appropriate for large scale construction operations that involve substantial earthmoving operations. The South Coast Air Quality Management District (SCAQMD) estimated that a percentage of their construction projects involve these types of operations, and applied the larger emission factor to these activities. For the remainder of the state, such detailed information is not readily available, so the average emission factor of 0.11 tons PM10 per acre -month is used by CARB. Activity Data. For the purpose of estimating emissions, it is assumed that the fugitive dust emissions are related to the acreage affected by construction. Regionwide estimates of the acreage disturbed by roadway construction may not be directly available. Therefore, the miles of road built and the acreage disturbed per mile of construction can be used to estimate the overall acreage disturbed. The miles of road built are based on the annual difference in the road mileage. These data, from the California Department of Finance9 and Caltrans'6, are split for each county into freeways, state highways, and city and county road. The acreage of land disturbed 3-11 per mile of road construction is based on the number of lanes, lane width, and shoulder width for each listed road type. The assumptions used are provided in Table 3-4. Because most projects will probably also disturb land outside of the immediate roadway corridor, these acreage estimates are somewhat conservative. The final parameter needed is project duration, which is assumed to be an average of 18 months.]° Multiplying the road mileage built by the acres per mile and the months of construction provides the acre -months of activity for road building construction. This, multiplied by the emission factor, provides the emissions estimate. Table 3-4. Roadway Acres per Mile of Construction Estimates Road Type Freeway Highway City & County Number of Lanes 5 5 2 Width per Lane (feet) 12 12 12 Shoulder Width (feet) 10'x4 = 40' 20'x2 = 40' 20'x2 = 40' Roadway Width* (feet) 100 76 64 Roadway Width* (miles) 0.019 0.014 0.012 Area per Mile** (acres) 12.1 9.2 7.8 *Roadway Width (miles) = [(Lanes x Width per Lane) + Shoulder Width] x (1 mile/5,280 feet) **Area per Mile (acres) = Length x Width = 1 Mile x Width x 640 acres/mile2 3.4.2 Temporal Activity Temporal activity is assumed to occur five days a week between the hours of 8 AM and 4 PM. The table below shows the percentage of construction activity that is estimated to occur during each month. The monthly activity increases during the spring and summer months as shown below. Some districts use a slightly different profile that has a larger peak during the summer months. ALL JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 100 7.7 7.7 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 7.7 3.4.3 Assumptions and Limitations 1. The current methodology assumes that all construction operations in all parts of the state emit the same levels of PM 10 on a per acre basis. 2. It is assumed that watering techniques are used statewide, reducing emissions by 50% and making it valid to apply the MRI emission factor without correction. 3. The methodology assumes that the acreage disturbed per mile for road building is similar statewide, and the overall disturbed acreage is approximately the same as the finished roadway's footprint. 4. The methodology assumes that construction dust emissions are directly proportional to the number of acres disturbed during construction. 3-12 3.5 Supplemental Emission Factors AP -42 lists uncontrolled TSP emission factors for specific activities at construction sites.2 These TSP emission factors as well as references to the relevant chapters of this handbook that provide PM10 and/or TSP emission factors for similar activities are presented in Table 3-5. Table 3-5. TSP Emission Factors for Specific Construction Site Activities Construction Phase Activity TSP Emission Factor* Demolition and Debris Removal Drilling soil 1.3 lb/hole Land clearing with bulldozer 5.7 (s)' ` / M1"' lb/hr Loading debris into trucks and subsequent unloading See Chapter 4 Truck transport of debris on paved or unpaved roads See Chapters 5 and 6 Site Preparation (earth moving) Bulldozing and compacting 5.7 (s)11 / M1' lb/hr Scrapers unloading topsoil 0.04 lb/ton Scrapers in travel mode See Chapter 6 Scrapers removing topsoil 20.2 lb/mile Grading 0.040 (S)25 lb/mile Loading excavated material into trucks and subsequent unloading See Chapter 4 General Construction Vehicular traffic See Chapters 5 and 6 Crushing and screening aggregate See Chapter 11 Material transfer See Chapter 4 * Symbols for equations: M = material moisture content (%), s = material silt content (%), S = mean vehicle speed (mph). 3.6 Demonstrated Control Techniques Because of the relatively short-term nature of construction activities, some control measures are more cost-effective than others. Frank Elswick of Midwest Industrial Supply Inc. presented an extensive summary of control measures for construction activities and their associated costs at a WRAP sponsored fugitive dust workshop in Palm Springs, CA in May 2005.'7 Elswick concluded that dust suppressant methods fall into the following six categories: 1. Watering * Watering works by agglomerating surface particles together. * No negative environmental impacts from using water. * Normally readily available. * Evaporates quickly, therefore typically only effective for short periods of time. * Frequency of application depends on temperature and humidity. * Generally labor intensive due to frequent application. * Costs associated with pre -watering and as needed watering are $55 to $80/hour. 3-13 2. Chemical Stabilizers (a) Water absorbing products (e.g., calcium chloride brine or flakes, magnesium chloride brine, sodium chloride) * These products work by significantly increasing surface tension of water between dust particles, helping to slow evaporation and further tighten compacted soil. * Products ability to absorb water from the air is a function of temperature and humidity. * These products work best in low humidity environments. * Frequent re -application in dry climates. * Must be watered to activate during dry months. * Potential costly environmental impacts to fresh water aquatic life, plants and water quality * Corrosive to metal and steel. * Not suitable for non -traffic areas. * Costs associated with traffic area program are $.03 - $.05 per square foot. (b) Organic Petroleum Products (e.g. asphalt emulsions, cut/liquid asphalt, dust oils, petroleum resins) * These products work by binding and/or agglomerating surface particles together because of asphalt adhesive properties. * Potentially costly environmental due to presence of polycyclic aromatic hydrocarbons that are "hazardous air and water pollutants" that may be subject to reporting requirements. * Can fragment under traffic conditions. * Not suitable for non -traffic areas. * Costs associated with traffic area program are $.05 - $.075 per square foot. (c) Organic Non -Petroleum Products (e.g., ligninsulfonates, tall oil emulsions, vegetable oils) * These products work by binding and/or agglomerating surface particles together. * Surface binding for these product may be reduced or destroyed by rains. * Generally limited availability of non -petroleum products. * Ligninsulfonates can impact freshwater aquatic life due to high B.O.D. and C.O.D. * Not suitable for non -traffic areas. * Costs associated with traffic area program are $.04 - $.08 square foot. (d) Polymer Products (e.g., polyvinyl acetates, vinyl acrylics) * These products work by binding soil particles together because of the polymer's adhesive properties. * Polymers also increase the load -bearing strength of all types of soils. * Polymers are non-toxic, non -corrosive, and do not pollute ground water. * Polymers dry virtually clear to create an aesthetically pleasing result. * Polymers create a tough yet flexible crust to prevent wind and water erosion. * Costs associated with traffic areas are $.05 - $.08 per square foot. * Costs associated with disturbed non -traffic areas are $300 - $800 per acre depending on longevity desired. 3-14 * Costs associated with slopes and inactive stockpiles are $500 to $1,000 per acre. (e) Synthetic Products (e.g., iso-alkane compounds) * Synthetic fluids work as a dust suppressing ballasting mechanism, while also acting as a durable re -workable binder. * Formulated with safe and environmentally friendly synthetic fluids; non- hazardous per OSHA, EPA and US DOT; contains no asphalt, oil or PAH's. * Easy application; no water required. * Costs associated with traffic area program are $.05 - $.10 per square foot. 3. * * * * Sand Fences Fabric on chain link fence. Redwood slat fence. Mylar sand fence. Most effective when used in conjunction with chemical stabilizers. 4. Perimeter Sprinklers * Most effective when used in conjunction with other methods. 5. * * Tire Cleaning Systems at Site Exit Rumble strips to prevent track -out from site onto pavement. Washed rock 100' prior to exit onto pavement. 6. On- Site Speed Control * Limiting on -site vehicle speed to 15mph. Wet suppression and wind speed reduction are the two most common methods used to control open dust sources at construction sites because a source of water and material for wind barriers tend to be readily available on a construction site. However, several other forms of dust control are available. Table 3-6 displays each of the preferred control measures by dust source.18' 19 Table 3-6. Control Options for General Construction Sources of PM10 Emission source Debris handling, Truck transport Bulldozers Pan scrapers Cut/fill material handling Cut/fill haulage General construction Recommended control methods(s) Wind speed reduction; wet suppressions Wet suppression; paving; chemical stabilization' Wet suppressiond Wet suppression of travel routes Wind speed reduction; wet suppression Wet suppression; paving; chemical stabilization Wind speed reduction; wet suppression; early paving of permanent roads a Dust control plans shou d contain precautions against watering programs that confound trackout problems. Loads could be covered to avoid loss of material in transport, especially if material is transported offsite. Chemical stabilization is usually cost-effective for relatively long-term or semipermanent unpaved roads. Excavated materials may already be moist and not require additional wetting. Furthermore, most soils are associated with an "optimum moisture" for compaction. b d 3-15 One of the dustiest construction operations is cutting and filling using scrapers, with the highest emissions occurring during scraper transit. In a 1999 MRI field study,5 it was found that watering can provide a high level of PM 10 control efficiency for scraper transit emissions. Average control efficiency remained above 75% approximately 2 hours after watering. The average PMI 0 efficiency decay rate for water was found to vary from approximately 3% to 14% hour. The decay rate depended upon relative humidity in a manner consistent with the effect of humidity on the rate of evaporation. Test results for watered scraper transit routes showed a steep increase in control efficiency with a doubling of surface moisture and little additional control efficiency at higher moisture levels. This is in keeping with past studies that found that control efficiency data can be successfully fitted by a bilinear function. In another recent MRI field study (MRI, 2001),20 tests of mud and dirt trackout indicated that a 10% soil moisture content represents a reasonable first estimate of the point at which watering becomes counter productive. The control efficiencies afforded by graveling or paving of a 7.6 m (25 ft) access apron were in the range of 40% to 50%. Table 3-7 summarizes tested control measures and reported control efficiencies for dust control measures applied to construction and demolition operation. Table 3-7. Control Efficiencies for Control Measures for Construction/Demolition2°' z' Source Control measure component PM10 control efficiency References/Comments Apply water every 4 hrs Active within 100 feet of a demolition and structure being debris removal demolished Gravel apron, 25" long Trackout by road width Apply dust suppressants (e.g., polymer emulsion) Apply water to disturbed soils after demolition is completed or at the end of each day of cleanup Post - demolition stabilization Demolition Activities Prohibit demolition Demolition activities when wind Activities speeds exceed 25 mph Apply water at various Construction intervals to disturbed Activities areas within construction site Require minimum soil moisture of 12% for earthmoving Scraper loading and unloading Limit on -site vehicle Construction speeds to 15 mph traffic (Scenario: radar enforcement) 36% MRI, April 2001, test series 701. 4 - hour watering interval (Scenario: lot remains vacant 6 mo after demolition) 46% MRI, April 2001 84% CARB April 2002; for actively disturbed areas 10% MRI, April 2001, test series 701. 14 -hour watering interval. 98% Estimated for high wind days in absence of soil disturbance activities 61% MRI, April 2001, test series 701. 3.2 -hour watering interval 74% MRI, April 2001, test series 701. 2.1 -hour watering interval 69% AP -42 emission factor equation for materials handling due to increasing soil moisture from 1.4% to 12% 57% Assume linear relationship between PM10 emissions and uncontrolled vehicle speed of 35 mph 3-16 3.7 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats downloaded from the Internet for several local air quality agencies in the WRAP region are presented in Table 3-8. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htrn • Maricopa County, AZ: www.maricopa.gov/envsvc/air/ruledsc.asp 3.8 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations (e.g., whether an unpaved road has been paved, graveled, or treated; whether haul truck beds are covered ; whether water trucks are being used during construction activities). An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 3-9 summarizes the compliance tools that are applicable to construction and demolition. 3-17 Table 3-8. Example Reulatory Formats for Construction and Demolition Source Control measure Goal Threshold Agency Paved Roads - Public and Private Track -out and Install track -out ctrl device Prevent/remove Paved roads within construction Maricopa Carryout track -out from haul sites, where haul trucks traverse; County Rule trucks and tires with disturbed surface area >2 acres, with 100 cubic yards of bulk material hauled 310 04/07/2004 Either immediately cleanup track -out (>50ft) and Control track -out on Immediate track -out clean-up Maricopa nightly clean-up of rest; install grizzly/wheel wash paved construction after 50ft, at end of workday for County system; install gravel pad-30ftx50ft, 6" deep; pave roads less; gravel pad standards are Rule 310 intersection-100ftx20ft; route traffic over track -out ctrl devices; limit access to unprotected routes; pave construction roadways ASAP min; paved intersection also min and must be accessible to public; limit access to unprotected routes with barriers 04/07/2004 Track -out control device must be installed at all Allow mud/dirt to drop For sites greater than 5 acres or SJVAPCD access points to public roads and there must be off before leaving site those with more than 100 yd3 of Rule 8041 mud/dirt removal from interior paved roads with sufficient frequency and prevent track -out daily import/export 11/15/2001 Removal of track -out within one hour or selecting a For sites greater than 5 acres or SCAQMD track -out prevention option and removing track -out at those with more than 100 yd3 of Rule 403 the end of the day daily import/export and track -out is less than 50ft 12/11/1998 Removing track -out ASAP Track -out greater than 50 ft SCAQMD Rule 403 12/11/1998 Require road surface paved or chemically stabilized Prohibits material For sites greater than 5 acres or SCAQMD from point of intersection with a public paved road to from extending more those with more than 100 yd3 of Rule 403 distance of at least 100 ft by 20 ft or installation of track -out control device from point of intersection with a public paved road to a distance of at least 25 ft by than 25 ft from a site entrance daily import/export 12/11/1998 20 ft Bulk Materials Transport Establishes speed limits. Requires at least 6" Limit visible dust Trucks entering paved public SJVAPCD freeboard when crossing paved public road, water emissions to 20% roads (6" freeboard); leaving work Rule 8031 applied to top of load. Haul trucks need tarp or opacity and prevent site; specific haul trucks need 11/15/2001 suitable cover and truck interior must be cleaned before leaving site spillage from holes covering Requires covering haul trucks or to use bottom- dumping if possible and maintain minimum 6" freeboard (in high winds) SCAQMD Rule 403 12/11/1998 Freeboard at least 3"; prevent spillage from holes; Prevent/remove Within the work site; removes Maricopa install track -out ctrl devices track -out onto paved roads possible track -out from tires, exterior of trucks that traverse work site County Rule 310 04/07/2004 Construction and Demolition Earthmoving Require water and chemical stabilizers (dust Limit visible dust SJVAPCD suppressants) be applied, in conjunction with optional emissions to 20% Rule 8021 wind barrier opacity 11/15/2001 Specifies Dust Control Plan must be submitted Limit visible dust For areas 40 acres or larger SJVAPCD emissions to 20% where earth movement of 2500 Rule 8021 opacity yd3 or more on at least 3 days is intended 11/15/2001 3-18 Table 3-8. Example Regulatory Formats for Construction and Demolition (Continued) Source Control measure Goal Threshold Agency Requires implementation of Best Available Control Prohibit visible dust SCAQMD Measures (BACM) emissions beyond property line and limit an upwind/downwind Rule 403 12/11/1998 PM10 differential to 50 ug/m3. Limit visible dust emissions to 100 ft from origin Construction and Demolition Demolition Application of dust suppressants Limit visible dust emissions to 20% opacity SJVAPCD Rule 8021 11/15/2001 Application of best available control measures Prohibits visible dust For projects greater than 5 acres SCAQMD (BACM) emissions beyond property line. Limits downwind PM10 levels to 50 ug/m3 or 100 yd3 of daily import/export Rule 403 12/11/1998 Construction and Demolition Grading Requires pre -watering and phasing of work Limit VDE to 20% SJVAPCD Operations opacity Rule 8021 11/15/2001 Requires water application and chemical stabilizers Increase moisture For graded areas where SCAQMD content to proposed construction will not begin for Rule 403 cut more than 60 days after grading 12/11/1998 Preapplication of water to depth of proposed cuts and Ensure visible SCAQMD reapplication of water as necessary. Also emissions do not Rule 403 stabilization of soils once earth -moving is complete extend more than 12/11/1998 100 ft from sources 3-19 Table 3-9. Compliance Tools for Construction and Demolition Record keeping Site inspection/monitoring Site map; description of work Observation of earthmoving and practices; duration of project activities; demolition activities, considering locations and methods for demolition timeframe of project; observation of activities; locations and amounts of all earthmoving and material (types) operation of dust suppression systems, vehicle/ equipment operation and handling operations; dust suppression disturbance areas; surface material equipment (types) and maintenance; sampling and analysis for silt and frequencies, amounts, times, and rates moisture contents; observation of truck of watering or dust suppressant spillage onto adjacent paved roads; application; mud/dirt carryout mud/dirt carryout prevention and prevention and remediation remediation; inspection of wind requirements; wind shelters; sheltering; real-time portable monitoring meteorological log. of PM; observation of dust plume opacity exceeding a standard. 3.9 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for construction and demolition. A sample cost-effectiveness calculation is presented below for a specific control measure (gravel apron at trackout egress points) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for construction and demolition, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Construction and Demolition (Mud/Dirt Egress Points) Step 1. Determine source activity and control application parameters. Egress traffic rate (veh/day) Number of egress points Duration of construction activity (month) Wet days/year Number of workdays/year Number of emission days/yr (workdays without rain) Control Measure Economic Life of Control System (yr) Control Efficiency Reference 100 2 24 10 260 250 Gravel apron 25 ft long by road width 2 46% MRI, 200120 3 -?0 The number of vehicles per day, wet days per year, workdays per year, and the economic life of the control are determined from climatic and industrial records. The number of emission days per year are calculated by subtracting the number of annual wet days from the number of annual workdays as follows: Number of workdays/year — Wet days/year = 260 - 10 = 250 Gravel aprons at the two construction site egress points have been chosen as the applied control measure. The control efficiency was obtained from MRI, 2001.19 Step 2. Obtain PM10 Emission Factor. The PM10 emission factor for construction and demolition dust is 6 g/vehicle.22 Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor, EF, (given in Step 2) is multiplied by the number of vehicles per day and by the number of emission days per year (both under activity data) and divided by 454 grams/lb and 2000 lb/ton to compute the annual PM10 emissions, as follows: Annual PM10 emissions = (EF x Veh/day x Emission days/year)/(454 x 2,000) Annual PM10 emissions = (6 x 100 x 250) / (454 x 2,000) = 0.165 tons/year Annual PM2.5 emissions = 0.1 x PM10 emissions' Annual PM2.5 emissions = (0.1 x 0.165 tons/year) = 0.0165 tons/year Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). For this example, we have selected gravel aprons at egress points as our control measure. Based on a control efficiency estimate of 46% for a gravel apron, the annual PM emissions are calculated to be: Annual Controlled PM10 emissions = (0.165 tons/yr) x (1 — 0.46) = 0.089 tons/yr Annual Controlled PM2.5 emissions = (0.0165 tons/yr) x (1 — 0.46) = 0.0089 tons/yr Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) Annual Operating/Maintenance costs ($) Annual Interest Rate Capital Recovery Factor Annualized Cost ($/year) 500 3,150 5% 0.54 3,419 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated as follows: Capital Recovery Factor = AIR x (1+AIR) Economic life / (1+AIR)E°°"°""°rte _ 1 Capital Recovery Factor = 5% x (1+ 5%)2 / (1+ 5%)2 — 1 = 0.54 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor and the Capital costs to the annual Operating and Maintenance costs: 3-21 Annualized Cost = (CRF x Capital costs) + Annual Operating and Maintenance costs Annualized Cost = (0.54 x $500) + $3,150 = $3,419 Step 6. Calculate Cost Effectiveness. Cost effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost effectiveness = Annualized Cost / (Uncontrolled emissions — Controlled emissions) Cost effectiveness for PM10 emissions = $3,420 / (0.165 - 0.089) = $44,991/ton Cost effectiveness for PM2.5 emissions = $3,420 / (0.0165 - 0.0089) = $449,908/ton 3.10 References 1. Midwest Research Institute, 1999. Estimating Particulate Matter Emissions From Construction Operations, Kansas City, Missouri, September. 2. U.S. EPA, 1995. Compilation of Air Pollutant Emission Factors. AP -42. Fifth Edition, Research Triangle Park, NC, September. 3. Muleski, G., 1996. Improvement of Specific Emission Factors (BACMProject No. 1), Final Report. Midwest Research Institute, March. 4. Cowherd, C. Jr., Axtell, K. Jr., Maxwell, C.M., Jutze, G.A., 1974. Development of Emission Factors for Fugitive Dust Sources, EPA Publication No. EPA -450/3-74- 037, NTIS Publication No. PB-238 262. 5. Muleski, G. E., Cowherd, C., 1999. Emission Measurements of Particle Mass and Size Emission Profiles From Construction Activities, EPA -600/R-99-091 (NTIS PB2000-101-11), U.S. Environmental Protection Agency, Research Triangle Park, NC. 6. Anderson, C.L., Brady, M.J. 1998. General Conformity Analysis for Major Construction Projects: An Example Analysis of Fugitive PM10 Emissions. Paper 98-MP4B.06 presented at the Annual Meeting of the Air & Waste Management Association, June 1998. 7. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 8. PEDCo Environmental Specialists, 1973. Investigation of Fugitive Dust Sources — Emissions and Control, prepared for the Environmental Protection Agency, OAQPS, contract No. 68-02-0044, May. 9. California Department of Finance, California Statistical Abstract - 2000, Section I, Construction, Economic Research Unit, (916) 322-2263. (www.dof.ca.gov) 3-22 10. Midwest Research Institute, 1974. Inventory of Agricultural Tilling, Unpaved Roads and Airstrips and Construction Sites, prepared for the U.S. Environmental Protection Agency, PB 238-929, Contract 68-02-1437, November. 11. South Coast Air Quality Management District, 1977. Emissions from Construction/Demolition, Emission Programs Unit, December. 12. Taback, J.J., et al, 1980. Inventory of Emissions from Non -Automotive Vehicular Sources, Final Report, KVB. 13. Personal Communication between CARB and Ben Bartolotto, Research Director of the Construction Industry Research Board, (818) 841-8210 (August 2002). 14. U.S. Census Bureau, Income 2000, Supplemental Information: Annual Average Consumer Price Index (CPI -U -RS); (www.census.gov/hhes/income/income00.cpiur). 15. U.S. Department of Labor, Bureau of Labor Statistics, Consumer Price Indexes, CPI Research Series Using Current Labor Methods (CPI -U -RS), (www.bls.gov/cpi/cpirsdc). 16. California Department of Transportation, Highway System Engineering Branch. 17. Elswick, F., 2005. Emission Control Methods for the Construction Industry, WRAP Fugitive Dust Control Workshop, Palm Springs, CA, May 10-11. 18. MRI, 1993. Background Documentation For AP -42 Section 11.2.4, Heavy Construction Operations, EPA Contract No. 69-D0-0123, Midwest Research Institute, Kansas City, MO, April. 19. C. Cowherd, et al., 1988. Control Of Open Fugitive Dust Sources, EPA -450/3-88- 008, U.S. Environmental Protection Agency, Research Triangle Park, NC, September. 20. Muleski, G. E., Cowherd, C., 2001. Particulate Emissions From Controlled Construction Activities, EPA -600/R-01-031 (NTIS PB2001-107255), U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC, April. 21. CARB April 2002. Evaluation of Air Quality Performance Claims for Soil-Sement Dust Suppressant. 22. Muleski, G.E., Page, A., Cowherd, C. Jr., 2003. Characterization of Particulate Emissions from Controlled Construction Activities: Mud/Dirt Carryout, EPA - 600/R -03-007. Research Triangle Park, NC: U.S. Environmental Protection Agency, February. 3-23 Chapter 4. Materials Handling 4.1 Characterization of Source Emissions 4-1 4.2 Emissions Estimation: Primary Methodology 4-1 4.3 Demonstrated Control Techniques 4-4 4.4 Regulatory Formats 4-5 4.5 Compliance Tools 4-7 4.6 Sample Cost -Effectiveness Calculation 4-7 4.7 References 4-9 4.1 Characterization of Source Emissions Inherent in operations that use minerals in aggregate form is the handling and transfer of materials from one process to another (e.g., to and from storage). Outdoor storage piles are usually left uncovered, partially because of the need for frequent material transfer into or out of storage. Dust emissions occur at several points in the storage cycle, such as material loading onto the pile, disturbances by strong wind currents, and loadout from the pile. The movement of trucks and loading equipment in the storage pile area is also a substantial source of dust. Dust emissions also occur at transfer points between conveyors or in association with vehicles used to haul aggregate materials 4.2 Emissions Estimation: Primary Methodology' -14 This section was adapted from Section 13.2.4 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.4 was last updated in January 1995. The quantity of dust emissions from aggregate storage operations varies with the volume of aggregate passing through the storage cycle. Emissions also depend on the age of the pile, moisture content, and proportion of aggregate fines. When freshly processed aggregate is loaded onto a storage pile, the potential for dust emissions is at a maximum. Fines are easily disaggregated and released to the atmosphere upon exposure to air currents, either from aggregate transfer itself or from high winds. However, as the aggregate pile weathers the potential for dust emissions is greatly reduced. Moisture causes aggregation and cementation of fines to the surfaces of larger particles. Any significant rainfall soaks the interior of the pile, and then the drying process is very slow. Table 4-1 summarizes measured moisture and silt content values for industrial aggregate materials. Silt (particles equal to or less than 75 micrometers [gm] in diameter) content is determined by measuring the portion of dry aggregate material that passes through a 200 -mesh screen, using ASTM-C-136 method.' Total dust emissions from aggregate storage piles result from several distinct source activities within the storage cycle: 1. Loading of aggregate onto storage piles (batch or continuous drop operations). 2. Equipment traffic in storage area. 3. Wind erosion of pile surfaces and ground areas around storage piles (see Chapter 9). 4. Loadout of aggregate for shipment or for return to the process stream (batch or continuous drop operations). Either adding aggregate material to a storage pile or removing it usually involves dropping the material onto a receiving surface. Truck dumping on the pile or loading out from the pile to a truck with a front-end loader are examples of batch drop operations. Adding material to the pile by a conveyor stacker is an example of a continuous drop operation. 4-I Table 4-1. Typical Silt and Moisture Contents of Materials at Various Industries' Industry No. of facilities Material Silt content (%) Moisture content (%) No. of samples Range Mean No. of samples Range Mean Iron and steel production 9 Pellet ore 13 1.3-13 4.3 11 0.64-4.0 2.2 Lump ore 9 2.8-19 9.5 6 1.6-8.0 5.4 Coal 12 2.0-7.7 4.6 11 2.8-11 4.8 Slag 3 3.0-7.3 5.3 3 0.25-2.0 0.92 Flue dust 3 2.7-23 13 1 — 7 Coke breeze 2 4.4-5.4 4.9 2 6.4-9.2 7.8 Blended ore 1 — 15 1 — 6.6 Sinter 1 — 0.7 0 — — Limestone 3 0.4-2.3 1.0 2 ND 0.2 Stone quarrying and processing 2 Crusted limestone 2 1.3-1.9 1.6 2 0.3-1.1 0.7 Various limestone products 8 0.8-14 3.9 8 0.46-5.0 2.1 Taconite mining and processing 1 Pellets 9 2.2-5.4 3.4 7 0.05-2.0 0.9 Tailings 2 ND 11 1 — 0.4 Western surface coal mining 4 Coal 15 3.4-16 6.2 7 2.8-20 6.9 Overburden 15 3.8-15 7.5 0 - - Exposed ground 3 5.1-21 15 3 0.8-6.4 3.4 Coal-fired power plant 1 Coal (as received) 60 0.6-4.8 2.2 59 2.7-7.4 4.5 Municipal solid waste landfills 4 Sand 1 — 2.6 1 — 7.4 Slag 2 3.0-4.7 3.8 2 2.3-4.9 3.6 Cover 5 5.0-16 9.0 5 8.9-16 12 Clay/dirt mix 1 — 9.2 1 — 14 Clay 2 4.5-7.4 6.0 2 8.9-11 10 Fly ash 4 78-81 80 4 26-29 27 Misc. fill materials 1 — 12 1 — 11 eferences 1-10. ND = no data. 4-2 The quantity of particulate emissions generated by either type of drop operation, expressed as a function of the amount of material transferred, may be estimated using the following empirical expression:1 Metric Units English Units where: E = k(0.0016) E=k(0.0032) U .3 2.2 (kg/megagram [Mg]) (S)1.3 � M)t.4 2 (pound [1b]/ton) (1) E = emission factor k = particle size multiplier (dimensionless) U = mean wind speed (meters per second, m/s, or miles per hour, mph) M = material moisture content (%) The particle size multiplier in the equation, k, varies with aerodynamic particle size range. For PM10, k is 0.35.11 There are two sources of fugitive dust associated with materials handling activities, namely particulate emissions from aggregate handling and storage piles, which typically consists of loader and truck traffic around the storage piles, and fugitive dust associated with the transfer of aggregate by buckets or conveyors. The PM2.5/PM10 ratios for these two sources of fugitive dust are 0.1 and 0.15, respectively.'2 In general, particulate emissions from loader and truck traffic around the storage piles predominates over particulate emissions from transfer of aggregate by buckets or conveyors. Equation 1 retains the assigned quality rating of A if applied within the ranges of source conditions that were tested in developing the equation; see table below. Note that silt content is included, even though silt content does not appear as a correction parameter in the equation. While it is reasonable to expect that silt content and emission factors are interrelated, no significant correlation between the two was found during the derivation of the equation, probably because most tests with high silt contents were conducted under lower winds, and vice versa. It is recommended that estimates from Equation 1 be reduced one quality rating level if the silt content used in a particular application falls outside the following range: Ran es of Source Conditions for Equation 1 Silt content (%) Moisture content (%) Wind speed m/s mph 0.44- 19 0.25-4.8 0.6-6.7 1.3- 15 For Equation 1 to retain the quality rating of A when applied to a specific facility, reliable correction parameters must be determined for the specific sources of interest. The field and laboratory procedures for aggregate sampling are given in Reference 3. In the event that site -specific values for correction parameters cannot be obtained, the 4-3 appropriate mean values from Table 4-1 may be used, but the quality rating of the equation is reduced by one letter. For emissions from trucks, front-end loaders, dozers, and other vehicles traveling between or on piles, it is recommended that the equations for vehicle traffic on unpaved surfaces be used (see Chapter 6). For vehicle travel between storage piles, the silt value(s) for the areas among the piles (which may differ from the silt values for the stored materials) should be used. Worst -case emissions from storage pile areas occur under dry, windy conditions. Worst -case emissions from materials -handling operations may be calculated by substituting into the equation appropriate values for aggregate material moisture content and for anticipated wind speeds during the worst -case averaging period, usually 24 hours. A separate set of nonclimatic correction parameters and source extent values corresponding to higher than normal storage pile activity also may be justified for the worst -case averaging period. 4.3 Demonstrated Control Techniques Watering and the use of chemical wetting agents are the principal means for control of emissions from materials handling operations involving transfer of bulk minerals in aggregate form. The handling operations associated with the transfer of materials to and from open storage piles (including the traffic around piles) represent a particular challenge for emission control. Dust control can be achieved by: (a) source extent reduction (e.g., mass transfer reduction), (b) source improvement related to work practices and transfer equipment such as load -in and load -out operations (e.g., drop height reduction, wind sheltering, moisture retention)), and (c) surface treatment (e.g., wet suppression). In most cases, good work practices that confine freshly exposed material provide substantial opportunities for emission reduction without the need for investment in a control application program. For example, loading and unloading can be confined to leeward (downwind) side of the pile. This statement also applies to areas around the pile as well as the pile itself. In particular, spillage of material caused by pile load -out and maintenance equipment can add a large source component associated with traffic - entrained dust. Emission inventory calculations show, in fact, that the traffic dust component may easily dominate over emissions from transfer of material and wind erosion. The prevention of spillage and subsequent spreading of material by vehicles traversing the area is essential to cost-effective emission control. If spillage cannot be prevented because of the need for intense use of mobile equipment in the storage pile area, then regular cleanup should be employed as a necessary mitigative measure. Fugitive emissions from aggregate materials handling systems are frequently controlled by wet suppression systems. These systems use liquid sprays or foam to suppress the formation of airborne dust. The primary control mechanisms are those that prevent emissions through agglomerate formation by combining small dust particles with larger aggregate or with liquid droplets. The key factors that affect the degree of agglomeration and, hence, the performance of the system are the coverage of the material 4-4 by the liquid and the ability of the liquid to "wet" small particles. There are two types of wet suppression systems —liquid sprays which use water or water/surfactant mixtures as the wetting agent and systems that supply foams as the wetting agent. Liquid spray wet suppression systems can be used to control dust emissions from materials handling at conveyor transfer points. The wetting agent can be water or a combination of water and a chemical surfactant. This surfactant, or surface-active agent, reduces the surface tension of the water. As a result, the quantity of liquid needed to achieve good control is reduced. Watering is also useful to reduce emissions from vehicle traffic in the storage pile area. Continuous chemical treating of material loaded onto piles, coupled with watering or treatment of roadways, can reduce total particulate emissions from aggregate storage operations by up to 90%.13'" Table 4-2 presents a summary of control measures and reported control efficiencies for materials handling that includes the application of a continuous water spray at a conveyor transfer point and two control measures for storage piles. Table 4-2. Control Efficiencies for Control Measures for Materials Handlin Control measure PM10 control efficiency References/comments Continuous water spray at conveyor transfer point 62% The control efficiency achieved by increasing the moisture content of the material from 1% to 2% is calculated utilizing the AP -42 emission factor equation for materials handling which contains a correction term for moisture content. Require construction of 3 -sided enclosures with 50% porosity for storage pile 75% Sierra Research, 2003.76 Determined through modeling of open area windblown emissions with 50% reduction in wind speed and assuming no emission reduction when winds approach open side. Water the storage pile by hand or apply cover when wind events are declared 90% Fitz et al., April 2000.16 4.4 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats for several local air quality agencies in the WRAP region are presented in Table 4-3. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: http://www.maricopa.gov/envsvc/air/ruledesc.asp 4-5 Table 4-3. Example Regulatory Formats for Materials Handling Control Measure Goal Threshold Agency Establishes wind barrier and watering or stabilization Limit visible dust emissions to 20% SJVAPCD requirements and bulk materials must be stored according to stabilization definition and outdoor materials covered opacity Rule 8031 11/15/2001 Best available control measures: wind sheltering, watering, chemical stabilizers, altering load-in/load-out Prohibits visible dust emissions beyond property line and limits SCAQMD Rule 403 procedures, or coverings upwind/downwind PM10 differential to 12/11/1998 50 pg/m3 Watering, dust suppressant (when loading, stacking, etc.); cover with tarp, watering (when not loading, etc.); Limit VDE to 20% opacity; stabilize soil For storage piles with >5% silt content, 3ft high, >/=150 sq ft; work practices for Maricopa County wind barriers, silos, enclosures, etc. stacking, loading, unloading, and when inactive; soil moisture content min 12%; or at least 70% min for optimum soil moisture content; 3 sided enclosures, at least equal to pile in length, same for ht, porosity <1=50% Rule 310 04/07/2004 Watering, clean debris from paved roads and other Stabilize demolition debris and Immediately water and clean-up after Maricopa surface after demolition surrounding area; establish crust and prevent wind erosion demolition County Rule 310 04/07/2004 Utilization of dust suppressants other than water when necessary; prewater; empty loader bucket slowly Prevent wind erosion from piles; stabilize condition where equip and Bulk material handling for stacking, loading, and unloading; for haul trucks Maricopa County vehicles op and areas where equipment op Rule 310 04/07/2004 4-6 4.5 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 4-4 summarizes the compliance tools that are applicable to materials handling. Table 4-4. Compliance Tools for Materials Handlin Record keeping Site inspection/monitoring Site map; work practices and locations; Observation of material transfer material throughputs; type of material operations and storage areas (including and size characterization; typical spills), operation of wet suppression moisture content when fresh; systems, vehicle/ equipment operation vehicle/equipment disturbance areas; and disturbance areas; surface material material transfer points and drop sampling and analysis for silt and heights; spillage and cleanup moisture contents; inspection of wind occurrences; wind fence/enclosure sheltering including enclosures; real-time installation and maintenance; dust portable monitoring of PM; observation of suppression equipment and main- dust plume opacities exceeding a tenance records; frequencies, amounts, times, and rates for watering and dust suppressants; meteorological log. standard. 4.6 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for materials handling. A sample cost-effectiveness calculation is presented 4-7 below for a specific control measure (continuous water spray at conveyor transfer point) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for materials handling, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Materials Handling (Conveyor Transfer Point) Step 1. Determine source activity and control application parameters. Material throughput (tons/hr) 25 Operating cycle (hours/day) 12 Number of workdays/year 312 Number of transfer points 1 Moisture content of material, M (%) 1 Mean wind speed, U (mph) 6 Control Measure Water spray located at conveyor transfer point Control application/frequency Continuous Economic Life of Control System (yr) 10 The material throughput, operating cycle, number of workdays per year, number of transfer points, material moisture content, wind speed, and economic life of the control system are assumed values for illustrative purposes. A continuous water spray located at a conveyor transfer point has been chosen as the applied control measure to increase the moisture content of the material from 1% to 2%. Step 2. Calculate Uncontrolled PM10 Emission Factor. The PM10 emission factor, EF, is calculated from the AP -42 equation utilizing the appropriate correction parameters (mean wind speed U = 6 mph and moisture content M = 1%), as follows: EF=(0.35) x (0.0032) x (6/5)1.3 / (1/2)1.4 = 0.00377 Ib/ton Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (calculated in Step 2) is multiplied by the material throughput, operating cycle, and workdays per year (all under activity data) and then divided by 2,000 lbs to compute the annual PM10 emissions in tons per year, as follows: Annual PM10 emissions = (EF x Material Throughput x Operating Cycle x Workdays/yr) / 2,000 Annual PM10 emissions = (0.00377 x 25 x 12 x 312) / 2000 = 0.175 tons Annual PM2.5 emissions = 0.15 x PM10 emissions12 Annual PM2.5 emissions = (0.15 x 0.175 tons) = 0.0263 tons Step 4. Calculate Controlled PM Emission Factor. The PM emission factor for controlled emissions, EF, is calculated from the AP -42 equation utilizing the appropriate correction parameters (mean wind speed U = 6 mph and moisture content M = 2%), as follows: 4-8 EF=(0.35) x (0.0032) x (6/5)1.3 / (2/2)1.4 = 0.00142 lb/ton Step 5. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) is calculated by multiplying the PM10 emission factor (calculated in Step 4) by the material throughput, operating cycle, and workdays per year (all under activity data) and then divided by 2,000 lbs to compute the annual emissions in tons per year, as follows: Annual emissions = (EF x Material Throughput x Operating Cycle x Workdays/yr) / 2,000 Annual PM10 Emissions = (0.00142 x 25 x 12 x 312) / 2000 = 0.0664 tons Annual PM2.5 emissions for material transfer = 0.15 x PM10 emissions12 Annual PM2.5 Emissions = (0.15 x 0.0665 tons) = 0.00100 tons Note: The control efficiency of using a water spray to increase the material moisture content from 1% to 2% is 62% (100 x (0.175 - 0.0664) / 0.175) Step 6. Determine Annual Cost to Control PM Emissions. Capital costs ($) 16,000 Annual Operating/Maintenance costs ($) 12,200 Annual Interest Rate 3% Capital Recovery Factor 0.1172 Annualized Cost ($/yr) 14,076 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: Capital Recovery Factor = AIR x (1+AIR) Economic life / (1+AIR) Economic life_ 1 Capital Recovery Factory = 3% x (1+ 3%)10 / (1+ 3%)10 - 1 = 0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor by the Capital costs with the annual Operating/Maintenance costs as follows: Annualized Cost = (CRF x Capital costs) + Operating/Maintenance costs Annualized Cost = (0.1172 x 16,000) + 12,200 = $14,076 Step 7. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = $14,076/ (0.175- 0.0664) = $129,267/ton Cost-effectiveness for PM2.5 emissions = $14,076/ (0.0263- 0.0100) = $861,779/ton 4.7 References 1. Cowherd, C., Jr., et al., 1974. Development of Emission Factors for Fugitive Dust Sources, EPA -450/3-74-037, U. S. EPA, Research Triangle Park, NC, June. 4-9 2. Bohn, R., et al., 1978. Fugitive Emissions from Integrated Iron And Steel Plants, EPA -600/2-78-050, U. S. EPA Cincinnati, OH, March. 3. Cowherd, C., Jr., et a/.,1979. Iron and Steel Plant Open Dust Source Fugitive Emission Evaluation, EPA -600/2-79-103, U. S. EPA, Cincinnati, OH, May. 4. MRI, 1979. Evaluation of Open Dust Sources in the Vicinity Of Buffalo, New York, EPA Contract No. 68-02-2545, Midwest Research Institute, Kansas City, MO, March. 5. Cowherd, C., Jr., and Cuscino, T. Jr.,1977. Fugitive Emissions Evaluation, MRI- 4343-L, Midwest Research Institute, Kansas City, MO, February. 6. Cuscino, T. Jr., et al., 1979. Taconite Mining Fugitive Emissions Study, Minnesota Pollution Control Agency, Roseville, MN, June. 7. PEDCO, 1981. Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources, 2 Volumes, EPA Contract No. 68-03-2924, PEDCO Environmental, Kansas City, MO, July. 8. TRC, 1984. Determination of Fugitive Coal Dust Emissions from Rotary Railcar Dumping, TRC, Hartford, CT, May. 9. MRI, 1987. PM10 Emission Inventory of Landfills in the Lake Calumet Area, EPA Contract No. 68-02-3891, Midwest Research Institute, Kansas City, MO, September. 10. MRI, 1988. Chicago Area Particulate Matter Emission Inventory - Sampling and Analysis, EPA Contract No. 68-02-4395, Midwest Research Institute, Kansas City, MO, May. 11. MRI, 1987. Update of Fugitive Dust Emission Factors in AP -42 Section 11.2, EPA Contract No. 68-02-3891, Midwest Research Institute, Kansas City, MO, July. 12. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 13. Jutze, G.A. et al. 1974. Investigation of Fugitive Dust Sources Emissions and Control, EPA -450/3-74-036a, U. S. EPA, Research Triangle Park, NC, June. 14. Cowherd, C. Jr., et al.,1988. Control Of Open Fugitive Dust Sources, EPA -450/3- 88-008, U. S. EPA, Research Triangle Park, NC, September. 15. Sierra Research, 2003. Final BACM Technological and Economic Feasibility Analysis, report prepared for the San Joaquin Valley Unified Air Pollution Control District. March 21. 16. Fitz, D., K. Bumiller, 2000. Evaluation of Watering to Control Dust in High Winds, J.AWMA, April. 4-10 Chapter 5. Paved Roads 5.1 Characterization of Source Emissions 5-1 5.2 Emissions Estimation: Primary Methodology 5-1 5.3 Emission Estimation: Alternate Methodology 5-8 5.4 Demonstrated Control Techniques 5-9 5.5 Regulatory Formats 5-10 5.6 Compliance Tools 5-12 5.7 Sample Cost -Effectiveness Calculation 5-12 5.8 References 5-14 5.1 Characterization of Source Emissions Particulate emissions occur whenever vehicles travel over a paved surface such as a road or parking lot. Particulate emissions from paved surfaces are due to direct emissions from vehicles in the form of exhaust, brake wear and tire wear emissions, and resuspension of loose material on the road surface. In general terms, resuspended particulate emissions from paved surfaces originate from, and result in the depletion of the loose material present on the surface (i.e., the surface loading). In turn, that surface loading is continuously replenished by other sources. At industrial sites, surface loading is replenished by spillage of material and trackout from unpaved roads and staging areas. Various field studies have found that public streets and highways as well as roadways at industrial facilities can be major sources of the atmospheric particulate matter within an area.1-9 Of particular interest in many parts of the United States are the increased levels of emissions from public paved roads when the equilibrium between deposition and removal processes is upset. This situation can occur for various reasons, including application of granular materials for snow and ice control, mud/dirt carryout from construction activities in the area, and deposition from wind and/or water erosion of surrounding unstabilized areas. In the absence of continuous addition of fresh material (through localized trackout or application of antiskid material), paved road surface loading should reach an equilibrium value in which the amount of material resuspended matches the amount replenished. The equilibrium surface loading value depends upon numerous factors. It is believed that the most important factors are: the mean speed of vehicles traveling the road, the average daily traffic (ADT), the number of lanes and ADT per lane, the fraction of heavy vehicles (buses and trucks), and the presence or absence of curbs, storm sewers and parking lanes.'