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Home My WebLink About781192.tiff E0 Sr4,. Sy, 4 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY ,ROtce •aar_^:�, ^:STREE' ':E E- ..N. _ ," E)C ( - - NEGATIVE DECLARATION TO ALL INTERESTED GOVERNMENT AGENCIES AND PUBLIC GROUPS: c'c)` As required by guidelines for the preparation of environmental pacC �,i statements, an environmental review has been performed on the proposed EPA action below: Project Wastewater Treatment Facility Location Northglenn, Colorado Project Number C 080416-01 (Step 2) Total Cost/EPA Share $685,900 (75% of eligible costs) EPA's share has_not been determined due to number_of unanswered- g - tions regarding the eligibility of the project for grant_funding. The level of funcTirig is dependent on several factors, the most significant of which is whether Thornton_ will be a part of the North lenn_sytsm. EPA will make a decision on the level of fpm rnase od— n the information available at the time of the Step II award. The proposed wastewater treatment facility will be designed for 4 popu- lation of 72}700; the existing_population of the study area is 42.0O0. The project tudy area includes floodplains, prime agricultural land, and a wild- life habitat area. a r primary iBPact of_t .e=aiect_will_bo_construrtion_of a- 74" intexcentor through a wildlife habitat AI:PA A major secondary impact of the proposed project is the possible conversion of prime agricultural land to urban use resulting from the construction of interceptors in the Lower Thornton service area. Another secondary impact is the additional air pol- lution that will result from increased automobile usage associated with the area's growth in population. Another secondary impact is potential ground- water depletion and degradation that would result if Northglenn is success- ful in implementing its proposed groundwater pumping program. The State Engineer's Office has denied 19 of 20 well permits required in order to implement the groundwater pumping program. Northglenn is appealing that decision. Consequently, it is not certain that this part of Northglenn's proposal will be implemented. An environmental impact appraisal which describes the project and analyzes the impacts in more detail is attached to the Negative Declaration, 781192. 7- ' ' ` , Page 2 The review process indicated that only parts of the facility plan can be approved at this time due to environmental considerations and other fac- tors. These components are: 1. Northglenn Force Main and Pump Station Aerated Lagoon (Weld County Site) N' , `3. Storage Reservoir (Weld County Site) 4. Bull Canal Delivery System 5L. Sludge Handling 6. Northglenn Collection System Improvements 7. Stonehocker Reservoir Components of the facility plan which cannot be approved are: 1. Branter Interceptor, Force Main, and Pump Station 2. Riverdale Force Main and Pump Station 3. Nott Interceptor There are two reasons that these items cannot be approved. First, Thornton has not agreed to implement the facility plan and second these interceptors will provide service in areas where prime agricultural lands are located. In addition to the above two items, EPA cannot approve any capacity that would be constructed to convey and/or treat Thornton's wastewater without Thornton entering into an agreement with Northglenn to have their wastewater treated at the Northglenn facility. EPA has awarded Step I funds to Denver Metro to evaluate the alternatives available to Thornton for wastewater treatment. Metro has passed the funds onto Thornton for its use in conducting this study. The results of this study will not be forthcoming for several weeks. EPA will rely on this study to complete the existing facility plans regarding the ultimate treatment of Thornton's wastewater. A preliminary decision has been made not to prepare an EIS on the North- glenn facility plan. This action is taken on the basis of a careful review • of the engineering report, environmental impact assessment, and other sup- porting data, which are on file in the above office and are available for public scrutiny upon request. Comments supporting or disagreeing with this decision may be submitted for consideration by EPA. After evaluating the comments received, the Agency will make a final decision; however, no administrative action will be taken on the project for at least fifteen (15) working days after release of the Negative Declaration. 0111941\104 Alan Merson Regional Administrator u, a. 12k)7`23 ankf /OJ 6,c.,0 647`-0 )eD 41: • ea 6 / ��1ED STq rF w((.-- PR SI r /GS�GP,�,.ber X3458,., ,) UNITED STATES ENVIRONMENTAL PROTECTION AG 'CY 6' �c FF .. 55, - v�'nd',TREE- °[�C� Ig?9 Nt(tAf1VE t)EGLARAa ION ' �#9i °qn �` TO ALL INI'ERESMD GOVERNMENT AGENCIES AND PUBLIC GROUPS: �`, eL1Qe 60vA' As required by guidelines for the preparation of environmental impact statements, an environmental review has been performed on the proposed EPA action below: Project Wastewater Treatment Facility Location Northglenn, Colorado Project Number C 080416-01 (Step 2) Total Cost/EPA Share $685,900 (750 of eligible costs) EPA's share has not been determined due to a number of unanswered ques- tions regarding the eligibility of the project for grant funding.[=The level of funding is dependent on several factors, the most significant of which is whether Thornton will be_apartof_the Northglenn_sy_stem.J EPA will make a decision on the level of funding based on the information available at the time of the Step II award. The proposed wastewater treatment facility will be designed for a popu- lation of 72,700; the existing population of the study area is 42,000. The project study area includes floodplains, prime agricultural land, and a wild- life habitat area. The major primary impact of the project will be construction of a 24" interceptor through a wildlife habitat area. A major secondary impact of the proposed project is the possible conversion of prime agricultural land to urban use resulting from the construction of interceptors in the Lower Thornton service area. Another secondary impact is the additional air pol- lution that will result from increased automobile usage associated with the area's growth in population. Another secondary impact is potential ground- water depletion and degradation that would result if Northgle is success- ful in implementing its proposed groundwater pumping program.(The State Engineer's Office has denied 19 of 20 well permits required in orderit0- unplement-the groundwater_pumping_program. Northglenn is appealing that__ cci ion�_J Consequently, it is not certain that this part of Northglenn's proposal will be implemented. rAn environmental impact appraisal which describes the project and / analyzes the impacts in more detail is attached to the Negative Declaration. I Page 2 The review process indicated that only parts of the facility plan can ha annrnved at this time due t(. environmental .considerations and other fac- tors. These components are: 1. Northglenn Force Main and Pump Station 2. Aerated Lagoon (Weld County Site) 3. Storage Reservoir (Weld County Site) 4. Bull Canal Delivery System 5. Sludge Handling 6. Northglenn Collection System Improvements 7. Stonehocker Reservoir Components of the facility plan which cannot be approved are: 1. Branter Interceptor, Force Main, and Pump Station 2. Riverdale Force Main and Pump Station 3. Nott Interceptor There are two reasons that these items cannot be approved. First, Thornton has not agreed to implement the facility plan and second these interceptors will provide service in areas where prime agricultural lands are located. U In addition to the above two items, EPA cannot approve any capacity that would be constructed to convey and/or treat Thornton's wastewater without Thornton entering into an agreement with Northglenn to have their wastewater treated at the Northglenn facility. EPA has awarded Step I funds to Denver Metro to evaluate the alternatives available to Thornton for wastewater treatment. Metro has passed the funds onto Thornton for its use in conducting this study. The results of this study will not be forthcoming for several weeks. EPA will rely on this study to complete the existing facility plans regarding the ultimate treatment of Thornton's wastewater. A preliminary decision has been made not to prepare an EIS on the North- glenn facility plan. This action is taken on the basis of a careful review • of the engineering report, environmental impact assessment, and other sup- porting data, which are on file in the above office and are available for public scrutiny upon request. Comments supporting or disagreeing with this decision may be submitted for consideration by EPA. After evaluating the comments received, the Agency will make a final decision; however, no administrative action will be taken on the project for at least fifteen (15) working days after release of the Negative Declaration. Oa6")111‘4A4 Alan Merson Regional Administrator Environmental Appraisal for Northglenn Wastewater Treatment Project (Project Number: C080416-01) September 29, 1978 s TABLE OF CONTENTS A. Project Identifier 1 B. Reference Documents 1 C. Introduction 3 D. Description of the Project 5 E. Description of the Environment 19 F. Environmental Impacts and Proposed Mitigating Measures 41 G. Significant Issues and EPA's Proposed Action 65 H. Other Alternatives Considered 71 I. Agencies Consulted by EPA 73 J. Public Participation 75 K. Reasons for Not Preparing an EIS 77 L. Grant Conditions 79 M. Appendix - Mailing List 87 i ENVIRONMENTAL IMPACT APPRAISAL A. PROJECT IDENTIFICATION Applicant: Northglenn Address: 10701 Melody Drive, Suite 313 Northglenn, Colorado 80234 Project Number: C080416-01 (Step 2) B. REFERENCE DOCUMENT(S) The following reference document(s) have been utilized by EPA in the environmental review of this project and are considered to be part of the project file: 1. "Predesign Report: Wastewater Management Lower South Platte Service Area", December 1973, CUM Hill. 2. "Sequel to Predesign Report: Wastewater Management Lower South Platte Service Area", June 1974, CH2M Hill. 3. "Lower South Platte Facility Plan", Volume 1, August 1977, CH2M Hill. 4. "Northglenn Water Management Program, Water Resources and Facili- ties, Volumes 1 and 2, April 1977, Wright-McLaughlin Engineers. 5. "Northglenn Water Management Program, Wastewater Facilities", Volume 3, April 1977, Sheaffer and Roland. 6. "Northglenn Water Management Program, 201 Wastewater Facilities Plan, Volume 4, November 1977, Sheaffer and Roland. 7. "Final Denver Regional Environmental Impact Statement for Waste- water Facilities and the Clean Water Program", Volumes 1 and 2, April 1978, EPA. 8. "Final Action on the Denver Regional Environmental Impacts State- ment for Wastewater Facilities and the Clean Water Program", August 1978, EPA. 9. "The Physical and Economic Effects on the Local Agricultural Economy of Water Transfer from Irrigation Companies to Cities in the Northern Denver Metropolitan Area", Anderson et.al. , NRED, Economic Research Service, USDA; Dept. of Political Science; Dept. of Agronomy, Environmental Resources Center, CSU. -1- 10. "Specification of Environmentally Significant Areas in the Denver Area," DRCOG, October, 1977. 11. "Draft Regional Growth and Development Plan for the Denver Region", PDrnr T,.1.. 9 n77 12. "Preliminary Engineering Geology and Soils Investigation for a Proposed Reservoir Sections 26 and 36, T - 1N. , R - 68W. , Weld County, Colorado," March 1978, Chen and Associates. 13. "Draft Regional Water Study", DRCOG, March 1978. 14. "Interim Division Guidance on Planning and Design Review for Land Application Systems," Colorado Water Quality Control and Public Health Engineering Division, March 18, 1977. 15. "Grant Eligibility of Land Acquisition by Leaseholds or Ease- ments for Use in Land Treatment and Ultimate Disposal of Residues," (PRM 77-5) , EPA, December 15, 1976. -2- C. INTRODUCTION Title tPi27Cle ae hes—a prggranta ,provide Federal assistance in the development and_implementat on of waste treatmeKf_ mangemenMans and__1�hP_rnnct ctio _nf rublica1 owned treatment works, Federal fi ng of waste treatment wo are imprmented in free steps: 4` _q_—fa t? 1a , eP- 7eparation of construction drawings and specifications,, and G"tep II construction otreatment works. Northglenn funded Step I without Federal assistance. On September 7, 1977, Northglenn presented copies of their draft facility plan to EPA. The Plan was revised in November 1977. On March 7, 1978 the State of Colorado Water Quality Control Division certified to EPA Northglenn's application for Step II funding. By regulation, EPA cannot award a Step II grant until it has approved a facility plan for the proposed project and performed an analysis of the environmental impacts of the project under the National Environmental Policy Act. EPA has been working with Northglenn to supplement the facility plan so that it will comply with EPA's facility planning requirements. EPA now has suffi- cient information that it can take action on the facility plan. A review of the facility plan and the supplemental information indicates an environmental impact statement is not warranted for this proposed project. EPA regulations require that a public notice in the form of this negative declaration/environmental appraisal be given to explain why EPA considers this proposed action to have an insignificant impact on the environment. The negative declaration/environmental appraisal is circulated for public, State and Federal review, after which EPA must make its final decision on whether or not to award the Step II grant. This document is the negative declaration/environmental appraisal for Volume 4 of the Water Management Plan, Northglenn, Colo- rado. In making this determination. EPA relied on those documents listed previously in this Negative Declaration to supply information relevant to the proposed project. -3- D. DESCRIPTION OF THE PROJECT 1. Background: Northglenn is proposing to construct a multi-purpose water resource project consisting of a drinking water supply, wastewater treatment and collection system, supplemental deep formation pumping system, and an urban runoff collection system, all in one integrated approach. The project will be located in the northern fringe of the Denver Metropolitan area (see Figures 1 and 2 for a definition of the study area) . EPA is being requested to participate in the costs of designing and constructing the waste- water treatment portion of the Northglenn water management program. Several factors contributed to Northglenn's decision to proceed with the water supply/wastewater management program. The major reasons are: a. Northglenn's need for a sure source of water for its customers through the year 2000. b. Northglenn's desire to improve the water quality of its potable water supply, since Thornton's water supply has experienced nitrite levels exceeding the National Drinking Water Standards. c. FRICO's willingness to enter into an agreement with the City of Northglenn for shared use of FRICO's water. The proposed project has an overall objective to manage the avail- able water resources as efficiently as possible through an exchange agreement with FRICO. This feature is consistent with EPA's objec- tives to give preference to innovative and nonconventional wastewater treatment technologies. Consequently, in concept, EPA has supported this project since its inception. 