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Home My WebLink About20060207.tiff FAX TRANSMISSION nWELD COUNTY ATTORNEYS OFFICE FAX: (97352-0242 C. PHONE 970) 3056-4000, EXT. 4391 COLORADO CONFIDENTIAL: THIS FACSIMILE IS INTENDED ONLY FOR THE USE OF THE INDIVIDUAL OR ENTITY TO WHICH IT IS ADDRESSED AND MAY CONTAIN INFORMATION THAT IS PRIVILEGED, CONFIDENTIAL, AND EXEMPT FROM DISCLOSURE UNDER APPLICABLE LAW. IF THE READER OF THIS FACSIMILE IS NOT THE INTENDED RECIPIENT NOR THE EMPLOYEE OR AGENT RESPONSIBLE FOR DELIVERING THE FACSIMILE TO THE INTENDED RECIPIENT,YOU ARE HEREBY NOTIFIED THAT ANY DISSEMINATION, DISTRIBUTION, OR COPYING OF THIS COMMUNICATION IS STRICTLY PROHIBITED. IF YOU HAVE RECEIVED THIS COMMUNICATION IN ERROR, PLEASE NOTIFY US IMMEDIATELY BY TELEPHONE AND RETURN THE ORIGINAL MESSAGE TO US AT THE ABOVE ADDRESS VIA THE U.S. POSTAL SERVICE. THANK YOU. This message consist of 1 page plus cover sheet. DATE: October 17, 2005 TO: Julie, WIPO, LLC FAX: (970) 226-2047 FROM: Diane Beckman, Paralegal Ext. 4388 SPECIAL INSTRUCTIONS: Attached please find Lee Morrison's approval of Falcon Ridge PUD. 2006-0207 P. 01 * TRANSACTION REPORT * OCT-17-2005 MON 10:22 AM * FOR: WELD CO GOVT 9703520242 X * DATE START RECEIVER TX TIME PAGES TYPE NOTE M# DP * * OCT-17 10:22 AM 919702262047 37" 2 SEND OK 232 * x TOTAL : 37S PAGES: 2 Kit FAX TRANSMISSION ' WELD COUNTY ATTORNEY'S OFFICE FAX: (970) 352-0242 CPHONE: (970) 356-4000, EXT. 4391 COLORADO CONFIDENTIAL: THIS FACSIMILE IS INTENDED ONLY FOR THE USE OF THE INDIVIDUAL OR ENTITY TO WHICH IT IS ADDRESSED AND MAY CONTAIN INFORMATION THAT IS PRIVILEGED, CONFIDENTIAL. AND EXEMPT FROM DISCLOSURE UNDER APPLICABLE LAW. IF THE READER OF THIS FACSIMILE IS NOT THE INTENDED RECIPIENT NOR THE EMPLOYEE OR AGENT RESPONSIBLE FOR DELIVERING THE FACSIMILE TO THE INTENDED RECIPIENT,YOU ARE HEREBY NOTIFIED THAT ANY DISSEMINATION,DISTRIBUTION, OR COPYING ..r+mimin rrwfw.flywTTr A Tif%T iQ QTDiI+TI V DDAT7iffl'Vl TF WATT HAVE �1 Aug 31 05 01 : 35p Bret Larimer, Ltd. (970) 226-2047 p. 1 WIPO, LLC A Colorado Limited Lability Company 1600 West Horsetooth Road,Fort Collins,CO 80526 970-226-2046 FAX To: 1 i HCflt n From: -bra— rat "110 ?�� -- ragas 61 Phone: `110- Y550- lflc Date of Re late PilThiad� u.� cc: • lib YA Comments: µ,,r. HUMS H�( /tuc9 rJL-1114_• C4WLCk' 19c1C+' Ct Y .rm i.tom Ul {yen-) R.11J 0_vdti Aug 31 05 O1 : 35p Bret Larimer, Ltd. (970) 226-2O47 p. 2 09/31/2005 10:47 970-395-0997 NORTH WELD WATER PACE 01 rautoOFDTRTxrwas NORTH WELD COUNTY WATER DISTRICT pyLRLE8AGQ10ER 33247 HIGHWAY 80 • LUCERNE.CO 80646 • RALPH PRIOR DON POSSE'S,DISTRICT MANAGER CE Buac NNEHART P.O.BOX 56 • PHONE(870)3663020 • FAX(970)386-0987 Mils NELSON - ' . - wa.weea-0fg • 'mat W Ili waf 0t9 TRANSMITTAL • Anglia 31,2005 To: WIPO,LLC Prom: North Weld County War District • Attar Brett Lorimer F.O.Box 56 1600 Wen Havemmh Rod 33247 Hwy 85 • Pat Collura,CO 80526 Lucent,CO*0646 Re: FalconRtdgePUD _ • Enclosed is a DRAFT Water Service Agreement for North Weld Canty Water District to provide we!service,and fire flows of 1,000 gpm to the Development with a Residual System • Warne of 20psi. . The following Table will sumsm'ise the comb for water service from North Weld County Water District. These coets ere meet sad ARR SUBJECT TO CHANGE WITHOUT NOTIFICATION. . Description of Fee AuermtDue Time of Payment• Review do lapectbn Fee 55.950 Up-Fran lifiestruebree Fee 5115,500 Up-From 3121,456 TotalUp-Praaa • • Plant Investment Fee 57,500 per Lot @ Banding Permit orWata Service Connection • Mirage Clause - 51,700 paint €BmNmg Femtit or Water Service Coonedon • Cash4*-Lieu ofRaw Water $11,000 per La @Building Permit or Water Service OameaOon Raw Witter Stange Fee $1,000 per Lot @ Balding Permit or Water • • • Service Cbmealm Mete Set Fee • • 5900 per Lot @ Water Service Came tion 331,600 per Lot Total Tap Cost®Water Serrvice Contain • • • Please icehouse the daemaema end ifyen lave sty questions give me a cell. If everything is • acceptable please fee-waged waterline neatenedan plans to the District for valor. The Maria is . requiring the internal piping system tube designed with restrained joint pipe for bends,tees and • dead ends rather than thrust bbeha. Please contact ma before desisting the Miami waterline to • get our anent specifications for pipe,=mica,sir releases,hydrants and giant design reguitematt This will save a lot of time on the drips of the wisterias. Once the waled ne 000anetimplea ere approved rite District will execute the Water Service Agreement(which will be needed before final Canty approssl). I have also ranched at most recent news letter which contains some geaaal infaematim. If yon have any questions,please contact me. • Shinaely. . •• Alan Carton • North Weld Canty Water Diaries • Rug 31 05 01 : 35p Bret Larimer, Ltd. (970) 226-2047 p.3 88/31/2885 10:07 970-395-0997 NORTH NELD WTER ..-E 82 WATER SERVICE AGREEMENT (FALCON RIDGE PUP -SINGLE SYSTEM) THIS AGREEMENT is made and entered into as of the _ day of 2005, by and between the North Weld County Water District,acting by and through the North Weld County Water District Enterprise(hereinafter'Distri t")and WIPO LLC, r•Jo Bret Latimer, (hereinafter 'Developers), of Falcon Ridge PUD, (hereinafter°Development'). RECITALS WHEREAS,District Is a statutory special district formed under the laws of the State of Colorado and is a quasi municipal corporation;and WHEREAS,the District Enterprise was created by the In order to comply with the provisions of Section 20,Article X of the Colorado - lion and Article 45.1 of Title 37 of the Colorado Revised Statutes,as eppli WHEREAS,the District owns,maintains a s for the storage of and disWbullon of potable water within Weld d Lorimer ,Colorado; and • qt WHEREAS,the Developer desires to ' for in potable water supplies and services for the Development Falcon Ridge PUD,located in the Southwest Quarter(SW'/.)of 4,Towns nth,Range 67 West of the 6a Principal Meridian,County of W= of Colorado, ascribed as Lot B of Amended RE-1452;and WHEREAS.Dev ,•, Intends to . ' . more than three residential lots which will require • of raw nd/or d cash in heu of raw water dedication In , a the - of this Agreement NOW, tan ? 'a premises and the covenants and agreements ,- - :r .,,'' and between the District and Town as follows: CLE 1 -WA SUPPLY/FACILITIES 1.1 1Dist ict N furnish Development a customary supply of water for a total of ' _ ": ::) •, dual Single-Family residential,and two(2)Irrigation/Open- Space water taps' ;,.: • The District shall tenth 70%of an acre foot(228,000 gallons)of water •- •ulvalent tap per annual water year,If the alotment for Colorado- Big Thompson(C: project water,which is determined by the Northern Colorado Water Conservancy District Is 50%or greater,North Weld County Water District will restrict the delivery as necessary when the CBT allotment Is lees than 50%. 1.2 The Water to be furnished by the District shall be potable water,which complies with the Federal Safe Drinking Water Act and any other applicable drkddng water regulations. No promise or guarantee of pressure Is made by the District or Is to be Implied from anything contained herein. 1.3 The District shall use reasonable Diligence to provide a constant and uninterrupted supply of water,except for Interruptions due to:(1)Uncontrollable forces; (2)Operations or devices installed for water system protection;(3)Maintenance,repair, replacement,Installation of equipment,or investigation and inspection of the water system,which interruption or reductions are temporary,and In the sole opinion of the District,a neoeesery. Rug 31 05 01 : 36p Bret Larimer, Ltd. (9701 226-2047 p. 4 06/31/2005 10:47 979-395-0397 NJRTH WELD WATER PAGE 03 14 The District shall Install,own,repair and maintain a meter vault at each individual lot 1.5 The District estimates the water supply to have a normal pressure range of one hundred to one hundred tweedy five pounds per square inch(psi). The maximum pressure that vial be supplied to any Tap may be as great one hundred thirty five psi. Therefore,the Developer(or Lot Owner)agrees to install preventative plumbing devices to reettict and/or release the pressure. Developer and/or Lot Owner releases District from any and all liability or claims that may be made against the District concerning damage from excessive water pressure suppled to the Development,Tap or lot. ARTICLE 2 RESIDENTIAL TAPS 2.1 The District must approve,in writing,al ar l construction plans and submittals for materials and appurtenances of Lines within any Development or Wets Lines leading to the er shall be responsible for payment of the total cost of the con for ' es within the Development(or Water tines that are necessary a De that will serve the Taps. 'Water Lines',means all tines ch carry water to t vault(s) within the Development 9' 22 From the meter to the structure or lot with water,water will be delivered through private service which are by the Developer or Lot Owner,and for which the District h..:`l;_:::.•• .:,bitty 2.3 After the Developer has a Water Lanes,the Developer wit be required to submit a of • e of the Water Lines: and such has been app,. ., di the r. . = DI '"I�i conditionally accept the Water Linea by its dtionel prance - (see Exhibit W), Two years after conditional a Water L' .subject to final approval by the District, + "- Developer shall ip oftithe W fines to the District. The Developer may use the Districts to -' the IMvidual Taps,lithe District determin-- ti . ;4 .. ..:mg Water Line may be accessed and has avallabl,;. * serve the Development. For al W nes ` :. within the Developments madway or utiiy .R sesame i _ °_•:'r of paving or other improved surfaces subsequ.. --F: - initial i talon of any Water Line shell be the responsibility of the Developer, n,or current owner of the Right-Of-Way. The District will rape': - � I the trench to the surface but will not rebuild any surface improvements,In but rut limited to pavement,ant and gutter,sidewalk,or landscaping other . grasses. 2.5 No water service will be provided to any water Tap within the Development unit al fees,expenses and charges as detemined by the District have been paid and/or raw water dedicated. The fees,charges and expenses,and/or water dedication shall be as determined and defned by the District and based upon such fees,charges and expenses,and water dedication requirements then in effect Developer understands that the amount due for such fees,charges and expenses, and/or water dedication are subject to change or modification at the sate discretion of District Rug 31 05 01 : 36p Bret Larimer, Ltd. (970) 226-2047 p. 5 88/31/2585 10:47 970-395-0997 NORTH WELD RATER PAGE 04 2.6 Pursuant to this Agreement,the lees,expenses and charges for a water Tap consist of. (1) Review&Inaoeetion Fee as provided In Paragraph 2.8; (2) infrestruchet Enhancement Fee as determined in Paragraph 2.9; (3) Plant Investment Fee as provided In Paragraph 2.10; (4) Mileage Charge pursuant to Paragraph 2.11;and (6) Raw Water or Cash in Lleu Fad as provided In Paragraph 2.12; (6) Raw Water Storage Fee as provided In Paragraph 2.12.2;and (7) Meter Fee as provided pursuant to Paragraph 2. Notwithstanding anything to the contrary herein, of all fees,expenses and charges as established pursuant to this Agreern all ndNfon precedent to the District providing water service to any Tap Deve Except as provided in 8.1,If the total fees,expenses and ch not ' r fees, expenses and charges paid by the Developer ray improvement the Developer shall be considered as forfeited Fetid liquidated d as accurate calculation and determination of da be possibility. 2.7 The Raw Water or C in Lieu Fee,P nt Fee,end Mic ge Charge must be completed and blfil ' „ before ct provides any water • service. Once these fees have been ,th or Lot Owner will then have one(1)year to pay for and set. U installation of the meter,or,after one(1)year of payment as,the District shall commence billing the • .- or Let • MI . . onthly Charge in accordance with the •strict - .: affect. he Minimum Monthly Charge shall apply whe' - -,,'M any = is taken';:rough the Tap. � iP S 2.8 The r 'L. • roes for review and inspection of the „ .ng review,Water Line inspection, surveys : ' ' d pressure testing of the Water Line constructed for the d u.pmard. required to reimburse the District for such d shell be c as^+ a . I _ . .., - . The Review and Ingle shall be s fined by the District,and for this Development said fee shell be'..,_,» of$5, r 00 .A portion of this payment determined to be$350.m of said Fee sh: "- id by Developer and payment shall be made upon execution of this Agreement e = rider$5,600.c°of said Fee be made prior to commencement of= Ilion of Water Lines that will serve the Development,or the issuance of any bu g per it,whichever occurs earliest. The Review and Inspection Fee,as established in this Paragraph 2.8 is non-refundable. 2.9 The District may be constricting substardial offslta Infrastructure Including but not limited to 12"x30"Wet tap along the southern boundary of the development and installation of approximately 300-feet of 12'waterline from the Northeast corner of the property east to connect to an existing 12'water fine(Crossing the W Indsor Outlet DiEch). A portion of this construction will be attrtutable to the Development and an Irdraafrudure Fee will be charged to the Developer. The Infrastructure Fee shall be solely determined by the District,and for this Development said fee shad be the sum of $115,500?. A portion of this payment determined to be$5,00000 of said Fee shed be paid by the Developer and parent shall be made upon execution of this Agreement and the remainder$110,500. of said Fee be made prior to commencement of construction of Water Lines that will serve the Development,or the issuance of any residential budding permit,whichever occurs earliest The Infreetructure Fee,as established it this Paragraph 2.9 is nonrefundable. Nue 31 05 01 : 36p Bret Larimer, Ltd. (970) 226-2047 p. 6 00/31/2905 10:47 970-395-0997 ICRTH MELD WATER PA(₹ 85 2.10 The Developer or Lot Owner wit be responsible for making payment of the 'rant Westmont Fee'. Said payment shall be made prior to the issuance of any building permit or the setting of a water meter,whichever occurs earliest. Alt Plant Investment Fees paid shall be in accordance with the Plant Investment Fee as established by the District end in effect at the tine of the payment No portion of the Plant Investment Fee shall be returned or refunded once established pursuant to this Agreement and the Development is approved by Weld County,even if the number of lots and/or Taps in the Development is later decreased or unsold. However,If the number of lots and/or Taps increases beyond the number initially established in Paragraph 1.1,Developer will pay the Plant investment Fee for each new Tap within the Development at the rate for Plant Invesbnend Fees then In effect 2.11 The Developer or Lot Owner will be responsible for making payment ofthe 'Masao,ChwoV. Said payment shall be made prior to the Issu nce of any building permit or the seeing of a water meter,whichever occurs , - Mileage Charges paid shell be in accordance with the Mileage Charge as :.