° 5.2 Emissions Estimation: Primary Methodology1-29 This section was adapted from Section 13.2.1 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.1 was last updated in December 2003. Dust emissions from paved roads have been found to vary with what is termed the "silt loading" present on the road surface as well as the average weight of vehicles traveling the road. The term silt loading (sL) refers to the mass of silt -size material (equal to or less than 75 micrometers [gm] in physical diameter) per unit area of the travel surface. The total road surface dust loading consists of loose material that can be collected by broom sweeping and vacuuming of the traveled portion of the paved road. The silt fraction is determined by measuring the proportion of the loose dry surface dust that passes through a 200 -mesh screen using the ASTM-C-136 method. Silt loading is the product of the silt fraction and the total loading, and is abbreviated "sL." Additional details on the sampling and analysis of such material are provided in Appendices C.1 and C.2 of AP -42. 5-1 The surface silt loading (sL) provides a reasonable means of characterizing seasonal variability in a paved road emission inventory. In many areas of the country, road surface silt loadings are heaviest during the late winter and early spring months when the residual loading from snow/ice controls is greatest.11.21 As noted earlier, once replenishment of fresh material is eliminated, the road surface silt loading can be expected to reach an equilibrium value, which is substantially lower than the late winter/early spring values. The quantity of particulate emissions from resuspension of loose material on the road surface due to vehicle travel on a dry paved road may be estimated using the following empirical expression: where, L=ki�I `0.("s5 1i, 1.5 xI— _C, (1) E = particulate emission factor (having units matching the units of k), k = particle size multiplier for particle size range, sL = road surface silt loading (grams per square meter, g/m2), W = average weight (tons) of the vehicles traveling the road, and C = emission factor for 1980's vehicle fleet exhaust, brake wear and tire wear.27 It is important to note that Equation 1 calls for the average weight of all vehicles traveling the road. For example, if 99% of traffic on the road are 2 -ton cars/trucks while the remaining 1% consists of 20 -ton trucks, then the mean weight "W" is 2.2 tons. More specifically, Equation 1 is not intended to be used to calculate a separate emission factor for each vehicle weight class. Instead, only one emission factor should be calculated to represent the "fleet" average weight of all vehicles traveling the road. The particle size multiplier (k) varies with aerodynamic size range. For PM10, k equals 0.016 lbNMT (i.e., 7.3 g/VMT or 4.6 gNKT). The PM2.5/PM 10 ratio for fugitive dust from travel on paved roads is 0.15.28 The PM2.5 and PM10 emission factors for the exhaust, brake wear and tire wear of a 1980's vehicle fleet (C) were obtained from EPA's MOBILE6.2 mode1.29 The emission factor also varies with aerodynamic size range as shown in Table 5-1. Equation 1 is based on a regression analysis of numerous emission tests, including 65 tests for PM10.10 Sources tested include public paved roads, as well as controlled and uncontrolled industrial paved roads. All sources tested were of freely flowing vehicles traveling at constant speed on relatively level roads. No tests of "stop -and -go" traffic or vehicles under load were available for inclusion in the database. The equation retains the quality rating of A, if applied within the range of source conditions that were tested in developing the equation, as follows: Silt loading: 0.03 - 400 g/m2; 0.04 - 570 grains/square foot Mean vehicle weight: 1.8 - 38 megagrams; 2.0 - 42 tons Mean vehicle speed: 16 - 88 kilometers per hour; 10 - 55 miles per hour 5-2 Table 5-1. Emission Factors for 1980's Vehicle Fleet Exhaust, Brake Wear, and Tire Wear Particle size C, Emission factor for exhaust, brake wear, and tire weara g/VMT gNKT IbNMT PM2.5 0.1617 0.1005 0.00036 PM 10 0.2119 0.1317 0.00047 a Units shown are grams per vehicle mile traveled (gNMT), grams per vehicle kilometer traveled (gNKT), and pounds per vehicle mile traveled (lb/VMT). NOTE: There may be situations where low silt loading and/or low average weight will yield calculated negative emissions from Equation 1. If this occurs, the emissions calculated from Equation 1 should be set to zero. Users are cautioned that application of Equation 1 outside of the range of variables and operating conditions specified above (e.g., application to roadways or road networks with speeds below 10 mph and with stop -and -go traffic) will result in emission estimates with a higher level of uncertainty. To retain the quality rating of A for PM 10 for the emission factor equation when it is applied to a specific paved road, it is necessary that reliable correction parameter values for the specific road in question be determined. With the exception of limited access roadways, which are difficult to sample, the collection and use of site -specific silt loading (sL) data for public paved road emission inventories are strongly recommended. The field and laboratory procedures for determining surface material silt content and surface dust loading are summarized in Appendices C.1 and C.2 of AP -42. In the event that site -specific silt loading values cannot be obtained, an appropriate value for a paved public road may be selected from the default values given in Table 5-2, but the quality rating of the equation should be reduced by two levels. Also, recall that Equation 1 refers to emissions due to freely flowing (not stop -and -go) traffic at constant speed on level roads. Equation 1 may be extrapolated to average uncontrolled conditions (but including natural mitigation) under the simplifying assumption that annual (or other long-term) average emissions are inversely proportional to the frequency of measurable (at least 0.254 mm [0.01 inch]) precipitation by application of a precipitation correction term. The precipitation correction term can be applied on a daily or an hourly basis.26 For the daily basis, Equation 1 becomes: E =[k(-2 -T) (W\is ex,IL Il 2 JI 3) P l — C (1-4N) (2) where k, sL, W, and C are as defined in Equation 1 and EeX, = annual or other long-term average emission factor in the same units as k, P = number of "wet" days with at least 0.254 mm (0.01 in) of precipitation during the averaging period, and N = number of days in the averaging period (e.g., 365 for annual, 91 for seasonal, 30 for monthly) 5-3 Note that the assumption leading to Equation 2 is based by analogy with the approach used to develop long-term average unpaved road emission factors in Chapter 6. However, Equation 2 above incorporates an additional factor of "4" in the denominator to account for the fact that paved roads dry more quickly than unpaved roads and that the precipitation may not occur over the complete 24 -hour day. Table 5-2. Ubiquitous Silt Loading Default Values with Hot Spot Contributions from Anti -Skid Abrasives for Public Paved Roads (g/m2) Average Daily Traffic (ADT) Category < 500 500-5,000 5,000-10,000 > 10,000 Ubiquitous baseline (g/m2) 0.6 0.2 0.06 0.03 0.015 limited access Ubiquitous winter baseline multiplier during months with frozen precipitation X4 X3 X2 X1 Initial peak additive contribution from application of antiskid abrasive (g/m2) 2 2 2 2 Days to return to baseline conditions (assume linear decay) 7 3 1 0.5 For the hourly basis, Equation 1 becomes: Ems` k(2)o.6s (w)hi — C (1— 1.2P) (3) where k, sL, and W, and C are as defined in Equation 1 and Eext = annual or other long-term average emission factor in the same units as k, P = number of hours with at least 0.254 mm (0.01 in) of precipitation during the averaging period, and N = number of hours in the averaging period (e.g., 8,760 for annual; 2,124 for season; 720 for monthly). Note that the assumption leading to Equation 3 is based by analogy with the approach used to develop long-term average unpaved road emission factors in Chapter 6. Also note that in the hourly moisture correction term (1-1.2P/N) for Equation 3, the 1.2 multiplier is applied to account for the residual mitigative effect of moisture. For most applications, this equation will produce satisfactory results. However, if the time interval for which the equation is applied is short (e.g., 1 hour or 1 day), the application of this multiplier makes it possible for the moisture correction term to become negative. This will result in calculated negative emissions which is not realistic. Users should expand the time interval to include sufficient "dry" hours such that negative emissions are not calculated. For the special case where this equation is used to calculate emissions on an hour by hour basis, such as would be done in some emissions modeling situations, the moisture correction term should be modified so that the moisture correction "credit" is applied to the first hours following cessation of precipitation. In this special case, it is 5-4 suggested that this 20% "credit" be applied on a basis of one hour credit for each hour of precipitation up to a maximum of 12 hours. Maps showing the geographical distribution of "wet" days on an annual basis for the United States based on meteorological records on a monthly basis are available in the Climatic Atlas of the United States.23 Alternative sources include other Department of Commerce publications such as local climatological data summaries. The National Climatic Data Center (NCDC) offers several products that provide hourly precipitation data. In particular, NCDC offers a Solar and Meteorological Surface Observation Network 1961-1990 (SAMSON) CD-ROM, which contains 30 years worth of hourly meteorological data for first -order National Weather Service locations. Whatever meteorological data are used, the source of that data and the averaging period should be clearly specified. It is emphasized that the simple assumption underlying Equations 2 and 3 has not been verified in any rigorous manner. For that reason, the quality ratings for Equations 2 and 3 should be downgraded one letter from the rating that would be applied to Equation 1. Table 5-2 presents recommended default silt loadings for normal baseline conditions and for wintertime baseline conditions for public paved roads in areas that experience frozen precipitation with periodic application of antiskid material.24 The winter baseline is represented as a multiple of the nonwinter baseline, depending on the average daily vehicle traffic count (ADT) value for the road in question. As shown, a multiplier of 4 is applied for low volume roads (< 500 ADT) to obtain a wintertime baseline silt loading of 4 x 0.6 = 2.4 g/m2. It is suggested that an additional (but temporary) silt loading contribution of 2 g/m2 occurs with each application of antiskid abrasive for snow/ice control. This was determined based on a typical application rate of 500 lb per lane mile and an initial silt content of 1%. Ordinary rock salt and other chemical deicers add little to the silt loading because most of the chemical dissolves during the snow/ice melting process. To adjust the baseline silt loadings for mud/dirt trackout, the number of trackout points is required. It is recommended that in calculating PM10 emissions, six additional miles of road be added for each active trackout point from an active construction site, to the paved road mileage of the specified category within the county. In calculating PM2.5 emissions, it is recommended that three additional miles of road be added for each trackout point from an active construction site. It is suggested the number of trackout points for activities other than road and building construction areas be related to land use. For example, in rural farming areas, each mile of paved road would have a specified number of trackout points at intersections with unpaved roads. This value could be estimated from the unpaved road density (miles per square mile). The use of a default value from Table 5-2 should be expected to yield only an order - of -magnitude estimate of the emission factor. Public paved road silt loadings are dependent upon: traffic characteristics (speed, ADT, and fraction of heavy vehicles); road characteristics (curbs, number of lanes, parking lanes); local land use (agriculture, new residential construction) and regional/seasonal factors (snow/ice controls, wind blown 5-5 dust). As a result, the collection and use of site -specific silt loading data is highly recommended. In the event that default silt loading values are used, the quality ratings for the equation should be downgraded two levels. Limited access roadways (high speed freeways) pose severe logistical difficulties in terms of surface sampling, and few silt loading data are available for such roads. Nevertheless, the available data do not suggest great variation in silt loading for limited access roadways from one part of the country to another. For annual conditions, a default value of 0.015 g/m2 is recommended for limited access roadways.9' 22 Even fewer of the available data correspond to worst -case situations, and elevated loadings are observed to be quickly depleted because of high traffic speeds and high ADT rates. A default value of 0.2 g/m2 is recommended for short periods of time following application of snow/ice controls to limited access roads.22 The limited data on silt loading values for industrial roads have shown as much variability as public roads. Because of the variations of traffic conditions and the use of preventive mitigative controls, the data probably do not reflect the full extent of the potential variation in silt loading on industrial roads. However, the collection of site specific silt loading data from industrial roads is easier and safer than for public roads. Therefore, the collection and use of site -specific silt loading data is preferred and is highly recommended. In the event that site -specific values cannot be obtained, an appropriate value for an industrial road may be selected from the mean values given in Table 5-3, but the quality rating of the equation should be reduced by two levels. AP -42 measurements of silt loading for paved roads involve periodic sampling from representative roads that are then used to calculate emissions. These silt loadings have been shown to be highly variable in time and space, and the labor required for their acquisition mitigates against frequent sampling that covers a wide spatial extent. Several groups — Desert Research Institute (DRI) and UC Riverside (CE-CERT) - have developed vehicle -based mobile sampling systems for PM10 emissions of re -entrained paved road dust over the past several years.3° Both systems (DRI's system is called TRAKER and CE-CERT's system is called SCAMPER) have been calibrated in Las Vegas against actual AP -42 silt loadings determined for samples taken in the study area for a complete range of paved roadway classifications and a large range of visible paved road surface loadings. The study results showed a reasonable relationship between the continuous vehicle -based PM10 emission measurements and actual silt loadings. 5-6 Table 5-3 Typical Silt Content and Loading Values for Paved Roads at Industrial Facilitiesa (Metric And English Units). Industry No. of sites No. of samples Silt content (%) No. of travel lanes Total loading x 10-3 Silt loading (g/m2) Range Mean Range Mean Unitsb Range Mean Copper smelting 1 3 15.4-21.7 19.0 2 12.9-19.5 15.9 kg/km 188-400 292 45.8-69.2 55.4 lb/mi Iron and steel production 9 48 1.1-35.7 12.5 2 0.006-4.77 0.495 kg/km 0.09-79 9.7 0.020-16.9 1.75 lb/mi Asphalt batching 1 3 2.6-4.6 3.3 1 12.1-18.0 14.9 kg/km 76-193 120 43.0-64.0 52.8 lb/mi Concrete batching 1 3 5.2-6.0 5.5 2 1.4-1.8 1.7 kg/km 11-12 12 5.0-6.4 5.9 lb/mi Sand and gravel 1 3 6.4-7.9 7.1 1 2.8-5.5 3.8 kg/km 53-95 70 processing 9.9-19.4 13.3 lb/mi Municipal solid waste landfill 2 7 — — 2 — — — 1.1-32.0 7.4 Quarry 1 6 — — 2 — — 2.4-14 8.2 References 1-2, 5-6, 11-13; dashes indicate information not available. b Multiply entries by 1,000 to obtain stated units: kilograms per kilometer (kg/km) and pounds per mile (lb/mi). 5-7 5.3 Emission Estimation: Alternate Methodology This section was adapted from Section 7.9 of CARB's Emission Inventory Methodology. Section 7.9 was last updated in July 1997. The paved road dust category includes emissions of fugitive dust particulate matter entrained by vehicular travel on paved roads. The California Air Resources Board (CARB) estimates road dust emissions for the following four classes of roads: (1) freeways/expressways, (2) major streets/highways, (3) collector streets, and (4) local streets. Dust emissions from vehicle travel on paved roads are computed using the emission factor equation provided in AP -42 (see Section 5.2 of this document). Inputs to the paved road dust equation were developed from area -specific roadway silt loadin and average vehicle weight data measured by Midwest Research Institute (MRI, 1996).3 Data from states and air districts are used to estimate county specific VMT (vehicle miles traveled) data.32' 33 State highway34 data are used to estimate the fraction of travel on each of the four road types in each county. The statewide average vehicle weight for California is assumed to be 2.4 tons. This estimate is based on an informal traffic count estimated by MRI while they were performing California silt loading measurements.31 CARB assumes the following silt loadings for the four road categories: 0.02 g/m2 for freeways, 0.035 g/m2 for major roads, and 0.32 g/m2 for collector and local roads.35 Temporal activity is assumed to be the same as on -road vehicle travel: uniform in spring and fall, increasing slightly in summer, and decreasing slightly in winter. The monthly temporal profile shown below in Table 5-4 shows this trend. The weekly and daily activities are estimated to have higher activities on weekdays and during daylight hours. Table 5-4. Monthly Temporal Profile for On -road Vehicle Travel ALL JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 100 7.7 7.7 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 7.7 This alternative methodology utilized by CARB is subject to the following assumptions and limitations: 1. The current AP -42 emission factor assumes that road dust emissions are proportional to VMT, roadway silt loading, and average vehicle weight. 2. It may be necessary to assume that virtually the same silt loading values apply throughout the state because of lack of measured silt loadings. 3. The methodology assumes that roadway silt loading, and therefore the emission factor, varies by the type of road. 4. It is assumed that the EPA particle size multiplier (i.e., the `k' factor in the AP -42 equation) reasonably represents the size distribution of paved road dust. 5-8 5. The average vehicle fleet weight is assumed to be 2.4 tons in California (except for the SCAQMD that assumes 3 tons). 6. For freeway and major roads, emissions growth is assumed to be proportional to changes in roadway centerline mileage. For collector and local roads, emissions growth is assumed proportional to changes in VMT. 5.4 Demonstrated Control Techniques Because of the importance of road surface silt loading, control techniques for paved roads attempt either to prevent material from being deposited onto the surface (preventive controls) or to remove from the travel lanes any material that has been deposited (mitigative controls). Covering of loads in trucks and the paving of access areas to unpaved lots or construction sites are examples of preventive measures. Examples of mitigative controls include vacuum sweeping, water flushing, and broom sweeping and flushing. Actual control efficiencies for any of these techniques can be highly variable. Locally measured silt loadings before and after the application of controls is the preferred method to evaluate controls. It is particularly important to note that street sweeping of gutters and curb areas may actually increase the silt loading on the traveled portion of the road. Redistribution of loose material onto the travel lanes will actually produce a short- term increase in the emissions. In general, preventive controls are usually more cost effective than mitigative controls. The cost-effectiveness of mitigative controls falls off dramatically as the size of an area to be treated increases. The cost-effectiveness of mitigative measures is also unfavorable if only a short period of time is required for the road to return to equilibrium silt loading condition. That is to say, the number and length of public roads within most areas of interest preclude any widespread and routine use of mitigative controls. On the other hand, because of the more limited scope of roads at an industrial site, mitigative measures may be used quite successfully (especially in situations where truck spillage occurs). Note, however, that public agencies could make effective use of mitigative controls to remove sand/salt from roads after the winter ends. Because available controls will affect the silt loading, controlled emission factors may be obtained by substituting controlled silt loading values into the appropriate equation. (Note that emission factors from controlled industrial roads were used in the development of the equation.) The collection of surface loading samples from treated, as well as baseline (untreated) roads provides a means to track effectiveness of the controls over time. Table 5-5 summarizes tested control measures and reported control efficiencies for measures that reduce the generation of fugitive dust from paved roads. 5-9 Table 5-5. Control Efficiencies for Control Measures for Paved Roads36-3s Control measure PM10 control Source component efficiency References/Comments Implement street sweeping Local streets program with non -efficient vacuum units (14 -day frequency) Implement street sweeping program with PM10 efficient vacuum units (14 -day frequency) Arterial/collector streets Local streets Arterial/collector streets Require streets to be swept Local, arterial and by non -efficient vacuum collector streets units (once per month frequency) Require streets to be swept Local, arterial and by PM10 efficient vacuum collector streets units (once per month frequency) Require wind- or water- borne deposition to be cleaned up within 24 hours after discovery All Streets Install pipe -grid trackout- Mud/dirt carryout control device 26% 7% 11% MRI, September 1992. For non-PM10 efficient sweepers based on 55% efficient sweeping, 5.5 day equilibrium return time and CA-VMT weighted sweeping frequency (7 to 30 days) 16% MRI, September 1992. For PM10 efficient sweepers, based on 86% efficient sweeping, 8.6 day return time, and CA-VMT weighted sweeping frequency (7 to 30 days) 4% MRI, September 1992. For non-PM10 efficient sweepers based on 55% efficient sweeping, 5.5 day equilibrium return time and CA-VMT weighted sweeping frequency (7 to 30 days) 9% MRI, September 1992. For PM10 efficient sweepers, based on 86% efficient sweeping, 8.6 day return time, and CA-VMT weighted sweeping frequency (7 to 30 days) 100% Assumes total cleanup of spill on roadway before traffic resumes 80% Sierra Research, 2003. Install gravel bed trackout Mud/dirt carryout 46% MRI, April 2001 apron (3 in deep, 25 ft long and full road width) Require paved interior Mud/dirt carryout 42% MRI, April 2001 roads to be 100 foot long and full road width, or add 4 foot shoulder for paved roads 5.5 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Example regulatory formats for several local air quality agencies in the WRAP region are presented in Table 5-6. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/envsvc/air/ruledesc.asp 5-10 Table 5-6. Example Regulatory Formats for Paved Roads Control Measure Goal Threshold Agency Limit speed limit to 15 mph or less Limit track -out from bulk material Work site roads, crossing paved roads Maricopa County transport; reduce particulate matter transporting bulk materials; during Rule 310 emissions from paved roads disking and blading ops 04/07/2004 Requires paved travel section, and 4 ft of paved or stabilized shoulder Comply with stabilization standard: limit Newly constructed or modified paved Clark County on each side of travel section. Shoulders shall be paved with dust shoulder visible dust emissions to 20% roads Hydrographic palliative or gravel (2"). Medians shall be constructed as follows: with curbing, solid paving; apply dust palliatives, or with material that prevent track -Out such as landscaping or decorative rock. opacity; limit silt loading to 0.33 oz/ft2 Basins 212, 216, 217 Sect. 93 Air Quality Reg. 07/01/04 Requires paved shoulders. As an option to paving or vegetation Limit visible dust emissions to 20% Roads with average daily vehicle trips SJVAPCD Rule requirements, oils or chemical dust suppressants can be used and must be maintained opacity (ADVT) of 500 or more 8061 11/15/2001 Require average shoulder width to be 4 ft. Curbing adjacent to and Limit visible dust emissions to 20% Roads with average daily vehicle trips SJVAPCD Rule contiguous with a paved lane or shoulder can be used in lieu of shoulder width requirements. Intersections, auxiliary entry and exit lanes may be constructed adjacent to and contiguous with a paved roadway in lieu of shoulder requirements opacity (ADVT) 500-3000 8061 11/15/2001 Require average shoulder width to be 8 ft. Curbing adjacent to and Limit visible dust emissions to 20% Roads with average daily vehicle trips SJVAPCD Rule contiguous with a paved lane or shoulder can be used in lieu of shoulder width requirements. Intersections, auxiliary entry and exit lanes may be constructed adjacent to and contiguous with a paved roadway in lieu of shoulder requirements opacity (ADVT) greater than 3000 8061 11/15/2001 Medians constructed with minimum 4 ft shoulder widths adjacent to Meet stabilized surface requirements and Roads with average daily vehicle trips SJVAPCD Rule traffic lanes, and landscaped. Medians constructed with curbing id speed limit < 45 mph. limit visible dust emissions to 20% opacity (ADVT) of 500 or more and medians part of roadway 8061 11/15/2001 Curbing and shoulder width requirements in event of contingency Maintain stabilized surface; limit paved Roads with average daily vehicle trips SCAQMD Rule notification road dust (ADVT) of 500 or more 1186 9/10/1999 Require average shoulder width to be 4 ft. Limit visible dust emissions to 20% Roads with average daily vehicle trips SCAQMD Rule opacity (ADVT) 500-3000 1186 9/10/1999 Require average shoulder width to be 8 ft. Limit visible dust emissions to 20% Roads with average daily vehicle trips SCAQMD Rule opacity (ADVT) > 3000 1186 9/10/1999 For speed limit >45 mph: pave median area with typical roadway Maintain stabilized surface Roads with average daily vehicle trips SCAQMD Rule materials. For speed limit <45 mph: medians must be landscaped or treated with chemical stabilizers. (ADVT) of 500 or more 1186 9/10/1999 5-11 5.6 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 5-7 summarizes the compliance tools that are applicable to paved roads. Table 5-7. Compliance Tools for Paved Roads Record keeping Site inspection/monitoring Road map; traffic volumes, speeds, and Sampling of silt loading on paved road patterns; vacuum sweeping, mud/dirt surfaces; counting of traffic volumes; trackout precautions, spill cleanup, erosion observations of vacuum sweeping, high control, tarping of haul trucks; curbing of dust emission areas (including track -on roads; application of sand/salt for anti-skid and wash -on points), road operations; dust suppression equipment and curbing/shoulders; observation of dust maintenance records. plume opacity (visible emissions) exceeding a standard; real-time portable monitoring of PM. 5.7 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for fugitive dust originating from paved roads. A sample cost-effectiveness calculation is presented below for a specific control measure (PM10 efficient street sweeper) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost- effectiveness values for PMI0 and PM2.5. In selecting the most advantageous control 5-12 measure for paved roads, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Paved Roads (Arterial Road Through Industrial Area) Step 1. Determine source activity and control application parameters. Vehicles/day Average vehicle speed (mph) Length of road (miles) Control Measure Control application/frequency Economic Life of Control System (yr) Control Efficiency 200 40 10 Use of PM10 efficient street sweepers Once per month 10 9.2% The number of vehicles per day, the average vehicle speed, road length, and economic life are assumed values for illustrative purposes. Street sweeping, using PM10 efficient sweepers has been chosen as the applied control measure. The control application/frequency and control efficiency are default values provided by MRI.37 Step 2. Calculate PM10 Emission Factor. The PM10 emission factor is calculated from the AP -42 equation. E (IbNMT) = 0.016 (sL/2)0'65 (W/3)1'5 - C) x (1-(P/1460)) sL—silt loading (g/m2) W —average vehicle weight (tons) C —exhaust plus break and tire wear (lb/VMT) P —wet days/yr (number/yr) E = 0.106 IbNMT 12 5 0.00047 50 Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (calculated in Step 2) is multiplied by the number of vehicles per day and the road length (both under activity data) and then multiplied by 365/2,000 to compute the annual PM10 emissions, as follows: Annual PM10 emissions = (Emission Factor x Vehicles/day x Road length x 365 / 2,000 Annual PM10 emissions = (0.106 x 200 x 10) x 365 /2,000 = 39 tons Annual PM2.5 emissions = 0.15 x PM10 emissions28 Annual PM2.5 emissions = (0.15 x 39) = 5.8 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). 5-13 For this example, a PM10 efficient street sweeper with a control efficiency of 9.2% has been selected as the control measure. Thus, the annual controlled PM10 and PM2.5 emissions estimates are calculated to be: Annual Controlled PM10 emissions = (39 tons) x (1 — 0.092) = 35 tons Annual Controlled PM2.5 emissions = (5.8 tons) x (1 — 0.092) = 5.3 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) Annual Operating/Maintenance costs ($) Annual Interest Rate Capital Recovery Factor Annualized Cost ($/yr) 152,000 16,000 3% 0.1172 33,819 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: Capital Recovery Factor = AIR x (1+AIR) Economic life / (1+AIR) Economic life — 1 Capital Recovery Factory = 3% x (1+ 3%)1O / (1+ 3%)10 — 1 = 0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor and the Capital costs to the annual Operating/Maintenance costs: Annualized Cost = (CRF x Capital costs) + Annual Operating/Maintenance costs Annualized Cost = (0.1172 x 152,000) + 16,000 = $33,819 Step 6. Calculate Cost Effectiveness. Cost effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost effectiveness for PM10 emissions = $33,819 / (39 - 35) = $9,492/ton Cost effectiveness for PM2.5 emissions = $33,819 / (5.8 - 5.3) = $63,283/ton 5.8 References 1. Dunbar, D.R., 1976. Resuspension of Particulate Matter, EPA -450/2-76-031, U. S. EPA, Research Triangle Park, NC, March. 2. Bohn, R. et al., 1978. Fugitive Emissions from Integrated Iron and Steel Plants, EPA -600/2-78-050, U. S. EPA, Cincinnati, OH, March. 3. Cowherd, C. Jr., et al.,1979. Iron and Steel Plant Open Dust Source Fugitive Emission Evaluation, EPA -600/2-79-103, U. S. Environmental Protection Agency, Cincinnati, OH, May. 5-14 4. Cowherd, C. Jr., et al., 1977. Quantification of Dust Entrainment from Paved Roadways, EPA -450/3-77-027, U. S. EPA, Research Triangle Park, NC, July. 5. MRI, 1983. Size Specific Particulate Emission Factors for Uncontrolled Industrial and Rural Roads, EPA Contract No. 68-02-3158, Midwest Research Institute, Kansas City, MO, September. 6. Cuscino, T. Jr., et al.,1983. Iron and Steel Plant Open Source Fugitive Emission Control Evaluation, EPA -600/2-83-110, U. S. EPA, Cincinnati, OH, October. 7. Reider, J.P., 1983. Size -specific Particulate Emission Factors for Uncontrolled Industrial and Rural Roads, EPA Contract 68-02-3158, Midwest Research Institute, Kansas City, MO, September. 8. Cowherd, C. Jr., Englehart, P.J., 1984. Paved Road Particulate Emissions, EPA - 600/7 -84-077, U. S. Environmental Protection Agency, Cincinnati, OH, July. 9. Cowherd, C. Jr., Englehart, P.J., 1985. Size Specific Particulate Emission Factors for Industrial and Rural Roads, EPA -600/7-85-038, U. S. EPA, Cincinnati, OH, September. 10. MRI, 1993. Emission Factor Documentation for AP -42, Sections 11.2.5 and 11.2.6 - Paved Roads, EPA Contract No. 68-D0-0123, Midwest Research Institute, Kansas City, MO, March. 11. MRI, 1979. Evaluation of Open Dust Sources in the Vicinity of Buffalo, New York, EPA Contract No. 68-02-2545, Midwest Research Institute, Kansas City, MO, March. 12. MRI, 1987. PMI0 Emission Inventory of Landfills in the Lake Calumet Area, EPA Contract No. 68-02-3891, Midwest Research Institute, Kansas City, MO, September. 13. MRI, 1988. Chicago Area Particulate Matter Emission Inventory - Sampling and Analysis, Contract No. 68-02-4395, Midwest Research Institute, Kansas City, MO, May. 14. MDHES, 1992. Montana Street Sampling Data, Montana Department Of Health and Environmental Sciences, Helena, MT, July. 15. PEI, 1989. Street Sanding Emissions and Control Study, PEI Associates, Inc., Cincinnati, OH, October. 16. Harding Lawson, 1991. Evaluation of PM10 Emission Factors for Paved Streets, Harding Lawson Associates, Denver, CO, October. 17. RTP, 1990. Street Sanding Emissions and Control Study, RTP Environmental Associates, Inc., Denver, CO, July. 18. AeroVironment, 1992. Post -storm Measurement Results - Salt Lake County Road Dust Silt Loading Winter 1991/92 Measurement Program, AeroVironment, Inc., Monrovia, CA, June. 5-15 19. Written communication to MRI from Harold Glasser, Department of Health, Clark County, Nevada. 1990. 20. ES, 1987. PM10 Emissions Inventory Data for the Maricopa and Pima Planning Areas, EPA Contract No. 68-02-3888, Engineering -Science, Pasadena, CA, January. 21. MRI, 1992. Characterization of PM10 Emissions from Antiskid Materials Applied to Ice- and Snow- Covered Roadways, EPA Contract No. 68-D0-0137, Midwest Research Institute, Kansas City, MO, October. 22. MRI, 1997. Fugitive Particulate Matter Emissions, EPA Contract No. 68-D2-0159, Work Assignment No. 4-06, Midwest Research Institute, Kansas City, MO, April. 23. Climatic Atlas of the United States, U.S. Department of Commerce, Washington, D.C., June 1968. 24. Cowherd, C. Jr., et al., 2002. Improved Activity Levels for National Emission Inventories of Fugitive Dust from Paved and Unpaved Roads, presented at the 11th International Emission Inventory Conference, Atlanta, Georgia, April. 25. Cowherd, C. Jr., et al., 1988. Control of Open Fugitive Dust Sources, EPA -450/3- 88-008, U. S. EPA, Research Triangle Park, NC, September. 26. Written communication (Technical Memorandum) from G. Muleski, Midwest Research Institute, Kansas City, MO, to B. Kuykendal, U. S. Environmental Protection Agency, Research Triangle Park, NC, September 27, 2001. 27. USEPA, 2002. MOBILE6 User Guide, United States Environmental Protection Agency, Office of Transportation and Air Quality. EPA420-R-02-028, October. 28. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 29. Written communication (Technical Memorandum) from P. Hemmer, E.H. Pechan & Associates, Inc., Durham, NC to B. Kuykendal, U. S. Environmental Protection Agency, Research Triangle Park, NC, August, 21, 2003. 30. Langston, R., et al., 2005. Alternative Technologies for Evaluating Paved -Road Dust Emission Potential — Mobile Sampling Methodology as an Alternative to Traditional AP -42 Silt Measurements, paper presented at the USEPA 15th International Emission Inventory Conference, New Orleans, LA, May 24. 31. Muleski, G., 1996. Improvement of Specific Emission Factors (BACM Project No. 1), Final Report. Midwest Research Institute, March 29. 32. CARB, 1993. 1993 Vehicle Miles Traveled by County from 1993 Ozone SIP EMFAC/BURDEN7F runs, California Air Resources Board, Technical Support Division. 5-16 33. County VMT data for 1993 for the San Joaquin Valley Unified Air Pollution Control District and South Coast Air Quality Management District were obtained from district staff (who collected the information from local transportation agencies). 34. Cal Trans, 1995. California 1993 Daily Vehicle Miles of Travel for Public Maintained Paved Roads based on Highway Performance Monitoring System (HPMS) Data from TRAV93 , California Department of Transportation. 35. Gaffney, P., 1987. Entrained Dust from Paved Road Travel, Emission Estimation Methodology, Background Document. California Air Resources Board, July. 36. MRI, April 2001. Particulate Emission Measurements from Controlled Construction Activities (EPA/600/R-01/031). 37. MRI, September 1992. Fugitive Dust Background Document for BACM (EPA - 450/2 -92-004). 38. Sierra Research, 2003. Final BACM Technological and Economic Feasibility Analysis, prepared for the San Joaquin Valley APCD, March. 5-17 Chapter 6. Unpaved Roads 6.1 Characterization of Source Emissions 6-1 6.2 Emission Estimation: Primary Methodology 6-1 6.3 Emission Estimation: Alternate Methodology for Non -Farm Roads 6-6 6.4 Emission Estimation: Alternative Methodology for Farm Roads 6-7 6.5 Demonstrated Control Techniques 6-8 6.6 Regulatory Formats 6-14 6.7 Compliance Tools 6-16 6.8 Sample Cost -Effectiveness Calculation 6-16 6.9 References 6-18 6.1 Characterization of Source Emissions When a vehicle travels on an unpaved surface such as an unpaved road or unpaved parking lot, the force of the wheels on the road surface causes pulverization of surface material. Particles are lifted and dropped from the rolling wheels, and the road surface is exposed to strong air currents in turbulent shear with the surface. The turbulent wake behind the vehicle continues to act on the road surface after the vehicle has passed. The quantity of dust emissions from a given segment of unpaved road varies linearly with the volume of traffic. Field investigations also have shown that emissions depend on source parameters that characterize the condition of a particular road and the associated vehicle traffic. Characterization of these source parameters allow for "correction" of emission estimates to specific road and traffic conditions present on public and industrial roadways. 6.2 Emission Estimation: Primary Methodology1-26 This section was adapted from Section 13.2.2 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.2 was last updated in December 2003. Dust emissions from unpaved roads have been found to vary directly with the fraction of silt (particles smaller than 75 micrometers [µm] in physical diameter) in the road surface materials.1 The silt fraction is determined by measuring the proportion of loose dry surface dust that passes a 200 -mesh screen using the ASTM-C-136 method. A summary of this method is contained in Appendix C of AP -42. Table 6-1 summarizes measured silt values for industrial unpaved roads. Table 6-2 summarizes measured silt values for public unpaved roads. It should be noted that the ranges of silt content for public unpaved roads vary over two orders of magnitude. Therefore, the use of data from this table can potentially introduce considerable error. Use of this data is strongly discouraged when it is feasible to obtain locally gathered data. Since the silt content of a rural dirt road will vary with geographic location, it should be measured for use in projecting emissions. As a conservative approximation, the silt content of the parent soil in the area can be used. Tests, however, show that road silt content is normally lower than in the surrounding parent soil, because the fines are continually removed by the vehicle traffic, leaving a higher percentage of coarse particles. Other variables are important in addition to the silt content of the road surface material. For example, at industrial sites, where haul trucks and other heavy equipment are common, emissions are highly correlated with vehicle weight. On the other hand, there is far less variability in the weights of cars and pickup trucks that commonly travel publicly accessible unpaved roads throughout the United States. For those roads, the moisture content of the road surface material may be more dominant in determining differences in emission levels between a hot desert environment and a cool moist location. 6-1 Table 6-1. Typical Silt Content Values of Surface Material on Industrial Unpaved Roadsa Industry Road use or surface material Plant sites No. of samples Silt content (%) Range Mean Copper smelting Plant road 1 3 16-19 17 Iron and steel production Plant road 19 135 0.2-19 6.0 Sand and gravel processing Plant road 1 3 4.1-6.0 4.8 Material storage area 1 1 — 7.1 Stone quarry and processing Plant road 2 10 2.4-16 10 Haul road to/from pit 4 20 5.0-15 8.3 Taconite mining and processing Service road 1 8 2.4-7.1 4.3 Haul road to/from pit 1 12 3.9-9.7 5.8 Western surface coal mining Haul road to/from pit 3 21 2.8-18 8.4 Plant road 2 2 4.9-5.3 5.1 Scraper route 3 10 7.2-25 17 Haul road (freshly graded) 2 5 18-29 24 Construction sites Scraper routes 7 20 0.56-23 8.5 Lumber sawmills Log yards 2 2 4.8-12 8.4 Municipal solid waste landfills Disposal routes 4 20 2.2-21 6.4 a References 1, 5-15. Table 6-2. Typical Silt Content Values of Surface Material on Public Unpaved Roadsa Industry Road use or surface material Plant sites No. of samples Silt content (%) Range Mean Publicly accessible roads Gravel/crushed limestone 9 46 0.1-15 6.4 Dirt (i.e., local material corn pacted, bladed, and crowned) 8 24 0.83-68 11 a References 1, 5-16. 6.2.1 Emission Factors The PMl O emission factors presented below are the outcomes from stepwise linear regressions of field emission test results of vehicles traveling over unpaved surfaces. For vehicles traveling on unpaved surfaces at industrial sites, PM10 emissions are estimated from the following empirical equation: E = 1.5 (s/12)°.9 (W/3)o.4s 6-? ( la) where and, for vehicles traveling on publicly accessible roads, dominated by light duty vehicles, PM10 emissions may be estimated from the following equation: 1.8 (s/12)18 (S/30)05 E= (M/0.5)°2 E PM10 emission factor (lb/VMT) s = surface material silt content (%) W = mean vehicle weight (tons) M = surface material moisture content (%) S mean vehicle speed (mph) C = emission factor for 1980's vehicle fleet exhaust, brake wear and tire wear. (lb) The source characteristics s, W and M are referred to as correction parameters for adjusting the emission estimates to local conditions. The metric conversion from lb/VMT to grams (g) per vehicle kilometer traveled (VKT) is 1 lb/VMT = 281.9 gNKT. Equations la and lb have a quality rating of B if applied within the ranges of source conditions that were tested in developing the equations shown in Table 6-3. Table 6-3. Range of Source Conditions Used in Developing Equations la and lb Emission factor Surface silt content, % Mean vehicle weicht Mean vehicle speed Mean No. of wheels Surface moisture content, Mg ton km/hr mph Industrial roads (Equation 1a) 1.8-25.2 1.8-260 2-290 8-69 5-43 4-17a 0.03-13 Public roads (Equation 1 b) 1.8-35 1.4-2.7 1.5-3 16-88 10-55 4-4.8 0.03-13 As noted earlier, the models presented as Equations la and lb were developed from tests of traffic on unpaved surfaces, mostly performed in the 1980s. Unpaved roads have a hard, generally nonporous surface that usually dries quickly after a rainfall or watering, because of traffic -enhanced natural evaporation. Factors influencing how fast a road dries are discussed in Section 6.5 below. A higher mean vehicle weight and a higher than normal traffic rate may be justified when performing a worst -case analysis of emissions from unpaved roads. The PM2.5/PM10 ratio for fugitive dust from vehicles traveling on unpaved roads is 0.1.23 The PM2.5 and PM10 emission factors for the exhaust, brake wear, and tire wear of a 1980's vehicle fleet (C) are shown in Table 6-4. They were obtained from EPA's MOBILE6.2 mode1.24 Table 6-4. Emission Factors for 1980's Vehicle Fleet Exhaust, Brake Wear, and Tire Wear Particle size C, Emission factor for exhaust, brake wear, and tire wear (IbNMT) PM2.5 PM10 0.00036 0.00047 6-3 A PM10 emission factor for the resuspension of fugitive dust from unpaved shoulders created by the wake of high -profile vehicles such as tractor -trailers traveling on paved roads at high speed has been developed by Desert Research Institute (DRI). A discussion of the emissions estimation methodology for fugitive dust originating from unpaved shoulders is presented in Chapter 14. 6.2.2 Source Extent It is important to note that the vehicle -related source conditions refer to the average weight, speed, and number of wheels for all vehicles traveling the road. For example, if 98% of the traffic on the road are 2 -ton cars and trucks while the remaining 2% consists of 20 -ton trucks, then the mean weight is 2.4 tons. More specifically, Equations la and lb are not intended to be used to calculate a separate emission factor for each vehicle class within a mix of traffic on a given unpaved road. That is, in the example, one should not determine one factor for the 2 -ton vehicles and a second factor for the 20 -ton trucks. Instead, only one emission factor should be calculated that represents the "fleet" average of 2.4 tons for all vehicles traveling the road. Moreover, to retain the quality ratings when addressing a group of unpaved roads, it is necessary that reliable correction parameter values be determined for the road in question. The field and laboratory procedures for determining road surface silt and moisture contents are given in Appendices C.1 and C.2 of AP -42. Vehicle -related parameters should be developed by recording visual observations of traffic. In some cases, vehicle parameters for industrial unpaved roads can be determined by reviewing maintenance records or other information sources at the facility. In the event that site -specific values for correction parameters cannot be obtained, then default values may be used. In the absence of site -specific silt content information, an appropriate mean value from Tables 6-1 and 6-2 may be used as a default value, but the quality rating of the equation is reduced by two letters. Because of significant differences found between different types of road surfaces and between different areas of the country, use of the default moisture content value of 0.5 percent in Equation lb is discouraged. The quality rating should be downgraded two letters when the default moisture content value is used. It is assumed that readers addressing industrial roads have access to the information needed to develop average vehicle information for their facility. 6.2.3 Natural Mitigation The effect of routine watering to control emissions from unpaved roads is discussed below in Section 6.5. However, all roads are subject to some natural mitigation because of rainfall and other precipitation. The Equation la and lb emission factors can be extrapolated to annual average uncontrolled conditions (but including natural mitigation) under the simplifying assumption that annual average emissions are inversely proportional to the number of days with measurable (more than 0.254 mm [0.01 inch]) precipitation: 6-4 Eext = E[(365 - P)/365] (2) where, Eext = annual size -specific emission factor extrapolated for natural n-itiga_.on (lb/VMT) E = emission factor from Equation la or lb P = number of days in a year with at least 0.254 mm (0.01 in) of pfecipiation Maps showing the geographical distribution of "wet" days on an annual basis for the United States based on meteorological records on a monthly basis are available in =_ie Climatic Atlas of the United States.16 Alternative sources include other Depd hu e-= of Commerce publications such as local climatological data summaries. The National Climatic Data Center (NCDC) offers several products that provide hourly precipitjon data. In particular, NCDC offers a Solar and Meteorological Surface Obserior. Network 1961-1990 (SAMSON) CD-ROM, which contains 30 years worth of hourly meteorological data for first -order National Weather Service locations. Whaxver meteorological data are used, the source of that data and the averaging period shoi d be clearly specified. Equation 2 provides an estimate that accounts for precipitation on an annual average basis for the purpose of inventorying emissions. It should be noted that Equation 2 does not account for differences in the temporal distributions of the rain events, the quErtity of rain during any event, or the potential for the rain to evaporate from the road surface. In the event that a finer temporal and spatial resolution is desired for inventories of public unpaved roads, estimates can be based on a more complex set of assumptioni. 'These assumptions include: 1. The moisture content of the road the quantity of water added; 2. The moisture content of the road Class A pan evaporation rate; 3. The moisture content of the road traffic volume; and 4. The moisture content of the road observed in the area. surface material is increased in prcport_.cn to surface material is reduced in proportion to the surface material is reduced in proportion to the surface material varies between the ext-=mes The CHIEF Web site (www.epa.gov/ttn/chief/ap42/ch13/related/c13s02 2) ha6 a file that contains a spreadsheet program for calculating emission factors that are temporally and spatially resolved. Information required for use of the spreadsheet program includes monthly Class A pan evaporation values, hourly meteorological data for precipitation, humidity and snow cover, vehicle traffic information, and road surface material information. It is emphasized that the simple assumption underlying Equation 2 and the mc•-e complex set of assumptions underlying the use of the procedure which prodLzes a finer 6-5 temporal and spatial resolution have not been verified in any rigorous manner. For this reason, the quality ratings for either approach should be downgraded one letter from the rating that would be applied to Equation 1. 6.3 Emission Estimation: Alternate Methodology for Non -Farm Roads This section was adapted from Section 7.10 of CARB's Emission Inventory Methodology. Section 7.10 was last updated in August 1997. This source category provides estimates of the entrained geologic particulate matter emissions that result from vehicular travel over non-agricultural unpaved roads. The emissions are estimated separately for three major unpaved road categories: city and county roads, U.S. forests and park roads, and Bureau of Land Management (BLM) and Bureau of Indian Affairs (BIA) roads. The emissions result from the mechanical disturbance of the roadway and the vehicle generated air turbulence effects. Agricultural unpaved road estimates are computed in a separate methodology; see Section 6.4. 