2. Total Water Resource Project: Northglenn has entered into a water exchange agreement with the Farmer Reservoir Irrigation Company (FRICO) . This agreement allows Northglenn to utilize up to 7,785 acre feet of water for municipal use, all of which is appropriated and stored by FRICO in Standley Reservoir. Northglenn is committed to return 110% of the water diverted for municipal use to FRICO whenever it is called. Therefore, in addition to a water treatment plant and a wastewater treatment plant, Northglenn is proposing to construct a year-round storage reservoir, and a plan for replacing any water that is consumed by the City of Northglenn. This plan includes the proposal to collect and treat the urban runoff in North- glenn, pumping large quantities of groundwater, and obtaining addi- tional water through purchase, etc. Under the agreement, FRICO is under no obligation to provide water to Northglenn until FRICO is assured that all related facilities are constructed and North- -5- glenn has secured approval of its plan for providing make-up water. Northglenn may continue to rely on Thornton for domestic water up to the time when FRICO water is delivered for use by residents in Northglenn. November of 1980 has been Northglenn's target date for severing its relationship with Thornton for both water supply and wastewater treatment services. The total project cost (excluding OEM) for both water supply and wastewater systems will probably exceed $50 million. To date, cost has not deterred Northglenn's efforts to implement the project. The community, by a 2 to 1 vote, has authorized 31 million dollars of general obligation bonds for use in implementing the water supply/ wastewater program. City officials have been seeking other sources of funds, including EPA construction grants, to make-up the differ- ence between the 31 million and the anticipated cost of 50 million dollars or more. 3. Wastewater Project: Currently, Northglenn's wastewater is conveyed through Thornton to the Metro (MDSDD#1) facility for treatment (see Figure 3) . Thornton has contracts with each property owner (etc.) in Northglenn to provide this service. All of these contracts are scheduled to expire by 1988. Consequently, Northglenn has been negotiating with Thornton, an agreement whereby Northglenn will provide this service to its residents. The facility plan makes the following recommendations for wastewater transport, treatment, and disposal (see Figure 4) . a. Collection System - Once agreement is reached with Thornton, Northglenn will make improvements to the existing collection system to redirect the wastewater flows to the new Northglenn facility. These improvements include sealing off several lines and connecting them to a new interceptor which will convey the wastewater from the City of Northglenn to the treatment site. b. Conveyance System - Four major interceptors were identified in the facility plan as needed to convey wastes from Northglenn and the Lower Thronton service areas. They are: Brantner Force Main (15,500') , Riverdale Force Main (11,000') , Nott Interceptor (12,000') and the Northglenn Force Main (46,900') . Of these the last item is the only interceptor that is absolutely neces- sary to convey only Northglenn's wastewater. The others are designed to provide service to the Lower Thornton service area. -6- Figure 1 - 201 Facility Planning Area • .7 BOULDER " J.G(v�` J W . 4 • } �v Q • J��f' ��,j••� °�6r /AGRICU LTURAL REUSE :�.• c,"•1—," - ( SERVIC AREA • �� \\\• BARB �~ �' \\J�` LAKE WESTMINSTER/ • So if BROOMFIELD /- • \\� STANDLET •��/ +1 LAKE LOWER SOUTH � 2 PLATTE lie A. CLEAR'CREEK • 0 SO CLEAR CREEK p,...—••• 1.0%.."-'C / DENVER SOUTH c, LAKEWOOD �i.ffRRr \?"�-. t SAND- CREEK BEAR- CREEK -----'-‘. �... •\ CNERRT\ CREEK LAKE - �v y fly ' CHERRY-..CREEK/ - "f' LITTLETON/ENGLEWOOD GOLDSMITH\ GULCH CHATFIELD _ RESERVOIR • • Excerpt from Northglenn Plan, Vol. 4 -7- 1GURE 2 AGRICULTURAL REUSE ULn;ICE AREA F I I 1 I '1,045 { ee zL 'b 11 _ 11 11/01.1 O�•' Al I ��I '10ir 15/00f5) co HM1i �atfr.M,rr, Ey A.{ l �� I/I ` �„f t5A3" r-i •f 1 �J .L_� , r 5,6,E fy, O I / ,„„,...„7, , _,., J_. -i P t Irk I 1 , J11 -t / l I _ r, I / / I-i o R • f!1 - ura_Tiff_Arl_ __ ____ F.ti, r,kp ,/ j /,_... ,I l i 1 `� 7.7 �--i t r-----?"- ,A,, re f in «L B ANT Fa ' ' ' I . •I I. 1 r , rt I' // IPi� • _ Fir' }trod — t c1 TH A'VF� I i � —" ` r �, '� iM.1U i ' ,ff I { .... ___I \ 112 TM AVE _ up, -#1 , i LOWER �- ,/,_ / _ !� ' ,xr g. I, LI\ GRANG / : . . I'` , ^ ;4, ,' I CREED .,. N lelI t' ' . J �f 4 II —-- �, ASR: ' — f " tOb' q ,m1:, 1 i f.: '.rm* ti { {);C ��{) ,i / .1/ 1 ,J V /J r!� T 1� 't l:,1 11 t 4.� TH 1 fir-*-- _ I , ;,I'`'I II, iI•iIt,IIr 1 I I 1 50��, .0000 pY RNrQN. , ✓� +' ' \ ,' ; i ,. Excerpt from Northglenn "' r .M LEGEND Plan, Vol. 4' T al i�yc4}0.0 `11�41�ri a" ' .,.i.—,,4k,..,,, ,�„ 'I,,, ( ^' AGRICULTURAL REUSE.SERVICE } AREA t,}i '.\.- ri, ,i•, I ii'i'�III, `4 LIMIT _VIP:, y- ;;.;� a4,; :¢ ; ---- HORTHOLENN CITY I Y .' I_r'a- .,,.;. ,' E _ �* THORHTDN 3. ,� �� —, L.; t-,.•i r •� ---- CITY LIMIT fi.„ K � ,its ' Imo ,i ''°'"1l- t��, ' , r ,� 7'` am BIG DRY CREEK — SOUTH tu• �,' r;.,.0 ,tl.x' ' i, __,_-_,..,....-s-7"-:, '�` PLATTE BASIN BOUNDARY Y V I'� rr `1 4;,,,,,r14i 7.;_ 'yyU �� - -- SUB-BASIN BOUNDARY TI +a -7 - .,,,-;,.• - 1 -`,,>' • RE g EXISTING WASTEWATER MANA ENT SYSTEM 'WA V NV ....IP"‘IIIIL. .. • ,. - `e.4., ,c I `" / ,` _ BM 5045 _"e�6p e•a I ,rnvbI f I (1 5381 cL �� I—�- 1 srao ; - ei ayeOlap 4. Y ( i.. '.i{ 1E131 U' r is` , C'} I I` „RI' \\ I,AI v> I Sub C=I 1 _..._____.._---.1---.- - 1 '" 'S.—. -- - _it .. a vi'-'*`,..--- ,1 a L H 54.41( yn,F,,, F ; , i 5f , - I }' r I I rim 517''''',— nu -.II I v`' i I Mr k.nl „(14.83+ i H � r o a 1•«1 ' i I -1 "'"'iii"'--- ,, ? — r r14.1) 01 1 ' A' I WESTMINSTER i BIG DRY o �— ) II TREATMENT �t 1'I IPLANT SQUARE TO I { I EASTL KE ou,se 1'B" ',.'J J,1:1=142.1:=INASHI,'? 1 er �)`= ri 1 t.., : 8.53 * Corn 'S« re\A.FH+7 a'i Htn11 .Mt • 1 WOOOGLEN L. La,i,iJ� / '1 r,i0`• :/1127N_AVE —I ^" �" I r.' ,� { 1�.• • f I lz:NC —— r,.,Ti nr�— fit' A -i(h r�i u''I,.!h fl) I u,'' I IInN Il�lr I'/ tM6une N„91/31 V �. N +H 6 t I Ii ii" ,/ (GRANGE �� 1777 h e,khth • r, r~.i -Y i ,+ 10a . AV_ . • n i, Scwa,.i m, r _ ✓ C 'i \\t 11 It //ll , 'I } 0fi'T()\ {I E- `1- / '"Y"' 011 . • ''L'i 1 1•.,\! r ' ' E \ .'r, M 509'- T1 ,P _,r i ll'.1�4r41;t�' _ TH4)RNTON, 1 \� 0 5000 f e00 t errTT' I */ i �l),Iyf 1- 1 + ‘�. y t / I--- Y 1�'y$ I t ..111 _ , _ ''II,, t' 'u• r t,'y - ,4 '- �� : -.;j(i7,r1-.,.. .! - s ? LEGEND Excerpt from Northglenn P n, 1A',.``,/);� mot, iid�1,� r """ .."11`` Vol. 4 r�. &:', lla�il�lt,, .L, t � ' �: i� AGRICU,LIURAL REIISE«SERVICE AREArt , }jj,1{t;,'' ', _ I g1 NORTH_-l' a NORTHOLENN CITY LIMIT'.:y," I.! •*'t �' ,;,'.I ' • I y/ASkINGTON` I � l,,t'':';�'' `-� _ ! • .---- THORNTON CITY LIMIT . d{,. .,• 1, r11: ):I ..I f, ' — ® PUMP STATION a,.li, LEAF] REEK INTERCEOOR \ • • • • FORCE MAIN �,1-- ;, / 'rl'1' •,,-,., 'I,.'�d11 III INIIll HII IIN11111Mtn: —11- - ,--F.-. .,' ., , ; . t - - , I , nuuulluuuw GRAVITY INTERCEPTOR I '-1,. +DENVEIR ME p.' It �� — ; _ ' p1 .T"EA ;.), -''' 1 WASTEWATER TREATMENT PLANT RE 4 MAJOR FEATURES AGRICULTI REUSE ALTERNATIVE .2,, 1— �"-�---- .�.��.�� I `/ • .� I i ''111:: l ` , I. .IG TI N I I '1',l i'°.1 p t.PTATION } - \ k TR'ATM N-T--LAfi00 •'`v ` m -'<--- I"'� f ti l !`1nu.l S 44• I !Y I �� 1''11 ( NI I ' r 0, la IMISOI f4 rn�nniW 1 1 I ^�' 4r4Ei�ERV� R��,— .r �wf~ f -�,1-11-L�----�f`` :yy' • • • ®� ' C. -- t. • • f ! \:‘,.., .!,ZI an .J I 4 \ I it O r -. t: Io f u:,'• kflii ' v11z re, g -r 1 W;• .; Q $f. I i; I ... rz- U �i 1 I , O �� .« , ,,r+, .1 t 4ul 1 I / 1'' 0, I CI % J ' • 1'r IlM hFo - is , 3-' •. �,r i - fi Tt�1 1 Ji ) 1Y: 1 I I t TM i I ' I BRAIITNER PUMI+ STATIO�t-•I v y4x-' M,a I 181 5i I1.4..,...:I •.21......4_, llI ' • ` `„' ., • , •.I, , ' «11 • 7•• / Ill•I,,1 'r 1Ai ))i 7. V t `.tqi :1E r' r.� + \\\\\�`v` h / ,r,n h1 r cNN I�\` J i, I,:::z r ,,,,11,,, /ii,.,..: I, 'ri rlf4741.1 °w �' i 14 Alb 1 1, ; l' - 1„" I GRANGE CREEK /' I I ` -' \ 10. . A PUMP ST.'T ION # ..f �' ( ( • �R , : , "ef .i71f r4 l";f� .I,I -�I \/Jil 1 f�{�f{ \, v�''•. t«��I „i v ,I , tE7r�,'.C7 y�y�L4p p�' r C' 4titc- ~ Y 1 Itl T •I ti�, �; r1 0, _-,,ftt..kb$ T TH RNTCN r O • 5000/0000 y ± ! aig • {1 21 1 6 i 1 _,,ter r L f`1 t- . ,r,„.1;1 1,.. 4 ,1 j' �a� "'6',t'— T,T. o Excerpt from Northglenn f "\N. _,4''.'' '''t it i`Fi 1 '*rc� wer- f I' ,.. LEGEND Plan, Vol. 4 11`0' c FFF^^^¢¢¢mow. I, �; f ., . , r�`�' A ,;;\-;',,F��,;T1 .-1 ' i— AGR1 U1IIJRAL REUSE.SERVICE AREA , I ,, I - * 1 V% }" NORTHOLENN CITY LIMIT --t-y- s1 r 1 1 ,\ I 0111.1 ! ,t I Wit, t1,li.1I414M4 11lil l' 1 •�t \ I ----},' 1 i , , ',11 I,' THORNTON CITY LIMIT�r •ir, + '�+��.�'�'. I '' 'i I 11' � � w 1� 1 V, i� la•h 1�,"ti,I, ` ;; ,ji;'l' 'I 1�" _ A PUMP STATION li ,.Il¢ 1'. ', ,.''I , I 1' 1[1 I` 1.1 ',III°, `�`r c' • • • • FORCE MAIN —13— '"1-,1, I;t; Lilt, ` `,� n,• 1,1. � ■ WASTEWATER TREATMENT PLANT Y a„ '_ . , I IIIIIIIIIIIIIIIIIII F' :< r,1.- _ _.�='I�tf ' . GRAVITY INTERCEPTOR c. Wastewater Treatment - The facility plan is proposing an aerated, three cell lagoon system for treatment prior to storage and discharge. Figure 5 is a diagram of the pro- posed treatment and storage facility. Due to a 30 mg/1 suspended solids effluent limitation`the -lagoon treatment and storage system design includes provisions to control algae growth. The aerated lagoons will be designed to per- form nitrification. Through the nitrification process the alkalinity of the wastewater will be reduced. The facility design is based on the theory that carbon will be a limiting nutrient at the reduced alkalinity level, therefore limiting algae growth. d. Storage and Disposal - The facility plan recommends a 6000 acre feet reservoir be constructed in Weld County to provide for winter storage of the effluent. The treatment and storage sites are located adjacent to the Bull Canal, approximately, 11/2 miles northeast of the intersection of Interstate Highway 25 and Colorado State Highway 7 in Weld County, Colorado. During irrigation season, FRICO has the right to call the water that is in the reservoir. Consequently, the discharge rate will fluctuate based on the calls made on the reservoir. The outfall line is being sized to drain the reservoir to a three foot level within a few days. The plan recommends that a three foot mini- mum pool be maintained in the reservoir to prevent nuisance con- ditions from developing. Chlorination of the effluent will occur just prior to discharge from the storage reservoir to the Bull Canal irrigation ditch. e. Sludge Disposal - The facility plan recommends that sludge be removed every two to five years and be injected in the surrounding agricultural land. The plan is not explicit on defining the details of how this will be implemented, nor does it identify a contigency for disposing the sludge if agricultural reuse is not implemented. 4. Cost of the Proposed Project: The cost for the combined Northglenn/ Thornton wastewater reuse system are presented in Table 1. -15- Table 1 Costs of Northglenn's Proposed Project System Component Lost Annual OVM1 Capital Cost (does not include fees) a. Collection System 846,0001 10,000 Improvements b. Interceptors 6,543,0002 75,000 c. Treatment Facility 2,239,0002 435,000 d. Storage Reservoir 3,775,0002 35,000 e. Reservoir Site 905,0001(already purchased) f. Irrigation Delivery 265,0002 25,000 System g. Sludge Handling 400,0002 30,000 Total 14,973,000 610,000 1. Not eligible for EPA funding 2. Includes cost for handling Thornton wastewater flow. Eligibility for EPA funds to be determined at time of grant award. -16- . FIGURE 5 • STORAGE RESERVOIR PUMPING STATION WITH CHLORINATION -N- BULL FACILITIES CANAL A4 [i A\ / ` .. SCALE IN FEET ON MINNIIIIIIMINI 2 .4iri , , , . 100 400 BOO E h of t O • STORAGE RESERVOIR ' 0 6,000 ACRE FEET y;1; \ I l i lir.....2......-I'CFOP:ER:YM • 11 y�A° B1 LEP.)11111i : k' 5 FIN. SETTLING FOEDGE LAGOONS 313p 1444lE ��..y, t i 5j20, , :AlioilirnimamillitmqIimninim,_. ...,, ill i t '' C " '�"' AERATION i 1 \. SETTLING fUIIIj. LAGOONS BASINlip . 1 1141 EXISTING - ----�•• 0 ROAD �`.*;1?' (:1 ii ' 11 2 50 F T. ti O ro ' MIN:," __— A' • SEE FIGURE VI-3 I FOR FURTHER s,10 DETAILS B • • SHEAFFER AND ROLAND, INC.t)::oi CITY OF NORTHGLENN, COLORADO ENVIRONMENTAL PLANNING AND ENGINEERING WAS'TTEWATER SYSTEM BASIS OF DESIGN SOLAR ENERGY • RESOURCES MANAGEMENT PROPOSED WASTEWATER TREATMENT CHICAGO, ILLINOIS AND STORAGE FACILITIES Excerpt from Northglenn Plan, Response Letter -17- E. DESCRIPTION OF THE ENVIRONMENT _ 1. . General - As shown on Figure 2 Northglenn is surrounded by other incorporated communities. The Thornton areas of Brantner Gulch and Lower Grange Hall Creek are mostly undeveloped, but numerous new subdivisions are under construction or are proposed for con- struction for these two areas. To the North of 120th Avenue open space and agriculture are the primary uses of land. Northglenn is principally a light commercial and residential community. The study area is adjacent to the Denver metropolis and is located on the northern edge of the urban development in the Denver Region. The study area is located in the Big Dry Creek and Grange Hall Creek drainage basins. The drainage flows are intermittent and they consist only of groundwater seepage, stormwater, and/or irrigation water. The Denver Regional Council of Governments (DRCOG) Clean Water Plan recommended a secondary contact recrea- tion, agriculture, warm water biota, and wildlife classification for Big Dry Creek. No recommendation was made for Grange Hall Creek or any of the irrigation ditches in the area. The Colorado Water Quality Control Commission considers irrigation ditches as waters of the State which are subject to regulation by the Com- mission, although very few in the State are classified at this time. 2. Irrigation Systems - The Bull Canal and Farmers Highline irriga- tion ditches are the two largest supply canals for agriculture in and around Northglenn and Thornton (see Figure 6) . The Farmers Highline canal is also used as a conveyance system for part of Thornton's water supply as well as for irrigation. Potentially, the combined irrigated acreage for these two systems is approxi- mately 39,000 acres. The Farmer's Reservoir and Irrigation Company (FRICO) , which con- trols the water delivered to the Bull Canal, via Big Dry Creek is one of the largest mutual irrigation companies in the South Platte Basin. It is this company which has an agreement with Northglenn to allow Northglenn first use of 7785 acre feet of water stored in Standley Reservoir. In turn, Northglenn will return 110% of the FRICO water it uses to the Irrigation Company. FRICO maintains storage rights in Standley Reservoir for 30,000 acre feet of water of which about 70% is owned by farmers and small land owners. The remaining 30% is owned by cities and commercial interests. Westminster has storage rights of 12,000 acre feet in addition to FRICO's rights. Westminster and FRICO also have an agreement allowing each entity to store water in each other's storage space if it is not being utilized. However, the agreement precludes each party from mixing its water with the water that is owned and stored by the other party. This practice is referred to as "stacking" water rights. -19- Thornton, as part of its severance agreement with Northglenn is seeking an agreement with FRICO for storage rights in Standley Reservoir for about 9500 acre feet of water. Thornton has iden- tified this storage as capacity in excess of what FRICO needs to meet its commitments for irrigation _ - . . The principal crops that are grown with FRICO water are corn, alfalfa, and small grains. Depending on the water supply avail- able during a particular year, anywhere from 10,000 to 15,000 acres may be under irrigation using water from FRICO's holdings in Stand- ley Lake. Water delivered under the Highline Canal system is on a run-of- the-river basis and varies yearly with stream flow. Although there is no central storage reservoir for users of Highline water, there are over 80 small farmer owned reservoirs or holding ponds that are served by the Highline system. The City of Westminster has negotiated an exchange agreement with the Farmers' Highline Canal and Reservoir Company. This agreement allows Westminster to use 1 gallon of Highline water for every gallon of effluent Westminster discharges to the canal. Westmin- ster has constructed a pipeline from its wastewater treatment facil- ity to the canal in order to implement this agreement. The Farmer's Highline Canal services many speciality farms (e.g. nurseries, greenhouses, truck farms) and provides irrigation water to grow alfalfa, corn, and small grain crops. According to a recent report, only a small fraction of farms could remain in farming without this irrigation water. The area served by this ditch is constantly under pressure to urbanize. 