- the District and in effect at the timed the payment No portion ofthe M - rge shall be returned or refunded once established pursuant to this A® : : •: : opment is approved by Weld County,even if the number of • . Te i : Development is later decreased or unsold. However,if the nu • indlorT reases beyond the number initially established in P- • " h 1.1,Devel per 4• the Me Charge rge then for new Tap within the p , ttherate • - 2.12 The hin Lieu F:.•• :�." . ment(Grits Development shell be met by payment of in The •- ..• • Lot Owner will be responsible for making payment of • payment made prior to the issuance of any building pert or the ' t ichever occurs earliest. Ail Cash in Lieu Fees paid sit h -• the Cash in Lieu Fee as established by the • . n effect et of ell. 2.12.1 At . r•loth : of DI - the Distract may allow the Developer to dedicate Raw W r .., th;. water .• .nt The raw water requirement for a Residential Tap .. 4. . on one(1)lot shell be the dedkatlon d at least hot ' . ,. (CST)project water per Tap.or at least on; 'fi _ _:` • irrigation Company(NPIC)stock for every four(4) resit! Taps. r • 2. - -• in addition ad 'cation of the Raw Water or Cash in Lieu Fee.the Developer r :. •: respo le for a Raw Water Stomas Fee as determined by District. The Raw W: 17, f•rage :,'shall be applied once for each Unit of CST or four limes per shared I-, :.kgtted to the District The Raw Water Storage Fee payment shell be 'n conjunction with the dedication ofthe Raw Water. 2.13 The Developer shell provide the District with security,as deemed acceptable by District,to secure the installation and warranty of Water Lines within the Development during the two-year conditional acceptance period. Said security shall cover 25%of all costs for construction of said Water Lines,which shall be released at the expiration of the two-year warranty period and upon full acceptance of the Water Lines by the District. The type of security to be accepted shall be at the sole discretion of the District.which will normally be a letter of credit,certificate of deposit,or bond. 2.14 During the two-year conditional acceptance period,the Developer will be responsible for any repairs or maintenance of the Development Water Line • improvements. All such repairs and/or maintenance shall be in accordance with the District policies and engineering requirements,and shall be reviewed and approved by the District prior to any repairs or maintenance being effected except in emergency sauaticros. Rug 31 05 01 : 37p Bret Larimer, Ltd. (9701 226-2047 p. 7 00/31)2005 10:47 970-395-0997 MATH WELD WADER PAGE 06 2.15 Prior to a meter being set and water service being provided at or for any Tap,the Developer or percet owner shall be requited to complete the District's Tap application form,pay the Mater F_gg,and pay any snaking fees,expenses and charges.I any,in accordance with the policies and procedures of the District at the lime of any Tap application,or any other expenses or costs that may be incurred by the District In relation to the Development ARTICLES FRE PROTECTION • 3.1 Flre protection is a basic provision required far development activities in the Weld County for which this Development is to be constructed The Development may be located within an established fire protection district('F kit has as own policies,procedures and requirements concerning fire p wit may be in addition to or supplement any requirements imposed by County. Developer understands that District is not responsible for comp such FPD or Weld - County requirements and such requirements are the ' of Developer, FPD anther Weld County. Developer further u t required to provide fire flows or even allow fire protection ,including but i to hydrants,Water Lines,sprinklers,and viol note .Inspected, or provided by District. , 3.2 However,as a courts- and pudic sery will pent Developer to Install certah fire protection t . . : pursuant to rovision°f ells Article 4 and any other provisions or require _ ne ' 'ct,in its sole discretion. 3.3 Developer . to d Weld County plans and specifications for fine !realm• includ • not limited to location and size of Water Line -. - ydrants r Facilities"). Said plans shall be In accordance with : — and requ, established by District,Weld County andlor FPD. 3 f• sue. • the plans end design by District Weld County and FPD, eloper installation of the same including all costs District to - p on,and inspection of the same by District. Upon •,• of the all such fire facilities by District,Weld County and FPD, • Veneto - the responsibility of effecting maintenance end repairs of au ices b , ..:, ' will be compensated for such maintenance and repairs,in Dap-` :'; . ..: or Homeowners Association n the Development Additionally,respo for all costs of maintenance and repairs shall become a part of covenants that the title to all lots and property within the Development,and which shall constitute a first and prior lien upon all lots and property in said Development. 3.5 As additional consideration for this Agreement, Developer understand that . District has not and will not perform any independent review or analysis of the adequacy of icy tire facilities. Accordingly,Developer releases District from any and all liability or claims of any type that could be made against the District,including but not limited to water pressure,line size,lack of water,maintenance,volume or velocity of flow,or any other Item related to fire facilities in the Development. 3.8 Ai final approval of this Development must make reference to the responsibility of the property and owners concerning exposes of maintenance and repairs for the ire facilities pursuant to Paragraph 4.4 Rug 31 O5 01 : 38p Bret Larimer, Ltd. (97O) 226-2O47 p.8 88!31/2005 10:47 978-395-8997 KRIH WELD WATER PAEE 87 ARTICLE 4 PETITION OF INCLUSION 4.1 If determined to be necessary by District.the Developer agrees to sign and execute a standard Petition of inclusion,Exhibit'W. ARTICLE 5 EASEMENTS MD RIGHTS-OF-WAY 5.1 As additional consideration for this Water Service Agreement,Developer agrees to sign and execute any necessary Easements and Rigtes-of-Way regarding specific locations,widths.size of pipelines)and descdptlons for Water Lines as determined by the District. This Agreement is conditional upon execution and recording of the Easement and Right-of-Way Agreement,and until such EeserneM end Rigfit-of- Way Agreement is fnalzed to the satisfaction of the District and recorded,District shall not be required to pwride any services of any type. 5.2 Additionally.any final development plat mu and approved by District as to an aspects of Easements and Rig y rfacigtles, pipelines and fire facilities. Al such Items must be . d for use and District must approve the final plat. M ' MISCELLAN 8.1 This Agreement Is con. . :l as the fi ` ..- of the Develcpn ent has not yet been approved by Weld County. - -final plat is . -. on or before the la dayof September.2006.8de . then bete '. .. by Developer and the same shell be considered null and •,: .:rndag language to the contrary,Developer shall be'Stied to a and expenses paid pursuant toAnlde210 - nd2.124 for warn one year of the payment made to = 296 b!r . ..�.,•.� shell be considered as edminlatreive Any or the Developer insured pursuant to Arndes 2.1 2 8 . 15 not be a refund of any amount. 8.2 - : ned by Developer without the express written= . This re to and be binding upon the parties hereto and their h ' ntatives,successors and assigns. Rug 31 05 01 : 38p Bret Larimer, Ltd. (970) 226-2047 p. 9 08/31/2085 10:47 970-395-0997 NORTH MELD WATER PAGE 00 IN WITNESS WHEREOF,the parties have axewted this Agreement the day and year first above written. DEVELOPER: By: 8y. DISTRICT: ATTEST: NORTH WELD COU WATER DISTRICT BY: By: Secretary President STATE OF COLORADO ) _ COUNTY OF ) NIDDM The foregoing instrument was a ' - this day of Developer. Witness Y seal. Notary Public STATE OF COLO , ) as. COUNTY OF WELD ) The foregoing Instrument was acknowledged before me this_day of President end •2005.by as as Secretary of North Weld Water District. Witness'my hand and official sad. My commission expires: Notary Public BOARD OF DIRECTORS NORTH WELD COUNTY WATER DISTRICT CHARLES ACHZIGER 33247 HIGHWAY 85 • LUCERNE,CO 80646 �'ALPH PRIOR DON POSSELT,DISTRICT MANAGER JOHN JOHNSONmjfeaa CE BUCK RINEHART "s" P.O.BOX 56 • PHONE(970)356-3020 • FAX(970)395-0997 NELS NELSON www.nwcwd.org • e-mail: water@nwcwd.org July 6,2005 Bret Larimer/Wipo LLC • 1600 W Horsetooth Rd Fort Collins CO, 80526 • Re: Falcon Ridge:36Lot-Si bdivision-Developme nt of Farce#080;0430;X'!46 - - — - - -_-- - North Weld County Water District is able and intends to serve the proposed 36 Lots,located in a portion of the West %of the SouthWest % of Section 4,Township 6 North,Range 67 West,of the 6th Principal Meridian. To provide water service and a fire flow of 1000 gpm with a residual pressure greater than 20 psi, Falcon Ridge must be"looped"into the Distribution system. This will require the District to provide Off-Site infrastructure which includes two tie-ins and a ditch crossing. The cost of this Off-Site Infrastructure is TBA: r The fees,expenses and charges for a water tap consist of(1)Inspection &Review Fee; (2)Infrastructure Fee;(3) raw water or cash in lieu; (4) Plant Investment Fee; (5)Mileage Charge; and(6)Meter Fee. The District requires that the(3)dedication of raw water or cash in lieu; (4)Plant Investment; (5)Mileage requirements be fulfilled in conjunction. After the raw water dedication or cash in lieu, the Plant Investment Fee and the Mileage Charge have been dedicated and/or paid,the Developer or Lot Owner will have up to one year to have the meter set. Once the meter has been set or after one year of the payment and/or dedication of Raw Water,Plant Investment Fee and Mileage Charge,the District shall begin billing the Developer or Lot Owner a minimum monthly charge, as established by the District and in effect at the time. The Developer will be required to pay such fees on a per lot basis before water service is provided or before a building permit is released. • • .1 re, . . t 1 ' /. .s ..-. .. -?.... .-.11 t.,.,._. 12,4 �54: all !!{. f .-.c1 P:1Subdivisions\Falcon RidgeJmrnt(415-05):doc• . . .. • . • .. 39 r Refer to the following Table for the costs of the associated Fees. All Fees and Requirements are subject to change without notice,therefore;it is recommended to keep in contact with the District periodically for updated costs and requirements. Fees and Cost Time of Payment Requirements (as of March 25,2005) Inspection&Review $5,950 Before Construction of Water Line Off-Site Infrastructure $TBA TBD Plant Investment Fee $270,000($7,500 per Lot) Before Individual Meters will be Set Distance Fee $43,200($300 per mile x 4 Miles Before Individual Meters will be Set --- Ycr Lot) — — — -j Raw Water Requirement $432,000($12,000 per Lot)* Before Individual Meters will be Set Meter Set Fees Approx. $36,000(At Cost,per Lot) After Individual Meters have been Set Total Fees Total Cost for 36 Lots $TBA** (STBA per Lot) *Raw Water Requirement may be met by transfer of Water Rights and a Raw Water Storage Fee of$1,000 per Unit of Raw Water Transferred. Normal transfer is one Unit of Colorado Big Thompson Project Water(or Equivalent)per Lot. "*Cost does not include internal waterline design and construction. If you have any questions,you can contact me at the office(970)356-3020. Don Posselt North Weld County Water District P:\Subdivisionswakon RidgeVntent(4-25-05).doc Exhibit B BOARD OF DIRECTORS NORTH WELD CuwJTY WATER DISTRICT GARY SIMPSON 33247 HIGHWAY 85 • LUCERNE,CO 80646 ROBERT ARNBRECHT /•-CHARLES ACHZIGER DON POSSELT,DISTRICT MANAGER RALPH PRIOR JOHN JOHNSON P.O.BOX 56 • PHONE(970)356-3020 • FAX(970)395-0997 August 28,2002 . " w�n ' d..orgMr.Bret/Latimer 1111111111 1600 West Horsetooth Road 118.N1IIII IIIIItom■'II Ft. Collins,CO 80525 8230048 11/1612004 041W Weld County, CO 7 of 7 R 80.00 0 010 Stove Moreno CMdk&Recorder Re: Side letter agreement for North Weld Water District's proposed right-of-way. Dear Mr. Latimer, 1. North Weld Water District agrees to abandon the temporary workspace 60 (sixty)days after construction has been completed,including final grading. 2. Crop loss for 2 (two) years and seed cost will be paid to landowner. Landowner will be responsible for reimbursement to tenant. 3. Landowner and their heirs or assigns will have the right to purchase as many taps as he/she needs to for domestic water use for said property. This is a covenant running with the land described on Exhibit "A" attached hereto and incorporated herein by reference. 4. North Weld Water District requires septic systems to be set 10' from the waterline. 5. If any relocation of already existing hay needs to be done,North Weld Water District agrees to be responsible for such relocation. The location will be discussed with the landowner prior to any relocation. 