6.3.1 Emission Factor The PM10 emission factor used for estimates of geologic dust emissions from vehicular travel on unpaved roads is based on work performed by UC Davis28 and the Desert Research Institute.29 The emission factor used for all unpaved roads statewide is 2.27 lbs PM10/VMT.30 Because the emission measurements were performed in California, this emission factor was used by CARB to replace the previous generic emission factor provided in EPA's AP -42 document.31 The new emission factor is slightly smaller than the factors derived with the AP -42 methodology. The PM2.5/PM10 ratio for unpaved road dust is 0.1.23 6.3.2 Source Extent (Activity Level) For the purpose of estimating emissions, it is assumed that the unpaved road dust emissions are primarily related to the vehicle miles traveled (VMT) on the roads. State highway data are used to estimate unpaved road miles for each roadway category in each county. It is assumed that 10 daily VMT (DVMT) are traveled on unpaved city and county roads as well as U.S. forest and parks roads and BLM and BIA roads. Road mileage, if needed, can be simply computed by dividing the annual VMT values by 3650 (which is 10 DVMT x 365 days). Daily activity on unpaved roads occurs primarily during daylight hours. Activity is assumed to be the same each day of the week. Monthly activity varies by county and is based on estimates of monthly rainfall in each county. This is to reflect that during wet months there is less unpaved road traffic, and there are also lower emissions per mile of road when the road soils have a higher moisture content. Unpaved road growth is tied to on -road VMT growth for many counties. For other counties, growth is set to zero and VMT is not used. 6-6 6.3.3 Assumptions and Limitations CARB's methodology is subject to the following assumptions and limitations: 1. This methodology assumes that all unpaved roads emit the same levels of PM10 per VMT during all times of the year for all vehicles and conditions. 2. It is assumed that all unpaved roads receive 10 VMT per day. 3. This methodology assumes that no controls are used on the roads. 4. It is assumed that the emission factors derived in a test county are applicable to the rest of California. 6.4 Emission Estimation: Alternative Methodology for Farm Roads This section was adapted from Section 7.11 of CARB's Emission Inventory Methodology. Section 7.11 was last updated in August 1997. This source category provides estimates of the entrained geologic particulate matter emissions that result from vehicular travel over unpaved roads on agricultural lands. The emissions result from the mechanical disturbance of the roadway and the vehicle generated air turbulence effects. This emission factor used is oriented towards dust emissions from light duty vehicle use, but the activity data implicitly include some larger vehicle use for harvest and other operations. 6.4.1 Emission Factor The PM10 emission factor used for estimates of geologic dust emissions from vehicular travel on unpaved roads is based on work performed by UC Davis28 and the Desert Research Institute.29 The emission factor used for all unpaved roads statewide is 2.27 lbs PM10/VMT.30 Because the emission measurements were performed in California, this emission factor was used by CARB to replace the previous generic emission factor provided in EPA's AP -42 document.31 CARB's emission factor is slightly smaller than the factors derived with the AP -42 methodology. The PM2.5/PM10 ratio for unpaved road dust is 0.1.23 6.4.2 Source Extent (Activity Level) For the purpose of estimating emissions, it is assumed that the unpaved road dust emissions are primarily related to the vehicle miles traveled (VMT) on the roads. In 1976 an informal survey was made of several county agricultural commissioners in the San Joaquin Valley, who estimated that each 40 acres of cultivated land receives approximately 175 vehicle passes per year on the unpaved farm roads.32 This value of 4.28 VMT/acre-year has been used in the past by CARB to calculate emissions from unpaved farm roads. CARB is now proposing the following estimates of source extent for unpaved farm roads for different crops: 0.38 VMT/acre-year for grapes, 0.40 VMT/acre-year for cotton, and 1.23 VMT/acre-year for citrus.33 6-7 The crop acreage data used to estimate the road dust emissions are from the state agency summary of crop acreage harvested.34'3 The acreage estimates do not include pasture lands because it is thought that the quantity of vehicular travel on these lands is minimal. Daily activity on unpaved roads occurs primarily during daylight hours. Activity is assumed to be the same each day of the week. Monthly activity varies by county and is based on estimates of monthly rainfall in each county. This is to reflect that during wet months there is less unpaved road traffic, and there are also lower emissions per mile of road when the road soils have a higher moisture content. Unpaved road growth for farm roads is based on agricultural crop acreage or agricultural production. This value is set to zero for many counties. 6.4.3 Assumptions and Limitations CARB's methodology is subject to the following assumptions and limitations: 1. This methodology assumes that all unpaved farm roads emit the same levels of PM 10 per VMT during all times of the year for all vehicles and conditions. 2. It is assumed that all unpaved farm roads receive 175 VMT per 40 acres per year for all crops and cultivation practices. 3. This methodology assumes that no controls are used on the roads. 4. It is assumed that the emission factors derived in the test area are applicable to the rest of California. 5. This methodology assumes that unpaved road travel associated with pasture lands is negligible. 6.5 Demonstrated Control Techniques A wide variety of options exist to control emissions from unpaved roads. Options fall into the following three groupings: 1. Vehicle restrictions that limit the speed, weight or number of vehicles on the road 2. Surface improvement by measures such as (a) paving or (b) adding gravel or slag to a dirt road 3. Surface treatment such as watering or treatment with chemical dust suppressants Available control options span broad ranges in terms of cost, efficiency, and applicability. For example, traffic controls provide moderate emission reductions (often at little cost) but are difficult to enforce. Although paving is highly effective, its high initial cost is often prohibitive. Furthermore, paving is not feasible for industrial roads subject to very heavy vehicles and/or spillage of material in transport. Watering and chemical suppressants, on the other hand, are potentially applicable to most industrial roads at moderate to low costs. However, these require frequent reapplication to 6-8 maintain an acceptable level of control. Chemical suppressants are generally more cost- effective than water but not in cases of temporary roads (which are common at mines, landfills, and construction sites). In summary, then, one needs to consider not only the type and volume of traffic on the road but also how long the road will be in service when developing control plans. Vehicle restrictions. These measures seek to limit the amount and type of traffic present on the road, or to lower the mean vehicle speed. For example, many industrial plants have restricted employees from driving on plant property and have instead instituted bussing programs. This eliminates emissions due to employees traveling to/from their worksites. Although the heavier average vehicle weight of the busses increases the base emission factor, the decrease in vehicle -miles -traveled results in a lower overall emission rate. Surface improvements. Control options in this category alter the road surface. As opposed to "surface treatments" discussed below, improvements are relatively "permanent" and do not require periodic retreatment. The most obvious surface improvement is paving an unpaved road. This option is quite expensive and is probably most applicable to relatively short stretches of unpaved road with at least several hundred vehicle passes per day. Furthermore, if the newly paved road is located near unpaved areas or is used to transport material, it is essential that the control plan address routine cleaning of the newly paved road surface. The control efficiencies achievable by paving can be estimated by comparing emission factors for unpaved and paved road conditions. The predictive emission factor equation for paved roads, given in Chapter 5, requires estimation of the silt loading on the traveled portion of the paved surface, which in turn depends on whether the pavement is periodically cleaned. Unless curbing is to be installed, the effects of vehicle excursion onto unpaved shoulders (berms) also must be taken into account in estimating the control efficiency of paving. Other surface improvement methods involve covering the road surface with another material that has a lower silt content. Examples include placing gravel or slag on a dirt road. The control efficiency can be estimated by comparing the emission factors obtained using the silt contents before and after improvement. The silt content of the road surface should be determined after 3 to 6 months rather than immediately following placement. Control plans should address regular maintenance practices, such as grading, to retain larger aggregate on the traveled portion of the road. Surface treatments. These measures refer to control options that require periodic reapplication. Treatments fall into the two main categories of: (a) wet suppression (i.e., watering, possibly with surfactants or other additives), which keeps the road surface wet to control emissions, and (b) chemical stabilization that attempts to change the physical characteristics of the surface. The necessary reapplication frequency varies from minutes or hours for plain water under summertime conditions to several weeks or months for chemical dust suppressants. 6-9 Wet Suppression. Watering increases the moisture content, which in turn causes particles to conglomerate and reduces their likelihood of becoming suspended when vehicles pass over the surface. The control efficiency depends on how fast the road dries after water is added. This in turn depends on: (a) the amount (per unit road surface area) of water added during each application; (b) the period of time between applications; (c) the weight, speed and number of vehicles traveling over the watered road during the period between applications; and (d) meteorological conditions (temperature, wind speed, cloud cover, etc.) that affect evaporation during the period. Figure 6-1 presents a simple bilinear relationship between the instantaneous control efficiency due to watering and the resulting increase in surface moisture. The moisture ratio "M" (i.e., the x-axis in Figure 6-1) is found by dividing the surface moisture content of the watered road by the surface moisture content of the uncontrolled road. As the watered road surface dries, both the ratio M and the predicted instantaneous control efficiency (i.e., the y-axis in the figure) decrease. The figure shows that between the uncontrolled moisture content (M = 1) and a value twice as large (M = 2), a small increase in moisture content results in a large increase in control efficiency. Beyond that, control efficiency grows slowly with increased moisture content. 100 Control Efficiency (%) 75 _ 50 25 0 0 2 3 Moisture Ratio, M 4 5 Figure 6-1. Watering Control Effectiveness for Unpaved Travel Surfaces Given the complicated nature of how the road dries, characterization of emissions from watered roadways is best done by collecting road surface material samples at various times between water truck passes. AP -42 Appendices C.1 and C.2 present the recommended sampling and analysis procedures, respectively, for determining the surface/bulk dust loading. The moisture content measured can then be associated with a control efficiency by use of Figure 6-1. Samples that reflect average conditions during the watering cycle can take the form of either a series of samples between water applications or a single sample at the midpoint. It is essential that samples be collected during periods with active traffic on the road. Finally, because of different evaporation rates, it is recommended that samples be collected at various times during the year. If 6-10 only one set of samples is to be collected, these must be collected during hot, summertime conditions. When developing watering control plans for roads that do not yet exist, it is strongly recommended that the moisture cycle be established by sampling similar roads in the same geographic area. If the moisture cycle cannot be established by similar roads using established watering control plans, the more complex methodology used to estimate the mitigation of rainfall and other precipitation can be used to estimate the control provided by routine watering. An estimate of the maximum daytime Class A pan evaporation (based upon daily evaporation data published in the monthly Climatological Data for the state by the National Climatic Data Center) should be used to insure that adequate watering capability is available during periods of highest evaporation. Hourly precipitation values are replaced by the equivalent inches of precipitation resulting fro watering. One inch of precipitation is equivalent to an application of 5.6 gallons of water per square yard of road. Information on the long term average annual evaporation and on the percentage that occurs between May and October is available in the Climatic Atlas.16 This methodology should be used only for prospective analyses and for designing watering programs for existing roadways. The quality rating of an emission factor for a watered road that is based on this methodology should be downgraded two letters. Periodic road surface samples should be collected and analyzed to verify the efficiency of the watering program. Chemical Dust Suppressants. As opposed to wet suppression (i.e., watering), chemical dust suppressants have much less frequent reapplication requirements. These materials suppress emissions by changing the physical characteristics of the existing road surface material. Many chemical dust suppressants applied to unpaved roads form a hardened surface that binds particles together. After several applications, a treated unpaved road often resembles a paved road except that the surface is not uniformly flat. Because the improved surface results in more grinding of small particles, the silt content of loose material on a highly controlled surface may be substantially higher than when the surface was uncontrolled. For this reason, the models presented as Equations la and lb cannot be used to estimate emissions from chemically stabilized roads. Should the road be allowed to return to an uncontrolled state with no visible signs of large-scale cementing of material, the Equation la and lb emission factors could then be used to obtain conservatively high emission estimates. The control effectiveness of chemical dust suppressants appears to depend on: (a) the dilution rate used in the mixture; (b) the application rate (volume of solution per unit road surface area); (c) the time between applications; (d) the size, speed and amount of traffic during the period between applications; and (e) meteorological conditions (rainfall, freeze/thaw cycles, etc.) during the period. Other factors that affect the performance of chemical dust suppressants include other traffic characteristics (e.g., cornering, track -out from unpaved areas) and road characteristics (e.g., bearing strength, grade). The variability in these factors and differences between individual dust control products make the control efficiencies of chemical dust suppressants difficult to estimate. Past field testing of emissions from controlled unpaved roads has shown that chemical dust 6-11 suppressants provide a PMI0 control efficiency of about 80% when applied at regular intervals of 2 weeks to 1 month. Petroleum resin products historically have been the dust suppressants (besides water) most widely used on industrial unpaved roads. Figure 6-2 presents a method to estimate average control efficiencies associated with petroleum resins applied to unpaved roads.2° The following items should be noted: 1. The term "ground inventory" represents the total volume (per unit area) of petroleum resin concentrate (not solution) applied since the start of the dust control season. 2. Because petroleum resin products must be periodically reapplied to unpaved roads, the use of a time -averaged control efficiency value is appropriate. Figure 6-2 presents control efficiency values averaged over two common application intervals, 2 weeks and 1 month. Other application intervals will require interpolation. 3. Note that zero efficiency is assigned until the ground inventory reaches 0.05 gallon per square yard (gal/yd2). Requiring a minimum ground inventory ensures that one must apply a reasonable amount of chemical dust suppressant to a road before claiming credit for emission control. Recall that the ground inventory refers to the amount of petroleum resin concentrate rather than the total solution. As an example of the application of Figure 6-2, suppose that Equation 1 a was used to estimate a PM10 emission factor of 7.1 lb/VMT from a particular road. Also, suppose that, starting on May 1, the road is treated with 0.221 gal/yd2 of a solution (1 part petroleum resin to 5 parts water) on the first of each month through September. The average controlled PM10 emission factors calculated from Figure 6-2 are shown in Table 6-5. Besides petroleum resins, other newer dust suppressants have also been successful in controlling emissions from unpaved roads. Specific test results for those chemicals, as well as for petroleum resins and watering, are provided in References 18 through 21. 6-12 Average Control Efficiency (%) 100 80 60 40 20 Ground Inventory (liters/square meter) 0 0.25 0.5 .0.75 1 0 0.25 Note: Averaging periods (2 weeks or 1 month) refer to time between applications 0.5 0.75 1 T T I f 2 weeks —� I 1 month Total Particulate 1 I 0.05 0.1 0.15 0.2 0.25 0 0.05 (gallons/square yard) Ground Inventory 2 weeks ' r 1 month Particulate <10 utnA I I 0.1 0.15 0.2 0.25 Figure 6-2. Average TSP and PM10 Control Efficiencies for Two Common Application Intervals 6-13 Table 6-5. Average Controlled PM10 Emission Factors for Specific Conditions Period Ground inventory, gal/yd2 Average control efficiency, %a Average controlled PM10 emission factor, IbNMT May 0.037 0 7.1 June 0.073 62 2.7 July 0.11 68 2.3 August 0.15 74 1.8 September 0.18 80 1.4 a From Figure 6-2. Zero efficiency assigned if ground inventory is less than 0.05 gal/yd2. 1 IbNMT = 281.9 gNKT. 1 gal/yd2 = 4.531 L/m2. Table 6-6 summarizes tested control measures and reported control efficiencies for measures that reduce the generation of fugitive dust from unpaved roads. Table 6-6. Control Efficiencies for Control Measures for Unpaved Roads36' 37 PM10 control Control measure efficiency References/Comments Limit maximum speed on unpaved roads to 25 miles per hour Pave unpaved roads and unpaved parking areas Implement watering twice a day for industrial unpaved road Apply dust suppressant annually to unpaved parking areas 44% Assumes linear relationship between PM10 emissions and vehicle speed and an uncontrolled speed of 45 mph. 99% Based on comparison of paved road and unpaved road PM10 emission factors. 55% 84% MRI, April 2001 CARB April 2002 6.6 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats downloaded from the Internet for several local air quality agencies in the WRAP region are presented in Table 6-7. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/envsvc/air/ruledesc.asp 6-14 Table 6-7. Example Regulatory Formats for Unpaved Roads Control Measure Goal Threshold Agency Requires annual treatment of unpaved public roads Set applicability standard: unpaved SCAQMD beginning in 1998 and continuing for each of 8 years road must be more than 50 ft wide at Rule 1186 thereafter by implementing one of the following: paving at least one mile with typical roadway material, applying chemical stabilizers to at least two miles to maintain stabilized surface, implementing at least one of the following on at least three miles of road surface: installing signage at 1/4 mile intervals limiting speed to 15 mph, installing speed control devices every 500 ft, or maintaining roadway to limit speed to 15 mph all points or must not be within 25 ft of property line, or have more than 20 vehicle trips per day. All roads with average daily traffic greater than average of all unpaved roads within its jurisdiction must be treated 9/10/1999 Control measures implemented by June 1, 2003: pave, apply dust palliative, or other Complies with stabilization standard: limit visible dust emissions to 20% opacity, limit silt loading to 0.33 oz/ft2, and limit silt content to 6% All unpaved roads with vehicular traffic 150 vehicles or more per day Clark County Hydrographic Basins 212, 216, 217 Sect. 91 Air Quality Reg. 06/22/2000 Limit vehicle speed </=15mph and </=20 trips/day; BACM: watering, paving, apply/maintain gravel, asphalt, or dust Limit VDE to 20% opacity; limit silt loading to 0.33oz/ft^2, limit Construction site roads, inactive/active; limiting vehicle speed Maricopa County Rules suppressant; Dust control plan for construction site roads silt content to 6% and trips is alternative to stabilization requirement and max number of trips each day in control plan (also number of vehicles, earthmoving equip, etc.); for roads with >/=150 vehicles/day implement BACM by 06/10/2004; same for >/=250 vehicles day 310 and 310.01 04/07/2004 and 02/16/2000 (existing roads by 06/10/2000) 6-15 6.7 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (I) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 6-8 summarizes the compliance tools that are applicable for unpaved roads. Table 6-8. Compliance Tools for Unpaved Roads Record keeping Site inspection/monitoring Road map; traffic volumes, speeds, and Observation of water truck operation and patterns; dust suppression equipment and inspection of sources of water; maintenance records; frequencies, amounts, times, and rates for watering and dust observation of dust plume opacity exceeding a standard; counting of traffic suppressants (type); use of water surfactants; volumes; surface material sampling and calculated control efficiencies; regrading, graveling, or paving of unpaved road segments; control equipment downtime and maintenance records; meteorological log. analysis for silt and moisture contents; real-time portable monitoring of PM. 6.8 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for fugitive dust originating from unpaved roads. A sample cost-effectiveness calculation is presented below for a specific control measure (watering) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 0 and PM2.5. In 6-16 selecting the most advantageous control measure for unpaved roads, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost- effectiveness and feasibility characteristics is identified. Sample Calculation for Unpaved Roads at an Industrial Facility Step 1. Determine source activity and control application parameters. Road length (mile) 2 Vehicles/day 100 Wet days/year 20 Number of 8 -hour workdays/year 260 Number of emission days/yr (workdays without rain) Control Measure Watering Control Application/Frequency Twice daily* Economic Life of Control System (year) 10 Control Efficiency 55% * No nighttime traffic. The number of vehicles per day, wet days per year, workdays per year, and the economic life of the control measure are assumed values for illustrative purposes. Watering has been chosen as the applied control measure. The control ap35plication/frequency and control efficiency are default values provided by MRI, 2001. 240 Step 2. Calculate PM10 Emission Factor. The PM10 emission factor is calculated from the AP -42 equation utilizing the appropriate correction parameters. E (IbNMT) = 1.5 (s/12)" (w/3)0.45 s —silt content (%) 15 W —vehicle weight (tons) 15 E = 3.8 IbNMT Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (calculated in Step 2) is multiplied by the number of vehicles per day, by the road length and by the number of emission days per year (see activity data) and divided by 2,000 lb/ton to compute the annual PM10 emissions, as follows: Annual PM10 emissions = (EF x Vehicles/day x Miles x Emission days/yr) / 2,000 Annual PM10 emissions = (3.8 x 100 x 2 x 240) / 2,000 = 91 tons Annual PM2.5 emissions = 0.1 x PM10 Emissions23 Annual PM2.5 emissions = 0.1 x 91 tons = 9.1 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). 6-17 For this example, we have selected watering as our control measure. Based on a control efficiency estimate of 55% for the application of water to unpaved roads, the annual controlled emissions estimate are calculated to be: Annual Controlled PM10 emissions = (91 tons) x (1 — 0.55) = 41 tons Annual Controlled PM2.5 emissions = (9.1 tons) x (1 — 0.55) = 4.1 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) Annual Operating/Maintenance costs ($) Annual Interest Rate Capital Recovery Factor Annualized Cost ($/yr) 30,000 8,000 3% 0.1172 11,517 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: Capital Recovery Factor = AIR x (1 + AIR) Economic life / (1 + AIR)Economic life — 1 Capital Recovery Factor = 3% x (1 + 3%)10 / (1 + 3%)10 - 1 = 0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor and the Capital costs to the annual Operating/Maintenance costs: Annualized Cost = (CRF x Capital costs) + Annual Operating/Maintenance costs Annualized Cost = (0.1172 x 30,000) + 8,000 = $11,517 Step 6. Calculate Cost Effectiveness. Cost effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost effectiveness for PM10 emissions = $11,517 / (91 - 41) = $231/ton Cost effectiveness for PM2.5 emissions = $11,517 / (9.1 — 4.1) = $2,306/ton 6.9 References 1. Cowherd, C. Jr., et al., 1974. Development of Emission Factors for Fugitive Dust Sources, EPA -450/3-74-037, U. S. EPA, Research Triangle Park, NC, June. 2. Dyck, R.J., Stukel, J.J., 1976. Fugitive Dust Emissions from Trucks on Unpaved Roads, Envir. Sci. & Tech., 10(10):1046-1048, October. 3. McCaldin, R.O., Heidel, K.J., 1978. Particulate Emissions from Vehicle Travel over Unpaved Roads, presented at APCA Assoc. Meeting, Houston, TX, June. 4. Cowherd, C. Jr., et al., 1979. Iron and Steel Plant Open Dust Source Fugitive Emission Evaluation, EPA -600/2-79-013, U. S. EPA, Cincinnati, OH, May. 5. Muleski, G., 1991. Unpaved Road Emission Impact, Arizona Department of Environmental Quality, Phoenix, AZ, March 1991. 6-18 6. MRI, 1998. Emission Factor Documentation for AP -42, Section 13.2.2, Unpaved Roads, Final Report, Midwest Research Institute, Kansas City, MO, September. 7. Cuscino, T. Jr., et al., 1979. Taconite Mining Fugitive Emissions Study, Minnesota Pollution Control Agency, Roseville, MN, June. 8. MRI, 1984. Improved Emission Factors for Fugitive Dust from Western Surface Coal Mining Sources, 2 Volumes, EPA Contract No. 68-03-2924, Office of Air Quality Planning and Standards, U. S. EPA, Research Triangle Park, NC. 9. Cuscino, T. Jr., et al., 1983. Iron and Steel Plant Open Source Fugitive Emission Control Evaluation, EPA -600/2-83-110, U. S. EPA, Cincinnati, OH, October. 10. MRI, 1983. Size Specific Emission Factors for Uncontrolled Industrial and Rural Roads, EPA Contract No. 68-02-3158, Midwest Research Institute, Kansas City, MO, September. 11. Cowherd, C. Jr., Englehart, P., 1985. Size Specific Particulate Emission Factors for Industrial and Rural Roads, EPA -600/7-85-038, U. S. EPA, Cincinnati, OH, September. 12. MRI, 1987. PM10 Emission Inventory of Landfills in the Lake Calumet Area, EPA Contract 68-02-3891, Work Assignment 30, Midwest Research Institute, Kansas City, MO, September. 13. MRI, 1988. Chicago Area Particulate Matter Emission Inventory - Sampling and Analysis, EPA Contract No. 68-02-4395, Work Assignment 1, Midwest Research Institute, Kansas City, MO, May. 14. ES, 1987. PM10 Emissions Inventory Data for the Maricopa and Pima Planning Areas, EPA Contract No. 68-02-3888, Engineering -Science, Pasadena, CA, January. 15. MRI, 1992. Oregon Fugitive Dust Emission Inventory, EPA Contract 68-D0-0123, Midwest Research Institute, Kansas City, MO, January. 16. Climatic Atlas of the United States, U. S. Department Of Commerce, Washington, DC, June 1968. 17. National Climatic Data Center, Solar and Meteorological Surface Observation Network 1961-1990; 3 Volume CD-ROM. Asheville, NC, 1993. 18. Cowherd, C. Jr. et al., 1988. Control of Open Fugitive Dust Sources, EPA -450/3-88- 008, U. S. EPA, Research Triangle Park, NC, September. 19. Muleski, G.E. et al., 1984. Extended Evaluation of Unpaved Road Dust Suppressants in the Iron and Steel Industry, EPA -600/2-84-027, U.S. EPA, Cincinnati, OH, February. 6-19 20. Cowherd, C. Jr., Kinsey, J.S., 1986. Identification, Assessment and Control of Fugitive Particulate Emissions, EPA -600/8-86-023, U.S. EPA, Cincinnati, OH, August. 21. Muleski, G.E., Cowherd, C. Jr., 1986. Evaluation of the Effectiveness of Chemical Dust Suppressants on Unpaved Roads, EPA -600/2-87-102, U.S. EPA, Cincinnati, OH, November. 22. MRI, 1992. Fugitive Dust Background Document and Technical Information Document for Best Available Control Measures, EPA -450/2-92-004, Office Of Air Quality Planning and Standards, U.S. EPA, Research Triangle Park, NC, September. 23. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 24. Technical Memorandum from P. Hemmer, E.H. Pechan & Associates, Inc., Durham, NC to B. Kuykendal, U.S. EPA, Research Triangle Park, NC, August, 21, 2003. 25. USEPA, 2002. MOBILE6 User Guide, United States Environmental Protection Agency, Office of Transportation and Air Quality. EPA420-R-02-028, October. 26. Technical Memorandum from G. Muleski, Midwest Research Institute, Kansas City, MO, to B. Kuykendal, U. S. EPA, Research Triangle Park, NC, Subject "Unpaved Roads," September 27, 2001. 27. Technical Memorandum from W. Kuykendal, U.S. EPA, to File, Subject "Decisions on Final AP -42 Section 13.2.2 Unpaved Roads," November 24, 2003. 28. Flocchini, R. et al., 1994. Evaluation of the Emission of PM Particulates from Unpaved 10 Roads in the San Joaquin Valley, Final Report, University of California, Davis, Air Quality Group, Crocker Nuclear Laboratory, April. 29. Gillies, J. et al., 1996. Effectiveness Demonstration of Fugitive Dust Control Methods for Public Unpaved Roads and Unpaved Shoulders on Paved Roads, Final Report, Desert Research Institute, December. 30. Gaffney, P., 1997. Entrained Dust from Unpaved Road Travel, Emission Estimation Methodology, Background Document, California Air Resources Board, September. 31. USEPA, 1995. Compilation of Air Pollutant Emission Factors, AP -42, Section 13.2.2, Fifth Edition, January. 32. Bill Roddy, Fresno County Air Pollution Control District, personal communication to CARB, 1976. 33. Gaffney, P., 2005. Agricultural Dust Emissions: Summary of Sources and Processes, WRAP Fugitive Dust Control Workshop, Palm Springs, CA, May 10-11. 34. California Agricultural Statistics Service, 1996. 1993 acreage extracted from agricultural commissioner's reports. Sacramento, CA, December. 6-20 35. Gaffney, P.H., 1997. Agricultural Land Preparation: Geologic Particulate Matter Emission Estimates, Background Document, California Air Resources Board, September. 36. MRI, April 2001. Particulate Emission Measurements from Controlled Construction Activities, EPA/600/R-01/031. 37. CARB, April 2002. Evaluation of Air Quality Performance Claims for Soil-Sement Dust Suppressant. 38. Sierra Research, 2003. Final BA CM Technological and Economic Feasibility Analysis, prepared for the San Joaquin Valley Unified APCD, March. 6-21 Chapter 7. Agricultural Wind Erosion 7.1 Characterization of Source Emissions 7-1 7.2 Emission Estimation Methodology 7-1 7.3 Demonstrated Control Techniques 7-12 7.4 Regulatory Formats 7-12 7.5 Compliance Tools 7-14 7.6 Sample Cost -Effectiveness Calculation 7-14 7.7 References 7-16 7.1 Characterization of Source Emissions Wind blowing across exposed nonpasture agricultural land results in particulate matter (PM) emissions. Windblown dust emissions from agricultural lands are calculated by multiplying the process rate (acres of crop in cultivation) by an emission factor (tons of PM per acre per year). 7.2 Emission Estimation Methodology 9"13 This section was adapted from Section 7.12 of CARB's Emission Inventory Methodology. Section 7.12 was last updated in July 1997. MRI developed a PM10 emission factor for agricultural wind blown dust of 86.6 lb/acre on behalf of the EPA in 1992.1 However this emission factor is not included in AP -42. Thus, the methodology adopted by the California Air Resources Board2'3 (CARB) is presented as the emissions estimation methodology in lieu of an official EPA methodology for this fugitive dust source category. The methodology for estimating fugitive dust emissions from open area wind erosion is presented in Chapter 8 of this handbook. The standard methodology for estimating the emission factor for windblown emissions from agricultural lands is the wind erosion equation (WEQ). Although the WEQ is well established, it is controversial. The WEQ was developed by the United States Department of Agriculture -Agricultural Research Service (USDA-ARS) during the 1960s, for the estimation of wind erosion on agricultural land.4' 5 The U.S. EPA adapted the USDA-ARS methodology for use in estimating windblown TSP emissions from agricultural lands in 19745, and the California Air Resources Board (CARB) adopted the U.S. EPA methodology in 1989. The PM10/TSP ratio for wind erosion is 0.5.6 The PM2.5/PM 10 ratio for windblown fugitive dust posted on EPA's CHIEF website is 0.15 based on the analysis conducted by MRI on behalf of WRAP.7 The USDA-ARS has undertaken ambitious programs over the past decade to replace the WEQ with improved wind erosion prediction models such as the Revised Wind Erosion Equation (RWEQ)8 and the Wind Erosion Prediction System (WEPS)9 models. CARB does not consider these models feasible for use, although certain portions of the RWEQ were incorporated into the CARB methodology in 1997. According to CARB, the WEQ (with modifications) continues to be the best available, feasible method for estimating windblown agricultural emissions. 7.2.1 Summary of CARB's Wind Erosion Equation (ARBWEQ) Much of the controversy surrounding the WEQ has related to its tendency to produce inflated emission estimates. Some of the reasons for the inflated emissions relate to the fact that it was developed in the Midwestern United States, and that it does not take into account many of the environmental conditions and farm practices specific to the West. In the revised methodology developed by CARB (referred to as the ARBWEQ), CARB staff added adjustments to the WEQ to improve its ability to estimate windblown emissions from western agricultural lands. 7-1 The U.S. EPA -modified version of the USDA-ARS derived wind erosion equation (WEQ) reads as follows:6 Es=AIKCL'V' (1) where, Es = total suspended particulate fraction of wind erosion losses of tilled fields (tons TSP/acre/year) A = portion of total wind erosion losses that would be measured as total suspended particulate, estimated to be 0.025 I = soil erodibility (tons/acre/year) K = surface roughness factor (dimensionless) C = climatic factor (dimensionless) L' = unsheltered field width factor (dimensionless) V' = vegetative cover factor (dimensionless) As an aid in understanding the mechanics of this equation, the soil erodibility factor I may be thought of as the basic erodibility of a flat, very large, bare field in a climate highly conducive to wind erosion (i.e., high wind speeds and high temperature with little precipitation). This factor was initially established for the WEQ for a large, flat, bare field in Kansas that has relatively high winds along with hot summers and low precipitation. The parameters K, C, L' and V' may be thought of as reduction factors for a ridged surface, a climate less conducive to wind erosion, smaller -sized fields, and vegetative cover, respectively, to adjust the equation for applicability to field conditions that differ from the original Kansas field. The A factor in Equation I has been used in the ARBWEQ without modification. There has been concern that this factor doesn't take into account finite dust loading. The RWEQ8 and WEPS9 models are attempting to address that concern. Soil Erodibility, I. Soil erodibility by the wind is a function of the amount of erodible fines in the soil. The largest soil aggregate size normally considered to be erodible is approximately 0.84 mm equivalent diameter. The soil erodibility factor, I, is related to the percentage of dry aggregates greater than 0.84 mm as shown in Figure 7-1.6 The percentage of nonerodible aggregates (and by difference the amount of fines) in a soil sample can be determined experimentally by a standard dry sieving procedure, using a No. 20 U.S. Bureau of Standards sieve with 0.84 mm square openings. For areas larger than can be field sampled for soil aggregate size (e.g., a county) or in cases where soil particle size distributions are not available, a representative value of I can be obtained from the predominant soil type(s) for farmland in the area. Measured erodibilities, I (in units of tons/acre-year), of various soil textural classes are presented in Table 7-1 as a function of percent of dry soil aggregates greater than 0.84 mm in diameter.6 For California, the soil textural classes were determined by CARB staff from University of California soil maps.10 An additional level of detail was included in the ARBWEQ by using the United States Department of Agriculture -Natural Resources Conservation Service's (NRCS) State Geographic Data Base (STATSGO) of soil data.11 In addition, the USDA-ARS recommended an adjustment for changes to long term erodibility due to irrigation.12 This affects a property known as cloddiness, and refers to the increased tendency for a soil to form stable agglomerations after being exposed to irrigation water. 7-2 00 L 420 - f- 70 bo 1• 10 1 Figure 7-1. Soil Erodibility as a Function of Particle Size6 Table 7-1. Soil Erodibility, I, for Various Soil Textural Classes6 Predominant Soil Textural Class Erodibility (tons/acre-year) Sand 220 Loamy sand 134 Sandy loam, clay, silty clay 86 Loam, sandy clay loam, sandy clay 56 Silty loam, clay loam 47 Silty clay loam, silt 38 Surface Roughness Factor, K. The surface roughness factor, K, accounts for the resistance to wind erosion provided by ridges and furrows or large clods in the field and is crop specific. The surface roughness factor, K, is a function of the height and spacing of the ridges, and varies from 1.0 (no reduction) for a field with a smooth surface to a minimum of 0.5 for a field with the optimum ratio of ridge height (h) to ridge spacing (w). The relationship between K and h2/w is shown in Figure 7-2.6 Average K values of common field crops are shown in Table 7-2. Similar crops are assigned similar surface roughness values. 7-3 1.0 9 a SURFACE ROUGHNESS FACTOR .5 1.0 t5 2.0 2.5 h2 INCHES W Figure 7-2. Determination of Surface Roughness Factor, K6 Table 7-2. Surface Roughness Factor, K, for Common Field Crops6 Crop K Alfalfa, safflower 1.0 Grain hays, oats, potatoes, rice 0.8 Barley, corn, peanuts, rye, soybeans, sugar beets, vegetables, wheat 0.6 Beans, cotton, sorghum 0.5 Climatic Factor, C. The annual climatic factor, C, is based on data that show that erosion varies directly with the wind speed cubed, and as the inverse of the square of surface soil moisture. The C factor can be calculated from the following equation: C = 0.345 W3/ (PE)2 (2) where, W = mean annual wind speed (mph), corrected to a standard height of 10 meters PE = Thornthwaite's precipitation -evaporation index (i.e., ratio of precipitation to evapotranspiration) Monthly or seasonal climatic factors can be estimated from Equation 2 by substituting the mean wind speed of the period of interest for the mean annual wind speed. Climatic factors have been computed from National Weather Bureau data for 7-4 many locations throughout the country. The annual climatic factors for many areas of the US are shown in Figure 7-3. The monthly precipitation/evaporation ratio varies from <16 for arid deserts to >127 for rain forests. For the ARBWEQ, CARB staff improved the input data for calculating the factor C, as well as the methods associated with developing the county wide averaged annual climatic factor. Monthly climatic factors were obtained by modifying the annual climatic factor calculation method. Annual climatic factors for different counties within California range from 0.019 to 1.274.14 The reader is directed to CARB's website to obtain the list of climatic factors for counties within California (www.arb.ca.gov/emisinv/areasrc/fullpdf). Unsheltered Field Width Factor, L'. Soil erosion across a field is directly related to the unsheltered width along the prevailing wind direction. The rate of erosion is zero at the windward edge of the field and increases approximately proportionately with distance downwind until, if the field is large enough, a maximum rate of soil movement is reached. Correlation between the width of a field and its rate of erosion is also affected by the soil erodibility of its surface: the more erodible the surface, the shorter the distance in which maximum soil movement is reached. This relationship between the unsheltered width of a field (L), its surface erodibility (IK), and its relative rate of soil erosion (L') is shown graphically for different values of IK (ranging from IK = 20 to IK = 134) in Figure 7-4.6 If the curves of Figure 7-4 are used to obtain the L' factor for the windblown dust equation, values for the variables I and K must already be known and an appropriate value for L most be determined. L is calculated as the distance across the field in the prevailing wind direction minus the distance from the windward edge of the field that is protected from wind erosion by a barrier. The distance protected by a barrier is equal to 10 times the height of the barrier, or 10H. For example, a row of 30 -foot high trees along the windward side of a field reduces the effective width of the field by 300 feet. If the prevailing wind direction differs significantly (>25 degrees) from perpendicularity with the field. L should be increased to account for this additional distance of exposure to the wind. The distance across the field, L, is equal to the field width divided by the cosine of the angle between the prevailing wind direction and the perpendicularity to the field. 7-5 Figure 7-3. Annual Climatic Factor Used in Wind Erosion Equation [Note: Isopleths for several western and northeastern states were not available at the time this figure was prepared.] 7-6 Figure 7-4. Effect of Field Length on Relative Soil Erosion Rate6 Vegetative Cover Factor, V'. Vegetative cover on agricultural fields during periods other than the primary crop season greatly reduces wind erosion of the soil. This cover most commonly is crop residue, either standing stubble or mulched into the soil. The effect of various amounts of residue, V, in reducing erosion is shown qualitatively in Figure 7-5, where IKCL' is the potential annual soil loss (in tons/acre-year) from a bare field, and V' is the fractional amount of this potential loss which results when the field has a vegetative cover of V (in lb of air-dried residue/acre). The amount of vegetative cover on a single field can be ascertained by collecting and weighing clean residue from a representative plot or by visual comparison with calibrated photographs. The vegetative soil cover factor, V', is especially problematic for California, and was completely replaced by a series of factors in the ARBWEQ (see analysis below). This factor assumes a certain degree of cover year round based upon post harvest soil cover, and does not account for barren fields from land preparation, growing canopy cover, or replanting of crops during a single annual cycle. All of these factors are very important in the estimation of windblown agricultural dust emissions. Therefore, CARB staff replaced the vegetative soil cover factor, V', with separate crop canopy cover, post harvest soil cover, and post harvest replant factors. 7-7 Figure 7-5. Effect of Vegetative Cover on Relative Emission Rate6 7.2.2 Climate -Based Improvements in the ARBWEQ The calculation of the climatic factor C requires mean monthly temperature, monthly rainfall, and mean annual wind speed for a given location as data inputs. This factor is used to estimate climatic effects on an annual basis. In order to make estimates of emissions using the ARBWEQ that are specific to different seasons, it is necessary to estimate the climatic factor that would apply to each season. The changes to the agricultural windblown emissions inventory discussed here, include modifications to both the annual and the monthly climatic factor profile determination methodology included in the ARBWEQ. The Annual Climatic Factor for the ARBWEQ. Reference 6 includes a definition of the climatic factor that agrees with the method utilized by the NRCS.13 It incorporates the monthly precipitation effectiveness derived from precipitation and temperature, along with monthly average wind speeds. Garden City, Kansas is assigned a factor of 1.0 and the climatic factors for all other sites are adjusted from this value. The Monthly Climatic Factor for the ARBWEQ. There are several ways to create a climate -based monthly profile for the ARBWEQ. Because the ARBWEQ is an annual emission estimation model, CARB staff did not directly estimate monthly emissions using the monthly climatic factor. Instead, the annual climatic factor was used to determine annual emissions, and then the monthly -normalized climatic factors were multiplied by the annual emissions. This helped to limit the effect of extreme monthly values on the annual emissions estimate. CARB staff devised a method termed the "month -as -a -year" method which produced climatic factors that would apply if the 7-8 climate for a given month were instead the year round climate. These monthly numbers, once normalized, provided the climate -based temporal profile. The improvements arising from the use of the month -as -a -year method are due to the fact that it relies on temperature, and precipitation inputs, in addition to wind. The ARBWEQ further modified the temporal profile calculation, by also adding nonclimate-based temporal factors. The month -as -a -year method in the ARBWEQ produces pronounced curves with small climatic factors (resulting in lower emissions) in the cool, wet and more stagnant periods, and large climatic factors (and higher emissions) in the hot, dry, and windy periods. The U.S. EPA method yields gentler profiles, which are shifted into the cooler and wetter months from the ARBWEQ profiles. The 1989 CARB methodology established one erosive wind energy distribution statewide. This resulted in an unrealistic, nearly flat distribution, with very little seasonality. Therefore, the ARBWEQ month -as -a -year method provides a more realistic picture of the windblown dust temporal profile (see Reference 3 for comparison curves and supporting references). 