Loading...
HomeMy WebLinkAbout2.0 Supplemental InformationHIJG-31-EEE1 E1 : 13P FRI]I,1: BLOGPLFNGT]FIC!:I B7E3EJ+5q78 r\nl\Lfi Fil NUHtslNb '-Ult( TO:3P8761539 7t t/? P.AL August 30,2001 lvbrk Bcan . GarfieldCouu5f Planner Plaeliry Depar.tnsat l0gEigbilh Strcryt Sinr*ood Spriugls, CO 81501 Rr: Blue Creek Rauch Requcst'for Froviding W astewatrr lreaiment Serv icc DearMr. Bcau:: Represcutatives of'the proposed Blue Crcek Ranch housing development have requested thc Raaob at Roaring Fork Homeowners Association ("Ranch") to consider prgviding 50 EQR of,waste,,rrater treatnent service for the developmerrt. Ow decision aril ability rc provid,c scrvice will be genlingent on five factor$ ss describcd hercin, l. Aproval by en affirmative super-mqioritli vole of all Ranch Hornaowners. 2- Det€rrninatiaa that the initial Bluc Creek iap fecs will be sufEcient to permit redugtiu! of existing service line irJiltration so that, upon full build-out of all proportica served by the Ranch system, its usage wiil uot exceed E0,000 gallons/day. 3. Concemeoce Aom the State Watcr Quali$ Coutrol Division that, assuning zuch re<lucHon, providing the addjtional serv'ice will not require further expansion plpn4i'.'g by the Ranch. 4. Executiou of a service agt€ement between the Ranch and Bluc Creek. 5. Approval by Garfield County of, md connpliance by Blue Creek with, a PUD in subshilial cmforoaoce in all material rcspects with the planu w'hich havc bcen prcsmted to the Rancb by thc developer. Thc Rarrch cooplctrd soastrucrion of a rcnovatetl and expanded wastewater treatment facility in earlv 2001- Ths plant capacity was inueased from 50,000 gallou.v'day to 10{},000 Ballons/day. The plant is operational arrd providcs service to the Ranch and the Ranch Crceh Aspm Equcstriar Estates, and St. Finnbar horxing developmcnts, via Fa,x and Certified Mail Post-it'Fax Note 7671 tu' a,/.q,, fui I J"EL' > - z-W 7-^ Qa ,A f/n Co./Dept.Co. Phone #ffi076-BztL tux*Fax f. 14919 Highway Bg n Ca *C'.:lrjl1 UI : 1(H l- Hlil'lI E,LUul-Li1l.{irHt3.L,i-l :r fU.-{U{J{l i.Ul r\tativ I rat r\{Jalt\aatu Tr:i:3F8TEiS39 P! ii,'e l" t Vtc- Mark Besn PaSe 2 The RanchDeclaratioas wcrc previoruly amendetl to provide service tcr "'adiaceut propertitT"" As the proposed Blue Creek ltanch r{eveloprnr"nt rnay n*t be deemed to be djacemt to fhe Rsosb, noother vote of Rs"Erch Harneawners r.villhe nee{.led. A three-fourths supet-rnajority is required tlr anrend tt* De.r:lararions. f,hr R.a-nclr Board of Dinwurc bslieves this aurcberto be achievablc, but cannot guilrantes irri alfiruratirr vctE" Based on EJiscussioas with Mclaughlin Water Engi*ccru. our couzutting engrn.eering firq we believe that the new faciiity has sufficicnt treserv'e capacity to provide thr requested 50 EQn" Flowevetr, this additionai servicr;, together with existing inliltraticn, filsy inorearle the totsl ti€sffient load above 80,000 gailons/day at peak periods and trigger tbe State af Colorado requirement to begin pl,anning for plant expansion if a facility is operating *: rycater than 80% capacity. "l-his can be mitigated by repair af specific artss of infiitratioa that oumently exist in tne ltnnrh $cw$r collection line, At thls tfung, the Raneh at Roaring Fork has no intention of,increasing ttie capacity of its newly rsasveted $flasttsHmtsr trsatu,ent facitity. Theret'ore, it is imperadve l.hat wc r€cei=rs cpncuffignee fuonr the Sate of C,clorado 'Watcr Quality ConlroL Division that pmvidlag ttrr requested senricc wi.l! uot prornpt the plarur.irrg requircment, A sernice agreement betweenthe Ranch and Blue Creek ru'il-t b': requlred and is antisipated to ble au subsrantially the sarne trrms as those witli Aspvn Equcstriarr Estates and St. Finnbar, pmvid*d tbat the an:.ourst otlthe urp fecs nrust be adju:ttcd to re{lcct. the interest charged to Itanch i{orneowuers on their a.