3. Water Supply - Although the project being considered by EPA for funding is a wastewater project, Northglenn's need for the project stems, in part, from its water supply needs. Northglenn is not in isolation when looking into the future and projecting its demand for water versus its available supplies. The communities of West- minster, Thornton, and Broomfield all face the same problem. As Table 2 shows these communities have a projected water supply shortage based on the estimated year 2010 demand. -20- • FIGURE 6 AGRICULTURAL IRRIGA1._.. CANALS .. , , _:_...... , ,..,�', �•` 1If1tATfrIJ •tae QF\ , (15381 �11 Sa�1 • 0 G' r n 5100— .Qedep i� � ► • ,ii Orb6 31 I� rb. c1\\► 1` .t - . el lip"- ,01,,,,, � " d 1,4 - 510.C i' Sub •f ,ir N5 IrAl -,,I •• 6 V` .� r 1 I\ J i el c} � 1♦ i I • r �6 2"�t1WI nJ ojga '. - / r "2,7^�r�� I • 0 t /�� '■ / 150c 111 `111�lQ.a • u1 -� =r si I .pl S o-° c;‘`' i • I ` ,-- I 'U ft, r (f. 1111111 !t '��,�Q G'a'y. sti; ,^ . epilf_ 9M Skil 1 "" ...�• ' 11 t •A.,,., . lipilII Alibi I 2 ' ..)"° , ' A t Goli F-3ira ri •1,,,,47(., 4_ 1 I v 1 �� • `I '� I J6 `i'l w I .t S I .t . er r' ;-� Cern. /, 7� .d .! Z,F. flake e antn : - r v Hend ,- , rs Sdwsp,. t -• . •e DISC, r :I t.] = Dino ., r .� ` "e Lends (150; �� _ , 36 1 31 ,I, 5127 •. 120Yr1 —St I./ 'AVE l 1.! pu y r. �. :in T S Cr u --- Del _ -1/4;,,,, � g$49.21Sri i 0,P a, QP •• a,1.. . -. 1, dl's --•-, t. ace me , 0 ' M�P5. ' ,:111 I multi,� �L� ;��j!11 ". ,� r 1. ; - -- I P v aFi�'="t� r': 11 0 I FP J• elm \ s ly I • ��.�`\� ,'-►:GN�k / ,,,,,. iii --r annul , " I ~, e1'h�$��M41/ L- • 4{1 f II 182 •.� .• J /.'lilt( -- J/r W TucicR"pia ` .Willi& I' - \ +, LETERAL _ 4 111111911•' ; /' `_ ;.,,,,age I / 1• illil R te,,e�I .." TIT0RNT'0'N\ Q I 'C'.- `_ te £. :girl I. �1 •. : I 1 1p11 ►Th-' a T 4.11: \IT0�t�%INpll /�r��i „,. , , /� v b0.,4 1,..4 T,,• .g t_-,41 . 4! T, 1�, II I�tiy�_ ! •e.=� Excerpt from Northglenn "y"��l�/ S we• r •,.14; ► 1 a� p` • 11 p. LEGEND Plan, •Vol. 4 WI n� 3 . fi'li hi 1 ,.r. ►' 0 n Fi' .. 1 f /l n 1 �/ ,'t 1/4' L ► '\'lll _ 1 �� ■ W 1 RI" -�- AGRICULTURAL REUSE_SERV10E AREA fi WIj '1t. pi: LII11 1 11 If11I irk, 3 1; *," '' lhii=iri191' �`fUlli11 , / ` -weIb '''=. -.- NORTHfLENN CITY LIMIT . ,y �' it umpr■ n 1 t i Dina iiifIID `I ---.-.� ---- THORNTON CITY LIMIT �Illi :MVP_ .I�i unN f —� �rn ��. -, I •V .V a Rupp' ,� �'Itr "a` POTENTIAL EXCHANGE '' 9e 111)t,`� �� 'j �• •g, IRRIGATION CANALS ►im 1 Illllliimi s�w,• # -- 1N/ s.. 41-- .1 '�•y! mss'}''�=-1, •., ; .- _ , N Table 2 Projected Water Supplies and Needs Estimated Supply from Presently Year 2010 Owned and .Utilized Water-Rights , , Demand Potential Average Potential Dry Year Yield (ac-ft/yr) Year Yield (ac-ft/yr) Broomfield 4,720 2,340 14,200 Northglenn/ Thornton 12,100 8,980 25,400 Westminster 12,000 5,590 18,300 Source: "Draft Regional Water Supply," DRCOG, March, 1978 In order to obtain additional water supplies, the City of Thorn- ton initiated condemnation suits against three mutual irrigation companies (FRICO, Farmers Highline, and Lower Clear Creek) in 1973. Westminster did the same against two of the companies. One of the suits, Thornton against FRICO, was dismissed by the court in 1976. This suit has since then been appealed to the Colorado Supreme Court by Thornton. These cases have not been decided although the Supreme Court has ruled that "home rule" cities have the right to condemn agricultural water rights in order to meet future water supply needs. During the negotiations between the communities of Thornton/West- minster and the farmers, Northglenn has been busy trying to reach a compromise with the farming community regarding joint use of the available water resource. This compromise was reached between Northglenn and FRICO on September 2, 1976 and involved each party signing an exchange agreement whereby Northglenn would have right to use up to 7785 acre feet per year of FRICO water for domestic purposes in return for Northglenn promising FRICO 110% of any FRICO water that Northglenn used. This agreement has precipitated a series of events which has cul- minated with the development of proposed agreements between North- glenn, Thornton, Westminster, and FRICO. These agreements, if signed by all parties, would (a) transfer ownership of the water/ wastewater utility in Northglenn to FRICO; (b) give Thornton 9500 acre feet of storage rights in Standley Lake of which 500 acre feet would be given to Westminster; (c) allow Westminster to assume responsibility for operating and maintaining Standley Reservoir; and (d) eliminate the practice of stacking water rights in Standley Lake. The last two agreements are the most controversial and prob- ably will take some time to resolve. -23- Historically there has been a problem with the quality of the water supplies in the Denver North area. During the spring, Standley Lake turns over resulting in taste and odor problems in the West- minster drinking water supply. Westminster believes that this prob- lem is aggravated by Coors discharge to Croke Canal which feeds Standley Lake. On the other hand, Thornton has detected high nitrite levels in its water supply. Thornton believes that this prob- lem is traced to its South Platte alluvial well field which is recharged a short distance downstream from Metro Denver's wastewater disposal plant. The water quality problems associated with West- minster's and Thornton's water supplies are not addressed in Volumes 1 through 4 of the Northglenn Water Management Program Plan. Water quality of the water supply apparently was not a significant factor in Northglenn's decision to implement the selected water supply and wastewater alternatives although it has been cited elsewhere as a reason. 4. Water Quality - Presently wastewater from Northglenn and Thornton is treated and discharged to the South Platte River which is classified for a warm water fishery and secondary contact recrea- tion. The Clean Water Plan recommends that the fishery classifica- tion be deleted and that the South Platte below Metro's discharge be classified for agriculture, secondary contact recreation, and wildlife. Northglenn proposes to discharge into Bull Canal which is not classified by the State. The State includes irrigation canals as waters of the State which means they are subject to State regula- tion. Irrigation canals probably will be treated under the State's agriculture classification. The criteria that apply to this classification are presented in Table 3. The State's gui- dance on planning and design for land application systems requires a minimum of secondary treatment for all discharges to irrigation ditches that are not controlled by the treatment entity. This requirement is currently being revised to relax the effluent limitation for suspended solids. The present effluent requirements for discharge to Bull Canal versus discharge to the South Platte River are presented in Table 4. The consultant has designed the treatment system to meet the criteria in Tables 3 and 4 for discharge into the Bull Canal. EPA has questioned whether the proposed limit for suspended solids can be met with the proposed design for the treatment works. Metro is presently discharging effluent to meet the BOD and TSS requirements specified in its NPDES permit. Compliance with the ammonia and residual chlorine limitations is based on the avail- ability of EPA construction funds, but under no circumstances will noncompliance extend beyond July, 1983 and only if EPA grants an exception to the present permit compliance schedule of December -24- Table 3 Colorado's Criteria for Agricultural Use Parameter Criterion Dissolved Oxygen An effluent shall be regulated to maintain aerobic conditions, and a guideline of 2 mg/1 dissolved oxygen in an effluent should be maintained, unless demonstrated otherwise. Suspended Solids Suspended solids levels will be controlled by Effluent Limita- tions (i.e. 30 mg/1 for secondary treatment) and Basic Standards. Arsenic .1 mg/1 Beryllium .1 mg/1 Cadmium .01 mg/1 Chromium .1 mg/1 Copper .2 mg/1 Lead .1 mg/1 Manganese .2 mg/1 Molybdenum .15 mg/1 Nickel .2 mg/1 Selenium .02 mg/1 Zinc 2.0 mg/1 Cyanide .2 Nitrate (as N) 100.0 mg/1 Nitrite (as N) 10.0 mg/1 Boron .75 mg/1 Fecal Coliform per 100 ml (Geometric Mean) 1000 -25- Table 4 Effluent Reonjrementc for Existing Discharge to the South Platte River versus Proposed Discharge to Bull Canal Metro's Existing Discharge Limi- Proposed Dis- tations charge Limita- CO-0026638 tions for Bull Parameter (South Platte)a Canal B0D 20 30 SS 20 30 NH3-N 1.5 - NO3-N - - Cl2 (Total residual C1) 0.05 0.5 Fecal Coliform (#/100 ml) 1000 1000 Dissolved Oxygen 6.4 2.0 a. NPDES Permit requires compliance by December 31, 1979, dependent on the availability of adequate funding. -26- 31, 1979. Metro is presently conducting a Step I study to deter- mine the cost effective alternative to meet this requirement and/or any other requirements that may be imposed in order to protect downstream water supplies. Thornton has during the recent drought noted nitrite levels ex- ceeding national drinking water standards in its distribution system. Thornton has attributed these high levels to Metro's dis- charge, although identification of Metro as the source of this problem has not been verified. Even if Thornton is successful in reaching agreement with FRICO for 9500 acre feet of storage in Standley Lake, it will continue to rely on wells along the South Platte for water supply during the winter months. Consequently, consideration must be given to protecting Thornton's water supply which the present Metro facil- ity planning study is taking into account. 5. Groundwater - Northglenn is underlain by three bedrock aquifers which are the Denver, Arapahoe, and Laramie-Fox Hills. The Denver aquifer is the only one of the three that is defined as tributary by the State Engineers Office. Data for several wells in the vicinity of Northglenn indicate that yields are as great as 100 gpm. Since the majority of wells in the Arapahoe formation are being used for domestic purposes the yields average less than 40 gpm. Average yields for Laramie-Fox Hills wells are 75 to 100 gpm. Wright Water Engineers have esti- mated that a potential yield of 2300 acre feet per year is avail- able for appropriation from these two aquifers below the boundaries of Northglenn. The water quality in the Arapahoe and Laramie-Fox Hills aquifers is variable. Table 5 is a summary of the available water quality data on these aquifers. In general, the water quality of these formations in within the Public Health Services drinking water standards. The piezometric surfaces of the Arapahoe and the Laramie-Fox Hills aquifers have been declining during the last few decades. For example, the Laramie-Fox Hills aquifer has experienced a decline of 200 to 300 feet during the period of 1960 to 1976 in the vici- nity of Northglenn and Thornton. Similarly, the Arapahoe aquifer has experienced declines of 50 to 200 feet for the period since 1970 and the aquifer is now at or near water table conditions in the Northglenn area. The Laramie-Fox Hills aquifer is still under artesian pressure in this area. Northglenn has indicated that up to 2300 acre feet of water may be pumped from these aquifers during a dry year in order to make up consumptive losses that will be incurred in the Northglenn system. Volumes 1 and 2 of the Northglenn Water Management Plan proposes -27- that this water be pumped from a series of 10 to 20 wells located throughout the city. Northglenn's application to obtain rights to the Arapahoe and Laramie-Fox Hills water is presently before the Water Court. To date, the State Engineer has approved one (1) out of 20 permits requested by Northglenn to construct the neces- sa�y weii . There is still a legal question whether a. municipality such as Northglenn is entitled to appropriate groundwater under- lying private property. Because of the uncertainty of obtaining both rights to the water and the well permits, Northglenn is also actively seeking other sources of make-up water. 6. Air Quality - Volume 2 of the "Final Denver Regional Environmental Impact Statement for Wastewater Facilities and the Clean Water Program", presented a summary of Denver's air quality for the years 1974 and 1975. The eight-hour standard for carbon monoxide and the one-hour standard for ozone were the two criteria violated most frequently at the six air quality stations located in the metro- politan area. No air quality stations are located directly in Northglenn or Thornton. However, air quality modeling indicates that these problems pervade the entire metropolitan area, includ- ing both Northglenn and Thornton and will continue to be problems sometime into the future. 7. Population Projections - The population projections for the study areas are presented in Table 6. These projections are derived from and are consistent with DRCOG's projections for the area under study. Of the 30,000 people projected increase from 1977 to 2000, about 1/3 would occur within Northglenn's corporate limits, while most of the remainder falls within Thornton's city limits. Some growth will occur outside of both communities in Adams County. The facility plan evaluated the need for wastewater service in these areas and recommended that the proposed North- glenn WWTP serve the outlying areas in Adams County. To date, there is no commitment from Thornton or these other areas to have their wastewater treated at the Northglenn facility. 8. Land Use - The developed portions of Northglenn and Thornton are devoted primarily to residential and commercial uses. These communities provide a labor force for industry, business, and government located within downtown Denver and Boulder. Of the total study area about half the land is presently used for open space and for agricultural purposes. The majority of this land is located within Thornton's boundaries, or in the unincorporated areas of Adams County. -28- Table 5 SUMMARY OF NON-TRIBUTARY WATER QUALITY Arapahoe Aquifer Range Average (U.S.P.H.S.) Total Dissolved Solids (ppm) 210 - 467 250 - 300 500 Temperature (degrees F.) 61 - 68 65 SAR 14 - 25 18 - 20 pH 7.8 - 8.8 8.4 9.0 Hardness (ppm) 4 - 23 10 Iron (ppm) 0 - 2.5 0.2 - 0.5 0.3 Calcium (ppm) 0.6 - 8.1 2.5 - 3 Sodium (ppm) 79 - 164 100 - 120 Fluoride (ppm) 0.7 - 2.8 1.5 0.9 - 1.7 Sulfates (ppm) 12 - 123 30 - 50 250 Laramie-Fox Hills Aquifer Total Dissolved Solids (ppm) 440 - 714 600 500 Temperature (degrees F.) 67 - 77 72 SAR 15 - 50 20 - 30 pH 7.8 - 8.2 8.0 9.0 Hardness (ppm) 3 - 44 10 Iron (ppm) 0.05 -0.11 0.08 0.3 Calcium (ppm) 0.4 - 3.3 1.0 Sodium (ppm) 200 - 294 250 Fluoride (ppm) 1.2 - 3.6 2 0.9 - 1.7 Sulfates (ppm) 2.5 - 7.8 5 250 Excerpt from Northglenn Plan, Volume I -29_ TABLE 6 SUMMARY OF POPULATION PROJECTIONS BY MANAGEMENT AREA Population, Year Management Area 1975 1977 1980 1990 2000 Upper Grange Hall Creek Northglenn 29,000 32,000 35,000 42,500 42 ,500 Sub Total 29 ,000 32,000 35 ,000 42,500 42,500 Lower Grange Hall Creek Thornton 3,600 5,400 8,100 12 ,400 15,200 Other 500 800 1,300 1,800 2,100 Sub Total 4,100 6,200 9,400 14 ,200 17 ,300 Brantner Gulch Thornton 3,000 3,500 4 ,300 7,600 10 ,800 Other 100 300 700 1,500 2,100 Sub Total 3,100 3, 800 5,000 9 ,100 12,900 TOTAL 36,200 42,000 49 ,400 65,800 72,700 Excerpt from Northglenn Plan, Vol. 4 -30- DRCOG has defined an urban service area for the Big Dry Creek Basin which includes much of this open space and agricultural land (see Figure 7) . It is DRCOG's policy to restrict develop- ment to these urban service areas. Given DRCOG's growth policy, their definition of the Big. Dry Creek Service Area, and their population projections for this area, it can be expected that much of these lands will be converted to urban use during the next 20 years. It is EPA's policy, however, not to construct wastewater facilities that will provide service in areas where prime agricultural land is located. It has been estimated that 18,800 acres of land were converted to urban use from 1969 to 1975 for an area much larger than the Northglenn/Thornton study area, but which included this area. The relationship of the urban areas to three irrigation service areas is shown in Figure 8. A comparison of Figures 7 and 8 show a great potential for converting agricultural land to urban use. 9. Economy - Northglenn and Thornton are typical suburban communities. The economy of these communities centers on property taxes and sales taxes. Most of the income generated by the communities' work force is derived from sources outside Northglenn and Thornton. Northglenn passed a 31 million dollar general obligation bond issue for the purpose of paying for capital improvements asso- ciated with the recommendations of Volumes 1 through 4 of the Northglenn Water Resources Management Plan. In addition to this source of funding, Northglenn expects to receive funds from EPA as well as from other Federal and State sources. 