7.2.3 Nonclimate-Based Improvements in the ARBWEQ Among the nonclimate-based factors that influence windblown agricultural emissions are soil type, soil structure, field geometry, proximity to wind obstacles, crop, soil cover by crop canopy or post harvest vegetative material, irrigation, and replanting of the post harvest fallow land with a different crop. CARB has attempted to correct many of these limitations in the ARBWEQ. Many of the corrections are temporally based and rely upon the establishment of accurate crop calendars to reflect field conditions throughout the year. The long-term irrigation -based adjustment to erodibility, due to soil cloddiness, is not temporally based, and is therefore applied for the entire year.12 The change in erodibility varies based on soil type, but often results in a reduction in the tons per acre value for irrigated crops of about one-third. Crop Calendars: Quantifying Temporal Effects. Factors such as crop canopy cover, post harvest soil cover, irrigation, and replanting to another crop have a major effect on windblown emissions. Estimating the effects of these factors requires establishing accurate crop calendars. The planting and harvesting dates are principal components of the crop calendar. The list of references consulted to establish the planting and harvesting dates is included in Reference 3. Each planting month for a given crop was viewed by CARB staff as a separate cohort (maturation class). Since a single planting cohort may be harvested in several months, each cohort was split into cohort-plant/harvest date pairs. The cohort- plant/harvest date pairs were then assigned based upon a first -in -first -out ordering. The fraction of the total annual crop assigned to a given cohort-plant/harvest date pair was derived by multiplying the fraction of the total annual crop planted in a given month (cohort) by the fraction of the cohort harvested in a given month. The fraction of a cohort-plant/harvest date pair that has been planted, but not harvested at any given time, is termed the growing canopy fraction, or GCF (although the canopy may or may not actually be increasing at any given time). The growing canopy fraction determines the fraction of the acreage that will have the crop canopy factor applied to its emission calculations. The acreage that is not assigned to the growing canopy fraction is the postharvest/preplant (PHPP) acreage. The PHPP acreage will have the post harvest soil 7-9 cover, and replanting to a different crop factors applied when calculating its emissions. The effect of using cohort-plant/harvest date pairs is to blend the crop canopy, soil cover, replanting, and irrigation effects over both the planting and harvesting periods. This approach provides a more realistic estimate of the temporal windblown emissions profile during these periods. All of the monthly factor profile adjustments described below are calculated for each month of the year, for each cohort-harvest/plant date pair, for each crop, for each county. Adding a Short -Term Irrigation Factor for Wetness. This adjustment takes into account the overall soil texture, number of irrigation events, and fraction of wet days during the time period'2 (one month for the purposes of the CARB inventory). The list of references consulted to establish the irrigation profiles is included in Reference 3. The irrigation factor for months in which irrigations take place will typically be greater than 0.80. In other words, the irrigations will result in a reduction in erodibility of less than 20%. This is only an estimate for a typical case during the growing season. When averaged over the year, the overall reduction in erodibility is lower. Replacement Factors to Address Problems with the Vegetative Soil Cover Factor in the WEQ. According to CARB, there are many problems with the vegetative soil cover factor, V. For example, this factor is applied to the acreage year round, even during the growing season, and ignores the effect of disk -down and other land preparation operations on post harvest vegetative soil cover. The factor also does not account for canopy cover during the growing season. In addition, the WEQ was derived based on agricultural practices typical of the Midwestern United States. Crops such as alfalfa have full canopy cover for nearly the entire year. There is also a large amount of acreage that is used for more than one crop per year, and there was no provision in the vegetative soil cover factor for estimating the effects on emissions of this replanting. Whether the land is to be immediately replanted to a different crop, or is going to remain fallow until the next planting of the same crop, it is common practice to disk under the harvested crop within a month or two of harvest. The vegetative soil cover factor for the most part assumes that the post harvest debris remains undisturbed. References to support this agricultural practice are included in Reference 3. CARB staff replaced the vegetative soil cover factor in the ARBWEQ with the three adjustments discussed below to approximate the effects on windblown agricultural PM emissions of: (a) crop canopy cover during the growing season; (b) changes to post harvest soil cover; and (c) post harvest planting of a different crop on the harvested acreage. Crop Canopy Factor. Crop canopy cover is the fraction of ground covered by crop canopy when viewed directly from above. USDA-ARS staff provided CARB with methodology from the RWEQ for estimating the effects of crop canopy cover on windblown dust emissions.8 The soil loss ratio (SLRcc) is defined as the ratio of the soil loss for a soil of a given canopy cover divided by the soil loss from bare soil. SLRcc is the factor that is multiplied by the erodibility to adjust the erodibility for canopy cover. The greater the canopy cover, the smaller the SLRcc, and the greater the reduction in erodibility. SLRcc defines an exponential curve that demonstrates major differences in the erodibility reduction for the range of zero to 30 percent canopy cover (typically achieved within a few months after planting). Thereafter, reductions occur much more 7-10 slowly, and eventually the curve flattens out. This results in a rapid decrease in emissions during the first few months following planting, until the emissions are only a very small fraction of the bare soil emissions. The canopy cover then will remain, and the windblown emissions will consequently stay very low until harvest. Senescence effects (late growing season reduction in canopy) have been excluded from this model, and the rationale for that exclusion is discussed in Reference 3. Post Harvest Soil Cover Factor. Post harvest soil cover is the fraction of ground covered by vegetative debris when viewed directly from above. USDA-ARS staff provided CARB with methodology from the RWEQ for estimating the effects of post harvest soil cover on windblown dust emissions.8 The soil loss ratio (SLRsc) is defined as the ratio of the soil loss for a soil of a given soil cover divided by the soil loss from bare soil. SLRsc is the factor that is multiplied by the erodibility to adjust the erodibility for post harvest soil cover. The greater the post harvest soil cover, the smaller the SLRsc, and the greater the reduction in erodibility. The list of references consulted to establish the post harvest soil cover profiles is included in Reference 3. Post Harvest "Replant -to -Different -Crop" Factor. As discussed above, the vegetative soil cover factor does not include any adjustments for harvested acreages that are quickly replanted to a different crop. This multiple cropping is very common in California, and has been accounted for in this methodology by removing from the inventory calculation the fraction of the harvested acreage that is replanted, at the estimated time of replanting. This removed fraction is based on information provided by agricultural authorities (see reference list in Reference 3). The net result of the application of the fraction is that the post disk -down acreage (one to two months after harvest), and resultant emissions, is reduced by the fraction of harvested acreage converted to a new crop. Bare and Border Soil Adjustments. Most fields will have some cultivated areas that are barren. These bare areas could be due to uneven ground (e.g., water accumulation), uneven irrigation, pest damage, soil salinity, etc. Most fields will have some type of border. In some cases there is a large barren border, in other cases it is overgrown with vegetation. Many border areas are relatively unprotected, and prone to wind erosion. CARB staff established approximate fractions of cultivated acreage that would be barren and border areas, respectively. These barren and border acreage adjustments result in emission increases disproportionate to the acreage involved. The reason that the bare acreage -based increase is so large is that the bare acreage does not have either a crop canopy or post harvest soil cover factor applied. The same reasons apply to the border adjustment, but the border region is also assumed not to be irrigated. Therefore, no irrigation factor (wetness), and no long-term irrigation adjustment to erodibility (cloddiness) are applied. No border adjustment was applied to the pasture acreage, since pasture areas frequently lack a barren border. Temporal Activity. For the 1989 CARB methodology, the temporal profile was based on an estimated statewide erosive wind energy profile. The profile, implemented in the ARBWEQ included wind, precipitation and temperature climatic effects, along with the addition of the effects of crop canopy, postharvest soil cover, postharvest replanting to a different crop, and irrigation. In addition, the inclusion of bare ground and 7-1 1 field border effects also adjusted the profile in the ARBWEQ. The profile produced for the ARBWEQ is no longer a separate profile applied to annual emissions, but is now an intermediate output produced during the estimation of annual emissions. 7.3 Demonstrated Control Techniques The emission potential of agricultural wind erosion is affected by the degree to which soil management and cropping systems provide adequate protection to the exposed soil surface during exposure periods. Table 7-3 presents a summary of demonstrated control measures and the associated PM10 control efficiencies. It is readily observed that reported control efficiencies for many of the control measures are highly variable. This may reflect differences in the operations as well as the test methods used to determine control efficiencies. Table 7-3. Control Efficiencies for Control Measures for Agricultural Wind Erosion 1, 15-18 Control measure PM10 Control Efficiency References/comments Artificial wind barrier 64-88% MRI, 1992. Assumes a 50% porosity fence. 54-71% Grantz et al, 1998. Control efficiency is for a wind fence. 4-32% Bilbro and Stout, 1999. Control efficiency based upon reduction in wind velocity by a wind fence made from plastic pipe with a range of optical density of from 12% to 75%. Cover crop 90% Washington State Univ., 1998. Cross -wind ridges 24-93% Grantz et al, 1998. Control efficiency is for furrows. 40-80% Washington State Univ., 1998. Mulching 20-40% Washington State Univ., 1998. Control efficiency is for straw. Trees or shrubs planted as a windbreak 25% Sierra Research, 1997. Control efficiency is for trees. 7.4 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats for several local air quality agencies in the WRAP region are presented in Table 7-4. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/envsvc/air/ruledesc.asp (Note: The Clark County website did not include regulatory language specific to agricultural wind erosion at the time this chapter was written.) 7-12 Table 7-4. Example Regulatory Formats for Agricultural Wind Erosion Control measure Goal Threshold Agency Requires producers to draft and implement fugitive dust plan Limits fugitive dust from agricultural SJVAPCD with approved control methods sources Rule 8081 11/15/2001 Exemption from Rule 403 general requirements. Limit PM10 Levels to 50 µg/m3 Voluntary implementation of district approved conservation practices and complete/maintain self- monitoring plan SCAQMD Rule 403 12/11/1998 Requires dust plan that contains procedures assuring moisture Reduce fugitive dust from livestock ICAPCD factor between 20%-40% for manure in top 3" of occupied pens and outlines manure management practices and removal feed yards Rule 420 8/13/2002 Dust suppressants, gravel, install shrubs/trees Limit fugitive dust plume to 20% Commercial feedlot/livestock area; Maricopa County opacity shrubs/trees 50ft-100ft from animal pens; compliance with stabilization limitation Rule 310.01 02/16/2000 Record keeping for all ctrl measure taken Ensure that appropriate ctrl measures are implemented and All ops subject to Rule 310.01, provided within 48 hrs of ctrl officer Maricopa County Rule 310.01 maintained request 02/16/2000 7-13 7.5 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 7-5summarizes the compliance tools that are applicable to agricultural wind erosion. Table 7-5. Compliance Tools for Agricultural Wind Erosion Record keeping Site inspection/monitoring Land condition by date (e.g., vegetation; furrowing of fallow land; soil crusts), including residue management and percentages; meteorological log; establishment/ maintenance of windbreaks. Observation of land condition (crusts, furrows), especially during period of high winds. 7.6 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for fugitive dust originating from agricultural wind erosion. A sample cost- effectiveness calculation is presented below for a specific control measure (adding a straw mulch to the field) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous 7-14 control measure for agricultural wind erosion, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Agricultural Wind Erosion Step 1. Determine source activity and control application parameters. Field size (acres) Control Measure Control application/frequency Control Efficiency 320 1,000 lb mulch per acre Once post -harvesting 30% The field size is an assumed value, for illustrative purposes. Adding a straw mulch to the field at a rate of 1,000 lbs per acre has been chosen as the applied control measure. The control application/frequency and control efficiency are default values provided by WSU, 1998. Step 2. Calculate Pm10 Emission Factor. The PM10 emission factor is calculated from AP -42 equation utilizing the appropriate correction parameters: E (tons/acre-year) = 0.5 A I K C L' V' A 0.025 I — soil erodibility (tons/acre-year) 86 K- surface roughness factor 0.50 Climatic factor 0.33 Unsheltered field width factor 0.70 Vegetative cover factor 0.25 E = 0.031 tons/acre-year [Note: the correction parameters above were selected for illustrative purposes.] Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (given in Step 2) is multiplied by the field size (under activity data) to compute the annual PM10 emissions in tons per year, as follows: Annual emissions = (Emission Factor x Field Size) Annual PM10 emissions = (0.031 x 320) = 9.9 tons Annual PM2.5 emissions = 0.15 x PM10 emissions? = 0.15 x 9.9 tons = 1.5 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). 7-15 For this example, we have selected conservation tilling as our control measure. Based on a control efficiency estimate of 30%, the annual controlled emissions are calculated to be: Annual Controlled PM10 emissions = (9.9 tons) x (1 — 0.3) = 6.9 tons Annual Controlled PM2.5 emissions = (1.5 tons) x (1 — 0.3) = 1.0 tons Step 5. Determine Annual Cost to Control PM Emissions. The Annual Cost of mulching is calculated by multiplying the number of acres by the cost per acre. The cost of mulching is assigned a value of $40 per acre.17 Thus, the Annual Cost is estimated to be: 320 x 40 = $12,800 Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annual cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annual Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = $12,800 / (9.9 — 6.9) = $4,295/ton Cost-effectiveness for PM2.5 emissions = $12,800 / (1.5 — 1.0) = $28,636/ton 7.7 References 1. MRI, 1992. Fugitive Dust Background Document and Technical Information Document for Best Available Control Measures. U.S. EPA, Research Triangle Park, NC, September. 2. CARB, 1997. Windblown Dust - Agricultural Lands, Section 7.12 in Methods for Assessing Area Source Emissions, California Air Resources Board, Sacramento, CA. 3. Francis, S.R., 1997. Supplemental Documentation for Section 7.12, Windblown Dust - Agricultural Lands, Stationary Source Inventory Methodology, California Air Resources Board, Sacramento, CA. (This document contains the complete reference list for the development of the Section 7.12 methodology.) 4. Woodruff, N.P., Siddoway, F.H., 1965. A Wind Erosion Equation, Soil Sci. Am. Proc., Vol. 29(5): 602-608. 5. Skidmore, E.L., Woodruff, N.P., 1968. Wind Erosion Forces in the United States and Their Use in Predicting Soil Loss, Agriculture Handbook No. 346, U.S. Department of Agriculture, Agricultural Research Service. 6. USEPA, 1974. Development of Emission Factors for Fugitive Dust Sources, EPA 450/3-74-037, U.S. EPA, Research Triangle Park, NC, June. Updated in September 1988 in Control of Open Fugitive Dust Sources, EPA -450/3-88-008. 7. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 7-16 8. Fryrear, D. et al, 1996. Revised Wind Erosion Equation, U.S. Department of Agriculture, Agricultural Research Service, Big Spring, TX, August. 9. Hagen, L.J. et al, 1995. Wind Erosion Prediction System, U.S. Department of Agriculture, Agricultural Research Service, Manhattan, KS, September. 10. Generalized Soil Map of CA, University of California, Division of Agricultural Sciences, Agricultural Sciences Publications, Richmond, CA, May 1980. 11. State Geographic Data Base, U.S. Department of Agriculture, Natural Resources Conservation Service, September 1995. 12. Hagen, Lawrence. Personal communication to Krista Eley of ARB staff, U.S. Department of Agriculture, Agricultural Research Service, Manhattan, KS, September 25, 1995. 13. Bunter, Walter. Personal communication to Steve Francis, State Agronomist, U.S. Department of Agriculture, Natural Resources Conservation Service, Davis, CA, February 20, 1996. 14. CARB, 1997. Windblown Dust — Unpaved Roads, Section 7.13 in Methods for Assessing Area Source Emissions, California Air Resources Board, Sacramento, CA. 15. Bilbro, J. D., Stout, J. E., 1999. Journal of Soil and Water Conservation. 16 Grantz, D. A., Vaughn, D. L., Farber, R. J., Kim, B., VanCuren, T., Campbell, D, Zink, T., 1998. California Agriculture, Volume 52, July -August. 17. Washington State University, 1998. Farming with the Wind, College of Agriculture and Home Economics Miscellaneous Publication No. MISCO208, December. 18. Sierra Research, 1997. Particulate Control Measure Feasibility Study, Volume I and Volume II (Appendices), prepared for Maricopa Association of Government by Sierra Research, Inc., Sacramento, CA. January 24. 7-17 Chapter 8. Open Area Wind Erosion 8.1 Characterization of Source Emissions 8-1 8.2 Emission Estimation: Primary Methodology 8-2 8.3 Emission Estimation: Alternate Methodology 8-5 8.4 Emission Estimation: Other Methodologies 8-6 8.5 Demonstrated Control Techniques 8-18 8.6 Regulatory Formats 8-19 8.7 Compliance Tools 8-19 8.8 Sample Cost -Effectiveness Calculation 8-21 8.9 References 8-23 8.1 Characterization of Source Emissions Dust emissions may be generated by wind erosion of open areas of exposed soils or other aggregate materials within an industrial facility. These sources typically are characterized by nonhomogeneous surfaces impregnated with nonerodible elements (particles larger than approximately 1 centimeter [cm] in diameter). Field testing of coal piles and other exposed materials using a portable wind tunnel has shown that: (a) threshold wind speeds exceed 5 meters per second (m/s) (11 miles per hour [mph]) at 15 cm above the surface or 10 m/s (22 mph) at 7 m above the surface, and (b) particulate emission rates tend to decay rapidly (half-life of a few minutes) during an erosion event. In other words, these aggregate material surfaces are characterized by finite availability of erodible material (mass/area) referred to as the erosion potential. Any natural crusting of the surface binds the erodible material, thereby reducing the erosion potential. Loose soils or other aggregate materials consisting of sand -sized materials act as an unlimited reservoir of erodible material and can sustain emissions for periods of hours without substantial decreases in emission rates. If typical values for threshold wind speed at 15 cm are corrected to typical wind sensor height (7 to 10 m), the resulting values exceed the upper extremes of hourly mean wind speeds observed in most areas of the country. In other words, mean atmospheric wind speeds are not sufficient to sustain wind erosion from flat surfaces of the type tested. However, wind gusts may quickly deplete a substantial portion of the erosion potential. Because erosion potential has been found to increase rapidly with increasing wind speed, estimated emissions should be related to the gusts of highest magnitude. The routinely measured meteorological variable that best reflects the magnitude of wind gusts is the fastest mile. This quantity represents the wind speed corresponding to the whole mile of wind movement that has passed by the 1 -mile contact anemometer in the least amount of time. Daily measurements of the fastest mile are presented in the monthly Local Climatological Data (LCD) summaries. The duration of the fastest mile, typically about 2 minutes (for a fastest mile of 30 mph), matches well with the half-life of the erosion process, which ranges between 1 and 4 minutes. It should be noted, however, that peak winds can significantly exceed the daily fastest mile. The wind speed profile in the surface boundary layer is found to follow a logarithmic distribution as follows: u ** u(z) = In z (z>z°) w 0.4 z° here, u = wind speed (cm/s) u friction velocity (cm/s) z height above test surface (cm) zo roughness height (cm) 0.4 = von Karman's constant (dimensionless) The friction velocity (u*) is a measure of wind shear stress on the erodible surface, as determined from the slope of the logarithmic velocity profile. The roughness height (zo) is a measure of the roughness of the exposed surface as determined from the y -intercept (1) 8-I of the velocity profile, i.e., the height at which the wind speed is zero. These parameters are illustrated in Figure 8-1 for a roughness height of 0.1 cm. Arithmetic Representation Wind Speed at Z Wind Speed at 10 m Semi -Logarithmic Representation 0.5 Figure 8-1. Illustration of Logarithmic Wind Velocity Profile Emissions generated by wind erosion are also dependent on the frequency of disturbance of the erodible surface because each time that a surface is disturbed, its erosion potential is restored. A disturbance is defined as an action that results in the exposure of fresh surface material. On a storage pile, this would occur whenever aggregate material is either added to or removed from the old surface. A disturbance of an exposed area may also result from the turning of surface material to a depth exceeding the size of the largest pieces of material present. 8.2 Emission Estimation: Primary Methodology1-11 This section was adapted from Section 13.2.5 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.5 was last updated in January 1995. The PM 10 emission factor for wind -generated particulate emissions from mixtures of erodible and nonerodible surface material subject to disturbance may be expressed in units of grams per square meter (g/m2) per year as follows: where, N = number of disturbances per year Pi = erosion potential corresponding to the observed (or probable) fastest mile of wind for the ith period between disturbances (g/m2) In calculating emission factors, each area of an erodible surface that is subject to a different frequency of disturbance should be treated separately. For a surface disturbed N PM] OEmission Factor = 0.5 Pi i=1 (2) 8-2 daily, N = 365 per year, and for a surface disturbance once every 6 months, N = 2 per year. The erosion potential function for a dry, exposed surface is given as: P = 58 (u* - ut*)z + 25 (u* - ut*) (3 ) P=0 foru*≤ut* where, u = friction velocity (m/s) ut = threshold friction velocity (m/s) Because of the nonlinear form of the erosion potential function, each erosion event must be treated separately. The PM2.5/PM10 ratio for windblown fugitive dust posted on EPA's CHIEF website is 0.15. This ratio is based on the analysis conducted by MRI on behalf of WRAP." Equations 2 and 3 apply only to dry, exposed materials with limited erosion potential. The resulting calculation is valid only for a time period as long or longer than the period between disturbances. Calculated emissions represent intermittent events and should not be input directly into dispersion models that assume steady-state emission rates. For uncrusted surfaces, the threshold friction velocity is best estimated from the dry aggregate structure of the soil. A simple hand sieving test of surface soil can be used to determine the mode of the surface aggregate size distribution by inspection of relative sieve catch amounts, following the procedure described below. FIELD PROCEDURE FOR DETERMINING THRESHOLD FRICTION VELOCITY (from a 1952 laboratory procedure published by W. S. Chepil5) Step 1. Prepare a nest of sieves with the following openings: 4 mm, 2 mm, 1 mm, 0.5 mm, and 0.25 mm. Place a collector pan below the bottom (0.25 mm) sieve. Step 2. Collect a sample representing the surface layer of loose particles (approximately 1 cm in depth, for an encrusted surface), removing any rocks larger than about 1 cm in average physical diameter. The area to be sampled should be not less than 30 cm by 30 cm. Step 3. Pour the sample into the top sieve (4 -mm opening), and place a lid on the top. Step 4. Move the covered sieve/pan unit by hand, using a broad circular arm motion in the horizontal plane. Complete 20 circular movements at a speed just necessary to achieve some relative horizontal motion between the sieve and the particles. Step 5. Inspect the relative quantities of catch within each sieve, and determine where the mode in the aggregate size distribution lies, i.e., between the opening size of the sieve with the largest catch and the opening size of the next largest sieve. Step 6. Determine the threshold friction velocity from Table 8-1. The results of the sieving can be interpreted using Table 8-1. Alternatively, the threshold friction velocity for erosion can be determined from the mode of the aggregate size distribution using the graphical relationship described by Gillette.5' 6 If the surface material contains nonerodible elements that are too large to include in the sieving (i.e., greater than about 1 cm in diameter), the effect of the elements must be taken into account by increasing the threshold friction velocity.10 8-3 Table 8-1 Field Procedure for Determination of Threshold Friction Velocity (Metric Units Tyler Sieve No. Opening (mm) Midpoint (mm) ut* (cm/s) 5 4 9 2 3 100 16 1 1.5 76 32 0.5 0.75 58 60 0.25 0.375 43 Threshold friction velocities for several surface types have been determined by field measurements with a portable wind tunnel. These values are presented in Table 8-2. Table 8-2. Threshold Friction Velocities (Metric Units Material Threshold friction velocity (m/s) Roughness height (cm) Threshold wind velocity at 10 m (m/s) zo = Actual zo = 0.5 cm Overburdens 1.02 0.3 21 19 Scoria (roadbed material)' 1.33 0.3 27 25 Ground coal (surrounding coal pile)a 0.55 0.01 16 10 Uncrusted coal piles 1.12 0.3 23 21 Scraper tracks on coal pilea.b 0.62 0.06 15 12 Fine coal dust on concrete padc 0.54 0.2 11 10 Western surface coal mine; reference 2. b Lightly crusted. ° Eastern power plant; reference 3. The fastest mile of wind for the periods between disturbances may be obtained from the monthly local climatological data (LCD) summaries for the nearest reporting weather station that is representative of the site in question.? These summaries report actual fastest mile values for each day of a given month. Because the erosion potential is a highly nonlinear function of the fastest mile, mean values of the fastest mile are inappropriate. The anemometer heights of reporting weather stations are found in Reference 8, and should be corrected to a 10-m reference height using Equation 1. To convert the fastest mile of wind (u+) from a reference anemometer height of 10 m to the equivalent friction velocity (u*), the logarithmic wind speed profile may be used to yield the following equation: u* = 0.053 umo+ where, u = friction velocity (m/s) u io = fastest mile of reference anemometer for period between disturbances (m/s) This assumes a typical roughness height of 0.5 cm for open terrain. Equation 4 is restricted to large relatively flat exposed areas with little penetration into the surface wind layer. (4) 8-4 8.3 Emission Estimation: Alternate Methodology Duane Ono with the Great Basin Unified APCD and Dale Gillette developed a method called the Dust ID method to measure fugitive PM10 dust emissions due to wind erosion that has been approved for use in PM10 SIPs.12' 13 This method has been applied to the dry lake bed at Owens Lake, CA using an extensive sand flux monitoring network. Owens Lake is the largest single source of fugitive dust in the United States (estimated to be 80,000 tons PM10/year). The network consisted of co -located electronic Sensits and passive Cox Sand Catchers (CSCs) deployed on a 1 km x 1 km grid covering 135 square kilometers of the lake bed with their sensor or inlet positioned 15 cm above the surface. Sensits measure the kinetic energy or the particle counts of sand -sized particles as they saltate across the surface. Due to differences in the electronic response of individual Sensits, these units had to be co -located with passive sand flux measurement devices to calibrate their electronic output and to determine the hourly sand flux. The battery powered Sensits were augmented with a solar charging system. A data logger recorded hourly Sensit data during inactive periods and switched to 5 -minute data during active erosion periods. CSC's are passive instruments that are used to collect sand -sized particles that are blown across the surface during a dust event. These instruments were designed and built by the Great Basin Unified Air Pollution Control District as a reliable, low-cost instrument that could withstand the harsh conditions at Owens Lake. CSC's have no moving parts and can collect sand for a month at Owens Lake without overloading the collector. As an alternative to hourly sand (saltation) flux measurements relying on Sensits, Ono14 found that monthly sand flux measurements obtained with CSCs could be applied to a model developed by Gillette et al.15 to provide a good estimate of hourly sand flux rates. Hourly PM10 emissions from each square kilometer of the lake bed were estimated from the following equation: Fa=KfXq where, Fa = PM10 emissions flux (g/cm2/hr) q = hourly sand flux (g/cm2/hr) measured at 15 cm above the surface Kf, called the K -factor, =proportionality factor relating the PM10 emissions flux to the sand flux measured at 15 cm above the surface. Kf values were determined by comparing CALPUFF model predictions, based on meteorological data from thirteen 10 -meter towers and an Upper Air Wind Profiler to generate wind fields using the CALMET model, to observed hourly PM10 concentrations measured at six PM10 monitoring sites utilizing TEOM PM10 monitors. A K -factor of 5 x 10"5 was used to initially run the model and to generate PM10 concentration values that were close to the monitored concentrations. Hourly K -factor values were later adjusted in a post -processing step to determine the K -factor value that would have made the modeled concentration match the monitored concentration at each of the six PM10 monitor sites using the following equation: 8-5 Kf = K; [(Cobs — Cbac)/Cmod] where, K; = initial K -factor (5 x 10-5) Cobs. = observed hourly PM 10 concentration (µg/m3) Cbac. = background PM 10 concentration (assumed to be 20 µg/m3) Cmod = model -predicted hourly PM10 concentration (µg/m3) The results showed that Kf changed spatially and temporally at Owens Lake and that the changes corresponded to different soil textures on the lake bed and to seasonal surface changes that affected erodibility. The results also showed that some source areas were active all year, while others were seasonal and sometimes sporadic. Wind tunnel tests at Owens Lake independently confirmed these seasonal and spatial changes in Kf. Ono et a1.12 concluded that the emission estimates using their Dust ID method were more accurate than the AP -42 method for estimating daily emissions, since the emissions estimates correspond to measured hourly wind erosion on the lake bed. For daily emissions, Ono and co-workers believe that AP -42 drastically overestimates the emissions at low wind speed conditions, and underestimates emissions at high wind speeds. This large discrepancy in the emission estimates is due to the use of a single threshold friction velocity for the entire erosion area in the AP -42 method. The AP -42 method and the Dust ID method of estimating emissions resulted in very close agreement for the annual emissions. 8.4 Emission Estimation: Other Methodologies Several alternative emission estimation methods for open area wind erosion have been developed that are still in the developmental stage and have not yet been approved by federal or state agencies. Thus, the reader is cautioned in the use of these methods. 8.4.1 MacDougall Method MacDougall developed a method for estimating fugitive dust emissions from wind erosion of vacant land.] This method, which relies heavily on emission factors developed for different vacant land parcels using wind tunnels. The availability of wind tunnel results for the types of vacant land being assessed must be considered when deciding to use this method for other applications. It should be pointed out that in 2003 Environ (under contract to the Western Governors' Association) abandoned this approach due to the paucity' of sufficient wind tunnel data for many different vacant land parcels in the western U.S. 7 Also, the WRAP's fugitive dust expert panel had major reservations regarding the MacDougall method.]$ Panel members were skeptical about using the proposed methodology since wind tunnels have shortcomings and do not represent actual conditions in nature. The panel concluded that determining emission factors in the manner proposed will result in significant underestimation of windblown dust for those cases where saltation plays a role. The six steps described in the MacDougall method are summarized below. Step 1: Categorizing Vacant Land. Vacant land within the study area must be categorized based upon the potential of the parcels to emit fugitive dust during wind 8-6 events. Many wind tunnel studies have been conducted in the western United States, and the vacant land descriptions of the wind tunnel test areas should be used to categorize the vacant land within the study area. When categorizing vacant land, it is especially important whether the land has vegetation, rocks or other sheltering elements, whether the soil crust is intact or disturbed, and whether there are periodic activities on the vacant land such as vehicles or plowing that will change the land from fairly stable to unstable. Not every parcel of vacant land will necessarily fit into a category that has been wind tunnel tested. For parcels without a specific vacant land type wind tunnel test, assumptions will need to be made of the best representative land type and uncertainties noted. Step 2: Identify Wind Tunnel Emission Factors. Based upon the vacant land categorization, wind tunnel results should be reviewed and applied appropriately to each category of vacant land. Wind tunnel results should be reviewed to determine if "spikes" from the initial portion of the test are presented separately or averaged into an hourly factor. Whenever possible, spikes should not be included in an hourly factor. The spike values should be included only at the beginning of each wind event. Step 3: Develop Meteorological Data Set. For the area to be studied, hourly average wind speeds, rainfall, and if available peak wind gust data should be gathered. If a study area is particularly large, several different meteorological data sets may need to be gathered, and each land parcel matched with the meteorological data that impacts that parcel. Step 4: Determine Land Type Reservoirs, Threshold Wind Velocities, Wind Events, and Rainfall Events. Based upon the wind tunnel results for each vacant land type, the wind speed when emissions were first measured for the vacant land type, should be set as the threshold wind speed. Most vacant land does not have an endless reservoir of fugitive dust; however, land that has a high degree of disturbance will continue to emit throughout a wind event. Therefore, for each vacant land type, the wind tunnel results should be reviewed and a determination made on the length of time the parcel will emit for a give wind event. It is recommended that an assumption be made that parcels with sheltering elements, vegetated parcels, or parcels with a soil crust will only emit during the first hour of a wind event. Parcels with a relatively high silt component or with frequent disturbance will probably continue to emit throughout a wind event. Because most threshold wind speeds are relatively high (i.e., sustained hourly winds of 25 to 30 mph), a wind event may be defined as any time period when winds reach the threshold wind velocities separated by at least 24 hours before a new wind event is defined. Depending on the soils in an area, rain may have a large impact on wind erosion. Days with rain should not be included in the inventory. Step 5: Develop Emission Inventory Specific Emission Factors. Using the reservoir determination, threshold wind speeds, wind event determination and rainfall factors, determine hours when wind conditions produced emissions from each vacant land parcel for the time period of the emission inventory. The number of hours with wind speeds in each wind speed category should be totaled. The number of hours can then be multiplied by the wind tunnel emission factor and a total emission factor for the time period of the 8-7 inventory can be calculated. The emission factor equations for vacant land with and without sustained emissions are given as follows: (a) With sustained emissions: EF1 = (I (H P)) where, EF1 = PM10 emission factor (lb/acre) H = number of hours when wind conditions result in emissions P = emission factor for a given vacant land category (lb/hour-acre) (b) Without sustained emissions: EF1 = (I (W P)) where, EF1 = PM10 emission factor (lb/acre) W = number of wind events when wind conditions result in emissions P = emission factor for a given vacant land category (lb/acre) The emission factor equation for spike emissions is given as: EF2 = (I (E S)) where, EF2 = spike PM10 emission factor (lb/acre) E = number of events producing spike emissions S = spike mass for a given vacant land category (lb/acre) Emission factors will vary from time period to time period and from vacant land type to vacant land type. Generally speaking, disturbed lands will have unlimited reservoirs and lower threshold wind velocities leading to much higher emissions than stable or sheltered parcels with one hour reservoirs. An emission factor should be developed for each vacant land category in the inventory. Step 6: Apply Emission Inventory Specific Emission Factors to Vacant Land Categories. Once emission inventory emission factors have been developed, the number of acres in each category should be multiplied by the factor and the emissions totaled. It may be useful to develop certain factors over shorter time periods and then total the emissions over a longer time period. For example, one may want to develop winter factors and summer factors and then total them together for the annual inventory. For large areas, where vacant land categories will change over the duration of an inventory or different meteorological data sets will apply, it is advisable to subdivide the inventory by time period or area, and then total the inventory at the end. Annual emissions for each vacant land category are calculated as follows: E = A (EF1 + EF2) where, E = annual emissions for a given vacant land category A = vacant land category acreage EF1 = annual emission factor for a given vacant land category EF2 = spike emission factor for a given vacant land category 8.4.2 Drexler Method Based on an evaluation of available algorithms for calculating wind blown fugitive dust emissions, the WRAP expert fugitive dust panel's recommended the use of the 8-8 algorithm developed by Draxler et al.19 that was based on the earlier work of Marticorena et al.Z° This algorithm received the highest score on the basis of extensive field verification test results and having undergone peer review. Draxler and coworkers developed their algorithm for estimating fugitive dust emissions during desert dust storms in Iraq, Kuwait, and Saudi Arabia using a Lagrangian transport and dispersion model where the vertical dust flux was proportional to the difference in the squares of the friction velocity and threshold friction velocity. A proportionality constant was used to relate the surface soil texture to the PM10 dust emissions, and is defined as the ratio of vertical flux of PM10 to total aeolian horizontal mass flux. PM10 emissions caused by wind erosion were estimated in a stepwise process as follows: Step I. Obtain large scale and small scale wind fields Step II. Estimate sand movement (horizontal flux of saltation particles >50 gm) Step III. Calculate vertical resuspended dust emissions The horizontal flux of sand, Q (µg/meter-second), was modeled as follows: * *2 * Q = A (p/g) u(u — ut2) where, A = a dimensionless constant p = the density of air g= the acceleration due to gravity u* = the friction velocity (m/s) u*t = the threshold friction velocity (m/s) required for initiation of sand movement by the wind. The value of A is not constant if there is wetting followed by crusting of the surface sediments, or if there is a depletion of loose particles on the surface for a "supply - limited" surface. The value of A ranges from a maximum of —3.5 when the surface is covered with loose sand to —0 when the surface has a smooth crust with few loose particles larger than 1 mm. Suspended dust is proportional to saltation or sandblasting as follows: F=KQ where, F = the vertical flux of dust (µg/m2-second) K = proportionality factor (m-1) that relates the surface soil texture to PM10 dust emissions Q = the horizontal flux of saltating particles (µg/m-second) The value of K is not precisely known, but data sets of F versus Q are available so that estimates of K can be made for certain soils. For sand textured soils, K is estimated to be —5.6 x 10-4 m-1 and A is —2.8. 8.4.3 UNLV Method James and co-workers with the University of Nevada Las Vegas (UNLV) developed a wind blown dust inventory for Clark County, NV based on wind tunnel measurements.21 The method involved deriving estimates of wind blown fugitive dust emission factors for three categories of vacant land: disturbed vacant land, stabilized vacant land, and 8-9 undisturbed native desert soils. The emission factors included geometric mean hourly "spike" corrected emission rates (tons/acre-hour) for disturbed vacant land, stabilized vacant land and undisturbed native desert soils as well as geometric mean spike emissions (ton/acre) for disturbed vacant land and undisturbed native desert soils as a function of wind speed and soil type. The emission inventory assumed that the particulate reservoir for disturbed vacant land had no limit. For every hour the sustained wind speeds were within a given wind speed category above the "spike" wind speed, the emissions were calculated. A single "spike" mass was added for each acre of vacant land for those days that the wind speed exceeded a threshold wind speed, assuming each day represented a single wind event and reservoir recharging would not have occurred during a 24 -hour period. Wind speeds less than the "spike" speed were not included in the emission calculations. Because the native desert parcels have a limited PMl 0 reservoir, it was assumed that the reservoir would be depleted within one hour of sustained winds above the "spike" wind speed. Therefore, only one hour of emissions were calculated during each day that winds exceeded the threshold friction velocity ("spike" wind speed) for native desert parcels. The wind speed threshold for generating fugitive dust emissions was estimated by James et al.21 to be 20 mph for disturbed vacant land and 25 mph for native desert parcels. Because the parcels stabilized with dust suppressants had been subjected to some disturbance by vehicle traffic that may have caused some dust palliatives to break down, the initial wind threshold for this category was lower than the other categories, namely 15 mph. However, the use of dust palliatives greatly reduced the overall emission factors. Spikes were generally not observed from the stabilized parcels, and emission factors without spike corrections were used for stabilized parcels. As with native desert, it was assumed that the stabilized parcels have a limited PM 10 reservoir that would be depleted within one hour of sustained winds above the threshold wind velocity. Therefore, only one hour of emissions was calculated during each day for stabilized parcels. For a sustained wind speed of 25 mph, the geometric mean hourly spike corrected emission factors across all soil types for Clark County were estimated to be —5 x 10-3 ton/acre-hour for disturbed vacant land, —2 x 10-3 ton/acre-hour for native desert, and —2 x 10-4 ton/acre-hour for stabilized land. The geometric mean spike emissions for a sustained wind speed of 25 mph were estimated to be —2 x 10-i ton/acre for disturbed vacant land and —5 x 10"4 ton/acre for undisturbed native desert parcels. It should be pointed out that there was significant scatter in the observed data, with within category variability ranging over 1 to 2 orders of magnitude. 8.4.4 WRAP RMC Method The Dust Emissions Joint Forum (DEJF) of the Western Regional Air Partnership contracted with ENVIRON to develop a particulate emission calculation method for open area wind erosion in 2003. The DEJF extended ENVIRON's original contract (Phase 2) to provide windblown dust emissions inventories, and perform modeling simulations of the effects of those emissions on regional haze for calendar year 2002 and future year projections. The purpose of this additional effort was to improve the windblown dust 8-10 emissions model developed as part of Phase 1. The results of the initial model runs and subsequent sensitivity simulations had demonstrated a need to revise and/or update various assumptions associated with the development of the emission inventory. To this end, revised estimation methodologies and algorithms were evaluated in Phase 2 in order to address various shortcomings and limitations of the Phase 1 version of the model. Many of the assumptions employed in the Phase 1 methodology were necessitated by a lack of specificity in the underlying data used to characterize vacant land types and soil conditions in relation to the potential for wind erosion. Even in Phase 2, it was necessary to rely on some assumptions where data were lacking. Summary of the WRAP RMC Method The WRAP RMC windblown dust method utilizes wind tunnel -based emission algorithms for different soils and accounts for land use and local meteorology. The complete set of documents that describe the method in full detail may be found at www.wrapair.org. The summary of the method presented below is based on ENVIRON's final report submitted to the DEJF on May 5, 2006.22 There are two important factors for characterizing the dust emission process from an erodible surface. They are (a) the threshold friction velocity that defines the inception of the emission process as a function of the wind speed as influenced by the surface characteristics, and (b) the strength of the emissions that follow the commencement of particle movement. The two critical factors affecting emission strength are the wind speed (wind friction velocity) that drives the saltation system, and the soil characteristics. Friction Velocities Surface friction velocities are determined from the aerodynamic surface roughness lengths and the 10 -meter wind speeds based on MM5 model simulations. Friction velocity, u+, is related to the slope of the velocity versus the natural logarithm of height through the relationship: uZ l z =—ln— u. K zo where uZ = wind velocity at height z (m/s) u* = friction velocity (m/s) x = von Karman's constant (0.4) z° = aerodynamic roughness height (m) The threshold friction velocities, u=t, are determined from the relationships developed by Marticorena et al.2° as a function of the aerodynamic surface roughness length, z°. Figure 8-2 shows the comparison between Marticorena's modeled relationship of threshold friction velocity and aerodynamic surface roughness length and wind tunnel data obtained by different investigators.23-26 8-11 3 2.5 - 2 77 E 1.5 0.5 0 0.00001 0.0001 0.001 0.01 0.1 • wind tunnel data —Expon. (wind tunnel data) Figure 8-2. Threshold Friction Velocity vs. Aerodynamic Roughness Length z (cm) Marticorena et al. 1997 ••••••••••••Expon. (Marticorena et al. 1997) Surface friction velocities, including the threshold friction velocity, are a function of the aerodynamic surface roughness lengths. The surface friction velocities are in turn dependent on surface characteristics, particularly land use/land cover. While these values can vary considerable for a given land type, published data are available which provide a range of surface friction velocities for various land use types and vegetation cover. These data are presented in Table 8-3. Table 8-3. Threshold Friction Velocities for Typical Surface Types 23-26 agricultural ields 1.29 0.55 0.57 alluvial fan 0.72 0.60 0.17 desert flat 0.75 0.51 0.32 desert •avement 2.17 0.59 0.73 an surface 1.43 0.47 0.67 •la a, crusted 2.13 0.63 0.70 pla a 1.46 0.58 0.60 prairie 2.90 0.24 0.92 sand dune 0.44 0.32 0.27 8-12 Emission Fluxes Emission fluxes, or emission rates, are determined as a function of surface friction velocity and soil texture. The relationships that Chatenet et al.27 established between the 12 soil types in the classical soil texture triangle and their four dry soil types (silt [FSS], sandy silt [FS], silty sand [MS], and sand [CS]) are of key importance. The relationships developed by Alfaro and others28' 29 for each of the soil texture groups are used to estimate dust emission fluxes. These relationships are presented in Figure 8-3. 