$sessJten$ for t"he fu*ility expansicin. Sineerely yc.,irs, #f--M-**<" Ii4iclrael J. fferber, M.IJ. Chan:nan, Iluard of f)irectcrs Ran*h et Eoaring Fork Homeo$mets A,usociahon, Inc. Rob Cummings Ssott Mill€c Toru Zancanella Hsrdb Holues Mcl.;aughlin Watcr Engineers Drilsi! Watson To: Mark Bean From: Randy Russell Date: August 31,2041 Re. Ranch at Roaring Fork Letter, August 30 On review of this letter it would appear that the Ranch at Roaring Fork has undertaken a preliminary analysis that would indicate that if they were to solve infiltration problems in their existing lines the development proposed at Blue Creek could be accrmmodated without triggering an expansion of their existing facility. This letter has contingencies attached to it, and/or lacks the following information: 1. Approval of a service agreement remains contingent on a 75% affirmative vote of the HOA members, which can not be guaranteed by the Chairman of the Board of Directors of the HOA. Nor is a time certain and methodology suggested to secure that vote in the affirmative or otherwise by a date certain. 2. A series of contingencies is contained in the letter, beginning with a factor that Blue Creek Tap Fees will be adequate to resolve the Ranch at Roaring Fork's own infiltration problems. No information, estimate, or engineering report is provided to suggest what the magnitude of that cost to resolve infiltration problems would be in this submittal, to allow any cost comparison at this stage between treatment oPtions. 3. The letter makes approval contingent on an approval by the State Water Quality Control Division that such plans and proposals would not require plant expansion. Such approval is outside the authority of the County to assure, and is not a factor for consideration by the County in this specific site review . 4. The Ranch at Roaring Fork appears to imply its own review and approval of the PUD as it will be refined and submitted to the County, in "all material respects" in their Factor #5. While review and approval of the number of EQR's would certainly be part of their agreement and negotiations, as well as siting the line (most probably to the St. Finnbar lift station which would also require easement agreements with that entity if not others as well ), other aspects of the PUD would not fallwithin the review and approval of an HOA. Material aspects of the PUD impacting sewer consider:ations would certainly be a factor in the Ranch at Roaring Fork's review of a sewer service agreement, but those factors would be limited to only those impacting sewer service and agreements. While stafffinds that this letter from the Ranch at Roaring Fork is an invitation to enter into additional alternatives analysis, and may be welcomed by the Proponents of the Blue Creek PUD, it does not represent cause to delay or postpone review and decision-making on the proposal in front of the Board of County Commissioners. Certainly, the timing of the letter suggests after offers to explore this altemative for some period of time by the Blue Creek proponents, that the Ranch at Roaring Fork may have some difficulty moving on alternatives options within a reasonable time frame. The aggregation of private developments into a privately owned and operated sewage treatment fiacility meets the County concem about proliferation of such systems only in number and points of discharge, not in kind. What would occur in yet an additional service agreement, now three and potentially four developments each with their own HOA's collaborating on operations and maintenance issues, results in cumbersome and potentially troublesome alrangements between a set of private entities. This finding does not cause any reasonable staff rationale to suggest a delay in the review of an independent system alternative in relationship to conformance with the Comprehensive Plan. Approval or denial of the site request for the Blue Creek \flM/TP will not hinder an alternatives analysis that might be undertaken between the various