10. Soils - Of the 23,665 acres of land classified in the FRICO and Farmers Highline Irrigation Service areas (using the Soil Conser- vation Service's Soil Capability Classification System) 15,881 acres fall under Class II or III, both of which are highly suit- able for irrigated agriculture. Table 7 summarizes this infor- mation for these two irrigation service areas. Figure 9 shows where prime agricultural lands are located in the DRCOG planning region. It is assumed that these percentages characterize the soil types in the facility planning study area as far as suita- bility for agricultural use. Based on the Soil Conservation Service's rating and some additional criteria, DRCOG attempted to define where prime agricultural lands are located in the five county Denver metropolitan area. Figure 9 graphically depicts where these lands are located. Based on a comparison of Figures 7 and 9, it appears that the unincorporated areas in Adams County east of Thornton is the only area where prime -31- agricultural lands overlap with the DRCOG service area boundary. However, DRCOG's Regional Development Policies (RDP) numbered 1 and 35 would allow development in this area in that RDP 35 applies only to non-urban areas which are defined as areas outside of an urban service area_ Despite��te DRCOG' policy ?llcwing development in this area, EPA is required by regulation to evaluate other alternatives which will encourage the preservation of agricultural lands. 11. Proposed Storage Reservoir and Treatment Lagoon Site - A separate study investigated the suitability of the proposed site for the storage reservoir. This study characterized the site's topography as generally flat to gentle (1% to 7%) slopes. The site is presently being cultivated. Coal mining has occurred during the past 100 years in the area, but no known coal mines exist in the immediate vicinity of the proposed site. The proposed site overlays the southern border of the Boulder-Weld County coalfield. The site also overlays the Sprindle and Wattenburg oil and gas field. No sand and gravel deposits were detected during the field investigations of the proposed site. The geology is sandstone occurring in Milliken, Fox Hills, Laramie, and Arapahoe Formations, ranging in depths from 6 feet to 600 or more feet. Soils include up to one foot of topsoil underlain with claystone and clayey sand. The Laramie-Fox Hills aquifer occurs at a depth of 600 feet and is approximately 100 feet in thickness in the vicinity of the pro- posed site. -32- vs � 4 .I L , , ' -..1' ' ' ."--••,\-._ ..-_, , FIGURE 7 ' 1 \ a. Facilities Service�Areasl . ✓ .+!, -* 'r i .y - - •1 J. �* NOTE FACILT"Y SERVICE AREAS FOR AGENCIES '-""r _' _ NOT SHOWN ON THE MAP N'OULD BE COMPARABLE > , a . ` •a :-a• - -• TO THEIR EXISTING SERVICE AREA • ..._ -, , — c . t �� e. `'` , Y, 1, f11 , , I . , \ 1 ,I it I /. - y\ 1 tm I veR I . LAFAYETTE ' / INA I I I '��I . ,): 1. r.-LOUIS E' 1 • ''' / Er �.. -,4 L y P �' \ Ira i, p. _ - , ,p .� rte• :�,ri`,I .j ', _� , ' '-Y',' J ',"{-1 ' 'A Jr1 SOUTH ADgrMS COUNTY J.-- ��` — mil. wr _ J�. Mr i 'i �i _ ,� I, i � �`° I + -- 't�.F TH"`LAK�a',YAOD ,r '..) i i i tZSIMCKS'�,� ,. -y.�,.nLDE]'I 'a i _ f-- — r Tv { ..,,� ./ • l t ijENVER 6 J PEZ.�' v`L I. i,t.ii°k11r.'CREEK 'd\ I i �.ry, ` ,.-„,---,-4—N.,J-1 .... _c,. �' i; '►' --I'• ;J;4; ' i c A. '` �..-\ ti• " 1 _ f-, • . : Etil,' ^ 1TITAB,f s r i - . ._ I. ._ ) . , ) . V . "l" I ` , 1 . } iy 1 - l 1 ,- , ;" L• Ft*v. �r V ' .` �.V '' i i I� acs . - f , - ,. . ,rte f +.. r(.3 .3 a - :L..�.F t^i f' • ' 1 , '-_III from Clean Water Plan —33— RecW LBW Figure 8 irrigation Service Areas with City Boundaries and Urbanized L""" D,` ' a Areas:January,1974 -1 • .j Legend �▪ - P'7 • V. 1 Farmers Resevoir and Irrigation Co. j• - --- --• •- (Standley Lake Division) *°• '- _ 5� ar - S 71 Farmers'High Line Canal and �C • - .: .o`J Resevolr Co. e° =o.• ` _ 41 p Lower Clear Creek Ditch Co. -:Fon WELD CO •_ �' .lC - _---___ _ _Ia..,•-..- _ -.1.7.44...7.:4•:4... ..---... _ .,. ( 1 r ADAMS CO - t',..-...-.-:.-_-- -_-_-?-..---.-1:::::-,_ Urbanized Areas / -=�' • ci _ -- City Boundary m�▪ - °� � = ObA Lt _-'AeL I i 0 1 2 3 ♦ I -N- BROOMFIELD �- • - _ y_. Oil' L'---r- -1 • MILES lI __ . '. ,w.. -_-- Lee'_- 1.-_-_:::-.. )14--(:: t—•—• - -•.1 �- ;4::...i:_::_ '-7-.-.-_BOULDERS',O 1 _ -.. - = G• JEFFERSON CO -• r• 1 ••l'_:::.1 i-'� �D IC ____: - �"- L�-.1 1 Ga ......':.-:---7'.- i I :{-_'ew 1• L'/i ® —Oa {_-line i NORTI'. `3LENN _ L,L 0 re`�__ _-_:r- FEDERAL i - C• 6 T2S I, Stand/er\ '' HEL.HTS 1 1:0" \ �. 1 1 di. i THORNTON , i Leke \ Fermert F•--- Cen_a/:- 1 t �- ( 0V4e ...n. ./ J f% WEST ' Cr •� .1.-.::--*" -'' t— IMINSTER Jt - A I I __ jWtlb C'1.,--:"-:t-.= - .._-.-I • COMMERCE I e. =r-' RCE I '.=.r-_ ARVADA j-� •• eK - CITY i r---.% • J - i- G'e ., a j i l 1 4. _ 7 E . -t' �• 1 y�. i.-1-- 1 - I r J DENVER CO __ ..ice-- r�; I T38 Ga° - - _ 3\ ,—_______1r-1 e,, - O ' Cl.., L. -1-.perm WHEAT RIDGE o DENVER _ GOLDEN I I.� I— z. zo L j ♦•7_._ ,___._._._........f1—.2 L. 1 LAKEWOOD I -' il� AURO' - +s•w .nr .) R71W I I MOW R89W ® r _ _ R88W Excerpt from CSU Report by Anderson, et.al. -35- .. . .. ...,..„, . ... G ``,.S, _ 1 , .- .N- . ...• •,...3 - H s • v_ i %I LW e �. 1` 2 4, o \\1� O 7.�. 4J"alliop.,: !. a f /- Trolic... _ illirte24:1 , / \\�, O utsWil 1 ' 1 . _- 44 4.1 __ \ r___:___.! ` '_ • shyer-- u ,.'� i - 'ei • -,. ,-1: ` miirr', �_ w -.,, . ,:i.)..,;____„7.? •- ____,,,,,,,,- ,- . el 461 -.1 • ! r • • `L,i - 1 'L., `"' J' ' , J 1 i,-.;:.1�-„ \I->--Id,..�. !,...., ' 1 • r, i-_, i „,... , .:, _ .._ , • / , ,.__ . , . .-"--,r I ' ,• , - J.;11...-,‘j I c .✓�� `•1{�, -- I. 1 j~ rte\ !.{ 1 1 r� - i • .L> '.. 3'44. ).6% -37- Table 7 SCS Soil Capability Classification: Irrigated Cropland in the Farmer's Reservoir and Irrigation Company, Stanley Lake Division and the Farmer Highline Canal and Reservoir Company as of 1970. SCS Class Acres Percent II 12713 53.7% III 6653 28.2% N 3010 12.7% V 406 1.7% VI 310 1.3% VII 573 2.4% 23665 100.0% Class I - Soils in Class 1 have few limitations that restrict their use. Class II - Soils in Class 2 have some limitations that reduce the choice of plants or require moderate conservation practices. Class III - Soils in Class 3 have severe limitations that reduce choice of plants or require special conservation practices, or both. Class N - Soils in Class 4 have very severe limitations that restrict the choice of plants, require very careful management, or both. Class V - Soils in Class 5 have little or no erosion hazard, but have other limitations impractical to remove that limit their use largely to posture, range, woodland, or wildlife food and cover. Class VI - Soils in Class 6 have severe limitations that make them generally unsuited to cultivation and limit their use largely to posture or range, woodland, or wildlife food and cover. Class VII - Soils in Class 7 have very severe limitations that make them unsuited to cultivation and that restrict their use largely to grazing, woodland or wildlife. Class VIII - Soils and landforms in Class 8 have limitations that preclude their use for commerical plant production and restrict their use to recrea- tion, wildlife, or water supply, or to esthetic purposes. Source: Report by Anderson, et. al. -39- F. ENVIRONMENTAL IMPACTS AND PROPOSED MITIGATING MEASURES The facility plan evaluated six (6) general environmental issues in terms of what impacts can be expected with and without the project. They are: growth, water, air, energy, agricultural preservation, and environmentally sensitive areas. In addition to these issues the facility plan identified more site specific impacts related to the location of facilities (i.e. the interceptor, treatment lagoon, storage reservoir, and urban runoff collection reservoir) . The results of this and EPA's evaluation are presented below. 1. Growth - Growth is the common denominator for discussing impacts for the other five environmental issues. Without growth and assuming no increase in per capita demand for goods and services, there probably would not be any increase in the demand placed on the available air, water, land and energy resources. Zero growth is not and will be not a reality within the timeframe of this plan- ning period, as is evidenced by the facility plan's projection for an increase of 30,000 people between now and the year 2000. Northglenn and Thornton are implementing plans to provide essen- tial services for their expected increase of 10,000 and 20,000 people respectively. Similarly, both communities are developing new ways to manage growth in order to minimize the impacts that this growth will have on the urban and natural environments. These measures will be discussed in the sections below. EPA has established a policy of funding wastewater facilities in the Denver metropolitan region which are designed consistent with DRCOG's population projections. The proposed Northglenn facility meets this criterion. EPA will not, however, be able to fund capa- city for the Lower Thornton Service Area without an executed agree- ment stipulating that this area's wastewater will be treated at the Northglenn facility. EPA has taken the position that once con- struction begins on the wastewater treatment facility, no increase in funds will be forthcoming to construct capacity for treatment of flows from the Lower Thornton Service Area. 2. Water - Surface water quality, water supply, and water rights in the State of Colorado are all interrelated and this is especially true when discussing Northglenn's Water Management Program. The DRCOG Clean Water Plan concluded that achievement of EPA's 1983 water quality goals are not attainable for the South Platte River below Metro Denver's discharge. EPA is not convinced the documenta- tion presented in the Clean Water Plan supports this conclusion. -41- The Northglenn facility plan claims that withdrawal of their waste- water from the Metro facility and substituting discharge of a secon- dary treated effluent to Bull Canal will improve the overall water quality of the Denver Region. This claim cannot be reasonably sub- stantiared since the quantity of wastewater flows being divested are minor compared to the total Metro wastewater discharge and stream flows in the South Platte River. EPA is convinced that in- stream water quality of the South Platte will be improved, if Den- ver Metro constructs and operates a facility that is designed to control ammonia nitrogen and/or nitrates. As far as the water quality in Bull Canal is concerned, the projected discharge quality will be compatible with the quality of irrigation water flowing through the Canal. EPA's questions about the proposed design of the wastewater treat- ment facility have not been resolved. However, regardless of the alternative treatment technology that is finally selected, the facility that will be constructed will be designed to meet appli- cable discharge requirements. Consequently, EPA does not expect a change in the environmental impacts resulting from a resolution of the questions dealing with design of the facility. The effect of the proposed project on water supply will be positive once the FRICO/Northglenn agreement is implemented and Northglenn begins to use Standley Lake water. Implementation of the discharge agreement will result in immediately adding 6125 acre feet of water supply for domestic use (FRICO's commitment based on the dry year demand for 35,000 people) . Thornton has stated that the Northglenn severance will free 10,000 taps which is more than adequate to satisfy the projected growth in the Lower Thornton Service Area. The addition of this water, however, will not enable Thornton to abandon its South Platte alluvial wells. This is true even if Thornton is successful in obtaining 9500 acre feet of storage in Standley Lake, because the right to storage does not include any right to use FRICO water. Consequently, implementation of the FRICO/Northglenn exchange agreement will not solve Thornton's water supply problems. Northglenn will attempt to solve the taste and odor problems of Standley Lake through the design and construction of its new water treatment plant. Due to legal difficulties which Northglenn has encountered in ob- taining non-tributary water, the water rights for the make-up water for the project have not been identified. It is unclear at this point what procedure Northglenn will take in obtaining water rights. Northglenn could take the option of preparing an overall plan of augmentation for the development of its water supply. The augmenta- tion plan would include a description of the water rights which will be used in the plan including historic use, diversion records, water decrees and priorities, and proof of ownership. The plan would be -42- developed in order to insure that as Northglenn develops the water supply there will not be injury to any vested water right or decreed conditional water right. State laws which regulate water use pro- vide for administrative and judicial review of_ augmentation plans. ., . in order to protect water users. Northglenn has also indicated that until their own water rights are obtained they may take the option of using the water which is presently supplied by Thornton for their system. It is not clear if this proposed action would fall under the court ruling which permitted municipalities to change their wastewater discharge point to a location downstream when this change caused injury to water users. If Northglenn elects to go with this option EPA will require a legal opinion regarding this issue. It is not clear if there would be injuries to water users if this option is followed, thus environmental or economic impacts caused by these potential injuries have not been analyzed. EPA will require Northglenn to demonstrate that it has acquired all the necessary make up water it needs to implement the exchange project and has made provisions to pay all costs associated with them prior to award of a Step III grant and initiation of con- struction. At the time this negative declaration was written, no decisions were made on the quantity of groundwater (shallow or deep) to be pumped by Northglenn. Therefore, it is difficult for EPA to assess the impacts of the proposed project on the groundwater quality and quantity. EPA believes that if the full scale ground- water pumping program (3000 acre feet in a dry year versus 2700 acre feet in an average year) were implemented the groundwater impact could be significant. Northglenn did provide an estimated drawdown that could be expected in the Arapahoe aquifer if it were pumped at a rate of 1300 acre feet per year for a 100 years. Two cases were evaluated, the first for an average permeability of 20 gallons per day per §quare foot and the second for an average permeability