0.00001 ssion Flux (F, g c 0.000001 0.0000001 - 0.00000001 - 0.000000001 FFS F = 2.45x10.5 (u.)3•97 FS F = 9.33x10' (u.)214 MS F = 1.243x10'(u.)''" CS F = 1.24x10' (u.)3'" O 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Friction Velocity (m s ') 0.8 0.9 FSS FS MS CS — Power (FSS) — Power (FS) — —Power(MS) — --Power (CS) Figure 8-3. Emission Flux vs. Friction Velocity Predicted by the Alfaro and Gomes Model28 Constrained by the Four Soil Classes of Alfaro et al.29 Reservoir Characteristics Reservoirs are classified as limited for stable land parcels and unlimited for unstable land parcels. Classification of reservoirs as limited or unlimited has implications with respect to the duration of time over which the dust emissions are generated. In general, the reservoirs should be classified in terms of the type of soils, the depth of the soil layer, soil moisture content and meteorological parameters. Finally, the time required for a reservoir to recharge following a wind event is influenced by a number of factors including precipitation and snow events and freezing conditions of the soils. A recharge time of 24 hours is assigned to all surfaces. In addition, it is assumed that no surface will generate emissions for more than 10 hours in any 24 -hour period. The duration and amount of precipitation and snow and freeze events will also affect the dust emissions from wind erosion. Barnard30 has compiled a set of conditions for treating these events based on seasons, soil characteristics and the amounts of rainfall and snow cover. The time necessary to re -initiate wind erosion after a precipitation event ranges from 1 to 10 days, depending on the soil type, season of the year and whether the rainfall amount exceeds 2 inches. Soil Disturbance The disturbance level of a surface more appropriately has the effect of lowering the threshold surface friction velocity. Except for agricultural lands, which are treated separately in the model as described below, vacant land parcels are typically 8-13 undisturbed unless some activity is present such as to cause a disturbance (e.g., off -road vehicle activity in desert lands, or animal grazing on rangelands). It is recommended that all non-agricultural land types be considered undisturbed, since there is no a priori information to indicate otherwise for the regional scale modeling domain to be considered. Therefore, for the purpose of evaluating the sensitivity of the model to disturbance levels, all grassland, shrubland and barren land areas are assumed to have 10 % of their land area disturbed. Threshold surface friction velocities for these disturbed lands are assigned as follows: 3.1 m/s for grasslands and shrublands, and 0.82 m/s for barren land. Soil Characteristics Application of the emission factor relations described above requires the characterization of soil texture in terms of the four soil groups considered by the model. The characteristics or type of soil is one of the parameters of primary importance for the application of the emission estimation relations derived from wind tunnel study results. The State Soil Geographic Database (STATSGO) available from the USDA31 is used to determine the type of soils present in the modeling domain for which the emission inventory is developed. The classification of soil textures and soil group codes is based on the standard soil triangle that classifies soil texture in terms of percent sand, silt and clay. Combining the soil groups defined by the work of Alfaro et al.29 and Chatenet et al.27 and the standard soil triangle provides the mapping of the 12 soil textures to the four soil groups considered in their study. The soil texture mappings are summarized in Table 8-4. Table 8-4. STATSGO Soil Texture and Soil Group Codes No Data 0 N/A 0 Sand 1 CS 4 Loam Sand 2 CS 4 Sand Loam 3 MS 3 Silt Loam 4 FS 1 Silt 5 FSS 2 Loam 6 MS 3 Sand CIa Loam 7 MS 3 Silt CIa Loam 8 FSS 1 CIa Loam 9 MS 3 Sand CIa 10 MS 3 11 FSS 1 Cla 12 FS 2 Surface Roughness Lengths Surface roughness lengths can vary considerably for a given land type, as evidenced by examination of the data in Table 8-5. Surface roughness lengths are assigned as a function of land use type based on a review of the information in Table 8-5. The disturbance level of various surfaces has the effect of altering the surface roughness lengths, which in turn impact the potential for vacant lands to emit dust from wind erosion 8-14 Table 8-5. Aerodynamic Surface Aerodynamic Rou:hness Lengths, Zo agricultural fields (bare) 0.031 23 - 26 desert flat/pavement fan surface 0.133 0.088 23-26 23 - 26 playa, crusted playa prairie sand dune scrub desert sparse veg. (0.04% cover) sparse veg. (8% cover) sparse veg. (10.3% cover) sparse veg. (13.5% cover) sparse veg. (26% cover) thick grass thin grass sparse grass agricultural crops orchards decid. forests conf. forests 0.059 0.057 0.049 0.007 0.045 23-26 23 - 26 23-26 23 - 26 26 0.37 5.4 6.8 7.2 8.3 2.3 33 33 33 33 33 34 5 0.12 2-4 50-100 100-600 100-600 34 35 35 35 35 35 agricultural crops urban decid. forests (closed canopy) conif. forests (closed canopy) 15 100 121 36 36 134 36 36 An examination of Figure 8-2, which relates the threshold surface friction velocity to the aerodynamic surface roughness length, reveals that for surface roughness lengths larger than approximately 0.1 cm, the threshold friction velocities increase rapidly above values that can be realistically expected to occur in the meteorological data used in the model implementation. Therefore to simplify the model implementation, only those land types with roughness length less than or equal to 0.1 cm are considered as potentially erodible surfaces. For a given surface roughness, as determined by the land use type32, the threshold friction velocity has a constant value. Thus, the land use data is mapped to an internal dust code used within the model to minimize computer resource requirements and coding efforts. The mapping of land use types to dust codes 3 and above (except for code 5 that applies to orchards and vineyards) is presented in Table 8-6, which summarizes the surface characteristics by dust code. [Note: Dust codes 1 and 2 refer to water/wetlands and forest/urban, respectively.] Table 8-6. Surface Characteristics by Dust Code and Land Use Cateo Agricultural Grassland Shrubland Barren Land use category Surface roughness length, Zo (cm) 0.031 0.1 0.05 0.002 Threshold friction velocity (m/s) 3.72 6.17 4.30 3.04 Threshold wind velocity at 10 13.2 19.8 14.6 12.7 meter height (m/s [mph]) [29.5] [44.3] [32.8] [28.5] 8-15 Meteorology Gridded hourly meteorological data, which is required for the dust estimation methodology is based on MM5 model simulation results. Data fields required include wind speeds, precipitation rates, soil temperatures and ice/snow cover. Agricultural Land Adjustments Unlike other types of vacant land, windblown dust emissions from agricultural land are subject to a number of non -climatic influences, including irrigation and seasonal crop growth. As a result, several non -climatic correction or adjustment factors were developed for applicability to the agricultural wind erosion emissions. These factors included: • Long-term effects of irrigation (i.e., soil "clodiness") • Crop canopy cover • Post -harvest vegetative cover (i.e., residue) • Bare soil (i.e., barren areas within an agriculture field that do not develop crop canopy for various reasons, etc.) • Field borders (i.e., bare areas surrounding and adjacent to agricultural fields) The methodology used to develop individual non -climatic correction factors was based upon previous work performed by the California Air Resources Board in their development of California -specific adjustment factors for the USDA's Wind Erosion Equation.37 Other Adjustments Two other adjustments to modeled air quality impacts relate to fugitive dust transportability and partitioning between fine and coarse fractions of PM1 0. Transportability fractions as a function of land use are assigned on the basis of the methodology described by Pace.38 New fine fraction values developed by Cowherd39 from controlled wind tunnel studies of western soils are applied to determine the fine and coarse fractions of wind -generated fugitive dust emissions. Concerns Regarding the Method ENVIRON's methodology for calculating wind -generated fugitive dust emissions relies on several assumptions that may not be valid. As was mentioned above, many of the assumptions employed in Phase I were necessitated by a lack of specificity in the underlying data used to characterize vacant land types and soil conditions in relation to the potential for wind erosion. Even in Phase 2, it was necessary to rely on some assumptions where data were lacking. The pertinent vacant land characteristics that are most difficult to characterize are the dust reservoir capacities and resuspension characteristics in relation to the levels of surface disturbance and the presence of protective surface elements (vegetation, rocks). Another complex feature is the recharge time needed to re-establish all or part of the reservoir after depletion by a wind erosion event. Surface disturbance tends to have a much stronger impact than soil type in providing a high dust reservoir capacity. If the surface is disturbed in such a way that non -erodible 8-16 elements are minimized, it can be considered as having an "unlimited" erosion potential. This means that the reservoir is large enough to support hours of fine particle emissions during a high -wind event. Therefore, it is important any PM10 emission models or empirical relationships account for not only the soil type but also the state of aggregation of the exposed surface material. After a surface disturbance that creates an unlimited reservoir of available particles, precipitation events can have a major effect in restoring a surface crust and place the surface in a stable condition for an indefinite period. When this occurs, typically a "limited" reservoir will be present on the surface. This reservoir contains only minor amounts of accumulated deposition from previous area -wide wind erosion events or from other more localized fugitive dust sources such as unpaved roads. Because of the complexity of determining dust reservoir characteristics and their dynamic features, the Phase 2 methodology also tends to rely on assigned characteristics that do not appear to be well founded for most areas subject to wind erosion. For example, the assumed recharge period of only 24 hours is usually unrealistic. For example in the case of agricultural land, this would require a major disturbance to the soil such as a tilling operation that brings fresh, loose and dry soil to the surface. In the absence of a major surface disturbance, actual recharge times may extend to weeks and even months.4° In some cases, however, a stable surface can transition to a highly erodible state in the absence of mechanical disturbance. The highly alkaline soils at Owens Lake, California for instance are fairly stable during summer months, but can change to a very unstable surface in the winter and spring following periods with precipitation and cold temperatures.12 Another example of concern is the value assumed in the Phase 2 model for the estimated time after a precipitation event that it takes to re -initiate wind erosion. The times given for full restoration of the dust reservoir are in the range of 1 to 4 days, depending on the soil type and whether the precipitation exceeded 2 inches. These values are at variance with the results of a multiyear field study conducted by Cowherd et al. in the western Mojave Desert 41 That study showed that precipitation events of that order could re -stabilize soil surfaces for indefinite periods pending the next major surface disturbance. In the study area, scattered reservoirs of loose sand were stabilized by the presence of desert vegetation. Stable soils in windy areas tend to have limited reservoirs of erodible particles consisting of a thin surface layer of deposition from previous high wind events. These layers have been homogenized by successive resusupension and atmospheric mixing during wind erosion over many years. This is illustrated by a recently completed inventory of vacant lands in the Las Vegas Valley.42 This study showed that the vast majority of the land consisted of "native desert" as characterized by a single reflectance signature from satellite imagery with visible and infrared wavelength components. Landsat TM 5 with a 30 -meter pixel size was found to provide a useful reflectance averaging that eliminated the effects of micro -features associated with uneven patterns of vegetation. The thin layers of erodible particles appear to exhibit a relatively uniform 8-17 chemistry. Therefore, the known soil chemistry differences below the surface layer were not a confounding factor in establishing a single spectral signature for this vacant land category. On the other hand, areas where the soil had been turned as part of land preparation processes for construction projects could not be fitted to a single spectral signature because of surface soil chemistry differences. Due to the paucity of wind tunnel data, Mansell et al.'7 developed fugitive dust emission factors for wind erosion of vacant land, based on soil texture rather than using area -specific wind tunnel data as recommended by MacDouga11.16 The emission fluxes for four soil aggregate populations were expressed in terms of friction velocity, based on test data from a relatively large portable wind tunnel. It was assumed that the flux would remain constant at any friction velocity for a period of 1 hour or 10 hours depending on whether the surface was classified as having a limited or unlimited reservoir respectively. Mansell and coworkers did not rely on the wind tunnel emission factors derived for Clark County by James et al.21 because they appeared to be much greater than emission factors measured by other researchers using wind tunnels with a larger cross-section than the UNLV designed wind tunnel (6" wide by 6" high by 60" long). It should be noted that because ENVIRON's methodology assigns a very short recovery time on (a) replenishing soil losses from high wind events, and on (b) losing the mitigating effects of precipitation, the estimated emissions are driven mostly by wind speed. There is little accounting for the natural tendency of most unlimited reservoir surfaces to re -stabilize for long periods of time in the absence of major surface disturbances or large supplies of available loose sand that can abrade stable crusts. As noted in the land inventory of the Las Vegas Valley cited above, a frequent land disturbance pattern is found only on regularly traveled surfaces, with few exceptions. Recommendations In order to use ENVIRON's methodology/model for calculating wind -generated fugitive dust emissions, it is strongly recommended that the user review the necessary inputs for the model, and refine the inputs if better information is available. If a wind blown dust inventory is needed for a planning area, local wind tunnel data, or erosion monitoring using CSC sand flux samplers based on the methodology described by Ono et al.12 (see Section 8.3) is a very practical approach. 8.5 Demonstrated Control Techniques Control measures for open area wind erosion are designed to stabilize the exposed surface (e.g., by armoring it with a less erodible cover material) or to shield it from the ambient wind. Table 8-7 presents a summary of control measures and reported control efficiencies for open area wind erosion. 8-18 Table 8-7. Control Efficiencies for Control Measures for Open Area Wind Erosion Control measure Source Component PM10 Control Efficiency References/comments Apply dust suppressants to stabilize disturbed area after cessation of disturbance Disturbed areas 84% CARB, April 2002.43 Apply gravel to stabilize disturbed open areas Disturbed areas 84% CARB, April 2002.43 Estimated to be as effective as chemical dust suppressants. 8.6 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats for several local air quality agencies in the WRAP region are presented in Table 8-8. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/envsvc/air/ruledesc.asp 8.7 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. 8-19 Table 8-8. Example Regulatory Formats for Open Area Wind Erosion Control measure Goal Threshold Agency Watering, fencing, paving, graveling, dust suppressant, vegetative cover, restrict vehicular Maintain soil moisture content min 12%; or 70% min of optimum soil moisture content; reduce windblown Construction sites; fences 3ft-5ft, adjacent to roadways/urban areas; Maricopa County Rule 310 access emissions 04/07/2004 Cease ops (wind speed >25mph); applying dust Reduce amt of windblown dust leaving site; maintain Wind speed must be >25mph for Maricopa County suppressant 2x hr; watering and fencing (as soil moisture content 12% 60 min average; fencing must be Rule 310 above); for after work hours: gravel, water 3x/day (possibly 4) 3ft-5ft with <50% porosity; watering for after work, holidays, weekends increase to 4x/day during wind event 04/07/2004 Use of one of following for dust control on all Prevent visible fugitive dust from exceeding 20% Clark County disturbed soil to maintain in damp condition: soil opacity, and prevent dust plume from extending more Sect. 94 Air crusted over by watering or other, or graveling or treated with dust suppressant than 100 yd Quality Reg. 06/22/2000 Requires application of water or chemical For operations that remain inactive SCAQMD Rule stabilizers prior to wind event 3 times a day (possible increase to 4 times a day if evidence of wind driven dust), or establish a vegetative cover within 21 days after active operations have ceased to maintain a stabilized surface for 6 months for not more than 4 consecutive days 403 12/11/1998 8-20 Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 8-9 summarizes the compliance tools that are applicable to open area wind erosion. Table 8-9. Compliance Tools for Oven Area Wind Erosion Record keeping Site inspection/monitoring Soil stabilization methods; application frequencies, rates, and times for dust suppressants; establishment/ maintenance of wind breaks. Crust strength determination (e.g., drop ball test); observation of operation of dust suppression systems; inspection of heights and porosities of windbreaks. 8.8 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for fugitive dust originating from open area wind erosion. A sample cost- effectiveness calculation is presented below for a specific control measure (apply gravel) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for open area wind erosion, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation For Open Area Wind Erosion (Dirt Parking Lot) Step 1. Determine source activity and control application parameters. Area of dirt parking lot Disturbance frequency per day Duration of exposure (months) Roughness height (cm) Threshold peak wind speed at height of 10 m (m/s) 10,000 m2 1 12 0.5 10 8-21 P —erosion potential (g/m2) Threshold friction velocity u*t (m/s) = 0.053 u'10 Control Measure Control application/frequency Economic Life of Control System (yr) Threshold friction velocity for gravel (m/s) Control Efficiency (%) Reference for Control Efficiency Apply gravel Once every years 5 1.9 84 Sierra Research (2003) 44 The field size, source activity parameters, and control measure parameters are assumed values for illustrative purposes. Applying a 3" deep gravel bed over the dirt has been chosen as the applied control measure. Step 2. Obtain PM10 Emission Factor. N The PM10 emission factor is obtained from AP -42: PM10 EF = 0.5 I Pi i=1 P = 58 (u*-u*t)2 + 25 (u*-u*t) P=0for u*≤ut* 0.53 Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (obtained in Step 2) is applied to each day for which the peak wind exceeds the threshold velocity for wind erosion. The following monthly climatic data are used for illustrative purposes and are assumed to apply to each month of the year. Monthly erosion potential (P) a Peak Wind Day (u+to) u* P of Month mph m/s m/s g/m2 6 29 13.0 0.69 5.36 7 30 13.4 0.71 6.41 11 38 17.0 0.90 17.21 22 25 11.2 0.59 1.78 Sum of P 30.77 a Assumed to apply to 12 months of the year. The annual PM10 emissions are equal to the PM10 emission factor (i.e., 0.5 times the monthly erosion potential) multiplied by 12 and then by the field size (under activity data) and then divided by 454 g/Ib and 2,000 lb/ton to compute the annual PM10 emissions in tons per year, as follows: Annual PM10 emissions = (Emission Factor x Field Size) / (454 x 2,000) Annual PM10 emissions = (0.5 x 0.77 x 12 x 10,000) / (454 x 2,000) Annual PM10 emissions = 2.03 tons Annual PM2.5 emissions = 0.15 x PM10 emissions12 = 0.15 x 2.03 = 0.30 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). 8-22 For this example, we have selected applying gravel over the dirt parking lot as our control measure. Based on a control efficiency estimate of 84% for this control measure, the annual controlled emissions estimate are calculated to be: Annual Controlled PM10 emissions = 0.33 tons Annual Controlled PM2.5 emissions = 0.049 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) 50,000 Annual Operating/Maintenance costs ($) 4,000 Annual Interest Rate 3% Capital Recovery Factor 0.2184 Annualized Cost ($/yr) 13,173 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: Capital Recovery Factor = AIR x (1+AIR) E°°"°michte / (1+AIR)Economiclife —1 Capital Recovery Factor = 3% x (1+ 3%)5 / (1+ 3%)5 — 1 = 0.2184 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor and the Capital costs to the Annual Operating/Maintenance: Annualized Cost = (CRF x Capital costs) + Annual Operating/Maintenance costs Annualized Cost = (0.2084 x 50,000) + 4,000 = 14,918 Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = $14,918 / (2.03 - 0.33) = $8,735/ton Cost-effectiveness for PM2.5 emissions = $14,918 / (0.30 - 0.049) = $58,234/ton 8.9 References 1. Cowherd, C. Jr., 1983. A New Approach to Estimating Wind Generated Emissions from Coal Storage Piles, Presented at the APCA Specialty Conference on Fugitive Dust Issues in the Coal Use Cycle, Pittsburgh, PA, April. 2. Axtell, K., Cowherd, C. Jr., 1984. Improved Emission Factors for Fugitive Dust from Surface Coal Mining Sources, EPA -600/7-84-048, U.S. EPA, Cincinnati, OH, March. 3. Muleski, G.E., 1985. Coal Yard Wind Erosion Measurement, Midwest Research Institute, Kansas City, MO, March 1985. 4. MRI, 1988. Update of Fugitive Dust Emissions Factors in AP -42 Section 11.2 -Wind Erosion, MRI No. 8985-K, Midwest Research Institute, Kansas City, MO. 8-23 5. Chepil, W.S., 1952. Improved Rotary Sieve for Measuring State and Stability of Dry Soil Structure, Soil Science Society of America Proceedings, 16:113-117. 6. Gillette, D.A., et al., 1980. Threshold Velocities for Input of Soil Particles into the Air by Desert Soils, Journal of Geophysical Research, 85(C 10):5621-5630. 7. Local Climatological Data, National Climatic Center, Asheville, NC. 8. Changery, M.J., 1978. National Wind Data Index Final Report, HCO/T 1041-01 UC- 60, National Climatic Center, Asheville, NC, December. 9. Billings-Stunder, J.B., Arya, S.P.S., 1988. Windbreak Effectiveness for Storage Pile Fugitive Dust Control: A Wind Tunnel Study, J. APCA, 38:135-143. 10. Cowherd, C. Jr., et al., 1988. Control of Open Fugitive Dust Sources, EPA 450/3- 88-008, U.S. EPA, Research Triangle Park, NC, September. 11. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 12. Ono, D., Weaver, S., Richmond, K. April 2003. Quantifying Particulate Matter Emissions from Wind Blown Dust Using Real-time Sand Flux Measurements, paper presented at the 12th Annual EPA Emission Inventory Conference in San Diego, CA. 13. Gillette, D., Ono, D., and Richmond, K., 2004. A Combined Modeling and Measurement Technique for Estimating Windblown dust Emissions at Owens (dry) Lake, California, Journal of Geophysical Research 109, F01103. 14. Ono., D., 2006. Application of the Gillette Model for Windblown Dust at Owens Lake, CA, Atmos. Environ., 40: 3011-3021. 15. Gillette, D. A., Niemeyer, T. C., Helm, P. J, 2001. Supply -limited Horizontal Sand Drift at an Ephemerally Crusted, Unvegetated Saline Playa, Journal of Geophysical Research, 106, 18085-18,098. 16. MacDougall, C., 2002. Empirical Method for Determining Fugitive Dust Emissions from Wind Erosion of Vacant Land, memorandum prepared for Clark County Department of Air Quality Management, June. 17. Mansell, G. E., Wolf, M., Gillies, J., Barnard, W., Omary, M, 2004. Determining Fugitive Dust Emissions from Wind Erosion, ENVIRON final report prepared for Western Governors' Association, March. 18. Countess Environmental, 2002. A Review and Update of Fugitive Dust Emissions Estimation Methods, final report prepared for the Western Governors' Association, November. 19. Draxler, R.R., Gillette, D.A., Kirkpatrick, J.S., Heller, J., 2001. Estimating PMI0 Air Concentrations from Dust Storms in Iraq, Kuwait and Saudi Arabia, Atmospheric Environment 35:4315. 8-24 20. Marticorena, B., Bergametti, G., Gillette, D., Belnap, J., 1997. Factors Controlling Threshold Friction Velocity in Semiarid and Arid Areas of the United States, J. Geophys. Res., 102:23277. 21. James, D., Haun, J.A., Gingras, T., Fulton, A., Pulgarin, J., Venglas, G., Becker, J., Edwards, S., January 2001. Estimation of PM10 Vacant Land Emission Factors for Unstable, Stable and Stabilized Lands Using Data from 1995 and 1998-1999 UNLV Wind Tunnel Studies of Vacant and Dust -Suppressant Treated Lands, final report prepared for the Clark County Department of Comprehensive Planning. 22. Mansell, G.E., Lau, S., Russel, J and Omary, M., 2006. Fugitive Wind Blown Dust Emissions and Model Performance Evaluation Phase II, final report prepared by ENVIRON for Western Governors' Association, May 5. 23. Gillette, D.A., Adams, J., Endo, E. and Smith, D., 1980. Threshold Velocities for Input of Soil Particles into the Air by Desert Soils, Journal of Geophysical Research, 85(C10): 5621-5630. 24. Gillette, D.A., Adams, J., Muhs, D. and Kihl, R., 1982. Threshold Friction Velocities and Rupture Moduli for Crusted Desert Soils for the Input of Soil Particles into the Air, Journal of Geophysical Research, 87(C10): 9003-9015 25. Gillette, D.A., 1988. Threshold Friction Velocities for Dust Production for Agricultural Soils, Journal of Geophysical Research: 93(DI0), 12645-12662. 26. Nickling, W.G. and Gillies, J.A., 1989. Emission of Fine Grained Particulate from Desert Soils, in: Paleoclimatology and Paleometeorology: Modern and Past Patterns of Global Atmospheric Transport, M. Leinen and M. Sarnthein (Editors), Kluwer Academic Publishers, pp. 133-165. 27. Chatenet, B., Marticorena, B., Gomes, L., and Bergametti, G, 1996. Assessing the Microped Size Distributions of Desert soils Erodible by Wind, Sedimentolog. 43: 901- 911 28. Alfaro, S. C. and Gomes, L., 2001. Modeling Mineral Aerosol Production by Wind erosion: Emission Intensities and Aerosol Size Distributions in Source Areas, J. Geophys. Res.: 106 (16), 18075-18084. 29. Alfaro, S. C., Rajot, J. I., and Nickling W. G., 2003. Estimation of PM20 Emissions by Wind Erosion: Main Sources of Uncertainties, Geomophology. 30. Barnard, W. 2003. Personal communication between Gerry Mansell of Environ and Bill Barnard of MACTEC Engineering & Consulting, Gainesville, FL, April. 31. USDA, 1994. State Soil Geographic (STATSGO) Data Base, Data Use Information. U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Service Center, Miscellaneous Publication Number 1492, December. 8-25 32. Latifovic, R., Zhu, Z -L., Cihlar, J. and Giri, C., 2002. Land Cover of North America 2000, Natural Resources Canada, Centre for Remote Sensing US Geological Services, EROS Data Center. 33. Wolfe, S. A., 1993. Sparse Vegetation as a Control on Wind Erosion, Ph.D. thesis, University of Guelph, Guelph, Ontario. 34. Sutton, O. G., 1953. Micrometeorology, McGraw-Hill, New York. 35. Oke, T. R., 1978. Boundary Layer Climates, Methuen Company, London. 36. Deursen, W. van, Heil, G. W., and Boxtel, A., van, 1993. Using Remote Sensing Data to Compile Roughness Length Maps for Atmospheric Deposition Models, International Symposium "Operationalisation of Remote Sensing," ITC Enschede, Netherlands. 37. CARB, 1997. Section 7.11 - Supplemental Documentation for Windblown Dust - Agricultural Lands, California Air Resources Board, Emission Inventory Analysis Section, Sacramento, California, April. 38. Pace, T.G., 2005. Methodology to Estimate the Transportable Fraction of Fugitive Dust Emissions for Regional & Urban Scale Air Quality Analyses, U.S. EPA, June 2. 39. Cowherd, C., 2005. Analysis of the Fine Fraction of Particulate Matter in Fugitive Dust, Draft report prepared by Midwest Research Institute for the Western Governors Association, August 17. 40. Cowherd, C., Jr., Grelinger, M.A. and Kies, C., 2001. Effect of Wildfires and Controlled Burning on Soil Erodibility by Wind, final report prepared by Midwest Research Institute for Radian Rocky Flats Environmental Technology Site, May. 41. Cowherd, C., Jr., and M.A. Grelinger, 2005. Wind Erodibility Assessment of Stabilized Soils in the Antelope Valley, draft final report prepared by Midwest Research Institute for Southern California Edison. 42. Kemner, W., Hall, F., Cowherd, C. and Borengasser, M., 2005. Remote Sensing Imagery for an Inventory of Vacant Land Soil Stability and Unpaved Private Roads, draft final report prepared by Environmental Quality Management and Midwest Research Institute for Clark County NV, December. 43. CARB, April 2002. Evaluation of Air Quality Performance Claims for Soil-Sement Dust Suppressant. 44. Sierra Research, 2003. Final BACM Technological and Economic Feasibility Analysis, prepared for the San Joaquin Valley Unified APCD, March. 8-26 Chapter 9. Storage Pile Wind Erosion 9.1 Characterization of Source Emissions 9-1 9.2 Emission Estimation: Primary Methodology 9-2 9.3 Emission Estimation: Alternate Methodology 9-8 9.4 Demonstrated Control Techniques 9-8 9.5 Regulatory Formats 9-9 9.6 Compliance Tools 9-9 9.7 Sample Cost -Effectiveness Calculation 9-11 9.8 References 9-14 9.1 Characterization of Source Emissions Dust emissions may be generated by wind erosion of open areas of exposed soils or other aggregate materials within an industrial facility. These sources typically are characterized by nonhomogeneous surfaces impregnated with nonerodible elements (particles larger than approximately 1 centimeter [cm] in diameter). Field testing of coal piles and other exposed materials using a portable wind tunnel has shown that: (a) threshold wind speeds exceed 5 meters per second (m/s) (11 miles per hour [mph]) at 15 cm above the surface or 10 m/s (22 mph) at 7 m above the surface, and (b) particulate emission rates tend to decay rapidly (half-life of a few minutes) during an erosion event. In other words, these aggregate material surfaces are characterized by finite availability of erodible material (mass/area) referred to as the erosion potential. Any natural crusting of the surface binds the erodible material, thereby reducing the erosion potential. Loose soils or other aggregate materials consisting of sand -sized materials act as an unlimited reservoir of erodible material and can sustain emissions for periods of hours without substantial decreases in emission rates. If typical values for threshold wind speed at 15 cm are corrected to typical wind sensor height (7 to 10 m), the resulting values exceed the upper extremes of hourly mean wind speeds observed in most areas of the country. In other words, mean atmospheric wind speeds are not sufficient to sustain wind erosion from flat surfaces of the type tested. However, wind gusts may quickly deplete a substantial portion of the erosion potential. Because erosion potential has been found to increase rapidly with increasing wind speed, estimated emissions should be related to the gusts of highest magnitude. The routinely measured meteorological variable that best reflects the magnitude of wind gusts is the fastest mile. This quantity represents the wind speed corresponding to the whole mile of wind movement that has passed by the 1 mile contact anemometer in the least amount of time. Daily measurements of the fastest mile are presented in the monthly Local Climatological Data (LCD) summaries. The duration of the fastest mile, typically about 2 minutes (for a fastest mile of 30 mph), matches well with the half-life of the erosion process, which ranges between 1 and 4 minutes. It should be noted, however, that peak winds can significantly exceed the daily fastest mile. The wind speed profile in the surface boundary layer is found to follow a logarithmic distribution as follows: u* u(z) = In z (z>zo) w 0.4 zo here, u = wind speed (cm/s) u* = friction velocity (cm/s) z = height above test surface (cm) zo = roughness height (cm) 0.4 = von Karman's constant (dimensionless) The friction velocity (u*) is a measure of wind shear stress on the erodible surface, as determined from the slope of the logarithmic velocity profile. The roughness height (zo) is a measure of the roughness of the exposed surface as determined from the y -intercept (1) 9-1 of the velocity profile, i.e., the height at which the wind speed is zero. These parameters are illustrated in Figure 9-1 for a roughness height of 0.1 cm. Arithmetic Representation Wind Speed at Z Wind Speed at 10 m Semi -Logarithmic Representation Figure 9-1. Illustration of Logarithmic Wind Velocity Profile Emissions generated by wind erosion are also dependent on the frequency of disturbance of the erodible surface because each time that a surface is disturbed, its erosion potential is restored. A disturbance is defined as an action that results in the exposure of fresh surface material. On a storage pile, this would occur whenever aggregate material is either added to or removed from the old surface. A disturbance of an exposed area may also result from the turning of surface material to a depth exceeding the size of the largest pieces of material present. 9.2 Emission Estimation: Primary Methodology'"" This section was adapted from Section 13.2.5 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.5 was last updated in January 1995. The PMI0 emission factor for wind -generated particulate emissions from mixtures of erodible and nonerodible surface material subject to disturbance may be expressed in units of grams per square meter (g/m2) per year as follows: where, N = number of disturbances per year Pi = erosion potential corresponding to the observed (or probable) fastest mile of wind for the ith period between disturbances (g/m2) In calculating emission factors, each area of an erodible surface that is subject to a different frequency of disturbance should be treated separately. For a surface disturbed PMl 0 Emission Factor = 0.5 P i=i (2) 9-2 daily, N = 365 per year, and for a surface disturbance once every 6 months, N = 2 per year. The erosion potential function for a dry, exposed surface is given as: P = 58 (u* - ut*)2 + 25 (u* - ut*) ( 3 ) P=0 for u* ≤ut* where, u# = friction velocity (m/s) ut = threshold friction velocity (m/s) Because of the nonlinear form of the erosion potential function, each erosion event must be treated separately. The PM2.5/PM10 ratio for windblown fugitive dust posted on EPA's CHIEF website is 0.15 based on the analysis conducted by MRI on behalf of WRAP." Equations 2 and 3 apply only to dry, exposed materials with limited erosion potential. The resulting calculation is valid only for a time period as long or longer than the period between disturbances. Calculated emissions represent intermittent events and should not be input directly into dispersion models that assume steady-state emission rates. For uncrusted surfaces, the threshold friction velocity is best estimated from the dry aggregate structure of the soil. A simple hand sieving test of surface soil can be used to determine the mode of the surface aggregate size distribution by inspection of relative sieve catch amounts, following the procedure described below. FIELD PROCEDURE FOR DETERMINING THRESHOLD FRICTION VELOCITY (from a 1952 laboratory procedure published by W. S. Chepil5) Step 1. Prepare a nest of sieves with the following openings: 4 mm, 2 mm, 1 mm, 0.5 mm, and 0.25 mm. Place a collector pan below the bottom (0.25 mm) sieve. Step 2. Collect a sample representing the surface layer of loose particles (approximately 1 cm in depth, for an encrusted surface), removing any rocks larger than about 1 cm in average physical diameter. The area to be sampled should be not less than 30 cm by 30 cm. Step 3. Pour the sample into the top sieve (4 -mm opening), and place a lid on the top. Step 4. Move the covered sieve/pan unit by hand, using a broad circular arm motion in the horizontal plane. Complete 20 circular movements at a speed just necessary to achieve some relative horizontal motion between the sieve and the particles. Step 5. Inspect the relative quantities of catch within each sieve, and determine where the mode in the aggregate size distribution lies, i.e., between the opening size of the sieve with the largest catch and the opening size of the next largest sieve. Step 6. Determine the threshold friction velocity from Table 9-1. The results of the sieving can be interpreted using Table 9-1. Alternatively, the threshold friction velocity for erosion can be determined from the mode of the aggregate size distribution using the graphical relationship described by Gillette.5' 6 If the surface material contains nonerodible elements that are too large to include in the sieving (i.e., greater than about 1 cm in diameter), the effect of the elements must be taken into account by increasing the threshold friction velocity.10 9-3 Table 9-1. Field Procedure for Determination of Threshold Friction Velocity LMetric Units) Tyler Sieve No. Opening (mm) Midpoint (mm) ut* (cm/s) 5 4 9 2 3 100 16 1 1.5 76 32 0.5 0.75 58 60 0.25 0.375 43 Threshold friction velocities for several surface types have been determined by field measurements with a portable wind tunnel. These values are presented in Table 9-2. Table 9-2 Threshold Friction Velocities (Metric Units Material Threshold friction velocity (m/s) Roughness height (cm) Threshold wind velocity at 10 m (m/s) zo = Actual zo = 0.5 cm Overburdena 1.02 0.3 21 19 Scoria (roadbed material)a 1.33 0.3 27 25 Ground coal (surrounding coal pile)a 0.55 0.01 16 10 Uncrusted coal pilea 1.12 0.3 23 21 Scraper tracks on coal pilea,b 0.62 0.06 15 12 Fine coal dust on concrete padc 0.54 0.2 11 10 a Western surface coal mine; reference 2. b Lightly crusted. Eastern power plant; reference 3. The fastest mile of wind for the periods between disturbances may be obtained from the monthly local climatological data (LCD) summaries for the nearest reporting weather station that is representative of the site in question. These summaries report actual fastest mile values for each day of a given month. Because the erosion potential is a highly nonlinear function of the fastest mile, mean values of the fastest mile are inappropriate. The anemometer heights of reporting weather stations are found in Reference 8, and should be corrected to a 10-m reference height using Equation 1. To convert the fastest mile of wind (u+) from a reference anemometer height of 10 m to the equivalent friction velocity (u*), the logarithmic wind speed profile may be used to yield the following equation: u* = 0.053 umo+ (4) where, u* = friction velocity (m/s) u o = fastest mile of reference anemometer for period between disturbances (m/s) This assumes a typical roughness height of 0.5 cm for open terrain. Equation 4 is restricted to large relatively flat exposed areas with little penetration into the surface wind layer. 9-4 If the pile significantly penetrates the surface wind layer (i.e., with a height -to -base ratio exceeding 0.2), it is necessary to divide the pile area into subareas representing different degrees of exposure to wind. The results of physical modeling show that the frontal face of an elevated pile is exposed to wind speeds of the same order as the approach wind speed at the top of the pile. For two representative pile shapes (conical and oval with flattop, 37 -degree side slope), the ratios of surface wind speed (us) to approach wind speed (Ur) have been derived from wind tunnel studies.9 The results are shown in Figure 9-2 corresponding to an actual pile height of 11 m, a reference (upwind) anemometer height of 10 m, and a pile surface roughness height (zo) of 0.5 cm. The measured surface winds correspond to a height of 25 cm above the surface. The area fraction within each contour pair is specified in Table 9-3. Table 9-3. Subarea Distribution for Regimes of us/ur Pile subarea Percent of pile surface area Pile B3_ Pile A Pile B1 Pile B2 0.2a 5 5 3 3 0.2b 35 2 28 25 0.2c NA 29 NA NA 0.6a 48 26 29 28 0.6b NA 24 22 26 0.9 12 14 15 14 1.1 NA NA 3 4 NA = not applicable. The profiles of us/ur in Figure 9-2 can be used to estimate the surface friction velocity distribution around similarly shaped piles, using the following procedure: Step 1. Correct the fastest mile value (u+) for the period of interest from the anemometer height (z) to a reference height of 10 m (u to ) using a variation of Equation 1: _ + In (10/0.005) u1° — u In (z/0.005) where a typical roughness height (zo) of 0.5 cm (0.005 m) has been assumed. If a site -specific roughness height is available, it should be used. Step 2. Use the appropriate part of Figure 9-2 based on the pile shape and orientation to the fastest mile of wind, to obtain the corresponding surface wind speed distribution (u s): + (us) + us = uio ur (5) (6) Step 3. For any subarea of the pile surface having a narrow range of surface wind speed, use a variation of Equation 1 to calculate the equivalent friction velocity (u*): u* = (0.4 u+s) / In (25 / 0.5) = 0.10 u+s (7) 9-5 Flow Direction Pile A Pile B1 Pile B2 Pile B3 Figure 9-2. Contours of Normalized Surface Wind Speed Ratios, us/ur 9-6 From this point on, the procedure is identical to that used for a flat pile, as described above. Implementation of the above procedure is carried out in the following steps: Step 1. Determine threshold friction velocity for erodible material of interest (see Table 9-2 or determine from mode of aggregate size distribution). Step 2. Divide the exposed surface area into subareas of constant frequency of disturbance (N). Step 3. Tabulate fastest mile values (u+) for each frequency of disturbance and correct them to 10 m (u jo ) using Equation 5. Step 4. Convert fastest mile values (um) to equivalent friction velocities (u*), taking into account (a) the uniform wind exposure of nonelevated surfaces, using Equation 4, or (b) the nonuniform wind exposure of elevated surfaces (piles), using Equations 6 and 7. Step 5. For elevated surfaces (piles), subdivide areas of constant N into subareas of constant u (i.e., within the isopleth values of us/ur in Figure 9-2 and Table 9-3) and determine the size of each subarea. Step 6. Treating each subarea (of constant N and u*) as a separate source, calculate the erosion potential (P;) for each period between disturbances using Equation 3 and the emission factor using Equation 2. Step 7. Multiply the resulting emission factor for each subarea by the size of the subarea, and add the emission contributions of all subareas. Note that the highest 24 -hour emissions would be expected to occur on the windiest day of the year. Maximum emissions are calculated assuming a single event with the highest fastest mile value for the annual period. The recommended emission factor equation presented above assumes that all of the erosion potential corresponding to the fastest mile of wind is lost during the period between disturbances. Because the fastest mile event typically lasts only about 2 minutes, which corresponds roughly to the half-life for the decay of actual erosion potential, it could be argued that the emission factor overestimates particulate emissions. However, there are other aspects of the wind erosion process that offset this apparent conservatism as follows: 1. The fastest mile event contains peak winds that substantially exceed the mean value for the event. 2. Whenever the fastest mile event occurs, there are usually a number of periods of slightly lower mean wind speed that contain peak gusts of the same order as the fastest mile wind speed. Of greater concern is the likelihood of over prediction of wind erosion emissions in the case of surfaces disturbed infrequently in comparison to the rate of crust formation. 9-7 9.3 Emission Estimation: Alternate Methodology EPA published a total suspended particulate (TSP) emission factor equation for wind erosion of active storage piles in 1989 that is not included in AP -42.12 For days when there was at least 0.01 inch of precipitation, the TSP emissions were zero. The TSP emission factor equation (in units of lb/day/acre of surface) for days when there was less than 0.01 inch of precipitation was given as: ETSP = 1.7 (s/1.5) (f/15) where, s = silt content of material (weight %) f= percentage of time the unobstructed wind speed is greater than 12 mph at the mean pile height The annual TSP emissions factor equation for wind blown dust from active storage piles was given as follows: TSP (lb/year/acre of surface) = 1.7 (s/1.5) (365 [365-p] / 235) (f/15) where, s = silt content of material (weight %) p = number of days per year with at least 0.01 inch of precipitation f= percentage of time the unobstructed wind speed is greater than 12 mph at the mean pile height Based on the PM10/TSP ratio of 0.5 for wind blown dust from active storage piles published in Section 13.2.5 of AP -42 and a PM2.5/PM 10 ratio of 0.15 for wind blown dust1I, the PM10 and PM2.5 emission factor equations (in units of lb/day/acre) would be: EPMIo = 0.85 (s/1.5) (f/15) EPM25 = 0.13 (s/1.5) (f/15) The short-term hourly TSP emission factor equation for wind blown dust from active storage piles (in units lb/acre-hour) given in the 1989 EPA report was equal to the wind speed (in units of mph) multiplied by a factor of 0.72. Thus for a wind speed that averaged 25 mph during a one -hour period, the TSP emission factor during that hour would be 18 lb/acre which is equal to 2.02 g/m2. The corresponding PM10 and PM2.5 emission factors would be 1.01 g/m2 and 0.15 g/m2, respectively. 9.4 Demonstrated Control Techniques Control measures for storage pile wind erosion are designed to stabilize the erodible surface (e.g., by increasing the moisture content of the aggregate material being stored) or to shield it from the ambient wind. Table 9-4 presents a summary of control measures and reported control efficiencies for storage pile wind erosion. 9-8 Table 9-4. Control Efficiencies for Control Measures for Storat a Pile Wind Erosion Control measure PM10 control efficiency References/comments Require construction 75% Sierra Research, 2003.13 Determined through of 3 -sided enclosures with 50% porosity modeling of open area windblown emissions with 50% reduction in wind speed and assuming no emission reduction when winds approach open side Water the storage pile by hand or apply cover when wind events are declared 90% Fitz et al., April 2000.14 9.5 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Regulatory formats specify the threshold source size that triggers the need for control application. Example regulatory formats for several local air quality agencies in the WRAP region are presented in Table 9-5. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: http://www.maricopa.gov/envsvc/air/ruledesc.asp (Note: The Clark County website did not include regulatory language specific to storage pile wind erosion at the time this chapter was written.) 9.6 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. 9-9 Table 9-5. Example Regulatory Formats for Storage Pile Wind Erosion Control Measure Goal Threshold Agency Establishes wind barrier and watering or stabilization Limit visible dust emissions to 20% SJVAPCD requirements and bulk materials must be stored according to stabilization definition and outdoor materials covered opacity Rule 8031 11/15/2001 Best available control measures: wind sheltering, watering, chemical stabilizers, altering load-in/load-out Prohibits visible dust emissions beyond property line and limits SCAQMD Rule 403 procedures, or coverings upwind/downwind PM10 differential to 50 ug/m3 12/11/1998 Watering, dust suppressant (when loading, stacking, etc.); cover with tarp, watering (when not loading, etc.); wind barriers, silos, enclosures, etc. Limit VDE to 20% opacity; stabilize soil For storage piles with >5% silt content, 3ft high, >150 sq ft; work practices for stacking, loading, unloading, and when inactive; soil moisture content min 12%; or at least 70% min for optimum soil moisture content; 3 sided enclosures, at least equal to pile in length, same for height, porosity <50% Maricopa County Rule 310 04/07/2004 Utilization of dust suppressants other than water when Prevent wind erosion from piles; Bulk material handling for stacking, loading, and Maricopa County necessary; prewater; empty loader bucket slowly stabilize condition where equip and unloading; for haul trucks and areas where Rule 310 vehicles op equipment op 04/07/2004 9-10 On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 9-6 summarizes the compliance tools that are applicable to wind erosion from material storage piles. Table 9-6. Compliance Tools for Storage Pile Wind Erosion Record keeping Site inspection/monitoring Site map; work practices, including pile Sampling and analysis of storage pile surface formation and removal times (throughputs); material for silt and moisture contents; locations, sizes, and shapes of storage piles; moisture and silt contents of pile surface observation of pile formation and removal, including wet suppression systems; observation material; location/heights/densities of of vehicle/ equipment operation and disturbance vegetation or other wind breaks, including areas; inspection of wind sheltering including maintenance times; dust suppression enclosures; real-time portable monitoring of PM; equipment and maintenance records; observation of dust plume opacity exceeding a frequencies, amounts, times, and rates of watering or dust suppressant application; meteorological log. standard. 9.7 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for fugitive dust originating from storage pile wind erosion. A sample cost- effectiveness calculation is presented below for a specific control measure (3 -sided enclosure) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost- effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for storage pile wind erosion, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. 9-11 Sample Calculation for Storage Pile Wind Erosion Step 1. Determine source activity and control application parameters. Frequency of disturbance (days/yr) Height of pile (m) Base diameter (m) Total surface area (m2) Portion of pile exposed to high winds (%) Surface area exposed to high winds (m2) Threshold friction velocity u*t (m/s) Control Measure Economic Life of Control System (yr) Control Efficiency (%) Reference for Control Efficiency 365 11 29.2 838 12 101 0.85 3 -sided enclosure 10 74.7 Sierra Research, 200313 The pile size, source activity parameters and control measure parameters are assumed values for illustrative purposes. A 3 -sided enclosure has been chosen as the applied control measure. The control efficiency is provided by Sierra Research.13 The pile surface area within each surface wind speed range (see AP -42, Section 13.2.5) is as follows: Surface areas within each wind speed range Pile surface Area ID us / ur % Area (m2) A 0.9 12 101 B 0.6 48 402 C 0.2 40 335 Total Area 838 Step 2. Obtain PM10 Emission Factor. N The PM10 emission factor is obtained from AP -42: PM10 EF = 0.5 E P; 1=1 P —erosion potential (g/m2) P = 58 (u*-u*t) + 25 (u*-u*t) P = 0 for u* ≤ ut* Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor (given in Step 2) is applied to each day for which the peak wind exceeds the threshold velocity for wind erosion. The following monthly climatic data are used for illustrative purposes and are assumed to apply to each month of the year. Monthly erosion potential (P) Peak wind (u+1o) u+s (m/s) Day Area C Area B Area A of month mph m/s us / ur: 0.2 us / ur: 0.6 us / ur: 0.9 6 29 13.0 2.59 7.78 11.67 7 30 13.4 2.68 8.05 12.07 11 38 17.0 3.40 10.19 15.29 22 25 11.2 2.24 6.71 10.06 28 45 20.1 4.02 12.07 18.10 9-12 Monthly erosion potential (P)a Day u' (m/s) P (g/m2) of month Area C Area B Area A Area C Area B Area A 6 0.26 0.78 1.17 0 0 13.74 7 0.27 0.80 1.21 0 0 16.32 11 0.34 1.02 1.53 0 5.89 43.70 22 0.22 0.67 1.01 0 0 5.30 28 0.40 1.21 1.81 0 16.32 77.52 Sum of P (g/m2) 0 22.21 156.57 Area (m ) 335 402 101 Monthly PM10 emissions (g) 0 4,464 7,907 a Assumed to apply to 12 months of the year. b Monthly PM10 emissions = 0.5 times monthly erosion potential times surface area for each area of the pile. The annual PM10 emissions in units of tons for each section of the pile is equal to 12 times the monthly PM10 emissions for each section of the pile divided by 454 g/Ib and 2,000 lb/ton as follows: Annual PM10 emissions for Area A = (12 x 7,907) / (454 x 2,000) = 0.104 tons Annual PM10 emissions for Area B = (12 x 4,464) / (454 x 2,000) = 0.059 tons Annual PM10 emissions for Area C = 0 tons Annual PM10 emissions for storage pile = 0.104 + 0.059 + 0 = 0.163 tons Annual PM2.5 Emissions = 0.15 x PM10 Emissions" = 0.15 x 0.163 = 0.025 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency) For this example we have selected a 3 -sided enclosure as our control measure with a control efficiency of 74.7% Thus, the annual controlled PM10 and PM2.5 emissions estimates are calculated to be: Annual Controlled PM10 emissions = (0.163 tons/yr) x (1 — 0.747) = 0.041 tons Annual Controlled PM2.5 emissions = (0.025 tons/yr) x (1 — 0.747) = 0.006 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) 2,000 Annual Operating/Maintenance costs ($) 400 Annual Interest Rate 3% Capital Recovery Factor 0.1172 Annualized Cost ($/yr) 634 The Capital costs, Annual Operating/Maintenance (O & M) costs and Annual Interest Rate (AIR) are assumed values for illustrative purposes. 