6. Compensation shall be$2,500.00 for the permanent easement. This is a 50% valuation of the land as figured at$15,000 per acre. (.34/acre will be encumbered by this easement) Additionally landowner will be compensated $889.50 for the temporary construction easement. (.593/acre will be used during the initial construction phase) , ''' Presidrt a agreed upon this PS day of s feamin c 2002 40 11111111 I I 1111111111111111,...1111111111111 2769626 05/2212000 10:47A JA Sulu Tsukamoto 2 of 2 R 10.00 0 75.50 Weld County CO I IIIIII iIILIUR5t 00 D Moreno MO a Recorder 7 7 R "EXHIBIT A" LEGAL DESCRIPTION 111111111111111111111 11111.11111111 3288048 11116/2004 04.'88P Weld COO CO 6 of 7 R 38.00 D 0.00 $IBn Moreno Clerk a Recorder Lot B of Second AmendedrRecorded Exemption No. 0807-04-3-AMRE1452, recorded June 28, 1999 ds Reception No. 2702921, being a part of the SW1/4 of Section 4, Township 6 North, Range 67 West of the 6th P.M. , County of Weld, State of Colorado. EXCEPTING THEREFROM a strip of ground 20 feet wide running East 450 feet from the Southwest corner of the SW1/4 of Section 4, Township 6 North, Range 67 West of the 6th P.M. , as granted by Warranty Deed dated September 18, 1930, and recorded in Book 900 at Page 309 . ALSO EXCEPTING THEREFROM a portion conveyed to The Department of Highways, State of Colorado by Deed recorded July 22, 1966 in Book 571 as Reception No. 1493273 . TOGETHER WITH 30 Units of the Waters from the Northern Colorado Water Conservancy District TOGETHER WITH One (I) share of the capital stock of The Windsor Reservoir and Canal C Company TOGETHER° WITH One -(1) s1r5 r df Y1re J Company er I, Weld Irrigation TOGETHER WITH One (1) share of the capital stock of The Larimer 4 Weld Reservoir Company TOGETHER WITH Three (3) shares of the capital stock of The Lake Lee Lateral Company r Xce/Energy" PUBLIC SERVICE COMPANY 1901 East Horsetooth Road Fort Collins,Colorado 80525 May 12,2005 Whipo LLC %Brett Larimer 1600-W:Hotsetooth Rd. _. _ _ _ __ . _ Fort Collins, Co. 80525 Re: Availability of Natural Gas to Falcon Ridge PUD near Windsor,Co. Thank you for your request for information regarding natural gas service for the above-mentioned project. Public Service Company will provide natural gas service to this project according to the terms of our extension policies as they are on file with the Colorado PUC. We currently have an existing 3" PED gas main located along County Rd 72. This main ends approximately 1000 feet East of the intersection of Hwy 257 and County Rd. 72. I will be your primary contact at PSC for this project. My normal business hours are from 6:30 am to 3:00 pm, Monday through Friday. If I am unavailable, or if your need is immediate, you may contact my Engineering Manager, Lyle Sheeder, at 970-225-7840. If you have any questions or needs,please do not hesitate to contact me at once. Sincerely, 970-225-7848 Phone 970-225-7833 FAX Len Hilderbrand Design Engineer len.hilderbrand@xcelenergy.com r^ 45 POUDRE VALLEY RURAL Pou Valley E ^ELECTRIC ASSOCIATION, INC. P.O. BOX 272550 7649 REA PARKWAY FORT COLLINS, CO 80527-2550 FORT GOWNS, CO 80528 Bus. Phone 970-226-1234 FAX 970-226-2123 800-432-1012 www.pvrea.com June 1, 2005 Wipo LLC ATTN:Bret Larimer 1600 West Horsetooth Road Fort Collins, Colorado 80526 RE: FALCON RIDGE P.U.D. PROPERTY LOCATED IN SW 1/4 OF SECTION 4, TOWNSHIP 6 NORTH, RANGE 67 WEST OF THE 612t PM, COUNTY OF WELD, STATE OF COLORADO Mr. Larimer: Poudre Valley Rural Electric Association, Inc. is ready, willing and able to serve all electrical loads within our certificated service territory subject to the Rules and Regulations of Poudre Valley Rural Electric Association. The person(s) signing any contract (s) and or easement(s) grants to the Association the right to ingress and egress for meter readers, tree trimmers, engineers, line personnel, or any agents of the Association for the purpose of reading meters, engineering services, line repair, maintenance, tree trimming and or right-of-way clearing as deemed necessary by the Association. If you have any further questions, please call our office. Sincerely, erry elding � Engin ering Representative hhp CADocuments d SettnAlsppe6My DoaraisMOSTAWIPOLLC RDY ABIELTRADD 46 A.Box 7676 T eta` Phone: 970-663-7480 �1!oveland,Colorado 80537-0676 Logics „ Fax: 970-667-9959 Consulting,LLC • rh,r •n%,ms Ill,r i,•1111 m NonM n Cohn/Ida October 31, 2005 t •. WIPO, LLC Attn: Bret Larimer 1600 West Horsetooth Road Fort Collins, Colorado 80526 Subject: Evaluation of Proposed Onsite Wastewater System (OWS) Enhancements Falcon Ridge P.U.D. Weld County, Colorado " TLC Job No. 05-1062 Mr. Larimer, We have prepared this evaluation of proposed onsite wastewater system (OWS) enhancements for the response to a memorandum by Weld County Department of Public Health and Environment(WCDPHE)for the proposed the Falcon Ridge P.U.D.The memorandum was from Pam Smith of WCDPHE to Kim Ogle of the Weld County Planning Department, dated October 10,2005 requesting"the applicant demonstrate how the efficiency and nutrient reduction of the proposed enhancements will improve the quality of effluent over standard systems. .... to demonstrate that the impact on local water quality of the septic system at the proposed densities is less than or comparable to septic systems on densities of 2.5 or greater."Our goal of this report is to provide information that may quantify the benefits of some OWS enhancements and to elaborate on the benefits for those OWS enhancements that cannot be quantified. PROPOSED CONSTRUCTION A 38-lot P.U.D. is planned for the development. Wastewater services are to be provided by OWS for each individual residence. Drinking water is supplied by public water. An overall density of dwelling unit (DU)per 1.9 acres is proposed.. This is equal to an OWS density of 0.53 OWS per acre. PROPOSED OWS ENHANCEMENTS The WCDPHE has requested that the impact to water quality with enhanced OWS and overall density of one DU per 1.9 acres have a less or comparable impact of standard OWS on a density of one DU per 2.5 acres. On May 17,2005,we presented some of the proposed OWS enhancement methods to Pam Smith. . . The,items discussed were enhancements that we feel would improve the performance of the proposed OWS,both in nutrient reduction and longevity.The enhancements discussed include OWS Designs and Construction Observations, Effluent Filters, Oversized Septic Tanks, Absorption Trench Drain Fields, Alternating Drain Fields,Monitoring Ports and Management Plan and Program.In addition,"secondary" or"advanced"treatment systems with nitrogen reduction may be considered. e-mail: terralogics@att.net o�„/_ -a2 0-7 OWS Enhancements Job No.05-1062 Page 2 The OWS enhancements that can provide quantifiable benefits are effluent filters and "advanced" treatment systems. Some of the advantages are as follows: Effluent Filters Many effluent filters are available and should provide similar filtration characteristics and benefits. Some filters are easier to install and clean and some may require less frequent cleaning. Comparisons of the characteristics of unscreened septic tank effluent and screened septic tank effluent are presented in Table 2 and Table 3 of"Design and Performance of Septic Tanks" (see attached). Although the `screened effluent' from Table 3 is from pumped systems,there should be no difference from gravity systems.The comparison indicates approximately a 15 percent average reduction of biochemical oxygen demand (BOD5) and 64 percent reduction of total suspended solids (TSS) with screened effluent. "Advanced" Treatment Systems with Nitrogen Reduction There are several "advanced" treatments systems (ATS) on the market with various performance characteristics.Not all ATS significantly reduce nitrate levels. Most that do reduce nitrate levels utilize recirculating-sand-filter technology. Our evaluation for ATS were based on ANSI and NSF results presented in Advantex®Design Criteria(see attached).Figures 4a and 4b indicate an Advantex®under a hydraulic load of 30 gpd/ft2, the BOD5 and TSS both were reduced to less than 5 mg/l. This is approximately a 97 percent reduction of BOD5 and 94 percent reduction of TSS.The paper also indicates a typical reduction of 60 percent nitrogen reduction with Advantex ®systems in standard configuration and more than 70 percent reduction for systems configured in specialty mode. The benefits for some OWS enhancements cannot be readily quantified. Additional proposed OWS enhancements are as follows: Oversized Septic Tanks Oversizing the septic tanks will provide additional retention time for solids to settle, for lighter components to float and for additional bacteria breakdown. The benefit of oversizing septic tanks should be considered as an OWS enhancement although our brief research did not find literature that could quantify the benefits. Absorption Trenches Although trenches may not be considered an enhancement feature, trenches perform better than beds. This is due partly to better aeration of soil underneath the drain field and more sidewallabsorption area. Better soil aeration provides oxygen for aerobic bacteria and microbes that soil treatment relies upon. Biomat typically increases the drain field trenches mature, eventually plugging the soil. By designing alternating trenches, so that 50 percent of the trenches can be closed dnd rested for a period, biomat formation can be kept more robust in the"active" trenches to enhance treatment. The"closed"trenches can then rest to allow digestion of the mat, restoring infiltrative characteristics. Monitoring ports are proposed for all trenches to allow periodic observations to assess OWS performance. Although not quantified in this paper the benefits of alternating trench drain fields should be considered an enhancement over standard OWS by providing better soil aeration and aerobic digestion of the effluent and better treatment in the "active" trenches. OWS Enhancements Job No.05-1062 Page 3 OWS Designs, Construction Observations To help ensure compliance with the requirements and OWS enhancements for the subdivision,the OWS should be designed under the direction of a qualified registered professional engineer. The designer should conduct construction observations as necessary to verify compliance with the design. Management Plan and Program A management plan and program governed and financed by the Homeowners Association would provide periodic monitoring and maintenance of the OWS for the entire subdivision. Septic tank pumping, alternating drain field trenches, monitoring port observations and other issues would be scheduled and records kept. ENHANCEMENT EVALUATION The proposed overall density of the subdivision is approximately one DU per 1.9 acres, or and OWS density of 0.526 OWS per acre. WCDPHE policy is to have no more than one DU per 2.5 acres, or 0.40 OWS per acres where OWS are proposed. This is a net increase in density of approximately 32 percent. TSS and BOD5 can be reduced approximately 64 percent and 15 percent, respectively by installing effluent filters. For nitrogen reduction, "advanced"treatment systems with nitrogen reduction, or other technology would be required for some of the 38 proposed residences to reduce the nitrogen impact equivalent to a 2.5 acres per lot overall density.The basis of the following calculations are derived from a 60 percent reduction in nitrogen for "advanced" treatment. The nuinber of lots required for nitrogen reduction to be comparable to 2.5 acre per lot overall density is as follows: Where, x=number of houses with nitrogen reduction 38 = number of total lots proposed 0.4=factor for 60% nitrogen reduction 1.0=factor for no nitrogen reduction 28.4= equivalent number of lots on 71 acres and 2.5 ac/lot density (0.4)(x) + (1.0)(38-x) = 28.4 x = 16 houses CONCLUSION The benefits can be quantified for effluent filters with approximately 15 percent reduction in organic loading.Nitrogen reduction will not be significantly reduced with effluent filters. Although the benefits of alternating trenches and oversized septic tanks are not quantified in this report,these items should be considered as enhancing the performance of OWS as compared to minimum sized conventional `°absorption beds".Engineered designs and construction observations are proposed to ensure compliance with.subdivision OWS requirements. Nitrogen reduction may be achieved with "advanced" treatment with nitrogen reduction. In order to reduce nitrogen levels of the proposed 1.9 acre/lot equivalent to 2.5 acre/lot density, 16 of the 38 residences would need 60 percent nitrogen reduction.Organic loading would also be significantly reduced with "advanced"treatment with nitrogen reduction. OWS Enhancements Job No. 05-1062 Page 4 Other technologies and equipment may be available that can achieve higher results than stated in this report. Not all"advanced"treatment systems or other components provide levels of treatment presented in this report. There is no warranty, express or implied, as to the performance of the components mentioned in this report. This report is for planning purposes only and is not intended for the design of OWS. We look forward to assisting you with your project. If you have questions, please call me at 970-663-7480. Sincerely, Terra Logics Consulting, LLC_��o\`JtoF enoFpssp a ht. .pi',c\F\GATE li , •, ��• , ntPG N0 Thomas W. Finley, C.P.G. ;•• stilt 4.044s w.cv,0" 3 copies provided - Design and Performance of Septic Tanks T.R. Bounds, P. E.' Reference Bounds, T.R., " Design and Performance of Septic Tanks," Site Characterization and Design of Onsite Septic Systems ASTM STP 901 M.S. Bedinger, A.I. Johnson, and J.S. Fleming, Eds., American Society for Testing Materials, Philadelphia, 1997. Abstract More than forty million people in the United States currently use onsite wastewater disposal or decentralized sewerage collection and treatment that rely on septic tanks for primary treatment. There is a good reason why, in this age of advanced technology, the septic tank is still in use. It works. More than 45% of ultimate treatment can be accomplished in the septic tank. Advanced onsite and effluent sewer technologies have established their environmental importance by bringing highly reliable, affordable and permanent wastewater treatment to users worldwide. In short, passive—energy free—septic tanks provide the most cost efficient form of primary treatment available for nonindustrial sewage. Decentralized sewers and onsite alternatives have advanced us to a new era of wastewater treatment and management where designers must be able to rely on the many essential components of the system. System components must be designed and constructed with the same permanency and quality expected of any long-term option. Because the septic tank is an essential ingredient to the success of these systems, a new generation of structurally-sound, watertight