of 50 gpd/ft . The results of this analysis are presented in Table 8. Table 8 represents the drawdown that is expected from Northglenn's proposed groundwater pumping program only. The aggregate effect of all groundwater pumping, existing and proposed, from these aquifers is not known. The information presented in Table 8 is based on the assumption that the aquifer will yield water equivalent to 20 percent of its total volume as the aquifer dewaters. It should be emphasized that the value of the specific yield of 20% is an estimate. There is a possibility that the actual specific yield in the Northglenn area could be less than the estimated value which would increase the impacts due to pumping. An analysis was not done for the Laramie-Fox Hills aquifer since Northglenn would pump from this aquifer only during a dry year. -43- Since the shallow wells are tributary to the South Platte, any pumping from these wells will require Northglenn to acquire the rights to this water. Pumping from wells tributary to the South Platte will probably reduce stream flows. The effect on ground- " wdter quality Oi ire-stream water quality was not evaluated. Based on the relatively low proposed maximum quantity of 1440 acre feet per year, EPA does not expect any detectable changes in the sur- face or the groundwater quality. EPA will recommend to the State Engineer that additional studies be conducted to better define the average storage coefficient of the Arapahoe and Laramie-Fox Hills aquifers prior to approving any more well permits. EPA expects that a better analysis of the potential impacts of the proposed groundwater pumping pro- gram could be made once this study is completed. As part of EPA's final action on the Denver Regional Environmental Impact Statement, EPA is requiring applicants for construction grants to comply with the following provisions to promote water conservation in Metropolitan Denver. "Prior to making a grant for design of a wastewater facility the grant applicant must demonstrate (in conjunction with the appro- priate local jurisdictions) that: a. The feasibility and cost effectiveness of metering and pric- ing incentives have been studied and steps taken to implement these measures where cost effective. b. Building codes have been evaluated to incorporate, where feasible, water saving devices in plumbing systems on new construction or major remodeling and a program instituted to encourage voluntary retrofit of such devices by property owners. c. The design capacity on other features of the wastewater treat- ment facility reflect the projected reduction in wastewater flows. d. Wherever the dry weather wastewater base flow (excluding in- dustrial flows) to be used for planning a treatment works exceeds 70 gallons/capita/day, the applicant plan and imple- ment a water conservation program and use the reduction in wastewater flow as the measure of design capacity for new treatment facilities. As a guide, a 15 percent reduction in wastewater flow may be expected from the implementation of an in-house water conservation program." The facility plan included copies of several draft ordinances which are designed to ensure that water is conserved once Northglenn assumes responsibility for water treatment and distribution. EPA is satisified with the provisions of these ordinances as meeting the requirements of a and b above. EPA will condition Northglenn's grant award to require adoption of these ordinances. -44- Table 8 Drawdown (feet) in the Arapahoe Aquifer Due to Northglenn's Withdrawal of 1300 acre feet per year Case 1: Permeability = 20 gpd/ft2 Time Distance to Northglenn (miles) (yrs) 2 4 5 8 10 20 1 0 0 0 0 0 0 5 0 0 0 0 0 0 10 .25 0 0 0 0 0 20 2.2 0 0 0 0 0 40 8.1 .25 .03 0 0 0 60 14.0 1.0 .20 0 0 0 100 23.9 3.6 1.2 0 0 0 Case 2: Permeability = 50 gpd/ft2 Time Distance to Northglenn (miles) (yrs) 2 4 5 8 10 20 1 0 0 0 0 0 0 5 .23 0 0 0 0 0 10 1.42 .01 0 0 0 0 20 4.37 .23 .04 0 0 0 40 9.14 1.42 .49 0 0 0 60 12.62 2.91 1.31 .05 0 0 100 17.59 5.72 3.21 .35 0.10 0 Excerpt from Northglenn Plan, Response Letter -45- The facility plan used 90 gallons per day per capita as the basis for design. Records of water consumption for Thornton and North- glenn indicate that dry weather in-house use in 1977 was 62 gallons per capita. This figure is within EPA's criteria of 70 gpcd to be used for designing treatment works. Thus requirements c and d above are satisfied. 3. Air - The proposed project may have the effect of delaying the conversion of agricultural land to urban uses in the FRICO service area. By keeping agricultural land in production, the facility plan claims oxygen producing vegetation will promote cleaner air in this part of the Denver Region. The exact difference in air quality is not predictable but EPA would expect some air quality benefits from preserving open space and agriculture within and adjacent to the metropolitan area. Some of these benefits will be offset by the conversion of agricultural land to urban use in the Lower Thornton area. EPA, in an attempt to promote better air quality through the im- plementation of its programs requires the following of all its applicants for wastewater construction grants in the Denver Region. "EPA believes that funds be made available only where reasonable actions are being taken to deal with the air quality impacts of growth. Accordingly, EPA will require: a. A commitment from the elected policy body of the local govern- ments which are to be served by the proposed wastewater treat- ment facility, to: (1) Implement air pollution control measures considered rea- sonable for their area. The air quality program adopted by the City of Westminster is an example. (2) Participate in the process established by the State of Colorado and the Denver Regional Council of Govern- ments to revise the Denver element of the State Air Quality Implementation Plan. (3) Support the implementation of the Denver element of the State Air Quality Implementation Plan once approved by EPA. b. Design wastewater facilities based on DRCOG population pro- jections (or as revised during the State Air Quality Imple- mentation Process) with capacity increases staged in accor- dance with the April 25, 1978, regulations (43 FR 17697) pertaining to grants for construction of wastewater treatment works. -46- c. The grant applicant (in conjunction with local jurisdictions) to develop and implement a sewer tap program which annually determines the number of taps available for new residential development and which is consistent with the DRCOG popula- tion forecasts for 1980, 1990, and 2000. d. Development which will be served by the additional capacity to be within the adopted regional urban service area boundaries and contiguous to existing development as stated in DRCOG's Regional Plan Policies. EPA may require evidence that local governments within the service area are promoting contiguous development through zoning actions, building permit approvals and tap allocations." EPA has discussed these requirements with Northglenn and they have already taken measures consistent with these requirements or are committed to comply with the above requirements. EPA intends to condition its Step II and III grants based on compliance with these provisions. 4. Energy - EPA has adopted the following policy regarding energy conservation for EPA funded projects in the Denver Metropolitan area. "As a requirement for receiving a grant for planning or design of any wastewater treatment works, the considera- tion of solar energy and energy conservation technology and techniques must be demonstrated by showing that energy requirements, particularly for natural gas, have been reduced as much as possible." Supplemental material to the Northglenn facility plan provide a detailed analysis of the energy requirements for several alter- natives considered in the Plan. This information is summarized in Table 9. This analysis indicates that there will be consider- able energy saved by implementing Northglenn's proposed project. Consequently, EPA is satisfied that the proposed project meets the above requirement. 5. Land Use/Agricultural Land/Environmentally Sensitive Areas - A feature that has made the proposed project attractive from EPA's perspective is land application of the wastewater effluent. The facility plan claims that a direct result of the exchange program will be the maintenance of 16,000 acres of land in agricultural production. If this land were converted to urban use it is esti- mated that approximately $1,548,000 of net agricultural income will be lost annually. -47- Table 9 Energy Consumption (megawatt hours/year) Alternative Energy Consumed 1. Northglenn Agricultural 11,653 Reuse Plan 2. Metro Denver Alternatives a. Status Quo1 14,378 b. Modified Status Quo2 12,342 c. Protect Downstream Water Supplies 20,764 d. Meet 1983 Goals 45,901 1. Meets existing discharge permit requirements. 2. Meets existing discharge permit requirements, but assumes successful implementation of Adams County sludge plan. -48- EPA has a policy of promoting the preservation of prime agricultural lands. EPA is using its construction grant funds as a means to implement this policy by encouraging the use of these funds for constructing land application projects. EPA regulations and the Clean Water Act provide for 85% funding of land application projects in addition to giving a 15% preference to these types of projects in the cost effectiveness analysis. EPA has developed some requirements for ensuring that land appli- cation projects continue to operate as a land treatment scheme throughout the twenty year planning period. In general, EPA requires assurances that the applicant can control disposition of its effluent such that land application of the effluent is guaranteed for twenty years. Therefore, EPA is requiring all land treatment applicants to develop long term reuse agreements with the recipients of the wastewater, or as an option, to pur- chase sufficient land where the effluent can be land applied either under the management of the applicant or through a lease with another operator. Northglenn has not met this requirement and EPA, therefore, will condition the grant award to require these agreements, prior to making a Step III grant and the initi- ation of construction. Without these agreements, the Northglenn project will not meet the definition of an "alternative" techno- logy. The agricultural area that is most susceptible to urban develop- ment and which is located within the DRCOG Big Dry Creek Urban Service Area are those lands covered by the Farmers Highline and Lower Clear Creek irrigation service areas. There are no prime agricultural lands located within the urban service area for North- glenn. Thornton and Adams County are both encouraging development to occur in these prime agricultural areas and the Northglenn project, if constructed as proposed, would extend service for waste- water treatment into these areas. For EPA to fund the extension of interceptors into these prime agricultural areas is contrary to EPA regulations and policies. The facility plan has not demonstrated to EPA's satisfaction that wastewater treatment service is urgently needed in these areas, nor has the applicant evaluated the feasi- bility of implementing individual systems or cluster systems as a means of providing this service. Consequently, EPA will not fund those portions of the proposed project which extend service into the areas described above until such time as a full range of alternatives is evaluated and assurances are made which will pro- tect agriculture in these areas. Of the other 13 categories of environmentally sensitive areas identi- fied by DRCOG in their report, "Specification of Environmentally Sig- nificant Areas in the Denver Region," only 5 have potential for con- flict with the proposed project: that is, floodplains, shrink-swell soils, wildlife habitat areas, coal resources, and oil and natural gas fields (see Figures 10 - 14) . -49- • DRCOG's Regional Development Policy number 23 regarding flood plains states: "Development should not occur within the limits of the 100 year flood plain nor should any filling in of the floodplain that would reduce its flood carrying capacity. Parks, recreation and open apa.c.c uses are encouraged in Eloodplaiii areas." All Jie 100 year floodplains within the study area occur in Adams County and at this time, EPA does not have copies of Adams County's develop- ment policies and regulations as they apply to floodplains. The facility plan did not conduct a floodplain analysis. However, it appears to EPA that the proposed project will not extend into the South Platte River 100 year floodplain. The only component of the proposed project which will encroach the 100 year floodplain is the Northglenn interceptor where it crosses Big Dry Creek. This area is presently used for agricultural purposes and EPA intends to require Northglenn to prohibit any connections to the interceptor outside the urban service area which includes the Big Dry Creek floodplain. Therefore, EPA does not expect any new development to occur in the Big Dry Creek floodplain. The facility plan recognizes that shrink-swell soils exist in the vicinity of the site for the treatment lagoon and storage reservoir. The design phase will address any problems that could be encountered with construction of these facilities. The applicant has analyzed the suitability of these soils for the intended uses and has con- cluded that no major problems will be encountered. The Northglenn interceptor will cross a designated wildlife area (see Figure 12) . The impact of constructing the interceptor across this wildlife area was not evaluated in the facility plan. DRCOG's Regional Development Policy numbered 29 addresses this problem as follows: RDP 29 - Development in significant wildlife habitat areas areas of very high density and production) should occur only after an evaluation of the site has been made by the Colorado Division of Wildlife and it is determined that the impact on wildlife habitat is not adverse or the adverse impact is miti- gated. EPA has contacted the Division of Wildlife and has discussed the project with them. The area in question is not a habitat for any known threatened or endangered species. Rather it is a habitat for numerous communities of prairie dogs with densities as high as 700 animals per square mile. Development in the vicinity of these habitats would be a more serious impact than actual construction of the interceptor through the area. Prairie dogs are fairly tolerant to human activities and are known to exist in the midst of urban developments. Despite this, EPA will condition the grant to preclude development from occurring in this area and also to minimize construction impacts. -50- 0 0 0 o. 0 I-I - -_ a a. A Z b Q G D P O IQ Z Q p a nl N LD o i ; : � A = — =— to * a a w a1 1 - k a w— — — — f • • i ... - -1. .-L• ." L -- _ _._r::T,i% ; ....4 :, i T.,.....7:‘---?1 I. .,,,:- "\\'''. - - ._ s• 1f-.. \ _-_.L p , 1,...r..< .\ / , _� _ L , t. 1 I d 1 I• l k ye t�j PI \ , .� :I" i 1 /: • - /G£ 9 - `f • x' b31rNf' -5 1- ' -- Ill. .I.J C i 3 41 / 4J Q 'I: J_ 5 G a J y d Wi � rl J O o! 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V . `� a 41 1°4 , , , '1"-.0 .) k F uy M 'r,.,y a`i' $.t.e'' " 'f `• Y 1el ctl '. 1 _ �`1�-may.... - ` '�'-+ ,+. ;t,.: rte' e, '.-.. :-.q".„ V` i• ;' �� /S _ `rte - c — a s, w • - •2)tt i v :r- 1 .._—__ t -'� ^yam..-. .'..�..� , t_ _ - _ , P. • Va e__ \,, +'b b3N•a0 —57— N. � Q +, ova O a t • I Oa ® ` VI 9 O N o Q OO o O' D t, W 5. o• k.Jto 3 i H'i Q C.- D _9 O y �� © p 0 r-I Q ill W C7 c ri If © 0 i} / _ _ O cal gg Z A 3 <4 28 1 — o �Oi DQ . C 0 g ( Z . q 0. 1 O-- ... O• U rl p c3� w a I cs. o aA a r 7� ,✓' _ / -y e am 4 -- - t :-•,—.. -• •.:`:� ' L�T'___.i- \ �t J • r Jr .-,4 -, •.4 V r Z �'t ,,. f `-` l t 'f.-.",' ---1-----.. .