parties. Garfield County \ rill be more than pleased to consider such an alternative, at a later time, should one be worked out, in lieu of a separate facility in the PUD pennitting prrcess. ln the interim, staff recommends proceeding on the site application review for the Blue Creek facility on its own merits. RECEIVEDJUNll2OOl STATE OF COLOTUDO Bill Owens, Covernor Jane E. Norton, Executive Director Dedicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. s. Laboratory and Radiation services Division Denver, Coiorado 80246-1530 8100 Lowry Blvd. Phone (303) 692-2000 TDD Line (303) 691 -7700 Located in Clendale, Colorado hnp //ww w. c d p he. state. co. u s Denver, Colorado 80230-6928 (303) 692-3090 C.olondo Departrnent of PublicHealth andEnvironment May 24,2001 Thomas A. Zancanella, PE Zancanella and Associates, Inc. PO Box 1908 1005 Cooper Avenue Glenwood Springs, CO 81602 Re: Proposed Blue Creek Ranch WWTP, Garfield County Dear Mr. Zancanella: The Colorado Department of Public Health and Environment, Water Quality Control Division, has completed your r;quest for preliminary effluent limits (PELs) for the proposed Blue Creek Ranch wastewater treatment plant iWWTP). Your current proposal is for a wwTP with a hydraulic design capacity of 0.02 million gallons per day (MGD). This proposed facility would discharge into.the Roaring Fork River in the NW1/4 of SEl/4, Section 31, Township 7 South, i*g" g7 West oithe 6th p.M. in Garfield County. This portion of the Roaring Fork River is identified as striam segment COUCRF03, which means the Upper Colorado fuver Basin, Roaring Fork River Subbasin, Str"u* Segment 3. This stream segment is composed of the "Mainstem of the Roaring Fork River, including all tributaries, wetlands, lakes and reservoirs from a point immediately below the confluerrce *ith Hunter Creek, to the confluence with the Colorado fuver except for those tributaries included in Segment I and specific listings in Segments 3a through 10." These identifications are found in the Clissification and Numeric Standards for (lpper Colorado River Basin and North Platte River (Planning Region 12). Effluent limits for specific constituents are based on the type of permit a facility will require after construction. The Blue Creek Ranch WWTP may be covered by a general permit- The preliminary effluent limitations were developed for the Blue Creek Ranch WWTP based on effluent limits established in the Regulations for Effluent Limitations for a WWTP consisting of a mechanical wastewater treatment pro.Jrr, * *"il ut th" water quality-based effluent limits necessary for protection of the water quality of th" Roaring Fork River. A PELs evaluation is attached to document the findings and decisions that were used to derive the PELs in Table 1. @ Proposed BIue Creek Ranch WWTP Thomas A. Zancanella, PE May 24,2001 Page2 If you have any questions regarding this matter, please contact me at (303) 692-3614. Sincerely,, 2 /t*re Karen Young Environmental Protection Specialist Permits Unit, Water Quality Protection Section Water Quality Control Division ENCLOSURE Cc: Local Health DePartment Dwain Watson, District Engineer, Grand Junction Office Tom Bennett, Drinking Water and Wastewater Technical Services Garheld CountY File Proposed BIue Creek Ranch WWTP ": Preliminary Effluent,Limits for Discharge to the noq.i"g Fotk Rin. BODs(mdl)45@dery av eragp), 30 (3 0-day average) BOo, (X removal)85 Q0-day average) F, mechanical plant (mg/l)@e), 3o (30-day average) TSS mechanical plant oriy (%o removal)85 (30-day average) Oil and Grease (mg/l)10 (maximum) pH (s.u.)6353Iminrmum-maximum) Fecal Coliform (organisms/l00 ml)@ge), 6,ooo (30-day averyge) TotalResI-uarchlorine(mdl)0.5 (maximum) Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY Table I Assessment Summary glud-eek Ranch WWTP Name of Facility CO-PEL CDPS number @,RoaringFork River Subbasin, Stream Segment 3: Mainstem of the Roaring Fork