septic tanks is evolving. Keywords septic tanks, septage, structural adequacy; watertightness, biochemical, pumping interval, frequency, accumulation rates, retention time The Septic Tank The septic tank is an enclosed receptacle designed to collect wastewater, segregate settleable and floatable solids (sludge and scum), accumulate, consolidate and store solids, digest organic matter and discharge treated effluent. Currently more than one-third of the nation's wastewater treatment is provided by septic tank systems. The septic tank may be the single most important component used in all onsite.treatment and collection alternatives. Usage The most common usage is in rural residential applications. Besides its role in standard subsurface soil absorption systems, the pre-treatment provided by the septic tank is equally important in ensuring the success of other secondary treatment alternatives such as constructed wetlands,ponds, intermittent and fecircilating sand filters, peat filters, mound systems, synthetic filters or membrane systems, up-flow filters, pressure distribution systems, and nitrogen reduction systems. In addition, septic tank pre- 'T. R. Bounds, P.E., E.Vice President, Orenco Systems, Inc., 814 Airway Ave. Sutherlin, Oregon 97479 NTP-TNK-TRV-3 17/99 Page 1 treatment often precedes packaged aerobic treatment processes (see Figure 1). Multiple tanks are often used in parallel or series configurations when greater treatment, storage or surge capacity is necessary. The septic tank is also a major component in pressure and variable grade effluent sewer collection alternatives(STEP and STEG systems). The reason is simple: the primary-treated effluent discharged from the septic tank is mild, consistent, easy to convey and easily treated by either aerobic or anaerobic • secondary processes. In this age of advanced technology, there is a good reason why the septic tank is still in use; it works. Passive—energy free—septic tanks provide the most cost efficient method of primary treatment available for nonindustrial sewage; BOD (biochemical oxygen demand)removals of greater than 65 percent and TSS (total suspended solids) removals of greater than 70 percent are easily accomplished (Bitton, 1994). - '6,004 tom�� • Inlermittent,Sand Filter �. ` r Yt 41 •Recirculating Sand Filter `�• , • Mounds rr r7`,I x iito • Peat Filters N `"-.` t`� '1 '°" • Wetlands 1 ICI,t1- ,4-. h" ri i • Soil Absorption t �" g s, o i�� pi • Pressure Drainfields , ,ri i, yip • Aerobic Treatment , • Effluent Sewers �F S Figure 1: Typical applications that require septic tank pre-treatment. Unfortunately, the septic tank is often the most disregarded component in the system. The performance and success of a properly sized tank relies on its structurally-adequate, watertight design and construction. If these simple criteria are not met, infiltration or exfiltration will fix the fate of the system. Septic Tank Biology Septic tanks are passive low-rate anaerobic digesters, with their own ecosystem, in which facultative and anaerobic organisms perform complex biochemical processes. The tank operates as a plug-flow type of reactor(fluid and particles enter and exit the tank in progressive sequence), so there is usually no mixing or heating,particles ascend or descend and stratification develops. Effluent quality suffers when this stratification doesn't develop. The environment within the tank's clear zone is generally anoxic, or ' inadequate in oxygen, while sites within the sludge and scum layers may be completely free of oxygen, or anaerobic. , NIP-TNK-BB-3 12/94 Page i The inflowing wastewater directed into the clear zone(just beneath the scum layer) by the inlet fixture normally contains high levels of dissolved oxygen. The microbial population, however, rapidly depletes the dissolved oxygen as the flow disperses in the tank and moves towards the outlet. The bacteria found in residential wastewater are enteric, the same as those found in the gut(Ziebell et al. 1974). These organisms are primarily heterotrophic bacteria which oxidize and solubilize organic matter. Facultative microbes (organisms that can function in either aerobic or anaerobic conditions) solubilize complex organic material to volatile organic acids, while strict anaerobes ferment the volatile organic acids to gases (methane, carbon dioxide, hydrogen sulfide, etc.). The microbes use the solubilized nutrients in the wastewater for cell growth and energy. The microbes are enteric, therefore,natural habitants of the wastewater, but it takes years to develop volatile organic acid and metabolite concentrations sufficient for colonization of methane formers and optimum digestion. Their population, growth and effectiveness are dependent on the characteristics of the wastewater (e.g., temperature, organic load, inorganic trash, toxic chemicals or cleaners, excessive fats, oils, grease, detergents, high hydraulic loads, etc.) as well as the sizing and design features of the tank. Consequently, a tank must be adequately sized for the occupancy usage in order to ensure a long-term quiescent environment for the organisms to colonize. When long-term storage is allowed, the effectiveness of digestion within the layers of stored volatile solids can be as great as 80 percent (Metcalf and Eddy, Inc., 1972), and the microbial population (biomass) required to accomplish the feat may range from one-fifth to only one-twentieth of that generated in an equivalent aerobic treatment process-(Bitton, 1994). The dominant bacterial groups measured in the septic tanks by Ziebell et al. in 1974, were total and fecal coliform, fecal streptococci, lactic acid bacteria, anaerobes, and others. The total bacteria population can range up to 230,000,000 per ml (Tyler et al. 1978). Taber (1976) divided the bacteria into two groups, separating the methanogenic bacteria, or methane formers, from the non-methanogenic bacteria. Following are some of the bacteria identified in each group: The non-methanogenic bacteria include: Actimomyes, Alcaligenes viscolatis, A.faecalis, Bacillus, Bacteroides, Bifido bacterium, Branhamella catarrhalis, Clostridium, Corynebacterium,Desulfovibrio desulfuricans,E. coli,Eubacterium, Euterobacter atrotenes, Fusobacterium,Lactobacillus, Leptospira biflexa, Microccus varians, Micrococcus lateus, Peptococcus, Pseudomanos reptilivora, Ramibacterium, Spirillum,Veillonella, and Vibrio The methanogenic bacteria include: Methano bacterium, Methanobacterium formicicum, Methanobacterium ruminatum, Methanospirillum sp., and Methanoccus vanneilli. The digestion that takes place in the tank is performed predominately by bacteria. The most common bacteria shapes are spheres (coccus), rods (bacillus) and spirals (spirillum). These shapes can be observed as individual cells, or they may be seen grouped or linked together. Each organism is .encapsulated by a slime layer of extracellular enzymes. These extracellular enzymes hydrolyze organic material by adding water to the organic molecules,reducing them to simple soluble organic compounds small enough to be absorbed through the cell wall. Inside the cell, intracellular enzymes further metabolize and oxidize the volatile organic molecules creating the energy required for cell growth. Enzymes are complex proteins and can be precipitated, or have their enzyme reactive points tied up, by NTP-TNK-TRB-3 12/94 Page 3 • excessive amounts of salts and heavy metals. Either of these contaminants will inhibit the ability of the microbes to adequately produce their soluble organic nutrition, in effect, retarding the tank's performance. Taking precautions to reduce excessive disposal of household products containing large concentrations of zinc,copper, calcium, magnesium, iron, ammonium sulfate, sodium sulfate, sodium chlorides, etc., is an important first step in assuring natural biochemical processes. Normal or conservative residential uses of salts, bleaches and detergents, however, are not detrimental to the microbial population. Performance ' As the wastewater passes through the tank, its characteristics change and different bacterial cultures predominate as the bacteria break down complex proteins, carbohydrates, and fats. An assortment of typical wastewater characteristics are shown in the following tables. The values shown in Table 1 are averages for wastewater entering the tank(influent). • Table 1: Characteristics of Raw Domestic Sewage Source Flow BOD5 TSS Grease pH L(gal)/ca pita/daymg/1 mg/1 mg// Watson et al-Home 1 295(78) 542 363 95 8 Watson et al-Home 2 250(66) 284 293 33 8 Watson et al-Home 3 91 (24) 479 473 66 8.3 Watson et al-Home 1 269(71) 518 478 134 7.6 Watson et al-Home 2 193 (5/) 356 360 41 8.2 Watson et al-Home 3 110(29) 598 602 92 8.4 Kreissl 242(64) 435 380 65 Kreissl 490 480 89 Lawrence-Home 1 117(31) 241 200 21 7.5 Lawrence-Home 2 185(49) 146 126 16 7.2 Otis et al. 233 269 U. Wisconsin 121 (32) 415 296 122 U. Wisconsin 129(34) 465 394 129 U. Wisconsin 343 259 Bennett, ASAE 168 (45) 278 396 7.4 Carcich et al 121 (32) 330 310 81 7.8 Comm. on Rural Water $ 220(58) 207 165 Schmidt 151 (40) 400 Bounds, 1982-Grinders 189(50) 304 226 42 6.9 Metcalf and Eddy, 3rd. Ed. 189(50) 392 436 70 7.2 Ziebell, 1974 343 259 Average 179(47) 371 338 73 • NTP-TNK-TNB-3 1m4 Pogo4 • The values shown in Table 2 are averages for non-screened wastewater passing from the tank(effluent). Also shown in Table 2 are average strengths for single and multiple compartment tanks. Table 2: Characteristics of Septic Tank Effluent (unfiltered) Source Flow BOD5 TSS Grease pH (compartments) L(eal)/capita/dav mu/1 mg/I mg/I Kreissl 242(64) 218 114 Lawrence-Home 1 117(31) 224 130 26 7.5 Lawrence-Home 2 185 (49) 124 70 8.5 7.2 Otis et al 125 60 Otis et al 130 40 U. Wisconsin 158 51 Bennett, ASAE 134 :, Schmidt-(two) 151 (40) 90 7.1 Bounds, 1982-STEP-(one) 189(50) 118 52 16 6.9 PHS 2nd Series 178 . 111 7.4 PHS 3rd Series 92 112 19 7.5 PHS 4th Series 151 128 7.5 Barshied 223 39 7.1 Ronayne, 1982-(two) 208(55),, - 217 146 USEPA 1980 On-Site 167(44)" 155 88 Ziebell, 1974 158 51 Eastsound,WA,Bounds 1996 214 117 Loon Lake,WA,Bounds 1996 90 45 Cagle, 1993,Placer, CA-(two) 160 73 Average 180(48) 156 84 17 The values shown in Table 3 are averages for effluent passing from the tanks equipped with screened vault dosing assemblies. The data shown are from community effluent collection systems, nearly all of which have restaurants, schools and other commercial establishments in addition to residential connections. Table 3: Characteristics of Screened STEP and STEG Effluent Source Installed EDUsa Flow BODs TSS Deal)/capita/dav mg/1 me/I Gala Manor,CA 1991 100 200 22 Penn Valley, CA 1989 376 144(38) 129 28 . West Point, CA 1986 165 265 (70) 136 32 Ball, OR 1992 1 246(65) 125 28 Brooks, OR 1991 318 III 37 . Elkton, OR 1989 135 159(42) 136 32 Irrigon,OR 1989 446 314(83) 93 35 Lapine, OR 1988 205 103 Tangent, OR 1987 230 110 27 Boston Harbor,WA 1989 182 164 34 Camas, WA 1989 1070 108 35 Montesano,WA 1989 1500 160 30 - • • • , South Prairie, WA 1992 136 210 37 Stuth(Aqua Test), WA 1992 I 70 15 Average 226(60) A 133 30 a. Number of Equivalent Dwelling Unit based on the flow from an average single family dwelling with 3 occupants (150 gpd/EDU). . NTP-TNK-TRB-3 17A7 Page 5 The values shown in Table 4 are averages of various other septic tank effluent characteristics taken from the Glide, Oregon, Pressure Sewer Wastewater Characteristics report(Bounds 1982). Table 4: Septic Tank Effluent Characteristic from Glide.OR Characteristic Range Mean Alkalinity, mg/1 200-335 246 TSS, mg/1 17-130 52 VSS, mg/1 13-114 40 Grease,mg/1 6-59 16 pH 6.4-7.3 7.2 Temperatures,°C 10-23 16.1 SO4,mg/1 31-74 43 Na, mg/1 59-99 79 Mg, mg/1 4.7-26 15.4 Ca, mg/1 3-13 - 8 Ortho/Poly PO4,mg/1 8.8-15 12 PO4, mg/1 9.5-12 11 TKN-N,mg/1 40-58 50 NH3-N, mg/1 10.5-48 31.5 The difference between the average values of Tables 1 and ishows that 58 percent reduction in BOD5, 75 percent reduction in TSS and 77 percent reduction in oil and grease occurs as the wastewater passes through the tanks. The difference between the average values of Tables 1 and 3 are an indication that a 64 percent reduction in BOD5 and 91 percent reduction in TSS occurs with the addition of filtering devices. The addition of effluent filters significantly reduced the TSS in wastewater passing through the tanks. This reduction accomplished by a configuration designed to mitigate solids floated by gas ebullition and to retain coarse solids. Filters should be sized and configured so that cleaning is required no more often than every five to ten years. Good segregation and digestion is expected to reduce the total suspended solids by 80 to 90 percent and the biochemical oxygen demand by 60 to 70 percent. The organic(volatile) solids in the influent may vary from 40 to 70 percent; the mineral or inorganic (fixed) solids content, therefore, may range from 30 and 60 percent of the total solids. If solids discharged into tanks are well managed, the inorganic concentration will be reduced considerably.Depending on how well educated the users become regarding proper disposal practices and general care of their system,the digestible solid concentration could.reach 80 percent. Septic tank flora are very complex. For performance to be better understood and optimized, more in- depth and thorough research is necessary. .. .Septic Tank Design Defining the Tank Illustrated in figure 2 is a concrete septic tank typical of the type used in onsite disposal systems and in effluent sewers. The designation, 3785 L (1000 gal)to 5678 L (1500 gal), is nominal and refers-to the NTP-TNK-TRB-3 12/3I Page 6 volume normally occupied by the tank's contents, not including the reserve space. Total volume is usually 15 to 20 percent greater. Effluent Discharge t' ".#3.2 , to > t`aLleaIt )try; .arx:u 1 _ ;7 Depth(inches) dti .. 20 I ` Top ofscnm of alarm L I Alarm -� pl, , Voa� On / _ -g �`'{ 4 t t r"-+ Sy Liquld Level • 114 Vpv„ r- xO :^ s I �, i 10 3 r, Sctim Layer yewINE , 314`:w „,4 ,.». S _ — ,� o _. 7 it. E s l T n 3,. P . �? o flu) (75) 1y",4 Va. Centroid ofd►125"_A ,fit Scum Volume,L(gal) C2 Discharge 6_6" 5� ,.`A Depth(inches) Ports fi `E- 0 20 __ /V M��.(. 's8ts;� �,., 'z&a'��- �.i .'�'a try Ms,saR i ir. '�- h`.t Sludge Laayerx3 'usi` ' '�'el %, ,-/ y 10 :s 'Ix k 0 n 1, ; x k , ni ter i t tf c x, a ,xe„f 5n s-r .,D, ..