`"-.'1^ • �< f 2,-rt a t i` + l 2 4 —- .f e ____ eq0 -59- A report by Chen and Associates concluded that construction of the proposed reservoir and treatment lagoons will not interfere with development of the oil and gas resource lying beneath the proposed site. If this is true then no conflict exists with DRCOG's policy numbered 32 or any of EPA's policies. Regarding the coal resources that underlie the proposed site, the same report concluded that the coal is "uneconomical to mine because of the depth below ground surface, thin coal beds, and lack of lateral continuity of these coal beds." Consequently, the proposed project is consistent with DRCOG's RDP #31 and EPA policies. A separate archaeological and cultural evaluation of the proposed project was undertaken as part of the facility plan. The following excerpt presents the conclusion of this study. "On February 28 and March 1st, Dr. Dean E. Arnold conducted an archaeological survey of the proposed site. The survey included two proposed pumping stations within the city of Northglenn, a proposed reservoir located 8 miles north of Northglenn, and a pipeline route between one of the pumping stations and the reservoir following first the Union Pacific Railroad Tracks, and then York Road. This survey was carried out in conjunction with other studies to provide an environ- mental assessment of the project area. A site file search in the Office of the State Archaeologist, and a literature search revealed that there were no archaeological sites in any of the areas affected by the project. During the course of a walking survey of the project area, one isolated arti- fact (a chopper-scrapper) was found and only one archaeological site (5AM66) was located. This site consisted of a dump/midden of the recent period probably dating to 1900 - 1940 A.D. A copy of the OSAC Survey report for the site is attached. Neither of these cultural resources are important nor signifi- cant enough to recommend further investigation within the pro- ject area. Therefore, there are no known significant archaeo- logical sites nor cultural resources in the survey area that would be destroyed or adversely affected by the proposed pro- ject." The final land use issue considered in this negative declaration is one related to the control of urban runoff (nonpoint sources of water pollution) . The final action on the Denver Regional Environ- mental Impact Statement makes the following requirement: "Prior to granting funds for construction or expansion of wastewater facilities, the general purpose governments within the proposed service area must show progress, in the form of ordinances adopted or recent efforts taken, towards imple- menting the nonpoint source controls recommended by the Clean Water Plan." -61- EPA will make this a condition of the grant award. Since Thornton and Adams County will probably not be the beneficiaries of EPA funds at this time, EPA will not require that they satisfy the above requirement. 6. Enhancement of Recreation Opportunities - The Clean Water Act specifies that EPA shall not make grants from funds authorized after September 30, 1978 unless the grant applicant has analyzed the potential recreation and open space opportunities associated with the proposed treatment works. The Northglenn project has many aspects which will improve recreational opportunities that are available to the residents of Northglenn. The most notable is the proposed Stonehocker reservoir which will include recrea- tion facilities for biking, picnicking, and hiking. There may be opportunity to use all or part of the Northglenn interceptor right of way as a bike trail, etc. EPA will suggest to Northglenn that this opportunity be explored. Otherwise the applicant has evaluated the compatibility of the proposed project with other existing, plan- ned, and proposed recreation facilties and has integrated the wastewater project with these plans. 7. Other Site Related Impacts - a. Standley Reservoir: Although the reservoir is not a component of the wastewater project there has been some concern about the structural soundness of the dam and the potential for failure resulting from implementation of Northglenn's and Thornton's proposed water supply projects. Many new develop- ments have located in the valley below the reservoir and dam which would be endangered if the dam failed. It is EPA's understanding that Northglenn and Thornton are not seeking new storage capacity (rights) in Standley Reservoir. Rather both communities will be utilizing water that is al- ready in storage or storage capacity that is not presently being utilized. It is also EPA's understanding that the State Engineer's Office will not allow storage in the upper part of the reservoir until certain improvements are made. Since the proposed project will not affect the reservoir and dam, and because available operating capacity exists in the reservoir, EPA believes that this issue should not delay design and con- struction of the Northglenn successive use project. b. Stonehocker Reservoir (Stormwater Retention Reservoir) : The urban runoff from Northglenn will be collected and stored in Stonehocker Reservoir located on Grange Hall Creek. Northglenn proposes to construct the reservoir for recreation purposes in addition to using the runoff from shopping center parking lots as a source of make-up water. -62- domestic wells in the area. A more detailed analysis of this relationship is presently underway. Northglenn will be design- ing an early warning monitoring system to detect potential prob- lems that may result from sludge disposal and/or reuse of the wastewater for agricultural production. Based on available information no problems are expected. 8. Rocky Flats Emergency Evacuation Plan: In the Denver Regional Final Environmental Impact Statement, EPA identified an area of concern where new or existing housing is located near the Rocky Flats plutonium processing plant. Since EPA is funding waste- water treatment plants that could serve these areas, EPA devel- oped two policies to deal with this problem. These policies are: a. If EPA determines that a wastewater facility proposed for EPA funding will serve a development which is located in the "Area of Concern" as defined by the Colorado Department of Health (Interim Guidance dated November 1972 for the US AEC Rocky Flats Plant, Jefferson County, as amended) and appropriate mitigating measures have not been carried out according to existing state statutes, EPA will condition the grant of Federal funds to prohibit sewerage service to that development. b. Pending recommendations of the Rocky Flats Monitoring Committee on notification, EPA will require grantees (in conjunction with appropriate local governmental entities) to develop a notifica- tion mechanism (e.g. notification ordinance) for notifying exist- ing and prospective homeowners in the vicinity of the Rocky Flats Plant of the provisions of the State Radiological Emergency Re- sponse Plan and their role in carrying out prescribed protective actions. (Vicinity can be defined as the Category III and II areas, Rocky Flats Radiological Emergency Response Plan.) Since Northglenn does not lie within the "Area of Concern" defined by the Colorado Department of Health, there is no problem with the general eligiblity of the planned developable areas. Northglenn does lie partially within the Category area II defined by the Rocky Flats Monitoring Committee. EPA will require before Step III funding can be approved for this project, that the City of North- glenn take positive steps to adopt a City Ordinance or some suit- able mechanism to notify existing and prospective homeowners in the Category II areas concerning the Emergency Response Plan for Rocky Flats. -63- • G. SIGNIFICANT ISSUES AND EPA'S PROPOSED ACTION Several issues have surfaced during EPA's review of the Northglenn Water Management Plan and Northglenn's Step II grant request. These issues are highlighted in this Section to facilitate the reader's understanding of potential problems with the project and to learn how EPA intends to confront and/or resolve these problems. The narra- tive that follows provides additional detail and background informa- tion on the proposed project. Issue 1: Growth and development in the north part of the Denver region has resulted in about 18,000 acres of agricul- tural land in Adams County to be converted to urban use for the 6 year period of 1969-1975. The Northglenn facility plan projects growth to occur in presently defined irrigated agricultural areas and prime agri- cultural areas. Implementation of Northglenn's proposal will immediately free 10,000 taps for development within Thornton where all this agricul- tural land is located. All of the proposed interceptors will tra- verse prime agricultural lands except for the Nott Interceptor. EPA has endorsed DRCOG's Regional Development Policies Numbered 23 through 41 as found in the Council's "Draft Regional Growth and Development Plan for the Denver Region" (DRCOG, July 1977) . Policy Number 35 states: "Development should not be permitted in presently identified areas of prime agricultural soils which are located in the non-urban areas of the Denver Region". In addition to the DRCOG policy, EPA regulations published in April 25, 1978 place the following restrictions on EPA's funding of interceptors: "An interceptor may be provided in the initial stage to phase out or eliminate existing point source discharges and to accommodate flows from existing habitations. Unless neces- sary to meet those objectives, interceptors should not be extended into environmentally sensitive areas, prime agri- cultural lands and other undeveloped areas (density less than one household per two acres) . Where extension of an interceptor through such areas would be necessary to inter- connect two or more communities, the grantee shall reassess the need for the interceptor through further consideration of alternative wastewater treatment systems, analyze primary and secondary environmental impacts of the interceptor, and provide for appropriate mitigating measures such as re-routing the pipe to minimize adverse impacts or restricting connections to the pipe. Conditions to ensure implementation of mitigating -65- measures shall be included in NPDES permits when new permits are issued to the affected treatment facilities in those cases where the measures are required to protect the treatment facili- ties against overloading." EPA proposes the following actions in response to the above requirements: 1. EPA will not fund the Nott, Grange Creek and Brantner Interceptors until such time that "alternative" waste- water disposal systems (i.e. , individual or cluster systems) are investigated, and the impact of the pro- posed interceptors upon agricultural lands is fully. evaluated. 2. EPA will provide funding for the Northglenn interceptor north of the Big Dry Creek service area provided that Northglenn adopts a regulation prohibiting direct or indirect (through pump stations) connections to the inter- ceptor in the section from 136th Avenue north to the treat- ment lagoon in Weld County. Issue 2: Northglenn's proposal to pump groundwater from the Arapahoe and Laramie-Fox Hills aquifers may have irre- versible long term environmental consequences. Part of Northglenn's agreement with the Farmer's Reservoir and Irrigation Company (FRICO) is for Northglenn to have the right of first use for up to 7,785 acre feet of FRICO's water as long as Northglenn returns to FRICO 110% of the water that it uses. Typically, a city experiences 30-40% consumptive losses. Consequently, Northglenn needs to replace the water it consumptively uses and augment whatever FRICO water is used by 10%. Volume 2 of the Northglenn Water Management Program identified that almost half of the make-up water would be derived from groundwater sources, the majority being pumped from the Arapahoe formation. The status of the Northglenn proposal to pump large quantities of water from the Arapahoe formation is uncertain. The State Engineer has approved only 1 out of the 20 well permits requested by Northglenn. Even if all permits were approved, there is a chance that a class action suit would be filed on behalf of private well owners in the vicinity of Northglenn. Because of these factors, and others, North- glenn has been actively pursuing alternative sources of make-up water. EPA, in its comments on the Northglenn facility plan, identified as the major potential environmental problem the depletion of the groundwater resource in the Arapahoe and Laramie-Fox Hills aquifers. -66- EPA requested and Northglenn has provided some additional information on the impacts associated with the proposed groundwater pumping scheme. Given the fact that other sources of water are available, EPA has chosen to delay a more thorough analysis of. these impacts until such time it is certain Northglenn will implement the ground- water pumping program or a similar proposal. EPA could fund construction of the wastewater treatment facility prior to a final determination being made on whether the Arapahoe and Laramie-Fox Hills aquifers will be used as a major source of make-up water. EPA understands that Northglenn or its residents can continue to rely on Thornton for its water supply until such time the FRICO water becomes available and that Northglenn may be able to discharge Thornton water to Bull Canal. This may affect whether the project is considered an agricultural exchange project and hence would be defined as an "alternative" technology (see Issue 6) . If EPA funds a conventional treatment and discharge system, EPA will rely on the State Engineer to evaluate Northglenn's assessment of impacts of the proposed groundwater pumping program. If EPA funds an agricultural exchange project, EPA will require further analysis of the groundwater pumping program if it is still an integral part of the project and constitutes a significant portion of the make-up water. Issue 3: The "Denver Regional Environmental Impact Statement for Wastewater Facilities and the Clean Water Program" has identified several requirements with which Northglenn will need to comply. There are four items which are identified in the Overview EIS for which a response from Northglenn is still needed. These action items are: a. Northglenn needs to demonstrate the City Council's commitment to (1) implement reasonable air pollution control measures; (2) participate in the development of the Denver element of the State Air Quality Implementation Plan and (3) once ap- proved by EPA, support implementation of the Denver element of the State Air Quality Implementation Plan. At a minimum, the City Council needs to pass a resolution which identifies their commitment to improving Denver's air quality. b. Northglenn needs to develop a sewer tap program which annually determines the number of taps available for new residential development and which is consistent with the DRCOG population forecast for 1980, 1990, and 2000. -67- • c. Northglenn needs to demonstrate the consistency of its erosion control program with the recommendations contained in the DRCOG Clean Water Plan. • d. Northglenn must take steps to adopt a City Ordinance Or some suitable mechanism to notify existing and prospective home- owners in the Category II areas around the Rocky Flats plant, of the Emergency Response Plan for Rocky Flats. Northglenn has assured EPA it will comply with these requirements. EPA will require action on the above items as a precondition to re- ceiving a Step III award. Issue 4: Northglenn is proposing to design and construct a facility to treat both Northglenn's and Thornton's wastewater flows. Thornton has not made a commitment to have its wastewater treated at the Northglenn facility. Resolution of this problem will affect the proposed project's eligibility and correspondingly, EPA's funding. Northglenn is seeking EPA funding to design and construct a 7.2 million gallons per day (mgd) wastewater treatment facility. Of this amount, 3.2 mgd is being reserved for Thornton's wastewater flows. EPA has discussed this matter with Thornton's