9-13 The Capital Recovery Factor (CRF) is calculated as follows: Capital Recovery Factor = AIR x (1 + AIR) Economic life / (1 + AIR)Economiclife — 1 Capital Recovery Factor = 3% x (1 + 3%)10 / (1 + 3%)'° -1 = 0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor and the Capital costs to the annual O & M costs as follows: Annualized Cost = (CRF x Capital costs) + O & M costs Annualized Cost = (0.1172 x 2,000) + $400 = $634 Step 6. Calculate Cost Effectiveness. Cost effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost effectiveness = Annualized Cost/(Uncontrolled emissions — Controlled emissions) Cost effectiveness for PM10 emissions = $634 / (0.163 - 0.041) = $5,195/ton Cost effectiveness for PM2.5 emissions = $634 / (0.025 - 0.006) = $34,635/ton 9.8 References 1. Cowherd, C. Jr., 1983. A New Approach to Estimating Wind Generated Emissions from Coal Storage Piles, paper presented at the APCA Specialty Conference on Fugitive Dust Issues in the Coal Use Cycle, Pittsburgh, PA, April. 2. Axtell, K., Cowherd, C. Jr., 1984. Improved Emission Factors for Fugitive Dust from Surface Coal Mining Sources, EPA -600/7-84-048, U.S. EPA, Cincinnati, OH, March. 3. Muleski, G.E., 1985. Coal Yard Wind Erosion Measurement, Midwest Research Institute, Kansas City, MO, March 1985. 4. MRI, 1988. Update of Fugitive Dust Emissions Factors in AP -42 Section 11.2 -Wind Erosion, Midwest Research Institute, Kansas City, MO. 5. Chepil, W.S., 1952. Improved Rotary Sieve for Measuring State and Stability of Dry Soil Structure, Soil Science Society of America Proceedings, 16:113-117. 6. Gillette, D.A., et al., 1980. Threshold Velocities for Input of Soil Particles into the Air by Desert Soils, Journal Of Geophysical Research, 85(C 10):5621-5630. 7. Local Climatological Data, National Climatic Center, Asheville, NC. 8. Changery, M.J., 1978. National Wind Data Index Final Report, HCO/T1041-01 UC- 60, National Climatic Center, Asheville, NC, December. 9. Billings-Stunder, .J.B., Arya, S.P.S., 1988. Windbreak Effectiveness for Storage Pile Fugitive Dust Control: A Wind Tunnel Study, J. APCA, 38:135-143. 9-14 10. Cowherd, C. Jr., et al., 1988. Control of Open Fugitive Dust Sources, EPA 450/3- 88-008, Research Triangle Park, NC, September. 11. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, report prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 12. USEPA, 1989. Air/Superfund National Technical Guidance Study Series; Volume III — Estimation of Air Emissions from Cleanup Activities at Superfund Sites, Interim final report EPA -450/1-89-003, January. 13. Sierra Research, 2003. Final BACM Technological and Economic Feasibility Analysis, report prepared for the San Joaquin Valley Unified Air Pollution Control District, March 21. 14. Fitz, D., K. Bumiller, 2000. Evaluation of Watering to Control Dust in High Winds, J.AWMA, April. 9-15 Chapter 10. Agricultural Harvesting 10.1 Characterization of Source Emissions 10-1 10.2 EPA's Emission Estimation Methodology 10-1 10.3 CARB's Emission Estimation Methodology 10-1 10.4 Demonstrated Control Techniques 10-3 10.5 Regulatory Formats 10-4 10.6 Compliance Tools 10-5 10.7 Sample Cost -Effectiveness Calculation 10-6 10.8 References 10-8 10.9 Attachment 10-1. PM10 Emission Factors for Harvesting Crops in CA 10-9 10.1 Characterization of Source Emissions Harvesting emissions are generated by three different operations: crop handling by the harvest machine, loading of the harvested crop into trailers or trucks, and transport by trailers or trucks in the field. Emissions from these operations are in the form of solid particulates composed mainly of raw plant material and soil dust that is entrained into the air. These emissions may simply be due to the vehicles traveling over the soil, or via the mechanical processing of the plant material and underlying soil, or, as in the case of almonds, via the actual blowing or sweeping of the crop to remove waste materials and position it for pickup. Defoliants and/or desiccants are used on some crops several weeks before harvesting which can produce PM emissions from the drifting of these chemicals equal to about 1% of the product applied on the crop.' 10.2 EPA's Emission Estimation Methodology Section 9 of EPA's Compilation of Air Pollutant Emission Factors (AP -42) addresses emission factors for mechanical harvesting of three different crops (cotton, wheat and sorghum). This section of AP -42 was last updated in February 1980. However, it does not list TSP or PM 10 emission factors for agricultural harvesting. Instead it lists PM7 emission factors for the three crops expressed in units of pounds per square mile for crop handling by the harvest machine, loading of the harvested crop into trailers or trucks, and transport by trailers or trucks in the field. The sum of the PM7 emission factor for these three separate operations total 0.0086 lb/acre for mechanical picking of cotton, 0.041 lb/acre for mechanical stripping of cotton, 0.0027 lb/acre for wheat, and 0.012 lb/acre for sorghum.' The PM7 emission factors for harvesting cotton are based on an average machine speed of 3 mph for pickers and 5 mph for strippers, a basket capacity of 240 lb, a trailer capacity of 6 baskets, a lint cotton yield of 1.17 bales/acre for pickers and 0.77 bales/acre for strippers, and a transport speed of 10 mph. The weighted average stripping factors assumes that 2% of all strippers are 4 -row models with baskets and, of the remainder, 40% are 2 -row models pulling trailers and 60% are 2 -row models with mounted baskets. The PM7 emission factors for harvesting wheat and sorghum are based on an average combine speed of 7.5 mph, a combine swath width of 20 feet, a field transport speed of 10 mph, a truck loading time of 6 minutes, a truck capacity of 13 acres for wheat and 7 acres for sorghum, and a filled truck travel time of 2 minutes per load. These AP -42 PM7 emission factors developed more than 25 years ago for the entire US are much lower than CARB's PM 10 emission factors developed in early 2003 for California. 10.3 CARB's Emission Estimation Methodology This section was adapted from Section 7.5 of CARB's Emission Inventory Methodology. Section 7.5 was last updated in January 2003. The California Air Resources Board (CARB) has published a PM10 emission estimation method for fugitive dust emissions originating from agricultural harvesting 10-1 operations.2 Unlike the soil preparations activities (e.g., disking, tilling, etc.), harvest operations tend to be fairly unique for each crop. Because of this, harvest emission factors combine all of the operations that go into harvesting a commodity into a single factor that includes emissions from all of the relevant operations. PM10 emission factors have been measured in California by UC Davis for harvesting cotton, almonds and wheat.3 These emission factors are shown in Tablel0-1. Using these emission factors as a baseline, harvesting emission factors were assigned to other major crops grown California crops in consultation with agricultural experts. These PM10 emission factors are also included in Table 10-1. Table 10-1. Harvesting PM10 Emission Factors Crop PM 10 Emission Factor (lbs/acre) Almonds 40.8 Corn 1.7a Cotton 3.4 Fruit trees 0.085b Onions 1.7a Potatoes 1.7a Sugar beets 1.7a Tomatoes 0.17c Vine crops 0.17c Walnuts 40.8d Wheat 5.8 a EF = 50% EF for cotton b EF = 2.5% EF for cotton EF = 5% EF for cotton d EF = same EF as almonds UC Davis has recently completed a study measuring PM10 emissions from almond harvesting that indicates that CARB's PM10 emission factor for almond harvesting may be over -estimated by 62%.4 The complete list of harvesting emission factors assigned to over 200 crops is presented in Attachment 10-1 at the end of this chapter. The acreage data used for estimating harvest emissions for different crops are available from each state's Department of Food and Agriculture as well as from individual county agricultural commissioner reports. Crop Calendar and Temporal Activity. Harvesting is performed at very specific times each year, so crop calendar data, which tells when harvest activities occur, is important. Temporal activity for harvesting is derived by summing, for each county, the monthly emissions from all crops. For each crop, the monthly emissions are calculated based on its monthly profile, which reflects the percentage of harvesting activities occurring in that month. An example of the monthly harvesting profile for almonds, cotton, and wheat is shown in Table 10-2. Because the mix of crops varies by county, composite temporal profiles combining all of the other county crops vary by county. An example of a composite harvesting profile by month for Fresno County, showing the combined temporal profile for all of the harvesting activities in the county, is shown in Table 10-3. 10-2 Table 10-2. Sample Monthly Harvesting Profile of Crops Crops JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Almonds 0 0 0 0 0 0 0 0 50 50 0 0 Cotton 0 0 0 0 0 0 0 0 0 50 50 0 Wheat 0 0 0 0 0 50 50 0 0 0 0 0 Table 10-3. Sample County Harvesting Profile Composite County Fresno JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0.1 0.1 0.2 0.2 0.1 5.6 5.9 0.8 30.7 42.8 13.6 0.1 Assumptions. The CARB methodology is subject to the following assumptions: 1. The current harvest emission factors assume that for each crop, harvesting produces the same level emissions under all conditions for all equipment. 2. The emission factors for crops other than almonds, cotton, and wheat were assigned to reflect the relative geologic PM10 generation potential of various harvest practices. 3. Crop calendar data collected for San Joaquin Valley crops and practices were extrapolated to the same crops in the remainder of California. PM2.5 Emission Factors. In July 2006, EPA revised the PM2.5/PM10 ratios listed in AP -42 for fugitive dust resulting from different fugitive dust source categories based on MRI's controlled laboratory experiments conducted for WRAP in 2005. The revised PM2.5/PM10 ratios range from 0.1 for unpaved roads to 0.15 for paved roads, wind erosion, and transfer of aggregate material. CARB is considering adopting a PM2.5/PM10 ratio of 0.15 for both agricultural tilling and agricultural tilling based on MRI's findings.6 10.4 Demonstrated Control Techniques Soil dust emissions from field transport can be reduced by lowering vehicle speed. Also, the use of terraces, contouring, and strip cropping to inhibit soil erosion will suppress the entrainment of harvested crop fragments in the wind. Shelterbelts, positioned perpendicular to the prevailing wind, will lower emissions by reducing the wind velocity across the field. By minimizing tillage and avoiding residue burning, the soil will remain consolidated and less prone to disturbance from transport activities. Table 10-4 summarizes tested control measures and reported control efficiencies for measures that reduce the generation of fugitive dust from agricultural harvesting.7-9 A list of control measures for agricultural harvesting operations is available from the California Air Pollution Control Officers' Association's (CAPCOA) agricultural clearing house website (http://capcoa.org/ag_clearinghouse.htm). The list of control measures for harvesting field and orchard crops include: the use of balers to harvest crops that are traditionally harvested by chopping, new drying techniques for dried fruit, increasing equipment size to reduce the number of passes, fallowing land, green chop (i.e., harvesting a forage crop without allowing it to dry in the field), hand harvesting, night harvesting, switch to a crop that requires no waste/residue burning, applying a light 10-3 amount of water or other stabilizing material to the soil prior to harvest, packing commodities in an enclosed area, and utilizing a shuttle system to haul multiple trailers per trip. Table 10-4. Control Efficiencies for Control Measures for Harvesting7-9 PM 10 Control Measure Control References / Comments Efficiency Equipment modification 50% MRI, 1981. Control efficiency is for electrostatically charged fine -mist water spray. Land set-aside/fallowing 100% SJVAPCD, 2003. Limited activity during high 5 - 70% URS, 2001. Emissions reduction depends on winds wind speed. Night farming 10% SJVAPCD, 2003. Harvest when humidity and soil moisture is higher than during day. New techniques for drying fruit Continuous tray 25% SJVAPCD, 2003. Dried on vine (DOV) 60% Precision farming 8% SJVAPCD, 2003. Use of GPS system. Reduced harvest activity 29 — 71 % URS, 2001. Applicable to cotton, alfalfa, hay. Soil moisture monitoring 30% URS, 2001. 10.5 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. However, most air quality districts currently exempt agricultural operations from controlling fugitive dust. Air quality districts that regulate fugitive dust emissions from agricultural harvesting include Clark County, NV and several districts in California such as the Imperial County APCD, the San Joaquin Valley APCD and the South Coast AQMD. Imperial County APCD prohibits fugitive dust emissions from farming activities for farms over 40 acres. The San Joaquin Valley APCD and the South Coast AQMD prohibit fugitive dust emissions for the larger farms defined as farms with areas where the combined disturbed surface area within one continuous property line and not separated by a paved public road is greater than 10 acres. Example regulatory formats downloaded from the Internet are presented in Table 10-5. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • San Joaquin Valley APCD, CA: valleyair.org/SJV_main.asp • South Coast AQMD, CA: aqmd.gov/rules • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/aq CAPCOA's agricultural clearing house website (http://capcoa.org/ag_clearinghouse.htm) provides links to rules of different air quality agencies that regulate fugitive dust emissions from agricultural operations. 10-4 Table 10-5. Example Regulatory Formats for Harvesting Control Measure Agency Any person engaged in agricultural operations shall take all reasonable precautions to abate fugitive dust from becoming airborne from such activities. Clark County Reg. 41 7/01/04 Limit fugitive dust from off -field agricultural sources such as unpaved roads with more than 75 trips/day and bulk materials handling by requiring producers to develop and implement a Fugitive Dust Management Plan with district approved control methods. SJVAPCD Rule 8081 11/15/01 Cease activities when wind speeds are greater than 25 mph. SCAQMD Rule 403.1 4/02/04 10.6 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 10-6 summarizes the compliance tools that are applicable for harvesting. Table 10-6. Compliance Tools for Harvesting Record keeping Site inspection/monitoring Maintain daily records to document the specific dust control options taken; maintain such records for a period of not less than three years; and make such records available to the Executive Officer upon request. Observation of dust plumes during periods of agricultural harvesting; observation of dust plume opacity (visible emissions) exceeding a standard; observation of high winds (e.g., >25 mph). 10-5 10.7 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for agricultural harvesting. A sample cost-effectiveness calculation is presented below for a specific control measure (precision farming utilizing a GPS system) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for agricultural harvesting, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Agricultural Harvesting Step 1. Determine source activity and control application parameters. Field size (acres) Crop Frequency of operations per year Control Measure Control application/frequency Economic Life of Control System (yr) Control Efficiency 320 Cotton 2 (picking & stalk cutting) Precision farming Reduce overlap of passes by 8% 5 8% Precision farming utilizing a GPS system has been chosen as the applied control measure. The field size, frequency of operations, and control application/frequency are assumed values for illustrative purposes. The economic life of the control is determined from industrial records. The control efficiency of 8% is based on the proportional reduction in passes to harvest the cotton and cut the stalks after harvesting the cotton (SJVAPCD, 2003).8 Step 2. PM10 Emission Factor. The PM10 emission factor for harvesting cotton includes the emissions from picking the cotton plus the emissions from cutting the stalks after picking the cotton. The PM10 emission factor for each operation is 1.7 lb/acre.2 Step 3. Calculate Uncontroled PM Emissions. The PM10 emission factor, EF, (given in Step 2) is multiplied by the field size and the frequency of operations (both under activity data) and then divided by 2,000 lbs to compute the annual PM10 emissions in tons per year, as follows: Annual PM10 emissions = (EF x Field Size x Frequency of Ops) / 2,000 • Annual PM10 Emissions = (1.7 x 320 x 2) / 2,000 = 0.544 tons Annual PM2.5 emissions = (PM2.5/PM10) x PM10 emissions Assume PM2.5/PM10 ratio for agricultural harvesting is 0.15 (MRI, 2006).6 Annual PM2.5 emissions = 0.15 x PM10 emissions • Annual PM2.5 Emissions = (0.15 x 0.544 tons) = 0.0816 tons 10-6 Step 4. Calculate Controlled PM Emissions. The uncontrolled emissions (calculated in Step 3) are multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency) For this example, we have selected precision farming as our control measure. Based on a control efficiency estimate of 8%, the annual controlled PM emissions are calculated to be: Annual Controlled PM10 emissions = (0.544 tons) x (1 — 0.08) = 0.500 tons Annual Controlled PM2.5 emissions = (0.0816 tons) x (1 — 0.08) = 0.075 tons Step 5. Determine Annual Cost to Control PM Emissions. The Annualized Cost of control is calculated by subtracting the cost savings from reducing the overlap of harvesting passes by 8% from the annualized cost of purchasing the GPS system. Assuming that the cost of harvesting is equivalent to that of tilling, namely $10/acre (WSU, 199810), the cost savings using GPS precision farming is $512 (i.e., 0.08 x 320 acres x $10/acre x 2 harvesting passes [i.e., one pass to harvest the cotton and a second pass to cut the stalks]). GPS systems range in cost from $200 to $5,000 and have a lifetime of approximately five years (SJVAPCD, 20038). Using an estimate of $1,000 and an economic life (EL) of five years for the GPS system together with an annual interest rate (AIR) of 5%, the annualized cost of the GPS system is calculated by adding the product of the Capital Recovery Factor (CRF) and the capital costs to the annual operating and maintenance costs, which for this example are assumed to be $200 per year. The Capital Recovery Factor (CRF) is calculated as follows: CRF = AIR x (1+AIR) EL / [(1+AIR) EL -1] CRF = 5% x (1+ 5%)5 / [(1+ 5%)5 —1] = 0.231 Annualized capital cost = CRF x capital cost = 0.231 x $1,000 = $231 Annual cost of GPS system = Annualized capital costs + Annual O & M costs Annual cost of GPS system = $231 + $200 = $431 Annualized cost of control measure = Annual cost of GPS system minus the cost savings from reducing the overlap of harvesting passes Annualized Cost = $431 - $512 = -$81 The annualized cost is negative and represents a net savings. Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM1 0 emissions = -$81 / (0.544 - 0.500) = -$1,862/ton Cost-effectiveness for PM2.5 emissions = -$81 / (0.0816 - 0.075) = -$12,412/ton The negative cost-effectiveness values indicate cost savings. 10-7 10.8 References 1. USEPA, 2006. AP -42: Compilation of Air Pollutant Emission Factors Volume I: Stationary Point and Area Sources. 2. California Air Resources Board, 2003. Emission Inventory Procedural Manual Volume III: Methods for Assessing Area Source Emissions, Sacramento, CA, January. 3. Flocchini, R.G., James, T.A., et al., 2001. Sources and Sinks of PM10 in the San Joaquin Valley, Interim Report prepared for the United States Department of Agriculture Special Research Grants Program, August 10. 4. Flocchini, R.G., 2006. Recommended PM10 Emission Factors for Almond Harvesting, White Paper prepared for the San Joaquin Valley APCD by UC Davis, May 22. 5. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, Final Report prepared for the WRAP by Midwest Research Institute, Project No. 110397, February 1. 6. CARB, 2006. Private communication from Patrick Gaffney, CARB Emission Inventory Branch PTSD, May 2. 7. MRI, 1981. The Role of Agricultural Practices in Fugitive Dust Emissions, Final Report prepared for the California Air Resources Board by Midwest Research Institute, April 17. 8. SJVAPCD, 2003. Conservation Management Practices Program for the San Joaquin Valley, Final Report prepared by the San Joaquin Valley Air Pollution Control District, February 5. 9. URS, 2001. Technical Support Document for Quantification of Agricultural Best Management Practices, Final Report prepared for Maricopa County, Arizona Department of Environmental Quality, June 8. 10. WSU, 1998. Farming with the Wind, Washington State University College of Agriculture and Home Economics Miscellaneous Publication N.MISCO208, December. 10-8 10.9 Attachment 10-1. PM10 Emission Factors for Harvesting Crops in CA Crop Description Crop Profile Assumption PM10 Emission Factor (lb/acre) ALMOND HULLS Almonds Almonds/1 40.77 ALMONDS, ALL Almonds Almonds/1 40.77 ANISE (FENNEL) Lettuce Cotton/2 1.68 APPLES, ALL Citrus Cotton/40 0.08 APRICOTS, ALL Citrus Cotton/40 0.08 ARTICHOKES Melon Cotton/40 0.08 ASPARAGUS, FRESH MKT Melon Cotton/2 1.68 ASPARAGUS, PROC Melon Cotton/2 1.68 ASPARAGUS, UNSPECIFIED Melon Cotton/2 1.68 AVOCADOS, ALL Citrus Cotton/40 0.08 BARLEY, FEED Wheat Wheat/1 5.8 BARLEY, MALTING Wheat Wheat/1 5.8 BARLEY, UNSPECIFIED Wheat Wheat/1 5.8 BEANS FRESH UNSPECIFIED Dry Beans Cotton/20 0.17 BEANS, BLACKEYE (PEAS) Dry Beans Cotton/2 1.68 BEANS, FAVA Dry Beans Cotton/2 1.68 BEANS, GARBANZO Garbanzo Cotton/2 1.68 BEANS, GREEN LIMAS Dry Beans Cotton/2 1.68 BEANS, LIMAS, BABY DRY Dry Beans Cotton/2 1.68 BEANS, LIMAS, LG. DRY Dry Beans Cotton/2 1.68 BEANS, PINK Dry Beans Cotton/2 1.68 BEANS, RED KIDNEY Dry Beans Cotton/2 1.68 BEANS, SNAP FR MKT Dry Beans Cotton/20 0.17 BEANS, SNAP PROC Dry Beans Cotton/20 0.17 BEANS, UNSPECIFIED SNAP Dry Beans Cotton/20 0.17 BEANS,UNSPEC. DRY EDIBLE Dry Beans Cotton/2 1.68 BEETS, GARDEN Sugar Beets Cotton/2 1.68 BERRIES, BLACKBERRIES Grapes -Table Cotton/40 0.08 BERRIES, BOYSENBERRIES Grapes -Table Cotton/40 0.08 BERRIES, BUSH, UNSPECIFIED Grapes -Table Cotton/40 0.08 BERRIES, LOGANBERRIES Grapes -Table Cotton/40 0.08 BERRIES, RASPBERRIES Grapes -Table Cotton/40 0.08 BROCCOLI, FR MKT Vegetables Cotton/40 0.08 BROCCOLI, PROC Vegetables Cotton/40 0.08 BROCCOLI, UNSPECIFIED Vegetables Cotton/40 0.08 BROCCOLI,FOOD SERV Vegetables Cotton/40 0.08 BRUSSELS SPROUTS Melon Cotton/40 0.08 CABBAGE, CH. & SPECIALTY Lettuce Cotton/40 0.08 CABBAGE, HEAD Lettuce Cotton/40 0.08 CARROTS, FOOD SERV Sugar Beets Cotton/20 0.17 CARROTS, FR MKT Sugar Beets Cotton/20 0.17 CARROTS, PROC Sugar Beets Cotton/20 0.17 CARROTS, UNSPECIFIED Sugar Beets Cotton/20 0.17 CAULIFLOWER, FOOD SERV Vegetables Cotton/40 0.08 10-9 Crop Description Crop Profile Assumption PM10 Emission Factor (lb/acre) CAULIFLOWER, FR MKT Vegetables Cotton/40 0.08 CAULIFLOWER, PROC Vegetables Cotton/40 0.08 CAULIFLOWER, UNSPECIFIED Vegetables Cotton/40 0.08 CELERY, FOOD SERV Lettuce Cotton/40 0.08 CELERY, FR MKT Lettuce Cotton/40 0.08 CELERY, PROC Lettuce Cotton/40 0.08 CELERY, UNSPECIFIED Lettuce Cotton/40 0.08 CHERIMOYAS Citrus Cotton/40 0.08 CHERRIES, SWEET Citrus Cotton/40 0.08 CHESTNUTS Almonds Almonds/10 4.08 CHIVES Lettuce Cotton/40 0.08 CILANTRO Lettuce Cotton/40 0.08 CITRUS, MISC BY -PROD Citrus Cotton/40 0.08 CITRUS, UNSPECIFIED Citrus Cotton/40 0.08 CLOVER, UNSPECIFIED SEED Alfalfa Alfalfa/1 0 COLLARD GREENS Lettuce Cotton/40 0.08 CORN FOR GRAIN Corn Cotton/2 1.68 CORN FOR SILAGE Corn Cotton/20 0.17 CORN, SWEET ALL Corn Cotton/40 0.08 CORN, WHITE Corn Cotton/40 0.08 COTTON LINT, PIMA Cotton Cotton/1 3.37 COTTON LINT, UNSPEC Cotton Cotton/1 3.37 COTTON LINT, UPLAND Cotton Cotton/1 3.37 COTTONSEED Cotton Cotton/1 3.37 CUCUMBERS Vegetables Cotton/40 0.08 CUCUMBERS, GREENHOUSE No Land Prep Zero/1 0 DATES Citrus Almonds/20 2.04 EGGPLANT, ALL Vegetables Cotton/40 0.08 ENDIVE, ALL Lettuce Cotton/40 0.08 ESCAROLE, ALL Lettuce Cotton/40 0.08 FIELD CROP BY PRODUCTS Cotton Cotton/20 0.17 FIELD CROPS, UNSPEC. Corn Cotton/20 0.17 FIGS, DRIED Citrus Almonds/20 2.04 FOOD GRAINS, MISC Corn Cotton/2 1.68 FRUITS & NUTS, UNSPEC. Citrus Cotton/40 0.08 GARLIC, ALL Garlic Cotton/2 1.68 GRAPEFRUIT, ALL Citrus Cotton/40 0.08 GRAPES, RAISIN Grapes -Raisin Cotton/20 0.17 GRAPES, TABLE Grapes -Table Cotton/20 0.17 GRAPES, UNSPECIFIED Grapes -Wine Cotton/20 0.17 GRAPES, WINE Grapes -Wine Cotton/20 0.17 GREENS, TURNIP & MUSTARD Lettuce Cotton/40 0.08 GUAVAS Citrus Cotton/40 0.08 HAY, ALFALFA Alfalfa Alfalfa/1 0 HAY, GRAIN Alfalfa Cotton/2 1.68 HAY, GREEN CHOP Alfalfa Alfalfa/1 0 10-10 Crop Description Crop Profile Assumption PM10 Emission Factor (lb/acre) HAY, OTHER UNSPECIFIED Alfalfa Cotton/2 1.68 HAY, SUDAN Alfalfa Alfalfa/1 0 HAY, WILD Alfalfa Cotton/2 1.68 HORSERADISH Onions Cotton/40 0.08 JOJOBA Melon Cotton/40 0.08 KALE Lettuce Cotton/40 0.08 KIWIFRUIT Citrus Cotton/40 0.08 KOHLRABI Lettuce Cotton/40 0.08 KUMQUATS Citrus Cotton/40 0.08 LEEKS Onions Cotton/40 0.08 LEMONS, ALL Citrus Cotton/40 0.08 LETTUCE, BULK SALAD PRODS. Lettuce Cotton/40 0.08 LETTUCE, HEAD Lettuce Cotton/40 0.08 LETTUCE, LEAF Lettuce Cotton/40 0.08 LETTUCE, ROMAINE Lettuce Cotton/40 0.08 LETTUCE, UNSPECIFIED Lettuce Cotton/40 0.08 LIMA BEANS, UNSPECIFIED Dry Beans Cotton/2 1.68 LIMES, ALL Citrus Cotton/40 0.08 MACADAMIA NUT Almonds Almonds/10 4.08 MELON, CANTALOUPE Melon Cotton/40 0.08 MELON, HONEYDEW Melon Cotton/40 0.08 MELON, UNSPECIFIED Melon Cotton/40 0.08 MELON, WATER MELONS Melon Cotton/40 0.08 MUSHROOMS No Land Prep Zero/1 0 MUSTARD Lettuce Cotton/40 0.08 NECTARINES Citrus Cotton/40 0.08 NURSERY TURF No Land Prep Zero/1 0 OATS FOR GRAIN Wheat Wheat/1 5.8 OKRA Lettuce Cotton/40 0.08 OLIVES Citrus Cotton/40 0.08 ONIONS Onions Cotton/2 1.68 ONIONS, GREEN & SHALLOTS Onions Cotton/40 0.08 ORANGES, NAVEL Citrus Cotton/40 0.08 ORANGES, UNSPECIFIED Citrus Cotton/40 0.08 ORANGES, VALENCIAS Citrus Cotton/40 0.08 ORCHARD BIOMASS Almonds Cotton/40 0.08 PARSLEY Lettuce Cotton/40 0.08 PASTURE, IRRIGATED No Land Prep Zero/1 0 PASTURE, MISC. FORAGE No Land Prep Zero/1 0 PASTURE, RANGE No Land Prep Zero/1 0 PEACHES, CLINGSTONE Citrus Cotton/40 0.08 PEACHES, FREESTONE Citrus Cotton/40 0.08 PEACHES, UNSPECIFIED Citrus Cotton/40 0.08 PEANUTS, ALL Safflower Cotton/2 1.68 PEARS, ASIAN Citrus Cotton/40 0.08 PEARS, BARLETT Citrus Cotton/40 0.08 10-11 Crop Description Crop Profile Assumption PM10 Emission Factor (lb/acre) PEARS, UNSPECIFIED Citrus Cotton/40 0.08 PEAS, DRY EDIBLE Dry Beans Cotton/20 0.17 PEAS, EDIBLE POD (SNON/10 Dry Beans Cotton/20 0.17 PEAS, GREEN, PROCESSING Dry Beans Cotton/20 0.17 PEAS, GREEN, UNSPECIFIED Dry Beans Cotton/20 0.17 PECANS Almonds Almonds/10 4.08 PEPPERS, BELL Tomatoes Cotton/40 0.08 PEPPERS, CHILI, HOT Tomatoes Cotton/40 0.08 PERSIMMONS Citrus Cotton/40 0.08 PISTACHIOS Almonds Almonds/10 4.08 PLUMCOTS Citrus Cotton/40 0.08 PLUMS Citrus Cotton/40 0.08 POMEGRANATES Citrus Cotton/40 0.08 POTATOES SEED Sugar Beets Cotton/2 1.68 POTATOES, IRISH ALL Sugar Beets Cotton/2 1.68 PRUNES, DRIED Citrus Cotton/40 0.08 PUMPKINS Melon Cotton/20 0.17 QUINCE Citrus Cotton/40 0.08 RADICCHIO Lettuce Cotton/40 0.08 RADISHES Sugar Beets Cotton/40 0.08 RAPINI Sugar Beets Cotton/40 0.08 RHUBARB Lettuce Cotton/40 0.08 RICE, FOR MILLING Rice Cotton/2 1.68 RICE, WILD Rice Cotton/2 1.68 RUTABAGAS Sugar Beets Cotton/2 1.68 RYE FOR GRAIN Wheat Wheat/1 5.8 SAFFLOWER Safflower Wheat/1 5.8 SALAD GREENS NEC Lettuce Cotton/40 0.08 SEED BARLEY Wheat Wheat/1 5.8 SEED BEANS Dry Beans Cotton/2 1.68 SEED OATS Wheat Wheat/1 5.8 SEED PEAS Dry Beans Cotton/20 0.17 SEED RICE Rice Cotton/2 1.68 SEED RYE Wheat Wheat/1 5.8 SEED WHEAT Wheat Wheat/1 5.8 SEED, ALFALFA Alfalfa Alfalfa/1 0 SEED, BERMUDA GRASS Alfalfa Alfalfa/1 0 SEED, COTTON FOR PLANTING Cotton Cotton/1 3.37 SEED, GRASS, UNSPECIFIED Alfalfa Alfalfa/1 0 SEED, MISC FIELD CROP Corn Cotton/20 0.17 SEED, OTHER (NO FLOWERS) Alfalfa Cotton/20 0.17 SEED, SAFFLOWER, PLANTING Safflower Wheat/1 5.8 SEED, SUDAN GRASS Alfalfa Alfalfa/1 0 SEED, VEG & VINECROP Vegetables Cotton/20 0.17 SILAGE Wheat Cotton/20 0.17 SORGHUM, GRAIN Wheat Wheat/1 5.8 10-12 Crop Description Crop Profile Assumption PM10 Emission Factor (lb/acre) SPICES AND HERBS Lettuce Cotton/40 0.08 SPINACH UNSPECIFIED Lettuce Cotton/40 0.08 SPINACH, FOOD SERV Lettuce Cotton/40 0.08 SPINACH, FR MKT Lettuce Cotton/40 0.08 SPINACH, PROC Lettuce Cotton/40 0.08 SPROUTS, ALFALFA & BEAN Lettuce Cotton/40 0.08 SQUASH Melon Cotton/20 0.17 STRAW Alfalfa Wheat/1 5.8 STRAWBERRIES, FRESH MKT Melon Cotton/40 0.08 STRAWBERRIES, PROC Melon Cotton/40 0.08 STRAWBERRIES, UNSPECIFIED Melon Cotton/40 0.08 SUGAR BEETS Sugar Beets Cotton/2 1.68 SUNFLOWER SEED Corn Wheat/1 5.8 SUNFLOWER SEED, PLANTING Corn Wheat/1 5.8 SWEET POTATOES Sugar Beets Cotton/2 1.68 SWISSCHARD Lettuce Cotton/40 0.08 TANGELOS Citrus Cotton/40 0.08 TANGERINES & MANDARINS Citrus Cotton/40 0.08 TOMATILLO Tomatoes Cotton/40 0.08 TOMATOES, CHERRY Tomatoes Cotton/40 0.08 TOMATOES, FRESH MARKET Tomatoes Cotton/40 0.08 TOMATOES, GREENHOUSE No Land Prep Zero/1 0 TOMATOES, PROCESSING Tomatoes Cotton/20 0.17 TOMATOES, UNSPECIFIED Tomatoes Cotton/20 0.17 TURNIPS, ALL Sugar Beets Cotton/2 1.68 VEGETABLES, BABY Vegetables Cotton/40 0.08 VEGETABLES, ORIENTAL, ALL Vegetables Cotton/40 0.08 VEGETABLES, UNSPECIFIED Vegetables Cotton/20 0.17 WALNUTS, BLACK Almonds Almonds/1 40.77 WALNUTS, ENGLISH Almonds Almonds/1 40.77 WHEAT ALL Wheat Wheat/1 5.8 10-13 Chapter 11. Mineral Products Industry 11.1 Characterization of Source Emissions 11-1 11.2 Emission Estimation Methodology 11-1 11.2.1 Metallic Ores 11-3 11.2.2 Non-metallic Ores 11-4 11.2.3 Coal 11-7 11.2.4 Supplemental Emission Factors 11-9 11.3 Demonstrated Control Techniques 11-10 11.4 Regulatory Formats 11-11 11.5 Compliance Tools 11-13 11.6 Sample Cost -Effectiveness Calculation 11-13 11.7 References 11-15 11.1 Characterization of Source Emissions This chapter of the handbook addresses fugitive dust emissions from mineral products industries that involve the production and processing of various ores, as discussed in Chapter 11 of AP -42 1 In the mineral products industry, there are two major categories of emissions: ducted sources (those vented to the atmosphere through some type of stack, vent, or pipe), and fugitive sources (those not confined to ducts and vents but emitted directly from the source to the ambient air). Ducted emissions are usually collected and transported by an industrial ventilation system having one or more fans or air movers, eventually to be emitted to the atmosphere through some type of stack. Many operations and processes are common to all mineral products industries, including extraction of aggregate materials from the earth, loading, unloading, conveying, crushing, screening, loadout, and storage. Other operations are restricted to specific industries. These include wet and dry fine milling or grinding, air classification, drying, calcining, mixing, and bagging. Sand and gravel is typically mined in a moist or wet condition such that negligible particulate emissions occur during the mining operation. Construction aggregate processing can produce large amounts of fugitive dust, which due to its generally larger particle sizes tends to settle out within the plant. Some of the individual operations such as wet crushing and grinding, washing, screening, and dredging take place with high moisture content (>4% by weight). Such wet processes do not generate appreciable particulate emissions. For those processing and manufacturing operations that are housed in enclosed buildings with the dust captured by a control device (e.g., product recovery cyclones, fabric filters, and wet scrubber/suppression systems), no uncontrolled fugitive dust emissions are emitted directly into the outdoor air. The operations at a typical western surface coal mine include drilling and blasting, removal of the overburden with a dragline or shovel, loading trucks, bulldozing and grading, crushing, vehicle traffic, and storage of coal in active storage piles that are subject to wind erosion. All operations that involve movement of soil or coal, or exposure of erodible surfaces, generate some amount of fugitive dust. During mine reclamation, which proceeds continuously throughout the life of the mine, overburden spoils piles are smoothed and contoured by bulldozers. Topsoil is placed on the graded spoils, and the land is prepared for revegetation by furrowing and mulching. From the time an area is disturbed until the new vegetation emerges, all disturbed areas are subject to wind erosion. 11.2 Emission Estimation Methodology This section was adapted from EPA's documentation of methods used for the National Emission Inventory (NEI.2 and from Section 11, Mineral Products Industry, of EPA's Compilation of Air Pollutant Emission Factors (AP -42).1 Many of the categories addressed in AP -42 have not been updated by the EPA since the mid to late 1990's. This section addresses three different mineral categories: (a) metallic ores (b) non- metallic ores and rock, and (c) coal. Fugitive dust emission factors for mining and quarrying activities are based on EPA's methodology used for the annual National Emission Inventory that includes emissions from extraction of the ore or rock from the earth but not processing activities.2 Fugitive dust emission factors for processing activities are taken from AP -42 and represent average values based on a number of tests made under a variety of conditions such as material silt content, moisture content, and wind speed. As such, the actual uncontrolled emission factors will vary depending upon actual site conditions. The EPA methodology used to develop the annual National Emission Inventory (NEI) for fugitive PM10 dust emissions from mining and quarrying operations utilizes the sum of the emissions from the mining of metallic and nonmetallic ores and coal as well as rock quarrying, as follows: E=Em+E„+Ec (1) where, E = PM10 emissions from mining and quarrying operations Em = PM10 emissions from metallic ore mining operations En = PM10 emissions from non-metallic ore mining and rock quarrying operations Ec = PM10 emissions from coal mining operations The NEI PM10 emissions estimate for mining and rock quarrying operations involving extraction of ore or rock from the earth include three specific activities: (1) overburden removal, (2) drilling and blasting, and (3) loading and unloading. Ore processing activities that involve transfer and conveyance operations, crushing and screening operations, storage, and travel on haul roads are not included in the NEI emissions estimate since EPA assumes that the dust emissions from these activities are well controlled. Uncontrolled particulate emission factors for ore processing activities are presented in the subsections below for estimating fugitive dust emissions from these sources. Fugitive dust emissions from materials handling, travel on unpaved roads, and wind erosion of storage piles are addressed in Chapters 4, 6 and 9 of this handbook, respectively. The NEI emissions estimation methodology assumes that the TSP emission factors developed for copper ore mining apply to the three activities listed above for all metallic ore mining. PM10 emission factors for each of these three activities for metallic ore mining are based on the following PM10/TSP ratios: 0.35 for overburden removal, 0.81 for drilling and blasting, and 0.43 for loading/unloading operations.3 In the NEI emission estimation methodology, non-metallic ore mining emissions are calculated by assuming that the PM10 emission factors for western surface coal mining apply to mining of all non-metallic ores. The PMI0/TSP ratio for western surface coal mining is 0.40.4 Coal mining includes two additional sources ofPM10 emissions compared to the sources considered for metallic and non-metallic ores, namely overburden replacement and truck loading and unloading of that overburden. EPA assumes that the amount of overburden material handled equals ten times the amount of coal mined.5 11-2 EPA Method 5 (or equivalent) source tests used to generate particulate emission factors include a filterable PM fraction that is captured on or prior to a filter and a condensable PM fraction that is collected in the impinger portion of the sampling train. PM emission factors presented below include the sum of the filterable and condensable PM fractions for those cases where information exists for both fractions. For those cases where information only exists for the filterable PM fraction, this is clearly identified in the text below. Previous NEI PM emission inventories for fugitive dust from mineral products industries assumed a PM2.5/PM10 ratio of 0.29.2 In July 2006 EPA adopted revised PM2.5/PM 10 ratios for several fugitive dust source categories, including a ratio of 0.1 for heavy vehicle traffic on unpaved surfaces around aggregate storage piles and a ratio of 0.15 for transfer of aggregate associated with buckets or conveyors based on the recent findings of MRI.6 Thus, the PM2.5/PM10 ratio for fugitive dust from mineral products industries lies somewhere between 0.1 and 0.15. Estimates of the amount of metallic and non-metallic ores handled at surface mines are available from the U.S. Geological Survey. Production figures for coal mining operations are available from the Energy Information Administration (EIA) in the U.S. Department of Energy. 11.2.1 Metallic Ores EPA uses the following equation to calculate PM10 emissions from overburden removal, drilling and blasting, and loading and unloading from metallic ore mining operations: Em = Am [EFo + (B x EFb) + EFI + EFd] (2) where, Am = metallic crude ore handled at surface mines (tons) EFo = PM10 open pit overburden removal emission factor for copper ore (lbs/ton) B = fraction of total ore production that is obtained by blasting at metallic ore mines EFb = PMIO drilling/blasting emission factor for copper ore (lbs/ton) EF1 = PM1O loading emission factor for copper ore (lbs/ton) EFd = PM 10 truck dumping emission factor for copper ore (lbs/ton) Utilizing the TSP emission factors and PM10/TSP ratios developed for copper ore mining operations, PM10 emissions from metallic ore mining operations are calculated as follows: Em = Am [0.0003 + (0.57625 x 0.0008) + 0.022 + 0.032] = 0.0548 Am (3) Based on NEI's emission estimation methodology that excludes fugitive dust emissions from haul truck traffic on unpaved surfaces, PM10 emissions from loading and truck dumping account for 40% and 58%, respectively, of the total PM10 emissions from metallic ore mining operations. 11-3 Uncontrolled filterable TSP and PM10 emission factors for metallic ore processing operations are presented in Table 11-1. These emission factors are for emissions after product recovery cyclones. Uncontrolled PM emission factors for taconite ore processing are presented in Table 11-2. Table 11-1. Filterable TSP and PM10 Emission Factors for Metallic Ore Processinea Source TSP (lb/ton) PM10 (lb/ton) Low -moisture oresb Primary crushing 0.5 0.05 Secondary crushing 1.2 ND Tertiary crushing 2.7 0.16 Material handling and transfer — all minerals except bauxite 0.12 0.06 Material handling and transfer — bauxite/alumina 1.1 ND High -moisture ores Primary crushing 0.02 0.009 Secondary crushing 0.05 0.02 Tertiary crushing 0.06 0.02 Material handling and transfer — all minerals except bauxite 0.01 0.004 Material handling and transfer — bauxite/alumina ND ND Both low- and high -moisture ores° Wet grinding Neg Neg Dry grinding with air conveying and/or air classification 28.8 26 Dry grinding without air conveying and/or air classification 2.4 0.31 Drying — all minerals except titanium/zirconium sands 19.7 12 a b Emission factors in units of lb/ton of material processed. One lb/ton is equivalent to 0.5 kg/Mg. Neg = negligible. ND = no data. Low -moisture ore has a moisture content of less than 4% by weight; high - moisture ore has a moisture content of at least 4% by weight. Table 11-2. TSP and PM10 Emission Factors for Taconite Ore Processinga Source TSP (lb/ton) PM10 (lb/ton) Natural gas -fired grate/kiln 7.4 0.65 Gas -fired vertical shaft top gas stack 16 ND Oil -fired straight grate 1.2 ND a Applicable to both acid pellets and flux pellets. Emission factors in units of lb/ton of fired pellets produced. One lb/ton is equivalent to 0.5 kg/Mg. ND = no data. 11.2.2 Non-metallic Ores EPA uses the following equation to calculate the PM10 emissions from overburden removal, drilling and blasting, and loading and unloading from non-metallic ore mining and rock quarrying operations: Er, = An [EF„ + (D x EFr) + EFa + 0.5 (EFe + EFt)] (4) where, An = non-metallic crude ore handled at surface mines (tons) EFL, = PM10 open pit overburden removal emission factor at western surface coal mining operations (lbs/ton) 1 1 -4 D = fraction of total ore production that is obtained by blasting at non-metallic ore mines EF,. = PM10 drilling/blasting emission factor at western surface coal mining operations (lbs/ton) EFa = PM10 loading emission factor at western surface coal mining operations (lbs/ton) EFe = PM -10 truck unloading: end dump -coal emission factor at western surface coal mining operations (lbs/ton) EF, = PMI O truck unloading: bottom dump -coal emission factor at western surface coal mining operations (lbs/ton) Utilizing the PM10 factors developed for western surface coal mining operations, PM10 emissions from non-metallic ore mining and rock quarrying operations are calculated as follows: En = An [0.225 + (0.61542 x 0.00005) + 0.05 + 0.5 (0.0035 + 0.033)] = 0.293 An (5) PM10 emissions from overburden removal account for 77% of the total PM10 emissions from non-metallic ore mining and rock quarrying operations. Uncontrolled TSP and PM10 emission factors for non-metallic ore processing operations are presented in Table 11-3. The emission factors for mixer loading and truck loading for concrete batching operations were updated in June 2006.' These new AP -42 emission factors are approximately double the previous emission factors. Excluding road dust and windblown dust, the plant wide PM10 emission factors per yard of concrete for an average concrete batch formulation at a typical facility are 0.058 lb/yd3 for truck mix concrete and 0.037 lb/yd3 for central mix concrete. 11-5 Table 11-3. TSP and PM10 Emission Factors for Non-metallic Ore Processing Operations a Industry Source TSP (lb/ton) PM10 (lb/ton) Sand and Gravel Sand Dryer 2.0 ND Crushed Stone Tertiary crushing° 0.0054 0.0024 Fines crushing 0.039 0.0150 Screening 0.025 0.0087 Fines screening 0.30 0.072 Conveyor transfer point 0.0030 0.0011 Wet drilling — unfragmented stone ND 8.0 x 10-5 Truck unloading — fragmented stone ND 1.6 x 10-° Truck unloading — conveyor, crushed stone ND 1.0 x 10-4 Lightweight Aggregate Rotary Kiln 131 ND Concrete Batching Aggregate transfer 0.0069 0.0033 Sand transfer 0.0021 0.00099 Cement unloading to storage silo 0.72 0.46 Cement supplement unloading to silo 3.14 1.10 Weigh hopper loading 0.0051 0.0024 Mixer loading (central mix)` 0.524 0.156 Truck loading (truck mix)` 1.122 0.311 Phosphate Rock Dryer 5.7 4.8 Grinder 1.5 ND Calciner 15 14.4 Kaolin° Apron dryer 1.2 ND Multiple hearth furnace 34 16 Flash calciner 1,100 560 Fire Clay° Rotary dryer 65 16 Rotary calciner 120 30 Bentonite° Rotary dryer 290 20 Talc Railcar unloading 0.00098 ND Brick Manufacturing Grinding and screening wet materials 0.025 0.0023 Grinding and screening dry material' 8.5 0.53 Brick dryer 0.077 ND Natural gas -fired kiln 0.96 0.87 Coal-fired kiln 1.79 1.35 Sawdust -fired kiln 0.93 0.85 Sawdust -fired kiln and sawdust dryer 1.36 0.31 Natural gas -fired kiln firing structural clay 1.0 ND Portland Cement Manufacturing Wet process kiln 130 31 Preheater kiln 250 ND Gypsum Rotary ore dryers' 0.16(FFF)1.7 0.013(FFF)t'7 Continuous kettle calciners and hot pit 41° 26 Flash calciners 37° 14 Lime Manufacturing Primary crusher 0.017° ND Secondary crusher 0.62° ND Product transfer and conveying 2.2° ND Product loading, enclosed truck 0.61° ND Product loading, open truck 1.5° ND Coal-fired rotary kiln 352 44 Coal- and gas fired rotary kiln 80 ND Gas -fired calcimatic kiln 97 ND Product cooler 6.8 ND a Emission factors data. FFF is the b Emission factors Emission factors 2006. in units of lb/ton of material processed. One lb/ton is equivalent to 0.5 kg/Mg. ND = no ratio of gas mass rate per unit dryer cross section area to the dry mass feed rate.' for tertiary crushers can be used as an upper limit for primary or secondary crushing. for mixer loading and truck loading for concrete batching operations were updated June 11-6 d Filterable PM emission factors. e'f Units are lb/ton of raw material processed based on a raw material moisture content of 13% and of 4%, respectively. 11.2.3 Coal EPA uses the following equation to calculate the PM10 emissions from overburden removal, drilling and blasting, loading and unloading, and overburden replacement from coal mining operations: E, = Ac [10 (EFto + EFor + EFdt) + EFv + EFr +EFa + 0.5 (EFe + EFr)] (6) where, A. = coal production at surface mines (tons) EFta = PM10 emission factor for truck loading overburden at western surface coal mining operations (lbs/ton of overburden) EFor = PM10 emission factor for overburden replacement at western surface coal mining operations (lbs/ton of overburden) EFdt = PM 10 emission factors for truck unloading: bottom dump -overburden at western surface coal mining operations (lbs/ton of overburden) EF„ = PM10 open pit overburden removal emission factor at western surface coal mining operations (lbs/ton) EFr = PM10 drilling/blasting emission factor at western surface coal mining operations (lbs/ton) EFa = PM10 loading emission factor at western surface coal mining operations (lbs/ton) EFe = PM10 truck unloading: end dump -coal emission factor at western surface coal mining operations (lbs/ton) EF, = PM10 truck unloading: bottom dump -coal emission factor at western surface coal mining operations (lbs/ton) Utilizing the PM 10 factors developed for western surface coal mining operations, PM 10 emissions from coal mining operations are calculated as follows: Ec = Ac [10 (0.015 + 0.001 + 0.006) + 0.225 + 0.00005 + 0.05 + 0.5 (0.0035 + 0.033)] = 0.514 Ac (7) PM10 emissions from loading overburden into trucks and overburden removal account for 29% and 44%, respectively, of the total PM10 emissions from coal mining operations. PM10 emission factor equations for uncontrolled fugitive dust sources at western surface coal mines are presented in Table 11-4. Table 11-4. PM10 Emission Factor Equations for Uncontrolled Fugitive Dust from Western Surface Coal Minesa Operation Material PM10 Emission Factor Equations English Units Metric Units Truck loading Coal 0.089 /(M)" lb/ton 0.045 / (M)°'9 kg/Mg Bulldozing Coal 14.0(s)1' / (M)1'4 lb/hr 6.33(s)1' / (M)1' kg/hr Overburden 0.75(s)1.5 / (M)1 4 lb/hr 0.34(s)1.5 / (M)1 4 k9/hr Dragline Overburden 0.0016(d)0"7 / (M)°.3 lb/yd3 0.0022(d)°.7 i(v)u.3 kg/m3 Grading Overburden 0.031(S) IbNMT 0.0034(S)2 kgNKT 11-7 a Symbols for equations: VMT = vehicle miles traveled; VKT = vehicle kilometers traveled; ND = no data. M = material moisture content (%); s = material silt content (%); d = drop height (ft); S = mean vehicle speed (mph). In using the equations presented in Table 11-4 to estimate emissions from sources found at a specific western surface mine, it is necessary that reliable values for correction parameters be obtained for the specific sources of interest. For example, the actual silt content of coal or overburden measured at a facility should be used instead of estimated values. In the event that site -specific values for correction parameters cannot be obtained, the appropriate geometric mean values from Table 11-5 may be used. Table 11-5. Range and Geometric Mean of Correction Factors Used to Develop Emission Factor Equations Shown in Table 11-4. Source Correction Factor Range (Geometric Mean) English Units Metric Units Blasting Area Blasted 1,100 - 73,000 ft` (17,000 ft2) 100 - 6,800 m2 (1,590 m2) Coal loading Moisture 6.8 — 38% (17.8%) Bulldozers Coal Overburden Moisture 4 — 22% (10.4%) Silt 6 — 11.3% (8.6%) Moisture 2.2 — 16.8% (7.9%) Silt 3.8 - 15.1% (6.9%) Dragline Drop Distance 5 — 100 ft (28.1 ft) 1.5 - 30 m (8.6 m) Moisture 0.2 - 16.3% (3.2%) Scraper Silt 7.2 - 25.2% (16.4%) Weight 36 — 70 ton (53.8 ton) 33 — 64 Mg (48.8 Mg) Grader Speed 5.0 - 11.8 mph (7.1 mph) 8 - 19 kph (11.4 kph) Haul truck Silt content 1.2 — 19.2% (4.3%) Moisture 0.3 - 20.1% (2.4%) Weight 23 — 290 ton (120 ton) 20.9 - 260 Mg (110 Mg) TSP emission factors for fugitive dust sources not covered in Table 11-4 are presented in Table 11-6. These factors were determined through source testing at various western surface coal mines. It should be pointed out that AP -42 does not list PM10/TSP ratios for fugitive dust sources. Instead it lists TSP and PM 15 emission factor equations and PM10/PM15 ratios that range from 0.52 for blasting and 0.60 for grading to 0.75 for other operations. Calculating TSP and PM15 emission factors using typical correction factors provided in Table 11-5 together with the published PM10/PM15 ratios produces PM10/TSP ratios ranging from 0.15 to 0.30 for open area fugitive dust sources at western surface coal mines. 11-8 Table 11-6. Uncontrolled TSP Emission Factors for Western Surface Coal Mines' Source Material TSP Emission Factor English Units Metric Units Blasting Coal or overburden 0.000014 (A)lb lb/blast 0.00022 (A)''° kg/blast Drilling Overburden 1.3 lb/hole 0.59 kg/hole Topsoil removal by scraper Topsoil 0.058 lb/ton 0.029 kg/Mg Overburden replacement Overburden 0.012 lb/ton 0.006 kg/Mg Train loading by power shovel Coal 0.028 lb/ton 0.014 kg/Mg Bottom dump truck unloading Overburden 0.066 lb/ton 0.033 kg/Mg Wind erosion of exposed areasb Seeded land, stripped or graded overburden 0.38 ton/acre-yr 0.85 Mg/hectare-yr Wind erosion of storage pile Coal 0.72 (u) lb/acre-hr 1.8 (u) kg/hectare-hr a A = horizontal area (ft2 or m2) with blasting depth ≤ 70 ft (≤21 m); not for a vertical face of a bench. U = wind speed (mph or m/s) b To estimate wind erosion on a shorter time scale (e.g., worst -case day); see Chapter 8 of the handbook. 