} 'p t u: 3 t Wnt 0 I i 6finat..asy'1r.^ira n"i' a3 wzs�'n''�*.its t`�"R@°A`s'k"' .�i M.et:R n `l�t?,�i:Xfiti 0 757 1514 (200) (400) Sludge Volume,L(gal) Figure 2: Typical 3785 L(1000 gal) concrete dosing septic tank Tanks that are properly sized and constructed provide highly efficient treatment capable of yielding effluent that is relatively free of fats, oils, greases, solids and other constituents that can clog and foul collection and disposal equipment. Proper sizing is required to ensure adequate volume is available for development of the necessary microbial environments. Also vital to performance are the tank's structural-soundness and watertightness. These ingredients are essential to the success of every system (no exceptions) and should be strictly enforced in all applications, not just within management district boundaries. Methods are presented here to enable designers, regulators, and operations personnel to size tanks relative to occupancy loading, to achieve adequate hydraulic retention times for settlement of solids,to determine a tank's optimum effluent withdrawal level, and to predict septage pumping intervals. Wastewater flows for single-family dwellings typically range from 151 to 227 litres per capita per day (Lpcd) (40 to 60 gallons per capita per day (gpcd)); 189 Lpcd (50 gpcd) is a commonly-used design parameter and is the value used in calculations herein. The number of individuals (capita) is assumed to average three per dwelling. To ensure sufficient capacity each tank must meet these requirements: 1) Provide reserve space adequate for 24 to 48 hours of normal use, in case of malfunction, before repairs must be made. The reserve space (Vr) is that portion of the tank from the soffit to the top of the scum layer when the liquid level is at the alarm stage. The reserve storage capacity is normally the product of the number of occupants and the average daily flow per occupant-757 L ... NIP-INK-T00-3 17197 r Page 7 • (200 gal) is usually sufficient for most three and four bedroom homes. The reserve space also allows for adequate ventilation back through the inlet plumbing. 2) Provide an operating zone sufficient to modulate or surge peak inflows without causing nuisance alarms or excessive hydraulic gradients. The operating zone (Voa) is that portion of the tank between the "off' level and the"high-water alarm" level. Keeping this zone small has the advantage of maximizing sludge and scum storage volume and minimizing disturbance of the scum layer during pumping cycles. Dosing septic tanks may operate at a lower liquid level than tanks that discharge by gravity. If a system malfunction occurs, the resident(s) should be able to continue to use water for at least twenty-four hours, at their average daily flow, before depleting the reserve space. The need for emergency maintenance is minimal. 3) Provide a clear zone with sufficient hydraulic retention time for capturing grease, grit and other substances that settle or float. The clear zone (VcZ) lies between the scum and sludge layers. Dunbar(1908), Laak (1980) and Winneberger(1977) suggest minimum retention times from 6 to 24 hours for adequate suspended solids removal. Residential hydraulic retention based on average daily flows are usually adequate. The critical hydraulic retention time is determined just as the sludge and scum layers approach their minimum respective clear space limits. When a tank's hydraulic retention time is sufficient for settlement, the clear zone contains liquid waste fairly free of solids. 4) Provide sufficient storage capacity for sludge and scum so that septage pumping is infrequent. The scum layer(Vsc) is that portion of the septic tank's contents which floats. One-quarter of this layer is expected to float above the liquid level; three-quarters is submerged. Scum clear space (A) is the distance between the bottom of the scum layer at the pump's "off' level and the outlet (top of the discharge ports) of the septic tank. This distance should be a minimum of three inches. The sludge layer(Vs1) is the accumulation of solids that settle on the bottom of the tank. Sludge clear space (B) is the distance between the top surface of the sludge and the outlet(bottom of the discharge ports) of the septic tank. For tanks having surface area of 2.5 m2 (27 square feet) or more, this distance"B" should be a minimum of six inches. The following equation may be used to estimate the required sludge clear space for tanks with less than 2.5 m2 (27 square feet) of surface area (Wiebel et al., 1955). SCS (B) = 2.66 - 0.08AS1 (1) • where: SCS is the sludge clear space (B), in feet. Ad is the sludge surface area, in square feet. Solids Accumulation Rates Predicting scum and sludge accumulations in order to determine septage pumping intervals is possible using,data collected in various studies of septic tanks. The study most commonly cited is by Weibel, Bendixen and Coulter for the U.S. Public Health Service (1955), and its rate of accumulation has been corroborated by Winneberger(1977), and Bounds (1988). Sludge and scum accumulation rates, established with a high level of confidence (usually 95 percent), are used to estimate the frequency of septage removal, see figure 3. (The statistical confidence level indicates that 95 out of 100 tanks do not NTP-INK-11B-3 1790 Page 8 require pumping before the intervals shown.) These curves represent the gallons per person that have accumulated at any given time in years, so they can be used to project pumping intervals for any occupancy and size or shape tank, including compartmented tanks. 400- p615 350- ,411 ave: u 300= t14 l po,nAs S250— StudgO&S�µ +5096 ,13391=• 300- ( 11$itei - tudBB&Sc,1m Iso ) use • loo- ($ "c ''i so-- 0 I I 1 I I 1 I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time(t)(yrs) Figure 3: Rates of Septage(sludge/scum) accumulation (95 percent level of confidence) Garbage Disposals The 1980 EPA Onsite Wastewater Treatment and Disposal Systems Design Manual reports the use of kitchen garbage disposals increases both floatable and settleable solids accumulation in tanks; a U.S.PHS study (Weibel et al. 1955) quantified the increase in sludge and scum accumulation rates at about 37 percent. A study of the systems in Glide, Oregon (Bounds 1988)gave similar results: use of garbage disposals accelerated the scum accumulation by approximately 34 percent, yet made little difference, an increase of only 2 percent, in the rate of sludge accumulation. Septic Tank Capacities Effects of Occupancy, Loading and Tank Size The total volume of the tank in Figure 2 is expressed as the sum of the volumes of the individual zones: Vt =V, +Voa +VeZ +Vsc+Vsi (2) where: Vt = Total Volume, in L or gal Vr = Reserve Volume, in L or gal V„, = Volume between off and alarm levels, in L or gal V, = Volume of clear zone between scum and sludge layers, in L or gal '" Vse =Scum Volume =Rate of Accumulation (R„)x capita, in L or gal Vet =Sludge Volume =Rate of Accumulation (Red x capita, in L or gal The length of time between tank cleanings—the septage pumping interval—may be estimated by. substituting all the known values into Equation (2) for total volume (Vt): NIP-MK-TOB-3 17/99 Page 9 A typical interval range is illustrated in Figure 4. Given an average wastewater flow of 189 Lpcd (50 gpcd), scum clear space=7.6 cm (3 in.), sludge clear space= 15.2 cm(6 in.), operating space(liquid level off to alarm)= 14 cm (5.5 in.), and a reserve storage time=24 hours, a single family residential tank, for four(4) or fewer occupants, should be 3785 L (1000 gal) to 5678 L (1500 gal) for 5 to 7 occupants. The curves in Figure 4 result from the following nonlinear relationship developed for total sludge and scum accumulation shown in Figure 3, (Sludge &Scum)Bounds,95%: Nsi+se= 47 t"°675 (3) where: Nsi+ac is the volume of sludge and scum, in gallons/capita t is the time in years 25 3785 L (1000 gal) Tank Sizes 5678 L(1500 gal) aS 7570 L(2000 gal) en 20- , 9463 L (2500 gal) 11355 L 3000 al as '.I I �1:71, 15 I T Vat*aE ,gi$i, r - �r 5 z ,a cold 1 ' ; q�.. 2 4 6 8 10 12 14 16 18 20 Occupants Figure 4: Pump-Out Intervals at 95%level of Confidence The pump-out interval must be within a range that is affordable and provides adequate long-term solids retention for ensuring thorough digestion. Intervals that are too short not only retard digestion, but force users to pay significantly more for service and pumping. Philip et al. (1993) determined it takes about three (3)years to establish sufficient volatile organic acid concentrations for the methane formers. The initial additional cost for a larger prefabricated tank is usually insignificant, especially when compared to the present worth value of long-term maintenance. Optimum Effluent Withdrawal Level • -The product of the total septage accumulation, as expressed in Equation (3), and the occupancy load may be substituted into Equation (2), for the volumes of sludge (V51) and scum (V5c), to determine the value of"t" in years. Hence, the depth of sludge and the value of"x" in Figure 2 (the depth from the floor up to the center of the discharge ports or bottom of tee) may be determined. The depth of the discharge ports, for most tank configurations, is usually found to center at about 70 percent of the PITP-TNK-TRB-3 12/94 Page 1g • lowest operating liquid level. This is consistent with the requirement adopted by many governing jurisdictions that the withdrawal elevation"x" be at 65 to 75 percent of the lowest operating liquid depth. This method may be used to establish, for any given tank, the appropriate elevation from which the clear effluent should be withdrawn. Tank Construction Configurations Septic tanks are constructed with an inlet and an outlet, with accesses for periodic removal of digested solids,and with one or more compartments. They are available in many sizes and configurations. See Figures 5, 6, 7, and 8. For residential applications, tanks are usually 3785 L (1000 gal) or 5678 L (1500 gal) but may be larger for homes with higher occupancy. e atf, '"S ,:.4i41 -'--Sr 5 Fy 4 .• , P • 1' M k 1 5 U r1 I , !: :;.;;.;: ": i • ta • • r aV "" < < � IFrHH' IH Figure 5: Typical Gravity Septic Tank Figure 6: Typical Dosing Septic Tank (Single Compartment) (Single Compartment) Inlets The inlet tee performs several essential functions. It directs the inflow into the mid-depth of the liquid level,which enhances the retention and accumulation of floating materials by ensuring the scum layer is not mixed or disturbed by the inrushing flow. The change in direction of the flow dissipates its incoming velocity reducing the mixing action as the influent rushes in the tank; the settleable solids retention is improved by starting the settling at the clear zone level, nearer the bottom and sludge layer, rather,than at the surface. It also provides a path for digested gases to be drafted through the building sewer and house vent. Without a proper inlet fixture,the effluent quality degrades with more solids, fats, oils, greases, soaps etc., washing through. Shape Properly configuring the dimensions and general shape of the tank is important to its performance. For instance square tanks, or tanks with short distances between inlets and outlets, tend to short circuit. Short circuiting results in a degradation of effluent quality. The travel path from the inlet to the outlet fitting should be longer than the width or depth. Tanks that are too long and narrow,however,may be awkward to transport or difficult to pump clean. Typical precast length to liquid depth ratios (.1...13) NIP-INK-TBB-3 1297 Page 11 range from 1i 1 to 3:1 (1 1/2:1 to 2 1/2:1 are the most common). A typical height to width ratio (H:140 is 1:1. The reserve-storage/vent volume between the liquid surface and the soffit of the tank may range from 10 to 20 percent of the tanks total volume (determined minimum volume based on average daily water usage, type of service and service response time). Liquid depths may range from 76.2 cm (30 in.) to 213 cm (84 in.);,minimum and maximum depth criteria vary with local regulations. Tank dimensions have not been established based on empirical performance data, but rather on established practices and available products. General observations, though, suggest that tanks with a long travel distance between the inlet and outlet perform better. aE 7`M. fit:ry y�5.V, 4� .. • 1 \ } B --...-44t. ;4; I1 1 \ �X, Y'n -4 `x l I,i. i .. ^ogi t � �f � ? a Iy, �� -� }l Ty\"t.fib E F -P� `;41'E �[.. ii 'i'i i w ft., v n nr Y� Figure 7: Typical Gravity Septic Tank Figure 8: Typical Dosing Septic Tank (Two Compartment) (Two Compartment) Compartmentation Over the years there has been continuing controversy over single-compartment versus two-compartment tanks. Evidence of significant benefits to effluent quality that would support compartmentation of tanks, as they are presently constructed, is inconclusive. The Public Health Service concluded its study by stating, "It cannot be stated conclusively that there was any significant difference in the operation of the one- and the two-compartment tanks." Winneberger(1984) explains the effect that velocities and turbulence have on the migration path of particles traveling through septic tanks and concludes, like Seabloom(1982), that slow velocities through long tanks yield the highest effluent quality. Winneberger makes two generalizations. First, "the geometric shape of a tank, as such, seems not to be critical. It is the management of flow-through that is of concern" and, second, "the size of that second chamber matters little." However,the duration of these studies is insufficient for long-term predictions. Also, the studies have not adequately addressed how effluent quality is affected as sludge and scum accumulate in the primary compartment. An observation common to all the reports is that, as the hydraulic retention time increases, performance improves (i.e., larger compartments or tanks yield better quality effluents). Regardless of the number, size or shape of supplemental compartments the primary or first compartment's capacity should be designed based on hydraulic loading,velocity through the tank, reserve capacity, solids storage capacity and hydraulic retention time. Too little primary capacity can lead to excessive pump-out frequencies—a costly disaster for the community or individual that has to HIP-THK-TIM-3 12/91 Page 12 deal with the mess and pay for the corrective measures. The difference in cost between a 5768 L (1500 gal) single compartment tank and a smaller 3785 L (1000 gal) two compartment tank is negligible. A larger such tank reduces pumping occurrences by a factor of four or more when servicing a family of three.. Ultimately there will be less organic matter to dispose due to more complete digestion. Excessive hydraulic loads on holiday weekends or wash days will have less effect on the surge capacity of the larger tank. The money saved on unnecessary or less frequent pumping could wisely be spent on servicing and monitoring. Municipal size cast-in-place tanks are frequently divided longitudinally into multiple parallel chambers to improve solids retention by increasing the flow travel distance. Winneberger (1984) refers to these configurations as meander tanks. He suggests, that the width of successive chambers could be narrower depending on the velocity and expected solids accumulation. Figure 9 illustrates a precast partition tank constructed by Willamette Graystone of Eugene, Oregon (Bounds 1996). Partitioning has the added advantage of substantially improving the tank's structural strength. .