staff and the information gleaned from them indicates that Thornton is in the process of exploring alternatives for treatment of their wastewater, but no decisions have been made on which alternative they will select. The 1977 Clean Water Act and EPA's regulations promulgated in accordance with this Act, prohibit EPA from funding excessive reserve capacity in a facility. By funding the proposed project at the size requested, EPA could be in violation of the Law and its own regulations. Therefore, EPA has decided to limit its level of funding to those costs for a facility designed to treat only Northglenn's wastewater. EPA is willing to adjust its grant amount to include Thornton's flows if an agreement is executed between Northglenn and Thornton any time prior to EPA awarding a grant for construction (Step III) . After a grant is awarded for construction EPA will not make any adjustments to that grant to include capacity for Thornton. Issue 5: EPA has funded capacity in the Metropolitan Denver Sewage Disposal District #1 facility through 1990, a percentage of which is capacity for Northglenn's and Thornton's exist- ing and future flows. The facility plan indicates that continued treatment at Metro Denver's facility is the cost effective alternative to treat Northglenn's and Thornton's wastes. EPA's level of funding in the proposed Northglenn project will be affected by this analysis. -68- The Lower South Platte Plan evaluated a "status quo" alternative for continued treatment of Northglenn's and Thornton's wastewater at the Metro facility. The cost effectiveness analysis of this alterna- tive accounts for existing capacity in the Metro facility to treat Northglenn's wastewater through 1990. The Northglenn Water Management Plan evaluated several alternatives, but did not include an evaluation of the status quo alternative. A direct comparison of the two was not possible due to the different assumptions made in each plan. EPA requested and received a consistent analysis of these two alternatives. The results of that analysis follow: a. Present Worth Cost of the Northglenn Proposal $22,253,000 (1980 Capital Cost $16,301,801) b. Present Worth Cost of Status Quo Alternative $15,828,300 (Capital Cost $8,962,500) Given this fact, EPA is faced with a decision on how much of the Northglenn project to fund. EPA's most recent regulations may pro- hibit EPA from funding any projects that are not the most cost effec- tive alternative. The 1977 Clean Water Act includes specific language encouraging the reuse, reclamation, and recycling of wastewater. Congress man- dated that these types of projects would be eligible for 85% funding and allowed a 15% preference in the cost effectiveness analysis for these projects. EPA has not published any regulations which specify how to treat "innovative" and "alternative" projects which exceed the 15% allowance. This determination will occur just prior to the Step II grant award. Issue 6: EPA has a requirement that all land treatment applicants demonstrate control over the ultimate disposition of their effluent to guarantee long term (minimum 20 years) reuse/ successive use of the effluent. Northglenn has not yet met this requirement. EPA requires that land application types of projects continue to operate as a land treatment scheme throughout the twenty year planning period. Therefore, EPA is expecting land treatment applicants to pro- vide assurances which will satisfy this requirement. Without these assurances, EPA will not accept the project as an "alternative" tech- nology which could affect the level of EPA funding. -69- In an urban setting where farmers have the advantage of being able to sell their land for development purposes, it becomes increas- ingly difficult to negotiate long term agreements with individual farmers or groups of farmers who will commit the use of the land for agricultural purposes for the next twenty yeai�. Northglenn has sug- gested that these types of assurances can be accomplished through an agreement with the Farmers Reservoir and Irrigation Company. At a minimum, EPA expects the agreement to address how Northglenn will be able to provide land application for its effluent for the pro- ject life. EPA will evaluate the sufficiency of this agreement once it is developed. Northglenn might continue to use Thornton's water until the issues surrounding the use of FRICO's water are resolved. If this will be the case, there will arise a water rights problem regarding a change in the point of discharge. EPA will condition the Step II grant award in this situation to require Northglenn to provide a legal opinion regarding Northglenn's right to discharge water purchased from Thornton to Bull Canal. Should water rights difficulties prohibit the project from func- tioning, EPA reserves its usual right to recover funds due to the inability of the grantee to build and operate the facility as proposed. -70- H. OTHER ALTERNATIVES CONSIDERED Between the Northglenn Wastewater Facilities Plan and the Lower South Platte Facility Plan, a total of 21 alternatives to treat North- •• • . - glenn's and Lower Thornton's wastewater were evaluated. Most of these alternatives involved treatment of Northglenn's and Lower Thornton's wastewater at the Metro, Westminster, or Brighton facilities or some combination thereof. The Lower South Platte Facility Plan recommended that wastewater flows in these two service areas be treated in the Big Dry Creek Basin at the City of Westminster Plant primarily because of the opportunities to successively use the effluent within this drainage basin. The Northglenn Plan evaluated seven alternatives all of which involved construction of a new treatment facility at a new location rather than using existing facilities such as Westminster's or Metro's. A preliminary screening of the 21 alternatives eliminated all those that were too costly. EPA reviewed this information and con- cluded that the cost of treatment at the Westminster facility is about equal to the cost of treatment at the proposed Northglenn facility. Therefore, a single plant configuration does not appear to have any advantages over a two plant configuration for the Big Dry Creek Basin. Based on EPA's review, continued treatment at the Metro facility is the least cost pollution control alternative for the North- glenn and Lower Thornton service areas. The Metro alternative does not have the same benefits as the Northglenn proposal. These benefits include (1) an improved water supply (quantity and quality) ; (2) formation of a city/farmer alliance over the use of water in the basin; (3) develop- ment of agreements with farmers which will be a positive factor toward the preservation of agricultural land; and (4) a reduction in the amount of energy consumed in the disposal of Northglenn's and Thornton's wastewater. Nonmonetary costs associated with the proposed Northglenn project which are not associated with continued treatment at Metro are: (1) encroachment on an established wildlife habitat area; and (2) poten- tial groundwater depletion and degradation. Both alternatives would probably have the effect of accelerating the conversion of agricultural land to urban use in the Lower Thornton service area and parts of Adams County. The Northglenn Plan evaluated the feasibility of phasing the con- struction of facilities and recommended that the Northglenn interceptor be paralleled by another 24" line in 1990. Phased construction of the treatment lagoon storage reservoir and other interceptors was not cost effective. -71- I. AGENCIES CONSULTED BY EPA 1. Metropolitan Denver Sewage Disposal District #1: EPA requested cost information for the status quo alternatives evaluated by MDSDD#l. This information was provided to' EPA. 2. Thornton: EPA requested status of Thornton's plans for waste- water treatment disposal. Thornton indicated that studies have been initiated and an alternative will not be selected for several months. EPA also requested copies of the draft agreements which Thornton initiated with Northglenn and FRICO regarding ownership of the water and wastewater utilities. 3. Denver Regional Council of Governments: EPA inquired about the status of DRCOG's "Regional Growth and Development Plan" and Regional Development Policies. EPA was advised that the final plan with revisions would be completed and distribution within a few months. EPA asked whether the policies related to agri- cultural lands were changed. EPA was advised of the changes made to these policies and that the substance of the policies as pre- sented in the draft "Regional Growth and Development Plan" has not changed significantly. 4. Colorado Division of Wildlife: EPA requested comments from the Division about Northglenn's proposal to construct an interceptor through an identified wildlife habitat area. The area was iden- tified as a high density prairie dog habitat. EPA was advised that prairie dogs are not endangered or threatened species in Colorado, but that special precautions should be followed in con- structing the proposed Northglenn interceptor through this area. EPA believes that the proposed routing along York Street will mini- mize the impacts of construction on the prairie dog habitat. EPA will condition the grant to require that no new taps be allowed to connect to the interceptor through this area. 5. State Engineer's Office: EPA solicited more details from the State Engineer's Office on their A-95 comment and also on Northglenn's proposal to use Thornton water if FRICO water is not available. The State advised EPA on the type of information it should request from Northglenn and also had questions on Northglenn's ability to implement the project using the water supply sources which are proposed. -73- j, PUBLIC PARTICIPATION 1. Public Hearings: a. September 19, 1977, held at 11801 Community Drive, Northglenn Community Center, Northglenn, Colorado. Twelve people other than those directly associated with the project attended the hearing. All the comments received at this meeting are pre- sented in Appendix J of the Final Facilities Plan. These comments are summarized under 3 below. b. October 31, 1977, held at 11801 Community Drive Center, Northglenn, Colorado. Eight persons attended the hearing and only two, Cary Palmer of Thornton and William Page of Metro Sewage District, gave testimony. Mr. Palmer objected to the project citing four reasons why it should not proceed. The major area of concern expressed by Thornton related to the institutional relationship between Northglenn and Thornton over responsibility for treatment of Northglenn's wastewater. Mr. Page of Metro raised the same issue citing Metro's responsibility for treatment of Northglenn's wastewater. 2. A-95 Comments: The only adverse comment received by EPA on the proposed project was from Jeris Danielson of the State Engineer's Office. Mr. Danielson questioned whether the project can be im- plemented at this time due to the uncertainties surrounding the sources of make-up water. This concern is addressed in this Envi- ronmental Appraisal and a course of action is recommended which satisfies EPA. EPA is interested in the State Engineer's opinion on this matter. 3. Other Comments: Appendix J of the Facility Plan presents the written comments received on the August draft of the Plan. Numerous letters were received by Northglenn in support of the project. Numerous other letters were received by Northglenn commenting on conflict between the Lower South Platte Facility Plan and Northglenn's proposal. The majority of responses were favorable in support of the project. -75- K. REASONS FOR NOT PREPARING AN EIS Criteria for preparing an Environmental Impact Statement (EIS) are presented in Sections 6.200 and 6. 510 of 40 CFR Part 6 of EPA's regulations governing the preparation of EIS's. In general, if a proposed project has significant environmental effects or is the subject of controversy, EPA is instructed to prepare an EIS on that project. The reasons why EPA believes that an EIS is not warranted for this project are: 1. EPA recently completed an Overview EIS for the entire Denver Region. The secondary effects of the Northglenn project were addressed in that EIS. 2. The wildlife habitat area is not a habitat for any threatened or endangered species. Also, construction of an interceptor through this area will not stimulate development and EPA will require North- glenn to pass an ordinance which will exclude the connection of new taps to the interceptor in the vicinity of the wildlife habitat area 3. EPA is not approving the facility plan's recommendations to con- struct interceptors in the Lower Thornton service area. Conse- quently, EPA believes that the proposed action will not accele- rate the rate of conversion of agricultural land to urban since the most susceptable areas are located in the Lower Thornton area. 4. The State Engineer's Office is cognizant of the potential problems with groundwater pumping in the Arapahoe and the Laramie-Fox Hills aquifers. This is evidenced by their rejecting 19 out of 20 well permits applied for by Northglenn. EPA believes that the State Engineer's Office will evaluate Northglenn's assessment of the envi- ronmental impacts of the proposed groundwater pumping scheme prior to approving these permits. Also, since other sources of make-up water are available to Northglenn at a minimum additional cost and since Northglenn is actively pursuing these other alternative water sources, EPA believes that a smaller scale groundwater program is more likely to be implemented. EPA will be recommending to the State Engineer's Office that additional hydrologic studies be con- ducted to determine what is the average storage coefficient of the two aquifers and that the impacts be reassessed based on this infor- mation prior to approval of any more well permits in the Northglenn area. 5. The wastewater treatment project, although a part of the total water resources program, is not dependent on implementation of the FRICO exchange agreement before it can become operational. North- glenn expects to contract with Thornton for water until such time that FRICO water is diverted to the Northglenn system. -77- 6. The institutional and utility ownership problems appear to be nearing resolution. '7. Although Northglerirt will not solve dii of its water supply prob- lems with implementation of the proposed project, it will result in a better quality water supply for the residents of Northglenn. 8. The proposed project is being designed consistently with regional population forecasts and thus will not stimulate growth beyond what is reasonably expected for the Northglenn and Thornton urban service areas. -78- L. GRANT CONDITIONS The following conditions will be placed on the Northglenn grant award in an attempt to mitigate the unresolved problems which have been identified in this Environmental Appraisal. 1. Problem: Thornton has not decided whether it will be part of the Northglenn wastewater treatment system. Condition(s) : Costs incurred during the design of the treatment works shall be eligible only for those items directly related to the design of facilities for Northglenn. Costs incurred during design which directly relate to providing capacity for wastewater flows generated outside of Northglenn's incorporated boundaries will not be eligible for reimbursement under the terms of this grant without an executed service agreement between Northglenn and the affected party(ies) obligating such party(ies) to long term (20 years) use of the Northglenn facilities. Costs not related to the design of a facility for Northglenn and which are incurred prior to execution of such agreement will not be eligible for reimbursement. Costs incurred during construction which are not related to construction of wastewater works to satisfy North- glenn's year 2000 needs will not be eligible without said executed agreement prior to initiating construction of the treatment works. 