11.2.4 Supplemental Emission Factors TSP and PM 10 emission factors for operations associated with ten mineral products industries are published in the EPA's National Air Pollutant Emission Trends Procedures Document for 1900-1996.8 The PM 10 emission factors and PM 10/TSP ratios for these operations are presented in Table 11-7. It should be pointed out that several of the emission factors shown in Table 11-7 are not consistent with values presented in Tables 11-1 and 11-3. To be conservative, one may wish to adopt the higher of the two values. Table 11-7. Supplemental PM10 Emission Factors for Mineral Products Industries' Mineral Product Industry Operation PM10 (lb/ton) PM10/TSP Ratio Copper Ore Crushing 2.9 to 3.9 0.45 Open pit overburden removal 0.0003 0.37 Drill/blasting 0.0008 0.80 Loading 0.022 0.44 Truck dumping 0.032 0.80 Transfer/conveying 0.08 0.53 Storage 0.7 0.35 Iron Ore Mining 0.18 0.41 Lead Ore Crushing 5.1 0.85 Zinc Ore Crushing 2.3 0.38 Sand and Gravel Mining 0.029 0.29 Asphalt Concrete Fugitives 0.15 0.50 Brick Manufacturing Material Handling 1.4 0.31 Cement Manufacturing Fugitives 10.4 0.58 Lime Manufacturing Fugitives 1.75 0.37 Coal Surface Mining 0.2 0.40 Coal Handling 0.17 0.34 Pneumatic Dryer 1.5 0.50 a Emission factors in units of IbVton of material processed. One lb/ton is equivalent to 0.5 kg/Mg. 11-9 The predictive emission factor presented in Chapter 4 may be used to calculate emissions for materials handling operations if source specific data (moisture content, wind speed, and silt content) is available. 11.3 Demonstrated Control Techniques Emissions from mineral processing plants can be controlled by a variety of devices, including wet scrubbers, cyclones, venturi scrubbers, fabric filters, and electrostatic precipitators or baghouses. Rudimentary fallout chambers and cyclone separators can be used to control the larger particles. Conveyor belts moving dried rock may be covered and sometimes enclosed. Transfer points and bucket elevators are sometimes enclosed and evacuated to a control device. Dry rock is often stored in enclosed bins or silos, which are vented to the atmosphere, with fabric filters frequently used to control emissions. Cyclones are often used for product recovery from mechanical processes. In such cases, the cyclones are not considered to be an air pollution control device. Emissions from dryers and calciners can be controlled by a combination of a cyclone or a multiclone and a wet scrubber system. Fabric filters are used at some facilities to control emissions from mechanical processes such as crushing and grinding. Cyclones and fabric filters are used to control emissions from screening, milling, and materials handling and transfer operations. For moderate to heavy uncontrolled emission rates from typical dry ore operations, a wet scrubber with a pressure drop of 6" to 10" of water will reduce TSP emissions by approximately 95%. With very low uncontrolled emission rates typical of high -moisture conditions, the percentage reduction will be lower (approximately 70%). Wet suppression techniques include application of water, chemicals and/or foam, usually at crusher or conveyor feed and/or discharge points. Such spray systems at transfer points and on material handling operations have been estimated to reduce TSP emissions by 70 to 95%. Spray systems can also reduce loading and wind erosion TSP emissions from storage piles of various materials by 80 to 90%. Venturi scrubbers with a relatively low pressure drop (12" of water) have reported PM10 collection efficiencies of 80 to 99%, whereas high -pressure -drop scrubbers (30" of water) have reported PM10 collection efficiencies of 96 to 99.9%, and electrostatic precipitators have PM10 collection efficiencies of 90 to 99%. Over a wide range of inlet mass loadings, a well -designed and maintained baghouse will reduce emissions to a relatively constant outlet concentration. Such baghouses tested in the mineral processing industry consistently reduce emissions to less than 0.05 g/m3 (0.02 grains/ft"), with an average concentration of 0.015 g/m3 (0.006 grains/ft3). Under conditions of moderate to high uncontrolled emission rates of typical dry ore facilities, this level of controlled emissions represents greater than 99% removal of PM emissions. Control efficiencies depend upon local climatic conditions, source properties and duration of control effectiveness. Process fugitive emission sources include materials handling and transfer, raw milling operations in dry process facilities, and finish milling operations. Emissions from these processes can be controlled by fabric filtration (baghouses) with reported removal 11-10 efficiencies of approximately 95 to 99%. The industry uses shaker, reverse air, and pulse jet filters as well as some cartridge units, but most newer facilities use pulse jet filters. Successful control techniques used for haul roads are dust suppressant application, paving, route modifications, and soil stabilization. Controls for conveyors include covering and wet suppression; for storage piles, wet suppression, windbreaks, enclosure, and soil stabilizers; for conveyor and batch transfer points, wet suppression and various methods to reduce freefall distances (e. g., telescopic chutes, stone ladders, and hinged boom stacker conveyors); and for screening and other size classification, covering and wet suppression. Additional information on these control measures can be found in other chapters of this handbook. AP -42 lists both uncontrolled and controlled PM10 emission factors for different control devices for many mineral processing industries. Comparing the controlled emission factor for a specific control device to the uncontrolled emission factor provides the PM 10 control efficiency for that control device presented in Table 11-8. Table 11-8. PM10 Control Efficiencies for Mineral Processing Operations Mineral Products Industry Source Control Device PM10 Control Efficiency (%) Taconite ore Natural gas fired kiln Multiclone 79 Crushed stone Tertiary crushing Wet scrubber 78 Fines crushing Wet scrubber 92 Screening Wet scrubber 91.6 Fines screening Wet scrubber 96.9 Conveyor transfer point Wet scrubber 95.9 Pulverized mineral Grinding Fabric filter >99.5% Lightweight aggregate Rotary Kiln Wet scrubber 99.4 Rotary Kiln Fabric filter 99.8 Rotary Kiln Electrostatic precipitator 99.5 Kaolin Flash calciner Fabric filter 99.99 Fire clay Rotary dryer Cyclone 68 Rotary calciner Multiclone and wet scrubber 99.8 Bentonite Rotary dryer Fabric filter 99.6 Hot mix asphalt Dryer Fabric filter 99.4 Brick manufacturing Grinding and screening Fabric filter 99.4 Portland cement Wet process kiln Electrostatic precipitator 97.9 Cement batching Unloading into silo Wet scrubber 99.9 Mixer loading (central mix) Wet scrubber 96.5 Truck loading (truck mix) Wet scrubber 91.6 Gypsum manufacturing Flash calciner Fabric filter 99.8 Lime manufacturing Coal-fired rotary kiln Fabric filter 99.6 Coal-fired rotary kiln Electrostatic precipitator 90 11.4 Regulatory Formats PM stack emissions from taconite ore processing facilities constructed or modified after August 24, 1982 are regulated under 40 CFR 60, subpart LL to 0.05 g/m3 (0.022 grains/ft3). In addition, the opacity of stack emissions is limited to 7% unless the stack is equipped with a wet scrubber, and process fugitive emissions are limited to 10%. The standard does not affect emissions from indurating furnaces. Emissions from Portland cement plants constructed or modified after August 17, 1971 are regulated to limit PM emissions from kilns to 0.15 kg/Mg (0.30 lb/ton) of feed, and to limit PM emissions from clinker coolers to 0.050 kg/Mg (0.10 lb/ton) of feed. Emissions of filterable PM from rotary lime kilns constructed or modified after May 3, 1977 are regulated to 0.30 kg/Mg (0.60 lb/ton) of stone feed under 40 CFR Part 60, subpart HH. Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. Example regulatory formats downloaded from the Internet for several local air quality agencies in the WRAP region are presented in Table 11-9. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • San Joaquin Valley APCD, CA: valleyair.org/SJV_main.asp • South Coast AQMD, CA: aqmd.gov/rules • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/aq Table 11-9. Example Regulatory Formats for Mineral Processing Operations Control Measure Agency Limits PM emissions from cement kilns to 30 pounds per hour for kiln feed rates of 75 tons per hour or greater. Limits PM emissions to 0.40 pound per ton of kiln feed for kiln feed rates less than 75 tons per hour. SCAQMD Rule 1112.1 02/07/86 Limits opacity from cement manufacturing facilities to 20 % for open storage piles and unpaved roads and to 10 % for all other operations, Specifies covers for conveying systems and enclosures for conveying system transfer points, and loading/unloading through an enclosed system. SCAQMD Rule 1156 11/04/05 Limits opacity from an aggregate handling facility to 20% based on an average of 12 consecutive readings, or 50% based on five individual, consecutive readings, using the SCAQMD Opacity Test Method No. 9B. SCAQMD Rule 1157 01/07/05 Limits (a) PM emissions from stacks at a nonmetallic mineral processing plant to 0.02 grains/dry standard cubic foot (gr/dscf) (50 mg/dscm), (b) opacity of fugitive dust emissions from any transfer point on a conveying system to 7%, and (c) opacity of fugitive dust emissions from any crusher to 15%. Maricopa Co. Rule 316 6/08/05 No owner or operator of an existing tunnel kiln at a brick or structural product manufacturing facility shall emit more than 0.42 lbs. of particulate matter per ton of fired product from a tunnel kiln with a capacity throughput ≥ 1 ton/hour. Maricopa Co. Rule 325 8/10/05 Limits the opacity of fugitive dust emissions at metallic or non-metallic mineral mining and processing facilities (based on an aggregate of at least 3 minutes in any 1 -hour period) to (a) 10% for grinding mills, screening equipment, conveyors, conveyor transfer points, bagging equipment, storage bin, storage piles, stacker, enclosed truck, or rail car loading stations, (b) 15% for crushers, and (c) 7% for emissions from a stack or exhaust from a control device or building vent. Clark Co. Rule 34 7/01/04 11-12 11.5 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 11-10 summarizes the compliance tools that are applicable for mineral processing industries. Table 11-10. Compliance Tools for Mineral Processing Industries Record keeping Site inspection/monitoring Maintain daily records onsite for a period of five Observation of dust plumes during periods of years, and make such records available to the mining and processing operations; Executive Officer upon request for: (a) hours of observation of dust plume opacity (visible operation, (b) volume of ore or aggregate emissions) exceeding a standard; tests of mined, (c) watering and sweeping schedule for surface soil stabilization and aggregate internal paved roads, (d) number of haul trucks moisture content; monitoring device to record exiting the facility, (e) Fugitive Dust Advisories, (f) Dust Control Plan, (g) Operation and pressures, flow rates and other ECS operating conditions; posting of signs Maintenance Plan for the on -site emission restricting speeds to 15 mph; observation of control system (ECS), and (h) twice daily moisture results of aggregate material. high winds (e.g., >25 mph). 11.6 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for mineral processing operations. The reader is directed to Sections 4.6, 6.8, and 9.6 of the handbook for examples of calculating the cost effectiveness of specific control 11-13 measures for several minerals processing operations, namely materials handling, haul trucks traveling on unpaved industrial roads, and storage pile wind erosion, respectively. A sample cost-effectiveness calculation is presented below for a specific control measure (wet scrubber for tertiary crushing of crushed stone) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for mineral processing, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Tertiary Crushing at Crushed Stone Processing Plant Step 1. Determine source activity and control application parameters. Material throughput (tons/year) Control Measure Control application/frequency Economic Life of Control System (yr) Control Efficiency (Reference) 2,000,000 Wet scrubber Continuous 10 78% (AP -42) The material throughput and economic life are assumed values for illustrative purposes. A wet scrubber system has been chosen as the control measure for reducing fugitive dust emissions. The moisture content of the crushed stone averages 0.21 to 1.3% for facilities without a wet suppression system and 0.55 to 2.88% for facilities with a wet suppression system.' Step 2. Obtain Uncontrolled PM Emission Factors. The uncontrolled PM10 emission factor for tertiary crushing of crushed stone published in AP -42 is 0.0024 lb/ton of material throughput. The PM2.5/PM10 ratio for crushed stone aggregate is 0.15 (MRI, 2006).6 Step 3. Calculate Uncontrolled PM Emissions. The annual uncontrolled PM10 emissions are calculated by multiplying the PM10 emission factor by the material throughput and then divided by 2,000 lbs to compute the annual emissions in tons per year, as follows: Annual emissions = (EF x Material Throughput)/2,000 Annual PM10 Emissions = (0.0024 x 2,000,000)/2000 = 2.4 tons Annual PM2.5 Emissions = 0.15 (Annual PM10 Emissions) = 0.36 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). For this example, a wet scrubber/suppression system with a control efficiency of 78% has been selected as the control measure. Thus, the annual controlled PM10 and PM2.5 emissions estimates are calculated to be: 11-14 Annual Controlled PM10 emissions = (2.4 tons) x (1 — 0.78) = 0.53 tons Annual Controlled PM2.5 emissions = (0.36 tons) x (1 — 0.78) = 0.079 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) Operating/Maintenance costs ($) Annual Interest Rate Capital Recovery Factor Annualized Cost ($/yr) 16,000 12,200 3% 0.12 14,076 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: CRF = AIR x (1+AIR) Economic life / (1+AIR) Economic life— 1 CRF =3%x(1+3%)10/(1+3%)10-1 =0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor (CRF) multiplied by the Capital costs to the sum of the Operating and Maintenance costs, as follows: Annualized Cost = (CRF x Capital costs) + Operating/Maintenance costs Annualized Cost = (0.1172 x $16,000) + $12,200 = $14,076 Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = $14,075 / (2.4 - 0.53) = $7,519/ton Cost-effectiveness for PM2.5 emissions = $14,075 / (0.36 - 0.079) = $50,127/ton 11.7 References 1. USEPA, 2006. Compilation of Air Pollutant Emission Factors, AP -42 Section 11 (Minerals Products Industry), Fifth Edition. 2. USEPA, 2004. Documentation for the Final 1999 National Emissions Inventory (Version 3.0) for Criteria Pollutants and Ammonia: Area Sources, report prepared by E. H. Pechan and Associates for the USEPA OAQPS, January 31. 3. USEPA, 1986. Generalized Particle Size Distributions for Use in Preparing Size - Specific Particulate Emissions Inventories, EPA -450/4-86-013, July. 4. USEPA, 1990. AIRS Facility Subsystem Source Classification Codes and Emission Factor Listing for Criteria Air Pollutants, EPA -450/4-90-003, March. 5. USEPA, 2001. Procedures Document for National Emission Inventory, Criteria Air Pollutants, 1985-1999, EPA -454/R-01-006, March. 11-15 6. MRI, 2006. Background Document for Revisions to Fine Fraction Ratios Used for AP -42 Fugitive Emission Factors, prepared for the WRAP by Midwest Research Institute, Feb. 1. 7. USEPA, 2006. AP -42 Section 11.12: Concrete Batching, updated in June. 8. USEPA, 1998. National Air Pollutant Emission Trends Procedure Document for 1900-1996, EPA -454/R-98-008, May. 11-16 Chapter 12. Abrasive Blasting 12.1 Emission Estimation Methodology 12-1 12.2Demonstrated Control Techniques 12-1 12.3 Regulatory Formats 12-1 12.4Compliance Tools 12-3 12.5 Sample Cost -Effectiveness Calculation 12-4 12.6 References 12-6 12.1 Emission Estimation Methodology This section was adapted from Section 13.2.6 of EPA's Compilation of Air Pollutant Emission Factors (AP -42). Section 13.2.6 was last updated in September 1997. Abrasive blasting is the use of abrasive material to clean and prepare metal or masonry surfaces prior to painting. Sand is the most widely used blasting abrasive.' Other abrasive materials include coal slag, smelter slag, cast iron grit, cast iron shot, steel shot, garnet, walnut shells, carbon dioxide pellets, as well as synthetic abrasives such as silicon carbide, aluminum oxide, and glass or plastic beads. The PM10 and PM2.5 emission factors listed in AP -42 for sand blasting of mild steel are 13 lb/1,000 lb abrasive and 1.3 lb/1,000 lb abrasive, respectively, giving a PM2.5/PM10 ratio of 0.1. Using grit or shot instead of sand as the abrasive media reduces total PM emissions by 76% and 90%, respectively. 12.2 Demonstrated Control Techniques A number of different methods have been used to control the emissions from abrasive blasting. Theses methods include: blast enclosures; vacuum blasters; drapes; water curtains; wet blasting; and reclaim systems. Wet blasting controls include not only traditional wet blasting processes but also high pressure water blasting, high pressure water and abrasive blasting, and air and water abrasive blasting. For wet blasting, control efficiencies between 50 and 93 percent have been reported. Fabric filters are typically used to control emissions from enclosed abrasive blasting operations with reported control efficiencies in excess of 95%.' Muleski and Downing recently tested the use of a polyurethane sponge material impregnated with different abrasive materials and compared the particulate emissions from this new sponge media with that from traditional abrasive materials.2 The pliable nature of the sponge material allows it to surround the point of abrasive impact, thus capturing airborne dust emissions. The most commonly sold sponge media is a product containing 30 grit aluminum oxide known as "Silver 30". Using recycled sponge media mixed with fresh abrasive material per the manufacturer's recommendations reduced TSP emissions by 94% and PM10 emissions by 96% compared to traditionally used abrasives such as coal slag and silica sand. In other words, when used as recommended (i.e., recycled sponge media with fresh abrasive material added), the foam -based blasting media achieved a control level essentially identical to that of fabric filtration. 12.3 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. As an example, Maricopa County's Rule 312 states that all abrasive blasting operations shall be performed in a confined enclosure, unless one of the following conditions are met, in which case unconfined blasting may be performed: (a) the item to be blasted exceeds 8 ft. in any one dimension, or (b) the 12-1 surface being blasted is fixed in a permanent location, cannot easily be moved into a confined enclosure, and the surface is not normally dismantled or moved prior to abrasive blasting.3 Dry abrasive blasting in a confined enclosure with a forced air exhaust requires the use of either a certified abrasive (i.e., an abrasive certified by the California Air Resources Board), or venting to an emission control system (ECS) for which the operator must maintain an operation and maintenance plan. A list of abrasives currently certified by CARB as permissible for dry outdoor blasting can be obtained from Maricopa County's website (maricopa.gov/aq/divisions/planning.aspx#rules). For unconfined blasting, at least one of the following control measures shall be used: wet abrasive blasting, vacuum blasting, or dry abrasive blasting, provided that all of the following conditions are met: performed only on a metal substrate, use of certified abrasive for dry unconfined blasting, blasting paint that has a lead content of less than 0.1 percent, abrasive blasting operation directed away from unpaved surfaces, and the certified abrasive may only be used once unless contaminants are separated from the abrasive after each use. No dry unconfined abrasive blasting operation shall be conducted when the 1 - hour average wind speed is greater than 25 miles per hour. Maricopa County Rule 312 states no owner or operator shall discharge into the atmosphere from any abrasive blasting operation any air contaminant for an observation period or periods aggregating more than three minutes in any sixty minute period an opacity conducted in accordance with EPA Reference Method 9 ("Visual Determination of the Opacity of Emissions from Stationary Sources," 40 CFR 60, Appendix A) equal to or greater than 20 percent. At the end of the work shift the owner or operator shall clean up spillage, carryout, and/or track out of any spent abrasive material with a potential to be transported during periods where the wind exceeds 25 mph. The South Coast AQMD's Rule 1140 states that before blasting all abrasives used for dry unconfined blasting shall contain no more thanl% by weight material passing a No. 70 U.S. Standard sieve, and after blasting the abrasive shall not contain more than 1.8% by weight material five microns or smaller.4 Rule 1140 states that visible emission evaluation of abrasive blasting operations shall be conducted in accordance with the following provisions: 1. Emissions shall be read in opacities and recorded in percentages. 2. The light source should be behind the observer during daylight hours. 3. The light source should be behind the emission during hours of darkness. 4. The observer position should be at approximately right angles to wind direction and at a distance no less than twice the height of the source but not more than a quarter mile from the base of the source. 5. Emissions from unconfined abrasive blasting shall be read at the densest point in the plume, which point shall be at least 25 feet from the source. 12-2 6. Where the presence of uncombined water is the only reason for failure to comply with opacity limits, the opacity limits shall not apply. The burden of proof in establishing that opacity limits shall not apply shall be upon the operator. 7. Emissions from unconfined abrasive blasting employing multiple nozzles shall be evaluated as a single source unless it can be demonstrated by the operator that each nozzle, evaluated separately, meets the requirements of this rule. 8. Emissions from confined abrasive blasting shall be read at the densest point after the air contaminant leaves the enclosure. The website addresses for obtaining information on fugitive dust regulations for local air quality districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • San Joaquin Valley APCD, CA: valleyair.org/SJV_main.asp • South Coast AQMD, CA: aqmd.gov/rules • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/aq 12.4 Compliance Tools Compliance tools assure than the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Maricopa County Rule 312 states that as a minimum each owner or operator subject to this rule shall keep the following records onsite for at least 5 years at permitted Title V 12-3 sources and for at least 2 years at Non -Title V sources: (a) the type and amount of solid abrasive material consumed on a monthly basis, including the name of the certified abrasive used, as applicable; and (b) Material Safety Data Sheets (MSDS) or results of any lead testing that was performed on paint that is to be removed via unconfined blasting, as applicable. In addition if blasting operations occur daily or are a part of a facility's primary work activity, then records shall be kept of the blasting equipment including a description of the type of blasting (e.g., confined, unconfined, sand, wet, etc.), the location of the blasting equipment or specify if the equipment is portable, a description of the emission control system (ECS) associated with the blasting operations, the days of the week blasting occurs, and the normal hours of operation. If blasting operations occur periodically, then records shall be kept of the dates the blasting occurs, the blasting equipment that is operating including a description of the type of blasting, and a description of the ECS associated with the blasting operations. 12.5 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for abrasive blasting operations. A sample cost-effectiveness calculation is presented below for a specific control measure (fabric filtration used to capture particulates from sand blasting of mild steel) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for abrasive blasting, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost- effectiveness and feasibility characteristics is identified. Sample Calculation for Sand Blasting of Mild Steel Step 1. Determine source activity and control application parameters. Silica sand abrasive use (tons/year) Control Measure Control application/frequency Economic Life of Control System (yr) Control Efficiency (Reference) 10 Fabric Filter Continuous 10 95% (AP -42) The amount of abrasive material used on a yearly basis and the economic life of the control system are assumed values for illustrative purposes. A fabric filter filtration system has been chosen as the control measure for reducing fugitive dust emissions from abrasive blasting of mild steel. Step 2. Obtain Uncontrolled PM Emission Factors. The uncontrolled PM10 and PM2.5 emission factors for sand blasting of mild steel published in AP -42 are 26 lb/ton of abrasive and 2.6 lb/ton of abrasive. Step 3. Calculate Uncontrolled PM Emissions. The annual uncontrolled PM emissions are calculated by multiplying the PM emission factors by the amount of abrasive material used per year divided by 2,000 lb/ton to produce emission estimates in tons per year, as follows: 12-4 • Annual PM10 Emissions = (26 lb/ton x 10 tons/year) / 2,000 lb/ton = 0.13 tons • Annual PM2.5 Emissions = (2.6 lb/ton x 10 tons/year) / 2,000 lb/ton = 0.013 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). For this example, fabric filters with a control efficiency of 95%% has been selected as the control measure. Thus, the annual controlled PM10 and PM2.5 emissions estimates are calculated to be: Annual Controlled PM10 emissions = (0.13 tons) x (1 — 0.95) = 0.0065 tons Annual Controlled PM2.5 emissions = (0.013 tons) x (1 — 0.95) = 0.00065 tons Step 5. Determine Annual Cost to Control PM Emissions. Capital costs ($) Annual operating and maintenance costs ($) Annual Interest Rate Capital Recovery Factor Annualized Cost ($/yr) 10,000 1,000 3% 0.12 2,200 The capital costs, annual operating and maintenance costs, and annual interest rate (AIR) are assumed values for illustrative purposes. The Capital Recovery Factor (CRF) is calculated from the Annual Interest Rate (AIR) and the Economic Life of the control system, as follows: CRF = AIR x (1+AIR) Economic life / (1+AIR) Economic life— CRF =3%x(1+3%)1°/(1+3%)f°-1 =0.1172 The Annualized Cost is calculated by adding the product of the Capital Recovery Factor (CRF) multiplied by the Capital costs to the sum of the operating and maintenance costs, as follows: Annualized Cost = (CRF x Capital costs) + Operating and Maintenance costs Annualized Cost = (0.1172 x $10,000) + $1,000 = $2,172 Step 6. Calculate Cost-effectiveness. Cost-effectiveness is calculated by dividing the annualized cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions: Cost-effectiveness = Annualized Cost/ (Uncontrolled emissions — Controlled emissions) Cost-effectiveness for PM10 emissions = $2,172/ (0.13 - 0.0065) = $17,590/ton Cost-effectiveness for PM2.5 emissions = $2,172/ (0.013 - 0.00065) = $175,895/ton 12-5 12.6 References 1. USEPA, 1997. Abrasives Blasting, Section 13.2.6 of Compilation of Air Pollutant Emission Factors, September. 2. Muleski, G. E., and Downing, J., 2006. Control of Abrasive Blasting Emissions through Improved Materials, paper presented at the EPA 15th International Emission Inventory Conference, New Orleans, LA, May 16-18. 3. Maricopa County, 2003. Rule 312 - Abrasive Blasting, July 2. 4. South Coast AQMD, 1985. Rule 1140 — Abrasive Blasting, August 2. 12-6 Chapter 13. Livestock Husbandry 13.1 Emission Estimation Methodology 13-1 13.2 Demonstrated Control Techniques 13-2 13.3 Regulatory Formats 13-3 13.4 Compliance Tools 13-4 13.5 Sample Cost -Effectiveness Calculation 13-5 13.6 References 13-7 13.1 Emission Estimation Methodology This section was adapted from Section 7.6 of CARB's Emission Inventory Methodology. Section 7.6 was last updated in May 2004. AP -42 does not address livestock husbandry. Thus, the methodology adopted by the California Air Resources Board (CARB) is presented here as the primary emissions estimation methodology for this fugitive dust source category.' The CARB methodology only provides estimates of PM10 emissions from cattle feedlot and dairy operations. For each category, the emissions are calculated by multiplying a per animal emission factor by the population of each animal type. The livestock population is available from the US Department of Agriculture. Livestock emissions research is ongoing. CARB's PM10 emission factor for cattle feedlots is 28.9 lbs PM10/1000 head/day (i.e., 10.55 lb/head-year) based on a work performed by UC Davis.2 The corresponding PM10 emission factor for dairy cattle is 6.72 lbs PM10/1000 head/day (i.e., 2.45 lb/head- year) based on an emission factor of 4.4 lbs PM10/1000 lactating head/day, developed by Texas A&M.3 To make the Texas emission factor more California specific, it was multiplied by a scaling factor based on the ratio of the California feedlot PM10 emission factor to a Texas feedlot PM10 emission factor. This ratio is 29:19; thus, the scaling factor is 1.53. The PM10/TSP and PM2.5/PM10 ratios for this source category are 0.48 and 0.11, respectively. The CARB methodology is subject to the following assumptions: 1. Population data and residence time data adequately represent average animal population values for each county. 2. All animals within a single class produce the same emissions (e.g., dairy cows, calves, and heifers). 3. It is assumed that all dairies or feedlots produce the same PM10 emissions on a per -head basis. 4. For dairies, the baseline PM10 emission factor includes the effects of support stock such as calves and heifers. This is because the emissions testing included these animals within its analysis. 5. For feedlots, the baseline PM10 emission factor represents the population mix at a typical feedlot. 6. The method does not include emissions for animal waste composting or land application. 13-1 7. Due to insufficient temporal information, it is assumed that air emissions occur evenly throughout the year seven days a week and 24 hours a day. The San Joaquin Valley APCD has developed separate emission factors for different operations associated with dairies and cattle feedlots based on CARB's PM10 emission factors of 2.45 lb/head-year for dairies and 10.55 lb/head-year for cattle feedlots.4 These emission factors are shown in Table 13-1. Table 13-1. PM10 Emission Factors for Cattle Feedlot and Dairy Operations Source Category Operation PM10 Emission Factor Dairies Corral/Manure Handling 1.845 lb/head-yr (freestall) 4.6 lb/head-yr (open corral) Overall Management/Feeding 1.845 lb/head-yr (freestall) 4.6 lb/head-yr (open corral) Unpaved Road 0.369 lb/head-yr Unpaved Area 0.123 lb/head-yr Cattle Feedlots Pens/Manure Handling 7.94 lb/head-yr Overall Management/Feeding 0.53 lb/head-yr Unpaved Road 1.59 lb/head-yr Unpaved Area 0.53 lb/head-yr 13.2 Demonstrated Control Techniques CARB does not list any control measures for this fugitive dust source category. However, the San Joaquin Valley APCD (District) has been very proactive in identifying potential control measures for cattle feedlots and dairies. For example, fugitive dust emissions originating from the disturbance of dry and loose surface material (e.g., feed, bedding material, and manure) caused by animal movement and mechanical disturbances by vehicles can be controlled by sprinkling water on the surface of the open corral or pen, removing manure before it dries, using a layer of wood chips in dusty areas, housing dairy cattle in stalls with concrete floors rather than dirt floors, and adopting a feeding schedule when animals are less active. Wind blown fugitive dust originating from uncovered bulk materials can be controlled by applying water or chemical suppressants, covering the material with tarps or storing the material in enclosure, and erecting wind barriers. Since no data could be found in the literature on which to base a control efficiency factor for these practices, the District has conservatively assumed a minimal 10% control effectiveness. Control measures identified by the District for cattle feedlots and dairies are shown in Table 13-2. A list of control measures for cattle feedlots and dairies is available from the California Air Pollution Control Officers' Association's (CAPCOA) agricultural clearing house website (http://capcoa.org/ag_clearinghouse.htm). Control measures for unpaved roads and unpaved parking/traffic areas include application of chemical dust suppressants, paving the surface or placing a layer of gravel over the unpaved surface, speed reduction, access restriction, and track out control measures. These control measures and their associated control efficiencies are listed in Chapter 6 of the handbook. Control measures for storage piles of bulk materials other than manure include dust suppressants, watering, covering and wind barriers. These 13-2 control measures and their associated control efficiencies are listed in Chapter 9 of the handbook. Table 13-2. Control Measures for Cattle Feedlots and Dairiesa Source Category Control Measure Manure management Frequent manure removal (every 6 months) with equipment that leaves an evenly corral surface of compacted manure on top of the soil. Insert lie manure directly beneath the soil. Dust entrainment by animal Daily water sprinkling, and timing of watering around 6PM or before sunset Use of freestalls with concrete surface for animal housing/feeding areas to allow frequent manure removal. Stocking density adjustment in accordance to the moisture found in the unit area to reduce dust. Removal of loose material on surface and maintain a compacted layer of manure 1 to 2 inches thick. Addition of fibrous material such as wood chips to working pens. Delaying the last daily feeding to reduce end -of -day spike in livestock activity. Other Adding moisture to hay Using a totally enclosed delivery system and covered feeders, and using palletized feed. Planting rows of vegetation around a building to create a barrier for air exiting from the building. a Since no data could be found in the literature on which to base a control efficiency factor for these practices, the SJVAPCD has conservatively assumed a minimal 10% control effectiveness for each control measure. 13.3 Regulatory Formats Fugitive dust control options have been embedded in many regulations for state and local agencies in the WRAP region. However, most air quality districts currently exempt agricultural operations from controlling fugitive dust. Air quality districts that regulate fugitive dust emissions from agricultural operations include Clark County, NV and several districts in California such as the Imperial County APCD, the San Joaquin Valley APCD and the South Coast AQMD. Imperial County APCD prohibits fugitive dust emissions from farming activities for farms over 40 acres. The San Joaquin Valley APCD and the South Coast AQMD prohibit fugitive dust emissions for the larger farms defined as farms with areas where the combined disturbed surface area within one continuous property line and not separated by a paved public road is greater than 10 acres. SJVAPCD's Rule 4550 applies to animal feeding operations (AFOs) that house animals for a total of at least 45 days in any 12 month period for agricultural parcels exceeding 100 acres excluding the AFO. Example regulatory formats downloaded from the Internet for several local air quality agencies in the WRAP region are presented in Table 13-3. CAPCOA's agricultural clearing house website (http://capcoa.org/ag_clearinghouse.htm) provides links to rules of different air quality agencies that regulate fugitive dust emissions from agricultural operations. The website addresses for obtaining information on fugitive dust regulations for local air quality 13-3 districts within California, for Clark County, NV, and for Maricopa County, AZ, are as follows: • Districts within California: www.arb.ca.gov/drdb/drdb.htm • San Joaquin Valley APCD, CA: valleyair.org/SJV_main.asp • South Coast AQMD, CA: aqmd.gov/rules • Clark County, NV: www.co.clark.nv.us/air_quality/regs.htm • Maricopa County, AZ: www.maricopa.gov/aq Table 13-3. Example Re ulatory Formats for Cattle Feedlots and Dairies Control Measure Agency Limit fugitive dust from animal feeding operations for facilities exceeding 100 acres excluding the AFO by requiring owner/operator to implement a Conservation Management Practice (CMP) Plan with district approved control methods. SJVAPCD Rule 4550 5/20/04 Limit fugitive dust from off -field agricultural sources such as unpaved roads with more than 75 trips/day and bulk materials handling by requiring producers to draft and implement a Fugitive Dust Management Plan with district approved control methods. SJVAPCD Rule 8081 9/16/04 Producers that voluntarily implement district approved conservation practices and complete and maintain the self -monitoring plan can maintain an exemption from the Rule 403 general requirements. SCAQMD Rule 403 4/02/04 Cease tilling/mulching activities when wind speeds are greater than 25 mph. SCAQMD Rule 403.1 4/02/04 Limit fugitive dust from paved and unpaved roads and livestock operations by ceasing all hay grinding activities between 2 and 5 PM if visible emissions extend more than 50 feet from a hay grinding source, and treating all unpaved access connections to livestock operations and unpaved feed lane access areas with either pavement, gravel (maintained to a depth of 4 inches), or asphaltic road -base. SCAQMD Rule 1186 4/02/04 Reduce fugitive dust from livestock feed yards by requiring that the moisture content in the top three inches of manure piles for occupied pens be maintained between 20% and 40%. This rule also outlines manure management practices, including removal. SCAQMD Rule 1186 4/02/04 Reduce fugitive dust from livestock feed yards by requiring that the moisture content for manure piles be maintained between 20% and 40%. ICAPCD Rule 420 8/13/02 13.4 Compliance Tools Compliance tools assure that the regulatory requirements, including application of dust controls, are being followed. Three major categories of compliance tools are discussed below. Record keeping: A compliance plan is typically specified in local air quality rules and mandates record keeping of source operation and compliance activities by the source owner/operator. The plan includes a description of how a source proposes to comply with all applicable requirements, log sheets for daily dust control, and schedules for compliance activities and submittal of progress reports to the air quality agency. The purpose of a compliance plan is to provide a consistent reasonable process for documenting air quality violations, notifying alleged violators, and initiating enforcement action to ensure that violations are addressed in a timely and appropriate manner. 13-4 Site inspection: This activity includes (1) review of compliance records, (2) proximate inspections (sampling and analysis of source material), and (3) general observations. An inspector can use photography to document compliance with an air quality regulation. On -site monitoring: EPA has stated that "An enforceable regulation must also contain test procedures in order to determine whether sources are in compliance." Monitoring can include observation of visible plume opacity, surface testing for crust strength and moisture content, and other means for assuring that specified controls are in place. Table 13-4 summarizes the compliance tools that are applicable for cattle feedlots and dairies. Table 13-4. Compliance Tools for Cattle Feedlot and Dairies Record keeping Site inspection/monitoring Maintain daily records to document the specific dust Observation of dust control options taken; maintain such records for a period plumes and dust plume of not less than three years; and make such records opacity (visible available to the APCO upon request. Submit a emissions) exceeding a Conservation Management Practice (CMP) Plan to the standard; observation of APCO listing the selected CMPs for implementation, contact information for the owner/operator, a site plan or map of the site. high winds (e.g., >25 mph). 13.5 Sample Cost -Effectiveness Calculation This section is intended to demonstrate how to select a cost-effective control measure for cattle feedlots and dairies. A sample cost-effectiveness calculation is presented below for cattle feedlots for a specific control measure (frequent scraping and manure removal) to illustrate the procedure. The sample calculation includes the entire series of steps for estimating uncontrolled emissions (with correction parameters and source extent), controlled emissions, emission reductions, control costs, and control cost-effectiveness values for PM10 and PM2.5. In selecting the most advantageous control measure for cattle feedlots and dairies, the same procedure is used to evaluate each candidate control measure (utilizing the control measure specific control efficiency and cost data), and the control measure with the most favorable cost-effectiveness and feasibility characteristics is identified. Sample Calculation for Cattle Feedlots Step 1. Determine source activity and control application parameters. Number of cattle at the feedlot 1,000 Control Measure Scraping and manure removal 13-5 Frequency of operations per year 2 Control Efficiency 10% Scraping and removal of manure from feedlot pens every six months has been chosen as the applied control measure. The number of cattle at the feedlot is an assumed value for illustrative purposes. Since no data could be found in the literature on which to base a control efficiency factor for control measures for cattle feedlots and dairies, the SJVAPCD has conservatively assumed a minimal 10% control effectiveness for each control measure (SVAPCD, 20044). Step 2. Obtain Uncontrolled PM10 Emission Factor. The uncontrolled PM10 emission factor for cattle feedlots is 10.55 lb/head/year (CARB, 20041). Step 3. Calculate Uncontrolled PM Emissions. The PM10 emission factor, EF, (given in Step 2) is multiplied by the number of cattle (see activity data) and then divided by 2,000 lb/ton to compute the annual PM10 emissions in tons per year, as follows: Annual PM10 emissions = (EF x Number of Cattle) / 2,000 Annual PM10 Emissions = (10.55 x 1,000) / 2,000 = 5.28 tons Annual PM2.5 emissions = (PM2.5/PM10) x PM10 emissions where the PM2.5/PM10 ratio for cattle feedlots is 0.11 (CARB, 2004'). Annual PM2.5 emissions = 0.11 x PM10 emissions Annual PM2.5 Emissions = (0.11 x 5.28 tons) = 0.58 tons Step 4. Calculate Controlled PM Emissions. The controlled PM emissions (i.e., the PM emissions remaining after control) are equal to the uncontrolled emissions (calculated above in Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency) For this example, we have selected frequent scraping and removal of manure as our control measure. Based on a control efficiency estimate of 10%, the annual controlled PM emissions are calculated to be: Annual Controlled PM10 emissions = (5.28 tons) x (1 — 0.10) = 4.75 tons Annual Controlled PM2.5 emissions = (0.58 tons) x (1 — 0.10) = 0.52 tons Step 5. Determine Annual Cost to Control PM Emissions. The SJVAPCD assumes that the cost for scraping and removal of manure is $3 per head.4 Thus, the annualized cost of scraping and removal of manure from feedlot pens holding 1,000 head of cattle every six months is calculated as follows: Annual Costs = Cost per head to remove manure x Head of Cattle x Frequency of Ops/year Annual Costs = $3/head x 1,000 head x 2/year = $6,000 Step 6. Calculate Cost-effectiveness. The cost-effectiveness is calculated by dividing the annual cost by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions from the uncontrolled emissions as follows: Cost-effectiveness = Annual Cost/ (Uncontrolled emissions — Controlled emissions) 13-6 Cost-effectiveness for PM10 emissions = $6,000 / (5.28 — 4.75) = $11,374/ton Cost-effectiveness for PM2.5 emissions = $6,000 / (0.58 — 0.52) = $103,404/ton Note: The actual cost-effeciveness values for this control measure are lower than the calculated values shown here since the SJVAPCD assumes that the control efficiency is at least 10%. 13.6 References 1. CARB, 2004. Livestock Husbandry, Section 7.6 of CARB's Emission Inventory Procedural Manual, Volume III: Methods for Assessing Area Source Emissions, May. 2. Flocchini, R.G., James, T.A., et. al., 2001. Sources and Sinks of PM10 in the San Joaquin Valley, Interim Report prepared by the Air Quality Group, Crocker Nuclear Laboratory, University of California, Davis. August 10. 3. Goodrich, L.B., Parnell, C.B., Mukhtar, S., Lacey, R.E., Shaw, B.W., 2002. Preliminary PM10 Emission Factor for Freestall Dairies, Department of Biological and Agricultural Engineering, Texas A&M University, paper presented at the 2002 ASAE Annual International Meeting, Chicago, IL, July 28-31. 4. SJVAPCD, 2005. Emission Reduction Calculation Methodology for Dairies and Feedlot Conservation Management Practices, Draft Report prepared by San Joaquin Valley APCD, November 24. 13-7 Chapter 14. Miscellaneous Minor Fugitive Dust Sources 14.1 Introduction 14-1 14.2Windblown Dust from Unpaved Roads 14-1 14.3Uncovered Haul Trucks 14-3 14.4Unpaved Shoulders 14-3 14.5Leaf Blowers 14-4 14.6Explosives Detonation 14-5 14.7References 14-5 14.1 Introduction This Chapter identifies emission estimation methods for several minor fugitive dust source categories not addressed in other chapters of the handbook. Because several of these methods have not been approved by federal or state agencies, the reader is cautioned in the use of the emission factors included in these emission estimation methods. The emission estimation methods discussed here address: • windblown dust from unpaved roads • uncovered haul trucks, • unpaved shoulders, • leaf blowers, and • explosives detonation. 14.2 Windblown Dust from Unpaved Roads The California Air Resources Board adopted the U.S. EPA -modified version of the USDA-ARS derived wind erosion equation (WEQ) used to estimate windblown dust from agricultural fields to estimate windblown dust from unpaved roads2 as follows: Es=aIKCL'V' (1) where, Es = the quantity of unpaved road dust entrained to the air by wind erosion (tons TSP/acre/year) a = portion of total roadway wind erosion losses that are assumed to be suspended into the air; estimated to be 0.038 for TSP I = soil erodibility (tons/acre/year) K = surface roughness factor (dimensionless) C = climatic factor (dimensionless) L' = unsheltered width factor (dimensionless) V' = vegetative cover factor (dimensionless) In summary, the 'I' term in the windblown dust equation provides an estimate of the soil erosion from an area that is large, flat, bare, and highly erodible. The additional terms in the equation reduce emissions from this worst -case scenario. The climatic, C, factor helps to account for regional differences in wind and rainfall. If a surface is rough, as represented by K, soil erosion is decreased. If the length of the erodible area parallel to the wind is short, then the erosion is decreased, as represented by the L' factor. If there is crop residue on the erodible area, then erosion is further decreased by the V' factor. A detailed discussion of the parameters I, K, C, L', and V' is presented in Chapter 7 of the Handbook. Soil Erodibility —I. The soil erodibility, I, of an unpaved road is related to the soil type of the road surface. Because roadway soil types are not readily available, the county specific, average soil types are used to estimate the erodibility. The county soil types are computed using a geographic information system (GIS) to average detailed county soil profile maps provided by the Natural Resources Conservation Service. This approach 14-1 assumes that unpaved road surfaces have the same soil characteristics as the base soils in the vicinity of the roadway. Climatic Factor - C. The rate of soil erosion varies directly with the wind velocity and inversely with the soil surface moisture. The climatic factor is used to adjust for these parameters. CARB staff computed the county 'C' factors based on regional rainfall and wind speed data measured in California. Surface Roughness - K. Surface roughness can help to reduce soil erosion. The 'K' factor is used to account for ridges or furrows that help to minimize wind related erosion. Because most unpaved roads are flat, the surface roughness factor is assumed to be 1.0, indicating no reduction in emissions due to surface texture. Unsheltered Width Factor - L'. Soil erosion is directly related to the unprotected width of the area in the prevailing wind direction. For unpaved roads, depending on the wind direction, the width of the erosive area parallel to the wind direction could be very narrow, very long, or somewhere in between. CARB assumes that the wind direction is equally distributed for all roads and that the average value of L' is 0.32. Vegetative Cover Factor - V'. Vegetative cover reduces soil erosion. For unpaved roads, it is assumed that there is no vegetative cover, therefore a value of 1.0 is used. Based on analysis of resuspended California soil samples, CARB estimated that the PM 10/TSP ratio for windblown dust from unpaved roads is 0.5. Windblown dust emissions from unpaved roads are calculated for each county by multiplying the PM10 emission rate (i.e., 50% of the TSP emission rate calculated from the TSP emission factor equation, Equation 1) by the unpaved road mileage and the average width of the unpaved roads assumed to average 20 feet. CARB's estimates does not include windblown dust from agricultural unpaved roads since they assume that windblown emissions from agricultural unpaved roads are included in the source category for windblown dust from agricultural lands. The CARB methodology is subject to the following assumptions and limitations: 1. It is assumed that the unpaved road soil characteristics are approximately the same as the soils in the vicinity of the unpaved road that are not used for vehicular travel. This implies that no additional gravel or other treatments have been applied to the unpaved roads. It is assumed that the soil wind erosion equation may be reasonably applied to estimate windblown dust from unpaved roads. Because of the large differences between unpaved road surfaces and agricultural lands, the validity of this assumption is questionable. 