�► :,Effluent Discharge Inlets WeiS ' 12/ ^:45As T' kal i, a a Pe .. bl watt s a%-16,0,d En- Figure 9: Partition Tank Configuration with Removable Scum Baffle Methods of Discharge Properly sized and designed tanks result in relatively clear effluent that may be discharged either by gravity or with siphons or pumps. Gravity outlet assemblies have, in the past, been the cause of many septic system failures. Whether poorly constructed or poorly installed, many of the early style concrete fixtures or attached baffles would deteriorate and/or fall off allowing the scum layer to pass out of the tank. Greases, oils, fats and bulking solids would clog the system, necessitating costly repairs to the drainfield. Discharge teejinologies and tank standards have made tremendous advancements, so this is much less of a concern in current'tank designs. When discharged from screened assemblies, effluent may be conveyed through small diameter service lines (1 inch or 11/4 inches in diameter) to its final destination. NTP-TNK-TRB-3 12/91 Page 13 Watertightness Our greatest effort as an industry must be to get properly sized, structurally adequate and watertight tanks to all installations to ensure to quality and consistency of the discharge. The preponderance of septic tanks sold in the U.S. are structurally unsound and almost never watertight. Leaky tanks are unacceptable and watertightness is a requirement that should be mandatory for all onsite applications. Although most regulatory authorities require watertightness, enforcement is almost nonexistent. Testing criteria need to be established for gauging and enforcing quality. Explicit details and specifications are necessary to ensure quality tank construction. Even so, unless strict quality control is uniformly enforced, manufacturers of quality tanks will find it hard to compete with those who make inferior tanks and sell them cheaply. The extra cost of a high quality tank is insignificant when compared to the cost of maintaining or replacing a system with inadequate tanks. Where ground water levels are high, leaky tanks allow infiltration that causes solids and greases to wash through the tank, lowering treatment efficiency and leading to the eventual failure of onsite disposal systems. Infiltration/inflow (I/I) in effluent sewers overload both collection and treatment capacities. Hydraulic overloading, due to building sewer or tank leakage, causes degradation in the tank's effluent quality. Settleable and floatable solids, grease and oils are flushed from their storage zones. Hydraulically overloaded main lines restrict the user population of the system. Energy cost to convey this unnecessary contribution of water increases. Watertight systems allow more cost effective treatment and collection system designs. Ultimate population design potentials are not jeopardized by excessive hydraulic and organic stresses on treatment. • In 1985, the city of Montesano, Washington, was directed by the Washington Department of Ecology to correct the I/I problems in its municipal system. They had been considering a forty-acre lagoon system to handle I/I flows reported to be as much as 30 times normal dry weather flows. Instead, Montesano became the first community in history to convert from a gravity sewer to an effluent sewer. Currently there are 1230 connections serving an equivalent flow of about 1600 dwelling units. Residential tanks are fiberglass of 3785 L (1000 gal) capacity. Eighteen months following construction, engineers completed a year long study concluding that over 99 percent of the VI had been removed. Final treatment is accomplished in a three-cell lagoon located on three acres. Where high groundwater is not a problem, a leaky tank will exfiltrate, lowering the scum layer to the outlet level where the floatable solids, fats, soaps, oils and greases can be dosed or washed through the outlet assembly. Effluent that leaks directly into groundwater from a leaky tank contributes to • groundwater contamination. Exfiltration hinders segregation-and biological activity and proper development of a clear zone. Effluent quality degrades, organic digestion diminishes and service frequencies increase. Eventually, system failure ensues and/or maintenance becomes excessive and costly. It follows, then, that for wastewater systems with septic tanks to be efficient and reliable, and for predictions of solids accumulations and pumping intervals to have validity and continuity, septic tanks must be watertight. The success of onsite and effluent sewer technologies is directly dependent on the quality of the design and construction of the tank. • NTP-TNK-1118-3 17N7 Page 19 Materials and Quality of Construction The material most commonly used in the fabrication of septic tanks is reinforced concrete; fiberglass, polyethylene, and steel tanks are also options. Old-fashioned septic tanks, constructed without benefit of adequate design standards, quality control and with little or no reinforcing, are now outmoded. Designers demand and progressive manufacturers are now able to supply sophisticated constructions that are engineered to be structurally sound and watertight. Leaky tanks, which commonly turn many traditional onsite systems into nothing better than cesspools, are no longer acceptable. Reinforced concrete is usually the material of choice based on its cost-effectiveness, structural integrity, corrosion resistance, watertightness, buoyancy resistance, site suitability and installation ease. Fiberglass has many of the same qualities and may be preferred because of its light weight where site accessibility for heavy equipment is limited or restricted. Where permanent or temporary high ground waters exist, however, fiberglass tanks must be installed so that they resist buoyancy. Steel tank with thick corrosion resistive coatings and cathodic protection are used with success in some areas. The slightest damage to the protective coating, however, may expose the steel and severely shorten the tank's life, which is normally about 20 years. Polyethylene's strength is intrinsically less, so poly tank installations are typically restricted to unsaturated sites with reduced structural requirements. Poly tanks require additional bedding and backfilling efforts, and in some locations may require a low-strength concrete backfill. Design Guidelines Following are guidelines for quality tanks for standard locations. In areas where burial depth must be more than four feet or where heavy traffic or other loading is expected, additional support may be necessary. General Design Criteria a. Top=400 psf (The tank shall be capable of supporting long-term unsaturated soil loading in addition to the lateral hydrostatic load) b. Lateral Load =62.4 pcf (The tank shall be capable of withstanding long-term hydrostatic loading with the water table maintained at ground surface.) c. Concentrated Wheel Load=2500 lb. (The tank and accesses shall be capable of supporting short-term wheel load in addition to the unsaturated soil loading) d. Soil Bearing= 1500 psf (Soil bearing is site specific and must reflect the worst case conditions) e. Cold weather installations requiring deep burial need special consideration. 11 All tanks shall successfully withstand an above ground static hydraulic test. g. The inlet plumbing shall penetrate at least 30.5 cm,(12 in.) into the liquid from the inlet flow line. If the submerged scum depth is expected to be greater than 30.5 cm (12 in.), the inlet fixture should be extended into the liquid two inches below the expected lowest scum depth. General Specifications .. • . ,a,,Manufacturer's Guarantee shall be for a period of two years. b. All tanks shall be installed in strict accordance with the manufacturer's instructions. NTP-INK-TBB-3 12/91 Page 15 Concrete tanks The walls,bottom and top of reinforced-concrete tanks are usually designed spanning the shortest dimension using one-way slab analysis. Stresses in each face of monolithically-constructed tanks are determined by analyzing the tank's cross-section as a continuous fixed frame. The walls and bottom slab should be required to be poured monolithically. When a tank is expected to be submerged, subjected to heavy traffic loads, or buried deeply, the top slab must be cast onto the walls with wall reinforcement extending into the top slab. The bottom thickness of the wall should be equal to the thickness of the floor, which is usually thicker. At the wall-floor joint the stress is equally shared; therefore, steel spacing is more efficient and cost effective if the wall thickness is equal to the thickness of the floor. The wall can taper to three inches at the top. Tapering the interior mold at the bottom improves the flowability of the concrete around the walls and into the floor. Chamfering the wall-floor junction on the inside reduces the effect of suction between the tank-mold and concrete surfaces; thus the integrity of the concrete at the joint is better maintained and less effort is needed to remove the interior mold. Casting the top in place will produce a much stronger tank than will setting the top in place. A cast on lid, with wall reinforcement adequately tied to the top reinforcement, improves the structural capacity of the top and bottom by more than 40 percent and the walls by about 25 percent. The required rebar spacing will be wider, which reduces materials cost and labor in fabrication. With the wall and top joint cast together there is greater assurance that if differential settlement occurs the top will not separate from the wall causing loss'of lateral support at the top. Separation of the top lid from the wall would significantly reduce the tank's strength and its watertightness would be lost. Set in place lids must be mechanically attached to the walls to assure the joint does not separate when the tank shifts or settles. Concrete Specifications Concrete must achieve a minimum compressive strength of 4,000 psi in 28 days. The design of the concrete mix depends on the gradation of the aggregate and should be determined by a professional engineer. A common 4000 psi ready-mix design has a cement content of six and one half(61/2) sacks per cubic yard and maximum aggregate size of 19 mm (3/4 in.) (Ready-mix cement conforming to ASTM C- 150, Type IL) Water/Cement Ratio. To ensure proper curing and ultimate strength, it's important to keep the water/cement ratio low, 0.35 ±. • Air-entraining agents may be required depending on the mix design, although they are not usually necessary for small concrete tanks. Air-entrainment without additives is usually 1 to 2 %. FiberAdditives may be used to enhance watertightness by controlling concrete shrinkage. Jr Protective Coatings. Heavy cement-based sealants may be used inside and out. The manufacturer's directions must be followed exactly. Bituminous coatings are not necessary. In Pomeroy's work for the EPA,published as 1974 Sulfide Control In Sanitary Sewerage Systems, he recognized that bituminous coatings were not effective in reducing sulfide corrosion. Wiimeberger discusses the fact that the NTP-TNK•TN9.3 1791 Page 16 R atmosphere in a well vented septic tank is not greatly different from the atmosphere above grade. Hydrogen sulfide concentrations were lower than what could be measured by wet chemistry techniques. Methane was also non-detectable. Only the oxygen concentration was a bit below that of the outside atmosphere. Reinforcing Steel shall be Grade 60, fy= 60,000 psi (ASTMA-615 Grade 60). Size and placement must be determined by a structural engineer. Wire fabric is not acceptable. Weldable steel may be specified if the reinforcing cage is to be tack welded during assembly. Misalignment of reinforcement in a three inch thick section can significantly reduce the strength of the tank; for instance, a quarter inch of misalignment will reduce the capacity of that section by about thirty percent, one-half inch of misalignment will reduce the capacity by fifty percent. Form Release must be Nox-Crete or equal. Diesel or other petroleum products are not acceptable. Vibration. Tank molds must have attached vibrators to ensure adequate flow of concrete down the walls and across the bottom. Excess vibration can cause the aggregate to segregate. Curing. Proper curing techniques are necessary to ensure watertight tanks. Tanks must not be moved until they have cured for seven (7) days or have reached two-thirds of the design strength. Test Cylinders must be taken from each batch of concrete and tested until the minimum compression strength has been obtained. Fiberglass Tanks Glass fiber and resin content must comply with IAPMO IGC 3-74, and there should be no exposed glass fibers. Metal parts must be 300 series stainless steel. Wall thickness must average at least 6.3 mm (1/4 in.) with no wall thickness less than 4.8 mm ('/i6 in.) No delamination is allowable. Holes specified in the tank must be protected with an application of resin on all cut or ground edges sufficient so that no glass fibers are exposed and all voids are filled. • Neoprene gaskets, or an approved equal, must be used at the inlet to join the tank wall and the ABS inlet piping. ABS Schedule.40 pipe and fittings must be used at the inlets. Testing Follow these test procedures to ensure watertightness. Test every tank at the factory and again after • • installation:, 1) Fill the tank to its brim with water and let it stand for 24 hours. To help expedite larger orders a vacuum test may be substituted at the factory, and after the tanks are delivered to the job site. A vacuum test may not, however, take the place of the final installed static water test. NTP-INK-TBB-3 12/94 Pagel] • 2) Measure the water loss; if there is no water loss during the first 24 hours the tank is acceptable for installation. Some water absorption, however,may occur during this first time period. If so, refill the tank and determine any exfiltration by measuring the water loss over the next two (2) hours. Any water loss is cause for rejection. 