2. Problem: Interceptors are being proposed in the Lower Thornton service area which will traverse and provide wastewater service in areas defined as prime agricultural land. Condition(s) : EPA will not participate in the design and construc- tion of the Brantner Gulch and Grange Creek interceptors without a more detailed analysis of their impacts on agriculture in the areas they are intended to serve and appropriate measures are taken to mitigate these impacts. Such measures shall include, but not be limited to: (a) exploring alternatives other than central collection and treatment as a means to providing service to these areas; and (b) adopting regulations which would preclude develop- ment from occurring on specific parcels of land which are pre- sently used for agricultural production and which are defined as prime agricultural land. Additionally, the Grantee shall not receive final payment under Step II or be awarded a Step III grant until such time that the Grantee has passed an appropriate regulation which will prohibit direct or indirect (through pump station) connections to the Northglenn Interceptor for the Section located north of the Big Dry Creek Urban Service Area as currently defined in DRCOG's Regional Growth and Development Plan (generally north of 136th Avenue) . -79- 3. Problem: The Northglenn interceptor will traverse the Big Dry Creek 100 year floodplain and a designated wildlife habitat area which may result in urban encroachment into these areas. Condition(s) : The Grantee shall not receive final payment under Step II or be awarded a step if! grant until such time that the Grantee has passed an appropriate regulation which will prohibit direct or indirect (through pump station) connections to the Northglenn Interceptor (the interceptor conveying wastewater from the City of Northglenn to the treatment site) for the section that will be located outside Northglenn's incorporated boundaries as currently defined (generally north of 120th Avenue and including the area known as East Lake) . Exceptions to this condition, sub- ject to EPA approval, will need to be negotiated on a case by case basis for the area between 120th and 136th Avenues. 4. Problem: Northglenn has represented its project as a land appli- cation ("alternative method of treatment") project. To be able to implement the project as planned, Northglenn must obtain make- up water (consumptive use plus 10 percent) . Condition(s) : If the project is to be considered an "alternative method of treatment", the Grantee must provide assurances satis- factory to EPA that it has acquired or it reasonably can acquire all the necessary make-up water, prior to receiving a Step III award. 5. Problem: The project may use a water supply which may involve water rights issues and which may impede implementation of the project as planned. Condition(s) : If the project to be implemented involves water rights issues (e.g. , a change in the point of diversion or a change in the point of discharge) , then the Grantee shall provide EPA with a legal opinion which demonstrates to the satisfaction of EPA that the project can be implemented. This assurance will be needed prior to receiving a Step III award. Any costs incurred due to resolution of problems with water rights and which are not identified in the legal opinion will not be reimbursable under this grant. 6. Problem: Northglenn, to date, has not negotiated an agreement(s) with Thornton and/or FRICO which will assure EPA that Northglenn has sewage to treat and that the project will be implemented. Condition(s) : The Grantee shall provide EPA with a copy of the executed agreements which demonstrate that Northglenn will have sewage to treat once the facility becomes operational. These agreements must prove to be satisfactory prior to the Grantee receiving final payment under Step II and receiving a Step III award. -80- 7. Problem: In order to be considered an "alternative" project, North- glenn needs to assure EPA that the final disposition of Northglenn's effluent will be for land application. Condition(s) : - .The-Grantee shall provide EPA with assurances to the satisfaction of EPA that the effluent will be applied on the land for the life of the project (20 years) . 8. Problem: Northglenn needs to obtain clearance from the State Engineer's Office regarding approval to proceed with construction of the storage reservoir dam and Stonehocker dam. Condition(s) : The Grantee shall provide EPA with the State Engineer's clearance allowing the Grantee to proceed with con- struction of the proposed storage reservoir and Stonehocker reservoir dams prior to receiving a Step III award. 9. Problem: Weld County has not approved the design and sites for the proposed treatment lagoon and storage reservoir. Condition(s) : The Grantee shall provide EPA with a copy of Weld County's review and approval of the proposed project prior to receiving a Step III award. 10. Problem: Northglenn has not provided EPA with a detailed proposal for the disposal of sludge. No contingency plan has been developed in case the proposal cannot be implemented due to EPA restrictions or lack of interest from private land owners in the vicinity of the treatment site. Condition(s) : The Grantee shall submit to EPA for approval a monitoring program and a contingency plan which will detect poten- tial problems with the use of sludge on private agricultural lands and which will provide another means of disposal if the Grantee is precluded from disposing the sludge on private agricultural lands. The Grantee shall not receive final Step II payment until both the monitoring program and the contingency plan are approved by EPA. 11. Problem: The proposed project may require large quantities of water to be pumped from the Arapahoe and Laramie-Fox Hill aquifers which may result in significant adverse groundwater impacts. The quan- tities of water that will be pumped and the impacts of this pumping have not been fully determined. -81- Condition(s) : If the Grantee has developed a firm plan to pump significant (i.e. , greater than 500 acre feet per year) amounts of groundwater from either the Arapahoe or Laramie-Fox Hills aquifers, the Grantee shall provide to EPA a reassessment of the expected impacts based on a restudy of the aquifer's- torage coefficientJ and the amounts of water to be developed. The Grantee shall also provide evidence that the State Engineer has approved well permits which will allow the proposed development to occur. 12. Problem: As described above, there are several potential problems with the project which may prevent it from being implemented. Condition(s) : If the project can not be implemented due to legal, financial, or other problems, EPA reserves the right to recover all funds expended on the project under this or any future grants. In response to the actions taken by EPA in the "Denver Regional Environmental Impact Statement for Wastewater Facilities and the Clean Water Program," EPA will also place the following conditions on the Step II grant offer to Northglenn. 1. The Grantee shall before January 1, 1979, provide EPA with a reso- lution(s) passed by the general purpose government(s) to be served by the proposed project (i.e. , Northglenn and possibly Thornton and Adams County) which demonstrates the governing body's commitment to (a) implement reasonable air pollution control measures; (b) parti- cipate in the development of the Denver element of the State Air Quality Implementation Plan and (c) once approved by EPA, support implementation of the Denver element of the State Air Quality Implementation Plan. Failure to comply with this condition may result in EPA stopping payment under the provisions of this grant. EPA will not award a Step III grant until this condition is satisfied. 2. The Grantee shall develop and implement a sewer tap program which annually determines the number of taps available for new residential development and which is consistent with the DRCOG population fore- casts for 1980, 1990, and 2000 as presented in Northglenn's facility plan. EPA will not award a Step III grant until such time that a satisfactory sewer tap program has been provided to EPA. 3. The Grantee shall provide to EPA a schedule which identifies when the Grantee will consider for adoption erosion control ordinances and regulations. EPA will not make any payments under this grant until such time the schedule is submitted to EPA. EPA also will not award a Step III grant until such time that the Grantee has acted favorably on provisions to control erosion resulting from new development. This condition applies to all general governments which will receive wastewater service from Northglenn (e.g. Thorn- ton and Adams County if they decide to use the Northglenn system) . -82- 4. The Grantee shall adopt the municipal water conservation ordinances or similar ordinances as presented in Appendix F of the facility plan and shall provide EPA with a schedule for when these ordinances will be considered. EPA will not award a Step III grant until such time that a schedule is provided. Payments under Step III will lie conditioned on the Grantee taking favorable action on these ordi- nances. 5. The Grantee shall, as part of Step II design, investigate the feasi- bility of using the corridor for the Northglenn interceptor as a bike path, trail, etc. EPA shall be provided with the results of this investigation and the project shall be designed accordingly (i.e. , the design shall include a bike path, trail, etc if it proves feasible) . 6. The Grantee shall develop a notification procedure for notifying existing and prospective homeowners within the incorporated boun- daries of the provisions of the State Radiological Emergency Re- sponse Plan. The Grantee shall provide EPA with a copy of the pro- cedures, as adopted, prior to receiving a Step III grant from EPA. -83- APPENDIX -85- Mailing List Mr. Robert Farley, Executive Mr. Eric Eidsness, Jr. , 208 Project Director Director Mr. Jack Hibbert, 208 Project Larimer-Weld Regional Council of Director Governments Ms. Linda Nuzum 201 East Fourth Street, Room 201 Denver Regional Council of Loveland, Colorado 80537 Governments 2480 West 26th Avenue, Suite 200B Denver, Colorado 80211 Mr. Gary Broetzman, State 208 Coordinator 520 Centennial Building 1313 Sherman Street Ms. Shirley Whitten, Denver, Colorado 80202 Assistant to City Manager Mr. Richard Lundahl, Director Land and Resources Management Mr. James Perry, City Manager Project Mr. Cary Palmer City of Northglenn City of Thornton 10701 Melody Drive, Suite 313 8992 North Washington Northglenn, Colorado 80234 Thornton, Colorado 80229 Mr. William Korbitz, Manager Mr. Ron Schuyler Mr. Ray McNeil, Planner Mr. Frank Rozich MDSDD #1 Colorado Department of Health 6450 York Street Water Quality Control Division Denver, Colorado 80229 4210 East 11th Avenue Denver, Colorado 80220 Mr. Evan Dildine, Executive Secretary Mr. Marvin Thurber, Director of Colorado Water Quality Control Operational Services Commission City of Westminster 4210 Fast 11th Avenue 3031 West 76th Avenue Denver, Colorado 80220 Westminster, Colorado 80030 Mr. Jerome Zohn Mr. Evan Goulding, Commissioner City and County of Denver Colorado Department of Agriculture Wastewater Management Division 406 State Services Building 5055 washington Denver, Colorado 80203 Denver, Colorado 80216 Mr. Gary Fortner, Planning Director Mr. Harris Sherman, Executive Weld County Director 915 10th Street Colorado DepaiL,uent of Natural Greeley, Colorado 80631 Resources 1313 Sherman Street, Room 718 Denver, Colorado 80203 -87- Mr. Lewis Short, Manager of Board Mr. Robert Flemming Water and Sewer Commissioners Adams County Administration Building City of Lakewood 450 South 4th Avenue 1580 Yarrow Brighton, Colorado 80601 Lakewood, Colorado 80215 Mr. John Rayburn, Executive Secretary Mr. Hank Burback Central Colorado Water Conservancy Heritage Conservation and District Recreation Center 315 Denver Avenue P. 0. Box 25387 Fort Lupton, Colorado 80621 Denver Federal Center Denver, Colorado 80225 Mr. Charles Carroll, Deputy Director of Utilities Mr. Adolph Bohlender, President City of Aurora The Farmers Reservoir and 1470 South Havana Irrigation Company Aurora, Colorado 80012 80 South 27th Avenue Brighton, Colorado 80601 Mr. Stephen Hart, Chairman The State Historical Society of Colorado Mr. Phil Schmuck, Director Colorado State Museum Colorado Division of Planning 1300 Broadway Department of Local Affairs Denver, Colorado 80203 1313 Sherman Street Denver, Colorado 80203 Mr. Ken Miller, Director Planning and Water Resources Mr. Wayne Ward, President Denver Water Department Board of Directors 144 West Colfax Avenue South Lakewood Sanitation Denver, Colorado District 1595 Harlan Street Lakewood, Colorado 80214 Mr. Allen Williams, Manager South Adams County Water and Sanitation District Mr. Robert McGregor 6595 East 70th Avenue Sheaffer and Roland, Inc. Commerce City, Colorado 80022 1660 South Albion Street Denver, Colorado 80222 Mr. Jeris Danielson, Deputy State Engineer Burt Baker, Land Use Coordinator Mr. Hal Simpson Don Schrupp DeparLuient of Natural Resources Colorado Division of Wildlife Division of Water Resources 6060 North Broadway 1313 Sherman Street, Room 818 Denver, Colorado 80216 Denver, Colorado 80203 -88- . r Ms. Joanna Moorhead Ms. Susan Watkins Facility Requirement Branch Office of Federal Activities Environmental Protection Environmental Protection Agency (WH-547) Agency (A-104) 401 M Street, S.W. 401 M Street, S.W. Washington, D. C. 20460 Washington, D. C. 20460 District Engineer National Wildlife Federation U. S. Army Engineer ATTN: Dinah Flynn Omaha District 1412 16th Street, N.W. 6410 U.S. Post Office Washington, D. C. 20036 Omaha, Nebraska 58102 Mr. Louis Wall Colorado Wildlife Federation Advisory Council P. O. Box 12187 Office of Compliance Denver, Colorado 80212 P. O. Box 15085 Denver, Colorado 80225 State Conservationist Regional Director U.S. Soil Conservation Service U.S. Department of HEW Room 313 9017 Federal Building 2490 West 26th Avenue 19th $ Stout Denver, Colorado 80211 Denver, Colorado 80202 Regional Administrator State Director U.S. Department of HUD Farmers Home Administration, USDA 1405 Curtis Street 1 Diamond Plaza, Room 231 Executive Towers, 26th Floor 2490 West 26th Avenue Denver, Colorado 80202 Denver, Colorado 80211 Rocky Mountain Center Regional Director On Environment U.S. Bureau of Reclamation 1115 Grant Street Building 20 Denver, Colorado 80203 Denver Federal Center Denver, Colorado 80225 District Chief U.S. Geological Survey Regional Director Building 25 National Park Service Denver Federal Center 655 Parfet Street Denver, Colorado 80225 P. O. Box 25287 Denver, Colorado 80225 -89- Regional Forester Regional Director U.S. Forest Service U.S. Fish and Wildlife Service Building 85 P. O. Box 25486 Denver Federal Center Denver Federal Center lienver, Cululddu 80225 Deliver, Cuiuradu ouLLo Director Environmental Review Office Environmental Project Review U.S. Department of the Interior U.S. Department of the Interior Building 67, Room 688 Office of the Secretary Denver Federal Center Washington, D. C. 20240 Denver, Colorado 80225 Mr. Donald Norgren Mr. Walter Mayer Beeman Consolidated Ditch Meadow Island #1 Consolidated Company Ditch Company Rt. 2 Box 28 B Rt. 2 Box 39 Platteville, Colorado 80651 Platteville, Colorado 80651 Mr. Rueben Gustafson Mr. George Stieber Meadow Island #2 Consolidated Brighton Ditch Company Ditch Company • 11563 Weld County Road 6 10910 Weld County Road 28 Ft. Lupton, Colorado 80621 Ft. Lupton, Colorado 80621 Mr. John Briggs Mr. Albert Hattendorf Farmers Independent Ditch Company Fulton Irrigating Ditch Company Ft. 1, Box 29 639 Jessup, Apt. A Platteville, Colorado 80651 Brighton, Colorado 80601 Mr. Robert Brand Groundwater Appropriators of Rocky Mountain Consultants the South Platte (GASP) 647 17th Avenue P. O. Box 974 Longmont, Colorado 80501 Ft. Morgan, Colorado 80701 Mr. Ray Sarchet, President The Consolidated Ditches Company of Water District No. 2 P. O. Box 439 Brighton, Colorado 80601 -90- Hello