3. Using the soil erosion equation, it is assumed that 3.8% of the total eroded material is entrained to the air. (`a' factor = 0.038). 14-2 4. It is assumed that the county average soil erodibility, 'I', and climatic, 'C', factors are representative (on average) of the overall county conditions. 5. It is assumed that a value of 0.32 for the unsheltered width factor, L', is valid. 6. It is assumed that unpaved roads have no vegetative cover and are essentially flat. 7. The typical unpaved road width is 20 feet. 8. This methodology assumes no extraordinary windstorm activity; only average annual conditions are estimated. CARB is aware that their methodology for estimating windblown dust from unpaved roads is built on a foundation of dubious assumptions. Because of the differences between unpaved roads and agricultural lands, it is unlikely that the agricultural soil erosion equation provides very accurate estimates of windblown road dust. The emissions estimates could be improved by performing wind tunnel tests on unpaved roads, and then extrapolating the resulting emission factors to the remainder of the State. With the use of geographic information systems, it is also possible to incorporate localized climatological and soil texture properties into the emission estimates. In addition, the mileage of unpaved roads could be improved using available digital maps which include public, as well as private unpaved roads. 14.3 Uncovered Haul Trucks A total suspended particulate (TSP) emission factors for uncovered haul trucks was included in a USEPA report published in 1989.3 The hourly TSP emission estimate for uncovered haul trucks was estimated from the following equation: TSP (1b/yd2/hour) = 0.00015 u where, u = sum of wind speed and vehicle speed (mph) To estimate PM10 and PM2.5 emissions, PM 10/TSP and PM2.5/TSP ratios will need to be obtained for this source category. 14.4 Unpaved Shoulders DRI developed a PM10 emission factor for the resuspension of fugitive dust from unpaved shoulders created by the wake of high -profile vehicles such as tractor -trailers (semis) traveling on paved roads at high speed (50-65 mph).4 The emission factor for unpaved shoulder with surface loadings of 4,500 to 5,500 g/m2, silt content of 3 to 6%, and a surface moisture content under 1% was given as: EF = 0.028 + 0.014 lb/VMT DRI concluded that emissions from unpaved shoulders due to smaller vehicles such as cars, vans and SUVs were negligible. It should be pointed out that the PM10 14-3 emissions were estimated utilizing nephelometers that are not quantitative for coarse particles. Thus, PM10 emissions maybe underestimated. 14.5 Leaf Blowers Dennis Fitz and other researchers from CE-CERT at UC Riverside recently completed a study on behalf of the San Joaquin Valley APCD to determine PM2.5 and PM10 emissions from leaf blowing/vacuuming, raking and sweeping activities.5 Real- time PM2.5 and PM10 measurements were obtained with DustTrak aerosol monitors calibrated against Arizona road dust (NIST SRM 8632). The precision of the DustTrak PM2.5 and PM10 measurements were determined to be 19% and 27%, respectively, based on collocated DustTrak monitors. The accuracy of the DustTrak measurements was determined by comparing the DustTrak measurements to the filter -based measurements. In general the two data sets agreed to within 50%, which was similar to the variability between replicate tests. The PM2.5 and PM10 emission factors determined by DustTrak monitors for different cleaning activities and surfaces are summarized in Table 14-1. The DustTrak results for blowing leaves on asphalt and concrete surfaces as a function of power blower type are presented in Table 14-2. Table 14-1. PM Emission Factors for Leaf Blowinracuuming, Raking and Sweeping Activities (mg/m ) Cleaning Action and Surface Cleaned PM2.5 PM10 Power blowing/vacuuming over concrete surfaces 30 80 Power blowing/vacuuming over asphalt surfaces 20 60 Push broom to sweep asphalt surfaces 0 20 Push broom to sweep concrete surfaces 20 80 Raking asphalt surfaces 0 0 Raking on concrete surfaces 0 0 Raking lawns 0 1 Power blowing on lawns 1 2 Power blowing from gutters 9 30 Power blowing on packed dirt 80 120 Power blowing cut grass on walkways 2 6 Table 14-2. PM Emission Factors by Power Blower Type and Surface (mg/m2) Power Blower Type Surface PM2.5 PM10 Electric Asphalt 20 60 Gas Hand Held Asphalt 10 40 Gas Backpack Asphalt 20 60 Electric: vacuum mode Asphalt 40 120 Electric: vacuum mode, full bag Asphalt 20 70 Electric Concrete 40 130 Gas Hand Held Concrete 10 40 Gas Backpack Concrete 30 70 Electric: vacuum mode Concrete 30 80 14-4 14.6 Explosives Detonation Emissions from the detonation of industrial explosives and firing of small arms (excluding military operations) are addressed in Section 13.3 of AP -42.6 This section of AP -42 was last updated in February 1980 (and reformatted in January 1995). Such large quantities of particulate are generated in the shattering of rock and earth by the explosive that the quantity of particulates from the explosive charge cannot be distinguished. With the exception of a few studies in underground mines, most studies have been performed in laboratory test chambers that differ substantially from the actual environment. Any estimates of emissions from explosives use must be regarded as approximations that cannot be made more precise because explosives are not used in a precise, reproducible manner. 14.7 References 1. USEPA, 1974. Development of Emission Factors for Fugitive Dust Sources, EPA 450/3-74-037, U.S. EPA, Research Triangle Park, NC, June; updated in September 1988 in Control of Open Fugitive Dust Sources, EPA -450/3-88-008. 2. CARB, 1997. Windblown Dust — Unpaved Roads, Section 7.13 in: CARB's Emission Inventory Procedural Manual, Volume III: Methods for Assessing Area Source Emissions. 3. USEPA, January 1989. Air/Superfund National Technical Guidance Study Series; Volume III — Estimation of Air Emissions from Cleanup Activities at Superfund Sites, Interim final report EPA -450/1-89-003. 4. Moosmuller, H., Gillies, J.A., Rogers, C.F., Dubois, D.W., Chow, J.C., Watson, J.G., Langston, R., 1998. Particulate Emission Rates for Unpaved Shoulders along a Paved Road, J.AWMA 48:3198. 5. Fitz, D., et al., 2006. Determination of Particulate Emission Rates from Leaf Blowers, paper presented at the USEPA 15th International Emission Inventory Conference, New Orleans, LA, May 24. 6. USEPA, 2006. Compilation of Air Pollutant Emission Factors, AP -42 Section 13.3 (Explosives Detonation), Fifth Edition. 14-5 GLOSSARY Areal extent —Fraction (or percentage) of the source area that is affected by the control measure. Aerodynamic particle size —Diameter of a sphere of unit density, which behaves aerodynamically as a particle with different sizes, shapes, and densities. Aggregate material —Mineral particles, such as sand or stone, typically derived from a mechanical process. Agricultural tilling —Mechanical disturbance of agricultural soil by discing, shaping, chiseling, and leveling using a tractor or implement. Annual interest rate —The yearly cost of borrowing money, expressed as a percentage of the amount borrowed. Annualized cost of control —Average yearly costs of a control system including annual operating costs such as labor, materials, utilities and maintenance items, and annualized costs of the capital costs of purchase and installation. Annualized costs are dependent on the interest rate paid on borrowed money or collectable by the plant as interest (if available capital is used), the useful life of the control equipment, and depreciation rates of the equipment. AP -42 ---Abbreviation for the U.S. EPA's publication "Compilation of Air Pollutant Emission Factors." BACM—Abbreviation for Best Available Control Measures —techniques that achieve the maximum degree of emissions reduction from a source, as determined on a case - by -case basis considering technological and economic feasibility. Bare soil adjustment —Adjustment to windblown emissions for the planted acreage on which plants do not establish. Base year —Year for which the pre -control emissions inventory was performed. Baseline Emissions —Emissions (total or source) in the base year. Batch drop —Materials handling process involving free fall of aggregate, as from a bucket. Border adjustment —Adjustment to windblown emissions for the nonplanted regions of the acreage dedicated to a given crop that separate it from surrounding regions. CAPCOA—Acronym for California Air Pollution Control Officers' Association. 1 Capital recovery factor —Amount of money per dollar of machinery investment required to pay annual interest costs on unrecovered investment and to recover the costs of the investment within a specified number of years at the given interest rate. Chemical wetting agent —Compound added to water in order to enhance the penetration of water into dusty material and prevent dust emissions. Clay —Cohesive soil with individual particles not visible to the unaided human eye (less than 0.002 mm in diameter). Clay can be molded into a ball that will not crumble. Climatic factor "C," annual —Parameter used to estimate the effects of climate on soil erodibility. Garden City, Kansas is set to 1.0 and temperature, wind, and precipitation are used to adjust the factor. Climatic factor "C," monthly —Parameter used to modify the annual "C" factor equation for a particular month of the year. The U.S. EPA uses mean monthly wind speed in place of the annual wind speed. The ARB methodology uses the month -as - a -year method. Cloddiness—Level of relatively stable agglomerations in soil caused by exposure to water cohort (maturation class). Compliance tool —Means for checking whether a facility is meeting legal requirements for control of a pollutant. Compliance tools include record keeping logs, databases, and site inspection methods. Continuous drop —Materials handling process involving continual release of aggregate, such as from a conveyor. Control application rate/frequency—Amount of pollutant suppressant applied over a particular area and the number of times per period that the suppressant is applied. Control efficiency —Degree (e.g., percentage) to which a control measure is effective in limiting the release of a pollutant. Control efficiency decay rate —Decrease in control efficiency for a control measure with a limited life span. Control extent —Fraction of emissions from a source category that will be affected by a control method. Control measure —Procedure or course of action taken to reduce air pollution. Preventive measures reduce source extent or incorporate process modifications or adjust work practices to reduce the amount of pollutants. Mitigative measures involve the periodic removal of pollutant causing materials, such as the cleanup of 2 spillage on travel surfaces and cleanup of material spillage at conveyor transfer points. Controlled emissions —Estimated emissions (total or by source category) after application of control measures, i.e., remaining emissions. Cost effectiveness— Control cost divided by the mass of emissions reduced (most typically expressed in terms of "dollars per ton"). Crop calendar —Temporal distribution of agricultural activities (e.g., planting and harvesting dates). Crop canopy cover factor —Adjustment to windblown emissions based on the crop canopy cover. Crop canopy cover —Fraction of land sheltered by vegetation, as viewed directly from above. Crust —The hard outer surface of soil (or other dust producing material) that inhibits the wind erosion of underlying fine particles. Cut and fill —The activities of earthmoving equipment where soil or rock is removed from one area (cut) and deposited elsewhere on shallow ground (fill). De Minimis source —Facility or operation with emissions that are below a certain threshold, classifying them as insignificant sources of emissions; refer to 40 CFR, Part 52 for more details. Demonstrated control technique —A control measure that is supported by verifiable tests as to the control efficiency the measure will achieve. Deposition —Accumulation of airborne particles on ground -level surfaces through gravitational settling and other physical phenomena. Disturbance —Destabilization of a land surface from its undisturbed natural condition thereby increasing the potential for fugitive dust emissions. Dunes —Ridges or mounds of loose, wind-blown material, usually sand. Dust —Fine, dry particles of matter able to be suspended in the air. Dust Control Plan —Legally mandated plan for a geographical area or dust -producing operation that identifies how emissions will be controlled to attain the requirements of the Clean Air Act and Amendments. 3 Dust suppressants —Water, hygroscopic materials, solution of water and chemical surfactant, foam, or non-toxic chemical/ organic stabilizers not prohibited for use by the U.S. Environmental Protection Agency or any applicable law, rule or regulation, as a treatment material to reduce fugitive dust emissions. Economic Life —Length of time during which a product or piece of property may be put to profitable use. (Usually less than its physical life) Emission activity level —A numerical measure of the intensity of a process that emits pollutants (e.g., miles traveled by a vehicle, tons of transferred material). Also referred to as source extent or process rate. Emission factor —A representative value that relates the quantity of a pollutant released to the atmosphere with an activity associated with the release of that pollutant. These factors are usually expressed as the weight of pollutant divided by a unit weight, volume, distance, or duration of the activity emitting the pollutant. Emission parameters —Values that affect pollutant emissions, such as moisture level and silt content of the emitting material. Emission reduction —Amount (mass or percent) of emissions eliminated by control application. Enforcement/Compliance costs —Expenses associated with enforcing control measures, including government agency and source facility expenditures. Erosion potential —Value representing the potential for suspension of surface dust by wind erosion. Depending on the presence of a surface crust or surface disturbance, particle size distribution, and moisture content, a site is characterized as having 1) unlimited erosion potential, 2) limited erosion potential, or 3) no erosion potential. Fastest mile of wind —The highest wind speed over a specified period (usually the 24 - hour observational day) of any "mile" of wind. The fastest mile of wind is the reciprocal of the shortest interval (in 24 hours) that it takes one mile of air to pass a given point. Fetch —Distance over which soil is eroded by a wind having a relatively constant direction and speed. Friction velocity —Measure of shear stress of the wind on the exposed surface of soil or other aggregate material, causing loose particles to be lifted from the surface. Fugitive dust source —Emitter of airborne particles where the particulate emissions cannot reasonably be passed through a stack, chimney, vent, or other functionally equivalent opening. Fugitive dust sources include roadways, construction 4 (earthmoving and demolition), material handling operations, soil tillage, and wind erosion. Gravel —Soil particles ranging from 1/5 inch to 3 inches in diameter. Grid counting method —Method used to estimate areas contained between contour lines on maps. Ground inventory —A measurement of the amount of dust suppressant applied to an unpaved surface, usually expressed as gallons of suppressant per square yard of road surface. Growing canopy fraction (GCF)—The proportion of the acreage that will have the crop canopy cover factor applied to it. Half life of control —The time required for control efficiency to fall to half its initial value. Irrigation factor (wetness) —Adjustment to the erodibility due to surface wetness from irrigation. Long-term irrigation -based erodibility adjustment —Adjustment that takes into account changes in cloddiness of the soil, based upon differences between irrigated and nonirrigated soils. Material throughput —Output rate of processed material. Mitigative control —Control measure that periodically removes exposed dust -producing material. MOBILE model —Software tool developed by EPA to predict gram per mile emissions of hydrocarbons, carbon monoxide, oxides of nitrogen, carbon dioxide, particulate matter, and toxics from cars, trucks, and motorcycles under various conditions. Mode —The most frequent value in a group of values. The approximate mode of a particle size distribution (i.e., particle size diameter) can be found by sieving a surface material sample to find the threshold friction velocity using a modification to W.S. Chepil's method. Moisture content —A measurement, usually expressed as a percent, of the mass of water in a material sample. Moisture content is obtained by weighing the original sample and then drying the sample to obtain the mass of vaporized water. Month -as -a -year —Term used by California Air Resources Board (ARB) staff to describe method of calculating the climatic "C" factor profile by assuming that each month's data for a given site describes a unique annual climatic regime. 5 Most cost -effective —Having the lowest cost per mass of PM emissions reduced. Most efficient —Having the highest control efficiency (note that preventive controls are usually addressed before mitigative controls). Mulch —Any material used to cover a soil surface to conserve soil moisture and prevent erosion. Nonattainment area —Geographic area that is not in compliance with federal health - based air quality standards for an air pollutant (e.g., PM -10). Nonerodible material —Objects larger than 1 centimeter in diameter that are not susceptible to movement even on windy days (e.g., gravel, hard -packed soil clods). Operating/Maintenance costs —Expenses associated with personnel, materials, consumables, equipment repair, and other types of continuing expenses. Overhead costs —A broad category of costs associated with administration. Pan evaporation rate —The rate of evaporation from a US Class -A pan that is filled with water, with daily measurements made of the water level to compute the resulting daily water loss. Peak wind gust —A maximum wind speed defined by U.S. weather observing practice, with gusts reported when the peak wind speed reaches at least 16 knots and the variation in wind speed between the peaks and lulls is at least 9 knots. The duration of a gust is usually less than 20 seconds. Plant/harvest date pair —Methodology that uses planting cohorts split between harvest months, using the fraction of the total crop planted in a given month with the fraction of the total crop harvested in a given month. PMx—Airborne particulate matter with aerodynamic diameters equal to or less than x gm (e.g. PMl0, PM2.5) Portable wind tunnel —Moveable air channel with an open bottom through which air is drawn at different velocities. This type of wind tunnel with a backend sampling system is used to investigate particle emissions by wind erosion, as a function of wind speed. Postharvest soil cover factor —Adjustment to windblown emissions based on the fraction of land covered after harvest when viewed directly from above. 6 Precipitation effectiveness (PE) —See "Thornthwaite's precipitation -evaporation index"; the sum of 12 monthly values (ratios of precipitation to actual evapotranspiration). Preventive control —Control measure that inhibits or minimizes the accumulation of exposed dust -producing material. Prewatering—Application of water during construction and earthmoving operations to excavation areas and borrow pits before earth is excavated. The areas to be excavated are moistened to the full depth from the surface to the bottom of the excavation to achieve an optimum moisture content for fugitive dust control. Quality rating —An assessment level of A through E as assigned by EPA to each emission factor in AP -42, with A being the best. A factor's rating is a general indication of the reliability, or robustness, of that factor. Replant -to -different -crop factor —Adjustment to windblown emissions for harvested acreages that are quickly replanted to a different crop. Reservoir —Amount of surface particles available for sustaining wind erosion. Surface soil properties determine the duration of dust events, and limited reservoirs will emit dust for a shorter duration of time (i.e., minutes) than unlimited reservoirs (i.e., days). Revegetation—Vegetative cover that has been established on previously disturbed ground, such as a construction site. Revised Wind Erosion Equation (RWEQ)—Model that is intermediate in complexity between the wind erosion equation (WEQ) and the wind erosion prediction system (WEPS). Rock —Soil particles greater than 3 inches in diameter. Roughness height —Height above ground level where the wind speed is theoretically reduced to zero because of surface obstructions; a measure of surface protrusion into the boundary layer wind flow. Sand —Soil particles ranging from 0.05 to 2.0 mm in diameter; individual particles are visible to the unaided human eye. Senescence —Process of plant aging and dying that is characterized by decreasing growth rates, chlorophyll breakdown, and mobilization of nitrogen out of leaves and into other plant organs. Sheltering elements —Blockages to wind that inhibit wind erosion of soil. Examples include wind fences and trees. 7 SIC code —Abbreviation for Standard Industrial Classification code. A numbering system established by the Office of Management and Budget that identifies companies by industry. Sieving —Process of passing a material through a series of woven square meshes of decreasing size to separate particles into different particle size classes. For agricultural soil classification, wet sieving disperses the material in a liquid before passing the suspension through one or more sieves. Dry sieving is used to characterize material dustiness levels and can be performed either by a mechanical sieve shaker or by rotational hand sieving. Silt content —Percentage of particles less than 74 µm in physical diameter (i.e., fraction passing a standard 200 -mesh sieve). Silt—Noncohesive soil whose individual particles are not visible to the unaided human eye (0.002 to 0.05 mm). Silt will crumble when rolled into a ball. Soil classes (types) —Classifications used by soil scientists: representative erodibilities have been measured, which allow soil maps to be used to estimate erodibilities for agricultural land. Soil cover deterioration —Reduction in postharvest soil cover due to the effects of weather, sunlight, insects, microbes, etc. Soil loss ratio (SLR) —The ratio of the soil loss for a soil of a given cover divided by the soil loss from bare soil. Soil texture —The relative proportions of clay, silt, and sand in soil. Soil —Surface material consisting of disintegrated rock and organic material. Source Extent —See "Emission activity level.' State Geographic Data Base (STATSGO)—Database of soil data produced and maintained by the NRCS. Stepwise linear regression —Process of determining best -fit polynomials for a predictive mathematical model. The procedure involves least squares regression analysis in a forward stepping procedure Surface disturbance —See "Disturbance." Surface loading —Mass of loose material per paved road surface area. Total surface loading is measured by vacuuming a known area of paved road surface to obtain all material regardless of particle size. Silt surface loading is obtained by sieving the 8 total surface loading and refers only to particles with physical diameters less than 74 µm. Surface stabilization/treatment/improvement—The paving, graveling, chemical stabilization, or watering of a dust -emitting surface to prevent dust emissions due to mechanical disturbance and wind erosion. Thornthwaite's precipitation -evaporation index —A measure of soil aridity, calculated as the ratio of precipitation to evapotranspiration. Threshold friction velocity —Friction velocity that closely corresponds to the threshold wind speed for wind erosion of a specific surface. See "Friction velocity." Threshold source size —An emission level below which a facility or dust -emitting activity is not regulated. Threshold wind speed —Wind speed (measured at a reference height of 10 m) below which wind erosion does not occur from the exposed surface being considered. Tillage —Practice of producing a soil surface to maintain surface residue, prepare a seed bed, conserve soil moisture, and reduce wind erosion. Trackout—Accumulation of mud/dirt on paved roads, as deposited by vehicles that exit unpaved sites such as construction areas, agricultural fields, quarries, dumps, or batch plants. Traffic volume —Measure of the number of vehicles traveling over a road segment. Vehicle miles traveled (VMT) on a road equals the average daily traffic (ADT) times the roadway length. Uncontrolled emissions —Total emissions before application of any control measures. Unit -operation emission factors —Emission factors that represent sub -processes or separate activities associated with an emission source. Vegetative cover/residue—Organic matter, either growing or dead, that protects the soil surface from the erosive force of wind. Visible dust —For regulatory purposes, means airborne particles that obscure an observer's view to a degree equal to or greater than a specified opacity limit. Wet stabilization/watering—See "Surface stabilization." Wind barrier/Wind sheltering —See "Sheltering element." 9 Wind erosion equation (WEQ)—Methodology originally developed to estimate wind erosion from agricultural lands. Later modified by U.S. EPA to use for estimating PM emissions. Wind Erosion Prediction System (WEPS)—Detailed simulation model to predict wind erosion emissions; currently in development. May be useful in future, especially for episodic modeling. Wind erosion —Removal of dry soil particles from the ground surface by wind, causing airborne particulate matter downwind of the emitting soil area. Wind shear —Force of wind parallel to a surface that can remove loose particles, as opposed to wind directly impacting the surface. Worst -case emissions —See "Uncontrolled emissions." 10 Appendix A Emission Quantification Techniques EMISSION QUANTIFICATION TECHNIQUES Fugitive dust emission rates and particle size distributions are difficult to quantify because of the diffuse and variable nature of such sources and the wide range of particle sizes, including particles that deposit immediately adjacent to the source. Standard source testing methods, which are designed for application to confined flows under steady-state, forced -flow conditions, are not suitable for the measurement of fugitive emissions unless the plume can be drawn into a forced -flow system. The available source testing methods for fugitive dust sources are described in the following paragraphs. Mechanical Entrainment Processes Because it is usually impractical to enclose open dust sources or to capture the entire emissions plume, only two methods are suitable for the measurement of particulate emissions from most open dust sources: 1. The upwind -downwind method involves the measurement of upwind and downwind particulate concentrations, utilizing ground -based samplers under known meteorological conditions, followed by a calculation of the source strength (mass emission rate) with atmospheric dispersion equations.' 2. The exposure -profiling method involves simultaneous, multipoint measurements of particulate concentration and wind speed over the effective cross section of the plume, followed by a calculation of the net particulate mass flux through integration of the plume profiles.2 In both cases it is customary to use high -volume air samplers, so that quantifiable sample mass can be accumulated in sampling periods no longer than about six hours. Upwind -Downwind Method. The upwind -downwind method involves the measurement of airborne particulate concentrations both upwind and downwind of the pollutant source. The number of upwind sampling instruments depends on the degree of isolation of the source operation of concern (i.e., the absence of interference from other sources upwind). Increasing the number of downwind instruments improves the reliability in determining the emission rate by providing better plume definition. In order to reasonably define the plume emanating from a point source, instruments need to be located at a minimum of two downwind distances and three crosswind distances. The same sampling requirements pertain to line sources except that measurements need not be made at multiple crosswind distances. Net downwind (i.e., downwind minus upwind) concentrations are used as input to atmospheric dispersion equations (normally of the Gaussian type) to back -calculate the particulate emission rate (i.e., source strength) required to generate the pollutant concentrations measured. Emission factors are obtained by dividing the calculated emission rate by the source extent. A number of meteorological parameters must be concurrently recorded for input to this dispersion equation. As a minimum, the wind direction and speed must be recorded on -site. A-1 While the upwind -downwind method is applicable to virtually all types of sources, it has significant limitations with regard to the development of source -specific emission factors. Because of the impracticality of adjusting the locations of the sampling array for shifts in wind direction during sampling, it may be questionable to assume that the plume position is fixed in the application of the dispersion model. In addition, the usual assumption that a line or area source is uniformly emitting may not allow for a realistic representation of spatial variation in source activity. Exposure -Profiling Method As an alternative to conventional upwind -downwind sampling, the exposure -profiling technique utilizes the emission profiling concept, which is the basis for the conventional ducted source testing method (i.e., USEPA Method 53), except that, in the case of exposure -profiling, the ambient wind directs the plume to the sampling array. The passage of airborne particulate matter immediately downwind of the source is measured directly by means of a simultaneous, multipoint sampling of particulate concentration and wind velocity over the effective cross section of the fugitive emissions plume. For the measurement of noibuoyant fugitive emissions using exposure profiling, sampling heads are distributed over a vertical network positioned just downwind (usually about 5 m) from the source. Particulate sampling heads should be symmetrically distributed over the concentrated portion of the plume containing at least 80% of the total mass flux. A vertical line grid of at least three samplers is sufficient for the measurement of emissions from line or moving point sources (see Figure A-1), while a two- dimensional array of at least five samplers is required for quantification of the fixed virtual point source of emissions. For quantifying emissions of particles larger than about 10 gm, the particulate samplers should have directional intakes, as discussed below. At least one upwind sampler must be operated to measure the background concentration, and wind speed and direction must be measured concurrently on -site. Figure A-1. Exposure Profiling Method —Roadway A-2 The particulate emission rate is obtained by a spatial integration of the distributed measurements of exposure (accumulated mass flux), which is the product of mass concentration and wind speed: where, R C u h w A R = JC(h,w)u(h,w)dhdw (1) A = emission rate, (g/s) net particulate concentration, (g/m3) wind speed, (m/s) vertical distance coordinate, (m) lateral distance coordinate, (m) effective cross-sectional area of plume, (m2) Usually, a numerical integration scheme is used to calculate the emission rate. This mass -balance calculation scheme requires no assumptions about plume dispersion phenomena. Isokinetic Sampling Regardless of which method is used, isokinetic sampling is required for a representative collection of particles larger than about 10 µm in aerodynamic diameter. The directional sampling intakes are pointed into the mean wind direction and the intake velocity of each sampler is periodically adjusted (usually with intake nozzles) to closely match the mean wind velocity approaching the sampling intake. Because of natural fluctuations in wind speed and direction, some anisokinetic sampling effects will always be encountered. If the angle a between the mean wind direction and the direction of the sampling axis equals 30°, the sampling error is about 10%.4 For an isokinetic flow ratio of sampling intake speed to approach wind speed between 0.8 and 1.2, the sampling error is about 5%.4 Wind Erosion The two wind erosion source testing methods of interest are the upwind -downwind method as described above and the portable wind tunnel method. The wind tunnel method involves the use of a portable open -floored wind tunnel for in situ measurement of emissions from representative surfaces under predetermined wind conditions.5 Upwind -Downwind Method The upwind -downwind method is burdened with practical difficulties for the study of wind erosion, in that the onset of erosion and its intensity is beyond the control of the investigator. In addition, background (upwind) particulate concentrations tend to be high during erosion events, making source isolation very difficult. Wind Tunnel Method The most common version of the wind tunnel method utilizes a pull -through wind tunnel with an open -floored test section placed directly over the surface to be tested. Air is drawn through the tunnel at controlled velocities. The exit air stream from the test section passes through a circular duct fitted with a directional sampling probe at the downstream end. Air is drawn isokinetically through the probe by A-3 a high -volume sampling train. The wind tunnel method incorporates the essential features of the USEPA Method 5 stack sampling method.3 The one prime difference, the use of single -point sampling, is justified by the high turbulence levels in the sampling module. The measurement uncertainty inherent in this method is of the same order as that in Method 5, which has been subjected to extensive collaborative testing by EPA. The wind tunnel method relies on a straightforward mass -balance technique for the calculation of emission rate. By sampling under light ambient wind conditions, background interferences from upwind erosion sources can be avoided. Although a portable wind tunnel does not generate the larger scales of turbulent motion found in the atmosphere, the turbulent boundary layer formed within the tunnel simulates the smaller scales of atmospheric turbulence. It is the smaller -scale turbulence, which penetrates the wind flow in direct contact with the erodible surface and contributes to the particle entrainment mechanisms.6 Particle Sizing Concurrent with the measurement of mass emissions, the aerodynamic particle size distribution should be characterized. Chemical, biological, and morphological analyses may also be performed to characterize the nature and origin of the particles. For particle sizing, a high -volume cyclone/cascade impactor featuring isokinetic sample collection has been used. A cyclone preseparator (or other device) is needed to remove the coarse particles, which otherwise would bounce off the greased substrate stages within the impactor, causing fine -particle bias. Once again, the sampling intake is pointed into the wind and the sampling velocity adjusted to the mean local wind speed by fitting the intake with a nozzle of appropriate size. This system offers the advantage of a direct determination of aerodynamic particle size. Another particle sizing option includes an analysis of the particulate deposit by optical or electron microscopy. Disadvantages include: (a) potential artificial disaggregation of particle clusters during sample preparation, and (b) uncertainties in converting physical size data to equivalent aerodynamic diameters. In a collaborative field test of the exposure -profiling method, the cyclone/impactor method was judged to be more suitable than microscopy for the particle sizing of fugitive dust emissions.8 Control Efficiency Estimation Field evaluation of the control efficiency requires that the study design include not only adequate emission measurement techniques but also a proven "control application plan." In the past, two major types of plans have been used. Under the Type -1 plan, controlled and uncontrolled emission measurements are obtained simultaneously. Under the Type -2 plan, uncontrolled tests are performed initially, followed by controlled tests. In order to ensure comparability between the operating characteristics of the controlled and uncontrolled sources, many evaluations are forced to employ Type -2 plans. An example would be a wet suppression system used on a primary crusher. One important exception to this; however, is unpaved -road dust control. In this instance, A-4 testing under a Type -1 plan may be conducted on two or more contiguous road segments. One segment is left untreated and the others are treated with the dust suppressant. Under a Type -2 plan, a normalization of emissions may be required to allow for potential differences in source characteristics during the uncontrolled and controlled tests because they do not occur simultaneously. References 1. 1. Kolnsberg, H. J., 1976. Technical Manual for the Measurement of Fugitive Emissions: Upwind/Downwind Sampling Method for Industrial Fugitive Emissions, EPA -600/2-76-089a, NTIS Publication No. PB253092. 2. 2. Cowherd, C. Jr., Axtell, K. Jr., Maxwell, C.M., Jutze, G.A., 1974. Development of Emission Factors for Fugitive Dust Sources, EPA Publication No. EPA -450/3-74-037, NTIS Publication No. PB-238 262. 3. 3. U.S. EPA, 1977. Standards of Performance for New Stationary Sources, Revision to Reference Methods 1-8, Federal Register, 18 August 1977, Part II. 4. 4. Watson, H. H., 1954. Errors due to Anisokinetic Sampling of Aerosols, Am. Ind. Hyg. Assoc. Quart., 15:2 1, 1954. 5. 5. Cuscino, T. Jr., Muleski, G. E., and Cowherd, C. Jr., 1983. Iron and Steel Plant Open Source Fugitive Emission Evaluation, EPA -600/2-83-110, NTIS Publication No. PB84-1 10568. 6. 6. Gillette, D. A.,1978. Tests with a Portable Wind Tunnel for Determining Wind Erosion Threshold Velocities, Atmos. Environ., 12:2309. 7. 7. Cowherd, C. Jr., Kinsey, J.S., Wallace, D.D., Grelinger, M.A., Cuscino, T.A., Neulicht, R.M., 1986. Identification, Assessment, and Control of Fugitive Particulate Emissions, EPA -600/8-86-023, NTIS Publication No. PB86- 2300083. 8. 8. McCain, J. D., Pyle, B. E., McCrillis, R. C., 1985. Comparative Study of Open Source Particulate Emission Measurement Techniques, in Proceedings of the Air Pollution Control Association Annual Meeting, Pittsburgh PA: APCA. A-5 Appendix B Estimated Costs of Fugitive Dust Control Measures Source Category Control Measure Estimated Costs Comments/Assumptions Paved Roads 4' Paved Shoulders $8,200/mile-year Useful life of 20 years Polymer emulsion to stabilize shoulders $0.92/square yard Purchase PM10 efficient sweeper $190/mile-year Useful life of 8 years; sweep 15 centerline miles per day Clean up spills $640/cleanup Unpaved Roads and Parking Areas Pave unpaved roads $44,100/mile-year Useful life of 25 years Pave section 100' long before facility exit $716/year 30' wide with 3" of asphalt; useful life of 25 years Pave unpaved parking lots $0.23/ft2-year Useful life of 25 years Pipe grid trackout control device $1,820/year Useful life of 8 years Gravel bed to reduce trackout $1,360/year 50' x 30' x 3" thick Post speed limit sign $53/year for two signs Useful life of 15 years Apply water to unpaved parking lot once a day $68-$81/acre-day Chemical dust suppressant $5,340/acre-year Useful life of 1 year Construction and Demolition Chemical dust suppressant $5,340/acre-year Useful life of 1 year Apply water once a day $68-$81/acre-day Apply water during high winds $272/acre Prohibit activities during high winds $1.360 per 8 hour day idled Demolition of 1,000 ft2 structure on 1.2 acres Require air quality monitoring $7,500/month Onsite dust control coordinator $100/day Sprinkler system to maintain minimum soil moisture of 12% $138/acre Limit speed to 15 mph $22/inspection Radar gun = $700 Post speed limit signs $180/sign Bulk Materials 3 -sided enclosure with 50% porosity $109/year Useful life of 15 years; pile volume = 5 yd3 Disturbed Open Areas Polymer emulsion dust suppressant $2,140/acre Surface stabilized for 3 years if no vehicle disturbance Gravel, 1" deep $490/acre-year Useful life of 15 years Post no trespassing signs $53/sign Useful life of 15 years Windblown Dust Prohibit activities at construction sites during high winds $3,100 per high wind day 40 acre construction site Water storage pile each hour during high winds $22/day 100 cubic yard pile Reference: Sierra Research, Inc., Final BACM Technological and Economic Feasibility Analysis, prepared for the San Joaquin Valley APCD, March 21, 2003. B- 1 Appendix C Methodology for Calculating Cost -Effectiveness of Fugitive Dust Control Measures INTRODUCTION In compiling information on control cost-effectiveness estimates for the fugitive dust handbook, we discovered that many of the estimates provided in contractor reports prepared for air quality agencies for PM10 SIPs contain either hard to substantiate assumptions or unrealistic assumptions. Depending on which assumptions are used, the control cost-effectiveness estimates can range over one to two orders of magnitude. Rather than presenting existing cost-effectiveness estimates, we have prepared a detailed methodology containing the steps to calculate cost-effectiveness that is presented below. We recommend that the handbook user calculate the cost-effectiveness values for different fugitive dust control options based on current cost data and assumptions that are applicable to their particular situation. Based on field measurements of uncontrolled and controlled unpaved road emissions conducted by Midwest Research Institute, there were no significant differences in the measured control efficiencies for the PM2.5 and PM10 size fractions. Thus, the cost- effectiveness for PM2.5 reduction can be calculated by dividing the cost-effectiveness estimate for PM10 reduction by the PM2.5/PM10 ratio for that fugitive dust source. TECHNICAL APPROACH The steps necessary to calculate the cost-effectiveness for different fugitive dust control measures are listed below. This methodology was employed to calculate the cost- effectiveness for each control application case study for the different fugitive dust source categories addressed in the handbook. Step 1: Select a specific control measure for the fugitive dust source category of interest. Step 2: Specify the basic parameters required to calculate uncontrolled and controlled emissions for the specific source: (a) applicable emission factor equation (b) parameters used in the emission factor equation (c) source extent (activity level) (d) characteristics of the source (e) control measure implementation schedule (frequency, application rate) Step 3: Calculate the annual uncontrolled emission rate as the product of the emission factor and the source extent (from Step 2). Step 4: Determine the control efficiency for the selected control measure. This may involve either (a) using a published value, (b) calculating the control efficiency based on comparing the controlled emissions estimate derived from the applicable emission factor equation with the uncontrolled emissions estimate derived from the same emission factor equation, or (c) specifying the desired control efficiency which then will entail determining the appropriate level of control to achieve the desired control efficiency. C -1 Step 5: Calculate the annual controlled emissions rate (i.e., the emissions remaining after control) as the product of the annual uncontrolled emission rate (from Step 3) multiplied by the percentage that uncontrolled emissions are reduced, as follows: Controlled emissions = Uncontrolled emissions x (1 — Control Efficiency). Step 6: Calculate the reduction in emissions as the difference between the annual uncontrolled emission rate (from Step 3) and the annual controlled emission rate (from Step 5). Step 7: Gather cost estimates for implementing the selected control measure for the following items: (a) annualized capital costs (total capital costs/lifetime of the control) (b) annual operating and maintenance costs that include overhead, enforcement, and compliance costs Step 8: Calculate the annualized capital investment cost as the product of the annual capital cost and the capital recovery factor. The capital recovery factor is calculated as follows: CRF =[i(1+i)°]/[(1+i)°-1] where, CRF = capital recovery factor i = annual interest rate (fraction) n = number of payment years Step 9: Calculate the total annualized cost by combining the annualized capital investment cost (from Step 8) with annual operating and maintenance costs (from Step 7). Step 10: Calculate the cost-effectiveness of the selected control measure by dividing the total annualized costs (from Step 9) by the emissions reduction. The emissions reduction is determined by subtracting the controlled emissions (from Step 5) from the uncontrolled emissions (from Step 3). C-2 Appendix D Fugitive PM1O Management Plan Overview The San Joaquin Valley APCD's Regulation VIII that addresses fugitive dust specifies two general control methods for controlling fugitive dust: (1) limiting visible dust emissions and (2) maintaining a stabilized surface. Visible dust emissions (VDE) may not exceed 20 percent opacity during periods when soil or other dust -producing materials are being disturbed by vehicles, equipment, or the forces of wind. "Opacity" is a visual evaluation of the amount of one's view that is obscured by a dust plume. The VDE limit applies to construction sites, the handling and storage of bulk materials, and to unpaved roads and traffic areas. A stabilized surface is a treated surface that is resistant to wind effects. This requirement applies to vacant open areas that have previously been disturbed, unpaved roads and traffic areas, and outdoor bulk storage piles. Methods for creating and maintaining a stabilized surface may include applying chemical or organic stabilizers, road -mix or paving materials, vegetative materials, or water for soaking the soil or forming a visible crust. For unpaved roads and unpaved traffic areas, a Fugitive PM 10 Management Plan (FPMP) may be implemented as a compliance alternative to the Visible Dust Emission standard and the requirement to maintain a stabilized unpaved road surface. The FPMP identifies the control measures to be implemented whenever vehicular traffic reaches and exceeds the applicable thresholds i.e., ≥ 75 vehicles per day or ≥26 vehicles per day with 3 or more axles). Acceptable control measures are those that have demonstrated to achieve at least 50 percent PM10 control efficiency when properly applied to an unpaved surface. A FPMP may not be prepared for unpaved haul roads and access roads as well as traffic areas at construction projects nor as an alternative to a Conservation Management Practice (CMP) Plan for agricultural sources. Non-agricultural sources choosing to implement a FPMP are required to submit a plan to the District for approval. Once approved, the owner or operator is required to implement the District -approved FPMP on all days where traffic exceeds the applicable minimum thresholds. An approved plan remains active until the District notifies the owner or operator that it is no longer valid, or until the owner or operator notifies the District that plan implementation has been permanently discontinued. Required Information The FPMP must include the following information: 1. The names, addresses, and phone numbers of persons responsible for the preparation, submittal, and implementation of the FPMP, and of the persons responsible for the unpaved road or traffic area. D-1 2. A plot plan or map showing the location of each unpaved road or traffic area to be covered by the FPMP, the total length in miles of unpaved roads, and the total area in acres of unpaved traffic areas that will be subject to the plan. 3. The months (and weeks, if known) of the year when vehicle traffic is expected to exceed the minimum thresholds described in the applicable rules, and the types of vehicles (i.e. passenger vehicles, trucks, mobile equipment, etc.). 4. The control methodologies to be applied, including: a. Product specifications; b. Manufacturer's usage instructions (method, frequency, and intensity of application); c. Application equipment (type, number, and capacity); and d. Environmental impact information and approvals or certificates related to appropriate and safe use for ground application. 5. The condition of the treated surfaces to be achieved as a result of the use of suppressants or other dust control material. Record Keeping Requirements Owners and operators are required to maintain records and any other supporting documents to demonstrate compliance for those days when control measures were implemented. Records are to include the type of control measure implemented, the location and extent of coverage, and the date, amount and frequency of applying dust suppressants. Record keeping forms developed by the District or a facsimile that provides the necessary information may be used for record keeping purposes. Records are to be kept for a minimum of one year following termination of dust generating activities. Title V stationary sources are required to keep the records for a minimum of five years. Records must be made available to the District inspector upon request. The matrix below lists the forms to be used for Regulation VII record keeping. Activity at site and corresponding record keeping Earth Moving forms Trackout and Carryout Industry Bulk Materials Unpaved Roads Equip & Vehicle Storage Open Areas Construction AC ACD ACD AC A B Oilfields AC ACD ACD AC A B Off -field Ag Ops AC ACD ACD Ag Product Processing AC ACD ACD B Bulk Materials AC ACD ACD B Equipment & Vehicle Storage AC A C D A C D AC B Truck Stops AC ACD ACD AC B Form A = Daily watering schedule Form B = Sweeping/cleanup schedule for trackout and carryout Form C = Permanent control measure (e.g., paving, gravel, a grizzly, chemical dust suppressants) Form D = Daily schedule for wafer application onto unpaved roads and equipment areas D-2 Cs a is • ar- yS, N bry • . ;... : • r$I.* _•••• • 2y . I:t . • r :,t^ r M4.•• •4k • 0 . � •'4 -+ - .1 -• • •• - i - -.r- •..... _1 • .Yiy' , � -- a `•`,..r. .tom ' .l. • - r . 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