3) Install the tank and repeat steps 1 and 2. These procedures should be followed after setting and after backfrlling. Test the seal between the riser and the tank top for watertightness by filling the riser with water to a level 2" above the top brim of the tank. Caution: To prevent hydrostatic uplift damdge to the top joint of the tank, do not allow the level of water in the riser to exceed the level of the backftll. Buoyancy Improper septagd pumping of a buried tank may result in the tank suddenly "floating" to the surface, causing damage to piping,landscaping or worse, injuring maintenance personnel. The following precautions help to ensure tank submergence in areas with high groundwater: • Require a minimum cover where high groundwater conditions are suspected (evaluation must be provided after identifying site °specific soil conditions). • After setting the tank, pour an additional 15.25 cm (6 in.) of concrete over the top; extend a minimum of 30.5 cm (12 in.) beyond the sides of the tank. Lightweight plastic tanks (v•-:,400 lbs) require concrete or other counter measures sufficient to exceed the buoyant force. • The weight of concrete tanks can be increased by adding thickness to the walls, top and/or bottom. • Operation and maintenance instructions should clearly state that tanks must never have more than half(50%) of their contents pumped out during periods when the groundwater is high; especially if they are located in sandy soil. This recommendation is for cautionary purposes only, and is not a substitute for physical buoyancy restraints. Monitoring Even under ideal conditions; estimates of septage pumping intervals are useful in predicting the amount of maintenance required by a population of tanks, not in determining when an individual tank needs to be pumped. The only way to know when a tank needs to be pumped is through direct measurement of the scum and sludge thickness. The monitoring experience from Glide showed that after five years, considerably less than half of most tanks' scum and sludge capacity had been reached (Bounds, 1988). Onsite design manuals may encourage frequent pump-outs as a precautionary measure when an inspection program is not in effect, however, longer intervals are usually justified, particularly if an effluent screening device is in place. Conclusion In summary, structurally adequate and watertight septic tank systems are no longer considered a temporary stopgap until such time as a"real" sewer can be built. As technology has improved the image of the septic tank, it has come to be appreciated as a component of an efficient and permanent solution. As Such,jt deserves to be accorded the same scientific consideration as other treatment systems. Structural designs and quality assurance should be based on the same long-term and physical loading criteria required of all submerged wastewater treatment vessels. Adequate sizing procedures and designs for watertight tanks are available. Sizing must be based not only on occupancy, but on biological, hydraulic and chemical loading conditions. Predicting reasonable septic tank pumping intervals with a NTP-INK-TBB-3 PM Page la respectable degree of reliability is an achievable goal. Suggestions or requirements that all septic tanks must be pumped every two, three or even five years are simply unsupported by scientific evidence. The microbial activity that affects optimal decomposition takes up to three years to develop fully (Philip et al. 1993). When a management program is in place,pump-outs are scheduled based on inspections and monitoring records so that costs are controlled. Current septic tank technologies are capable of treating wastewater(onsite) to a higher level of quality than do the vast majority of municipal treatment plants. Properly designed, these onsite technologies are more fail safe and fail soft than municipal facilities. Effluent sewer and onsite wastewater technologies have been established as an affordable and reliable alternative. Passive—energy free—septic tanks provide the most cost efficient method of primary treatment available for nonindustrial sewage. References Ball, H.L., 1994, "Nitrogen Reduction in a Onsite Trickling Filter/Upflow Filter Wastewater Treatment System," Onsite Wastewater Treatment American Society of Agricultural Engineers, Atlanta, Georgia. Barshied,Robert D. and Hassan M. El-Baroudi, October 1974, "Physical-Chemical Treatment of Septic Tank Effluent," Journal of the Water Pollution Control Federation. Bennett, E.r. et al., 1975, "Rural Home Wastewater Characteristics," Proceedings of National Home Sewage Disposal Symposium American Society of Agricultural Engineers. Bitton, Gabriel, 1994, "Wastewater Microbiology," John Wiley & Son's, Inc. Publication. Bounds, T.R., 1982, "Wastewater Characteristics Glide, Oregon, Pressure Sewer System," Douglas County Department of Public Works, Roseburg, Oregon. Bounds, T.R., 1988, "Glide Audit 1986-1987, Summary of Sludge and Scum Accumulation Rates," Douglas County Department of Public Works, Roseburg, Oregon. Bounds, T.R., 1995, "Septic Tank Septage Pumping Intervals," 8th Northwest Onsite Wastewater Treatment Short Course and Equipment Exhibition. University of Washington Department of Civil Engineering/Washington State Department of Health. Bounds, T.R., February 1996, "Alternative Sewer Designs Effluent Sewer Technology Septic Tank Effluent Pump and Septic Tank Effluent Gravity Systems" Orenco Systems Inc., Sutherlin, Oregon. .. Bounds, T.R., 1996, "Design of Partition tank using tank dimensions for Willamette Graystone of Eugene, Oregon," Orenco Systems Inc., Sutherlin, Oregon. Cagle, Wm. A. and Johnson,Lynn A., 1994, "Onsite Intermittent Sand Filter Systems; A Regulatory/Scientific Approach to their study in Placer County, California," Onsite Wastewater Treatment American Society of Agricultural Engineers, Atlanta, Georgia. NTP-TNK-TBB-3 ty97 4 Page 19 Carcich, Italo G. et al, 1972, "A Pressure Sewer System Demonstration," Environmental Protection Agency. Commission on Rural Water, 1973, "Wastewater Treatment Systems for Rural Communities." Dunbar, Prof Dr., 1908, "Principles of Sewage Treatment," Charles Griffin & Co., Ltd., London, England. Kreissl,J.F., 1971 "Waste Treatment for Small Flows," Paper presented to the 1971 annual meeting, American Society of Agricultural Engineers. Washington State University,Pullman, Washington, June 27-30, 1971. Laak, Rein., 1980,"Wastewater Engineering Design for Unsewered Areas,"Ann Arbor Science Publishing/The Butterworth Group, Ann Arbor, Michigan. Lawrence, C.H.,Nov/Dec 1973, "Septic Tank Performance,"Journal of the Environmental Health, Volume 36,No. 3 page 220. McKinney, Ross E., 1962, "Microbiology for Sanitary Engineers," McGraw-I-Iill Book Company ISBN • 07-045180-X. Metcalf and Eddy, Inc., Collection, Treatment, Disposal 1972, "Wastewater Engineering," (New York: McGraw-Hill). - Metcalf and Eddy, Inc., 3rd Edition, 1990, "Wastewater Engineering," (New York: McGraw-Hill). Otis, R.N., N.J. Hutelek and W.C. Boyle, September 1973, "On-Site Household Wastewater Treatment Alternatives, Laboratory and Field Studies," paper,presented at the Rural Environmental Engineering Conference, Warren,Vermont. Philip, H., Maunoir, S., Rambaud, A., and Philippi, L.S., 1993. "Septic tank sludge's: accumulation rate and biochemical characteristics,"proceedings of the second international specialized conference on design and operation of small wastewater treatment plants. Trondheim, Norway. Pomeroy R.D.,Johnson and Bailey, 1974, Process Design Manual for"Sulfide Control in Sanitary Sewerage Systems," U.S. EPA Technology Transfer. Ronayne M.P., R.C. Paeth and S.A. Wilson, 1982, "Final Report: Oregon Onsite Experimental Systems Program," Oregon Department Of Environmental Quality. Seabloom Robert W., Dr., 1982, "Septic Tank Performance Compartmentation, Efficiency and Stressing,"Professor, Department of Civil Engineering, University of Washington, Seattle Washington. Stuth, Wm. Sr., 1993 "Effect of screened vault technology in a two compartment tank," lab results. NTP-TNK-TBB-3 12.91 Page 1B Taber, W.A. 1996, Wastewater Microbiolo y Ann, Rev. Microbial. 30:263-277. Tyler, E.J., R.B. Corey and M.U. Olotu., 1978 "Potential Effects of Water Softener use on Septic Tank Soil Absorption Onsite Wastewater Systems," Final Report to the Water Quality Research Council. University of Wisconsin, January 1975, "Papers by Small Scale Waste Management Project." U.S. Environmental Protection Agency, 1991. Manual: alternative wastewater collection systems, EPA/625/1-91-024. U.S. Environmental Protection Agency, 1980. Design Manual-Onsite Wastewater Treatment and Disposal Systems. U.S. Department of Health, Education, and Welfare;formerly U.S. Public Health Service, 1957 (reprinted 1972). Manual of Septic-Tank Practice, Publication No. 526. Water Pollution Control Federation, 1986, "Alternative Sewer Systems,"Manual of Practice, MOP No. FD-12. Watson, K.S., R.P. Farrell and J.S. Anderson. January 1967. "The Contribution from Individual Homes to the Sewer System." Journal of the Water Pollution Control Federation. Weibel, S.R., Bendixen, T.W., and Coulter, J.B., 1955, "Studies on Household Sewage Disposal Systems, Part III,"U.S. Public Health Service Publication No. 397. Weibel, S.R., et al. 1949, "Studies of Household Sewage Disposal Systems,"U.S. Public Health Service. Winneberger, John Timothy, Ph.D., 1977, Consultant, Septic tank systems, personal communication titled Interceptor tank design. Winneberger, John H. Timothy, 1984, "Septic-Tank Systems, A Consultant's Toolkit, Volume II the Septic Tank", Butterworth Publishers/Ann Arbor Science. Zeibell, W.A., D.H. Nero, J.F. Deininger and E McCoy, 1974, "Use of Bacteria in Assisting Wastewater Treatment and Soil Disposal Systems," Proceedings of the National Symposium.on Home Sewage Disposal,ASAE. This paper was first presented by Terry R. Bounds, PE., at the1997 conference of the American Society for Testing and Materials, in Philadelphia, Pennsylvania. NTP-TNK-TBB-3 17190 Page 21 40:ses CB AdvaliTex® Design Criteria o ems 1-800-348-9843 For Commercial and Multi-Family Applications System Description and Treatment Process Commercial AdvanTex®Treatment Systems are a multiple-pass, packed bed aerobic wastewater treatment technology specifically designed and engineered for long-term processing of domestic strength wastewater. Figure 1 shows a standard layout for the secondary treatment system(primary treatment and dispersal not shown). r—Air Inlet • � s I i AdvanTex AX100(typ.) • , Yv it Automatic Distribution Valve iiWe" �''' _ 4 ' I Ventilation Fan I r rr Assembly II I+t Screened Influent From Primary Tankage ProSTEP rumping Package Recirculating i I Splitter Valve I Discharge Recirc-Blend Tank Fig.1 Standard Commercial AdvanTex Treatment System:Top View AdvanTex Treatment Systems are capable of processing typical commercial AdvanTex influent wastewater (see Table 1) to better than"secondary standards." Prior to the AdvanTex Treatment System, . primary,treatment of raw sewage is accomplished through appropriately sized primary septic tanks. After primary treatment, the effluent enters the recirc-blend tank, where it blends with the contents of the tank. ProSTEPTm pump packages in the recirc-blend tank transport blended effluent to a distribution manifold in the AdvanTex filter pod. Effluent percolates down through the textile media,where it is treated by naturally-occurring microorganisms that populate the filter. After passing through the filter media, the treated effluent flows out of the filter pod through the filtrate return line that returns the • NDA-ATB-COMM-PKG-1 Bev.1.0,©5/03 Page 1 0110 effluent to the recirculating valve (RSV or MM). The valve automatically splits or diverts the flow between the recirc-blend tank and the final discharge and controls the liquid level within the tank. During extended periods of low forward flow into the system, 100% of the treated effluent is returned to the recirc-blend tank. The recirc-blend tank is set up so that incoming effluent from the primary septic tanks and filtrate from the AdvanTex system pods enter opposite the pump discharge to the pods so that mixing, blending, and dilution of the effluent occurs before being dosed onto the AdvanTex filter pods. System Selection: Configuration The AdvanTex Treatment System is typically configured as shown in Figure I. Excellent results with regard to cBOD5 and TSS should be achieved, and in addition, total nitrogen reduction will typically exceed 60% on average, assuming sufficient alkalinity is available. If additional nitrogen reduction is desired, a specialty mode in which a portion of the filtrate is routed to recirculate through the primary tank may be considered. This option allows for improved denitrification to enhance the overall nutrient removal. There are several other factors that influence the nitrogen process, and each of these should be considered when developing a plan for achieving significant reductions in this area. System Requirements: Typical Commercial AdvanTex Influent Wastewater Strength • As in residential applications, commercial wastewater strengths must remain within typical influent limits as shown in Table 1, below. Consult Orenco or an authorized Dealer for higher waste strength applications. • Table 1. Typical Commercial AdvanTex Influent Wastewater Strength ' Characteristic Average2 Weekly Peak Rarely Exceed rng/L mg/L mg/L BOD5 150 250 500 TSS 40 75 150 TKN 65 75 150 G&O 20 25 30 'Maximum allowable wastewater strength entering the Recirc-blend Tank of an AdvanTex Treatment System is "Typical Commercial AdvanTex Influent Wastewater Strength." - 'Commercial systems will occasionally elevate in strength based upon changes in flow characteristics or ownership. As the average influent strength approaches 80%of the weekly peak levels, consideration must be given to providing supplemental pre-treatment or additional treatment units. System Requirements: Recommended Primary Tankage Typical Primary Tank sizing will be based on Preferred HRTs (Hydraulic Retention Times) as described in the Primary Tank Sizing Chart* (NDA-TNK-1) provided as an Appendix to this document. Recommendations assume that peak weekly flows are typically two times normal average daily flows. In the primary tank(s), the raw sewage separates into three distinct zones: a scum layer, a sludge layer, and a clear layer. Heavy solids settle to the bottom to form the sludge layer, while the lighter material floats to the top to create the scum layer. Facultative and anaerobic digestion converts the organic matter to volatile organic acids while strict anaerobes ferment the volatile organic acids to gases (methane, carbon dioxide, etc.). Effluent from the clear zone is then passed through a Biotube®effluent • filter before being transported to the recirc-blend tank. See Figure 2. For the system to operate properly, N0A-ATK-00MM-PKG-1 Bev.1.0,®5/03 Page 2 0110 all tanks must meet minimum structural requirements, be completely watertight, and pass a watertight - test including the riser/tank connection. For detailed specifications, see structural and watertightness criteria in Orenco's Material Specifications (NDA-ATX-COMM—SPECS-1). A AWVe A PI i+le'": 'k ,3 .'S + 'dl..�f�:. '7,C tli S.j^_ "a4 .'i ' p. • Ih — . ..•, €s + Tamar t`t`,- x a4{ { - ' ,t�,��# t z ,x . �l= • ,I A �,�,�tu� fr�'{ic �_ .a�"...{ ,� {A I e e,, „r'I- ,$e rv�ila�y'' S�,4t e 1 c,r,:it r laa,'E: .. 7 .L=Y AV 1{ �§:W 1 �� } y Y � " y14 Clear n:Do •:... ?:' r. r2"c ! ,,, , _ t k -k s s-c 2vt s ¢`. ' ka �c{ a Y`v z^ ; ygyfr�i f'�'�a i ^.„,+rte x s a, i"r r Stud e� , Sr ! s Q fg;t a ft. i�3ds 4 fy a t P }y! 'x 4.?! O� { R1t z u 1—e k `� ts.'Y. Ya ,fr . � i %i th��"`. f ts-' iffirl; 6 '111M.0 u t Fig.2 Typical Primary Tank When the required tank size exceeds available premanufactured tank capacities, cast-in-place meander or multiple FRP or precast tanks as shown in Figures 3a and 3b are preferred configurations. Two separate documents, Septic Tank Sizing for Large Flows, (NTP-TNK-TRB-2) and Design and Performance of Septic Tanks, (NTP-TNK-TRB-3), provide significant background information specific to the primary tank design and configuration. PAe{ 1 fit '"`^-.. �' 1 �II7.:-..-,-..„.........„.,,te „'--,.,_. "A � - „ ` `-1 \_1 / 11)), i ,,_ -,.. zrt-- ,--;fr- K iia:<z i - bat J -1 :- 0 / \ 11 / • fig.3a. ,:> , Fig.36 Cast-in-Place Primary Meander Tank Multiple Primary FRP tanks Recirculation-Blend Tankage The recirculation-blend tank is sized to equal at least 80% of the peak flow (Q,). A larger tank may be recommended based on the expected organic or peak design hydraulic loads, or to accommodate special surge capacities or operator response capabilities. NDMFTK-COMM-PKG-1 Her.1.0,@ 5103 Page 3 a110 For nitrogen sensitive areas requiring greater than 60% nitrogen reduction, the recirc-blend tankage is sized to'equal at least 100% of the peak flow and greater primary tankage is recommended. Where access to a primary waste source is unavailable, this may be provided as two separate tanks,typically an 80%recirc-blend, preceded by a 20% denitrification tank. Consult with Orenco's Systems Engineering Department for details. Design Loading Rates Typical loading rates are based on the AdvanTex Loading Chart for Commercial and Multi-Family Applications, (NDA-ATX-4) provided as an Appendix to this document. Orenco's suggested design loading rates are based on typical per capita flow rates and average strength characteristics expected as listed in Table 1. Performance is a function of the expected typical loads with periodic weekly peaks. Orenco Systems, Inc.'s AX100 AdvanTex Treatment Systems packed bed media is configured in the same manner as our ANSI/NSF Standard 40 Class I treatment units. Typically, the daily mass loading is based on the expected daily flows and parameter strength. Figures 4a and 4b show average loading capacity at 95% confidence level. Effluent Quality vs. Hydraulic Loading Bates Third Party ANSI and NSF 40 Testing Results 60 ._.k' t Jta raa� espy• ,pr t`t;r'S�at�y>?� ki/�pp 1''-f r �rtc rS f CQODr�S 4�1 'l C,° ix} �. 3r 3' it � ifl �T tY C e iM1 �+ i tie}r o ° a , i It i t yip o f 41 50 ita tlI ie,, Y7S 1 r4 1 p r 44,,e 50 } r.-fe x a i sF 4 n t { ' £i '. r 11- 402 r 1- �'-rrt y TbP' t�� rIapry� rl� a, 1� i° � �liau�# lp'4 r �" i' i 3,{-r �a aYa aTe5a+r'� 72+x';, §nr H.. fm!�*x`ktr . r irk r it c . y >' , J^' r lu Y.: =Yc.",a NoveTec 40 a} t �. } r4 s 7Yi U 4 40 fiA, ii S a t }„Fy, b 1 l F 60 eilli C ti ie s '4 V4 W"Ta rth : 7xi 0111 ate ' 01 p7a}''9 n,'p3r -?, 1 i a a t >i 9V t t-'s- i8' itll tra.t a a r pit.x oogiit1N'sti 14 E x p lr !> t of tOmoa v, �z Nti 301'as >lr `(ti{t p.a, a y 1'°''dPS ov F `' E 30 sS-' , a cis FW'kr c ,t 1 o3 ,ci10mu a.n } r "al 4 i ' fir' , Fad 414 o-NOvaTed`€f �,1pO iLeti5{y '4ezi'4x1 , 3^I s NovaTec2 ��c rc . m YE,P 1�a iar�l'v NSFr 144'4 1iidif aieg F 20 kta;�t' p2,4d' 0:44�,"r a� ?; r4AgPo teg r it as a t IISF r n#, M k4ill00avia°��t2Bjgpolli ar rx TMrl z 14, a r4002Yt8� ^'2011bPdlfi"'` *4 t 4110 tv . 1tf VII F r Yx r1� i .t j i a ,4 S pia 10 S tlgpoltl' ,x sryy x i0 12 9Pd/lt1 r 6 mOr r i } t3 M py5 0 p t tisL1 axt t+C} 1110 sf .4t^` •rr_r aka, 1' 0µv x-��s r a 0 .tx..:..: -* " M, i_. o\40,1 att , xj7 o-0 10 20 30 40 50 60 0 10 20 30 40 50 60 ilydralilic Loadliig Rate, gpditt' — 95%Confidence Level —Average ■ Recommended Design Range for Residential Strength Waste Fig.4a—cBOD5 Fig.4b -TSS The base AdvanTex AX100 hydraulic load is 25 gpd/ft2 with a base organic loading rate of 0.04 lbpd BOD/ft2 (AX100: 2500 gpd—4.0 lbpd). At these loading rates "actual" design criteria targets a 5/5 effluent quality in the discharge effluent. Discharge levels may be projected at a 95% confidence level relative to the hydraulic loading rate. Peak hydraulic loads of 5000 gpd and peak organic stress loads of over 8 lbs per day can be handled for short periods of time with little effect on performance. Higher loading rates may be applicable relative to hiher discharge limits or sufficient operating documentation, but would not be allowed to exceed 50 gpd/ft at the typical average characteristics presented in Table 1. A thorough evaluation of all the typical wastewater characteristics will guide design limits. High oil and grease'c0ncehtrations may require pretreatment to ensure maintenance frequencies are not excessive. If the loading rate (or mass load) needs to be reduced to meet discharge limits, it's a simple matter of adding additional modular units. Operationally, the module's flexible and easily serviceable features make AdvanTex units an ideal, efficient, and effective solution for all wastewater treatment applications with domestic waste characteristics. NDA-ATX-COMM-PKG-1 eev.1.0.©5103 Page 4 of 10 Venting Commercial AdvanTex filters may come with either an active or passive vent system, depending on application type and'desired treatment levels. An active vent system utilizing a low wattage fan will typically be used, except for small systems with residential quality influent waste strengths. The internal volume of an AX100 is about 350 ft3; typically, air changes occur every other hour. The inlet plumbing to the recirc-blend tank should allow for natural ventilation back through the building sewer and vent stack. Building sewer lines provide a natural conduit for air movement and exchange throughout the recirc-blend tank and treatment system. The passive vent provided contains a carbon filter material to mitigate odors. However, a small amount of odor may still occur during a dosing event, as air from the pod is displaced by the dosed effluent. This should be taken into consideration before siting or locating a passive ventilated system in areas where this occasional odor may be perceived as a nuisance. Typical Effluent Quality Effluent quality is dependent on a number of factors, including influent characteristics and loading rates. Third party ANSI/NSF 40 testing results are shown in Figures 4a and 4b. The results demonstrate that low-to-moderate loading rates can produce cBOD and TSS of<5 mg/L,while higher loading rates produce cBOD and TSS in the range of 15-25 mg/L. Nitrogen reduction in the standard configuration will typically exceed 60 percent. Using a specialty mode, nitrogen reduction will typically exceed 70 percent, depending on wastewater strength and other characteristics like BOD5, grease and oils, pH, tankage (HRT), temperature, and alkalinity concentrations. Nitrification can be inhibited if the natural buffering capacity (alkalinity) is too low. On • a theoretical basis, 7.14 mg/L of alkalinity as CaCO3 is needed to nitrify 1 mg/L of NH4+. For more information on nitrogen reducing systems, contact Orenco Systems Engineering. Pumping Equipment The integrated treatment package includes an Orenco ProSTEPTNI pump package. Typically a single pump is necessary to energize the distribution manifold in the AX100 treatment pod. There are eight laterals in each filter with 4 nozzles each. The flow can be varied by adjusting the pressure at the pod inlet; however, our baseline operational flow is about 1.57 gpm/nozzle, which puts the pumping rate at about 50 gpm per each AX100. Model P5007 pumps are used for the AX100 units. Duplex or sufficient multiple pumps are required in all commercial applications to ensure operational integrity with one or more pumps out of commission. Distributing Valves Typically, Orenco automatic distributing valve assemblies are used to alternate doses to up to three AX100 pods utilizing a duplex ProSTEP pump package. This allows for a 4:1 recirc-blend ratio during periods of peak hydraulic loading without exceeding the maximum daily cycle rating of the pumps. ' tirenco•automatic distributing valve assemblies should be located at the high point between the recirc- blend tank and the AdvanTex AX100 pod to ensure proper operation of the valve. For more details on this product, please refer to Orenco Automatic Distributing Valve Assemblies for Wastewater Effluent Systems (NTP-VA-1). • NDA-ATX-00MM-PKG-1 flow.1.0,©5/03 Page 5 at 10 Residual Pressures The residual pressure will typically be set to 4.5 psi to attain the desired 1.57 gpm/nozzle. Each pod is supplied with a gauge tap and valve assembly to allow for pressure measurement at the pod inlet. Recirculation-Blend Ratios and Timer Settings Typical operating recirculation-blend ratios will vary between 2:1 and 4:1, and the"off' time varies as a function of the recirc-blend ratio. The AdvanTex Treatment System controls are initially set to a 4:1 recirc-blend ratio and initial timer settings are established based on the expected average daily flow. A typical dose event will vary between 1 and 2 minutes-and will deliver about 1-I/2 to 3 gallons per nozzle per dose. If flows vary significantly from expected flows, timer settings should be recalculated. • AdvanTex Control System Critical to the success of the AdvanTex Treatment System is the method in which the effluent is loaded onto the AdvanTex filter. Over the past three decades, timer controlled applications have proven to play an essential role in optimizing the performance of both fixed and suspended growth biological systems. A timer-controlled pump in the recirc-blend tank periodically doses effluent to a distribution system on top of the AdvanTex filter media. Each time the filter is dosed, effluent percolates through the filter media and is treated by naturally-occurring microorganisms that populate the filter. During periods of high flow, a timer override float will temporarily adjust the timer settings to process the additional flow. Remote telemetry control panels comiected to a dedicated phone line are an integral part of all commercial AdvanTex Treatment System equipment packages. Remote telemetry control panels give wastewater system operators and maintenance organizations the ability to monitor and control each individual system's performance remotely. This also allows Orenco to contact the panel directly to assist the operator in system evaluation and troubleshooting. Remote telemetry control panels also provide additional alarm functions to automatically page the operator in the event that trend data indicate potential problem conditions (e.g. high flows). Surge Volume AdvanTex tankage design is consistent with that of other packed bed filters. Flow equalization should be designed into the primary tanks with controlled (metered).feed to the recirc-blend tank. If surging needs to be done in the recirc-blend tank, then sizing and timer controls will be programmed to optimize performance and surge capacity. Churches, schools and assembly halls, are typical applications where weekly surge control practices provide optimum filter sizing. Other Design Considerations AdvanTex AX100 pods have been designed for installation in areas that are free of water. If a project requires placement of the pod in a high-water area, contact Orenco Systems Engineering for options. For cold weather applications, AX units are available with insulation attached to the bottom of the lid (1- inch thick; R-5 or 0.2 BTUs/hr/ft2/°F/inch thickness). Installing insulation around the sides of the filter • pods themselves is optional and is done onsite as needed. Other cold weather considerations include standard practices used with most onsite pump systems, such as allowing all lines to drain, insulating processing tank lids, and backfilling risers with pea gravel if frost-heave is a concern. For extreme climates with long periods of subfreezing weather, a warm air source may be required. Consult Orenco if supplementary options need to be considered. ND/WM-00MM-PM-1 Dev.1.0,©5/63 Page 6 of 10 Hello