fuver, including all tributaries, wetlands, lakes and reservoirs from a point immediately below the confluence with Hunter Creek, to the confluence with the Colorado River except for those tributaries included in Segment 1 and specific listings in Segments 3a through 10. COUCRFO3 WBID - Stream Segment CoiA watA-Aquatic Life Class I Class 1 Recreaction Agriculture Water Supply Classifications Undesignated Designation PnnlrrvrrxARY EFFLIIENT Lrvurs Ro^q.Rrxc Fonx Rrvnn Blur Cnrpx Raxcn WWTP I. Introduction The preliminary Effluent Limits (PELs) analysis of the Roaring Fork River near the proposed Blue Creek Ranch Wastewater Treatment plant Wwrpl was developed for the Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division (WQCD)' The PELs analysis was prepared to facilitate issuance of a Colorado Discharge Permit System (CDPS) permit for the proposed Blue Creek Ranch WWTP' Figure I on the following page contains a map of the study area evaluated as part of this PEL' The proposed Blue Creek Ranch wwrp will discharge the Roaring Fork River. The ratio ofthe low flow of the Roaring Fork River to the design flow of the proposed Blue Creek Ranch WWTP is 6065:1. Although four other facilities discharge within seven miles downstream of the proposed Blue Creek Ranch wwTp, due to the small design flow of the proposed facility versus the high flow rate of the receiving stream, analyses indicate that assimilative capacities are extremely large' Page 1 of15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY Figure I Study Area LEGEND I Discharges to 'rraterI Superfund sites I Hazardous waste ! Toxic releases I Air releases I others I ttultiple /\/ Streets E Water Bodies [3 Counties Source : EPA's EnviromaPPer, 8.2 mi across Information used in this assessment includes data gathered from the U' S' Geological Survey (usGS), the U.S. Environmental Protection Agency (EPA), Riverwatch, and the WQCD' The data used in the assessment consist of the best informaiion available at the time of preparation of this PELs package. II. Water QualitY The proposed BIue Creek Ranch WWTP will discharge to the Water Body Identification (WBID) stream segment coucRF03, which means the Upper colorado River Basin, Roaring Fork fuver Subbasin, stream Segment 3. This segment is composed of the "Mainstem of the Roaring Fork River, including att tributaries, wetlands, lakes and riservoirs from a point immediately below the confluence with Hunter Creek, to the confluence with the Colorado River except for those tributaries included in Segment I and specific listings in Segments 3a through 10'" Stream segment PELs Page 2 of 15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY couc-r* t, "l*ified for Cold water Aquatic Life class 1, Class 1 Recreaction, Agriculture, and Water SuPPlY. Numeric standards are developed on a basin-specific basis and are adopted for particular stream segments by the water eualitycontrol commission. To simpliff the listing ofthe segment-specific standards, many of the aquatic life standards are contained in a table at the beginning of each chapter of the regurations. The siandards in Table zhavebeen assigned to stream segment coUCRF03 in accordance with the Classification and Numeric Standards for (Jpper Colorado River Basin and North Platte River (Planning Region l2)' Standards for metals are generally shown in the regulations as Table value Standards (TVS), and these often must be derived from equations that depend on the receiving stream hardness or species In-stream Standards for Stream Segment COUCRF03 rm: 200 colontes ammonia acute = -ionizeilammonia chron tc : ree Cyanide acute: rsenic acute : 5U uB ffiacute for trout an solved Cadmium chronlc : ;IenTTfrornium acute : 5u u roffi[m acute and chronlc : ron chrontc : chrontc : lUUU uB acute and chrontc : anganese chrontc : btaTlvlercury chrontc: acute and chronlc : ium acute and chronrc = for trout : SolveclZinc acute and chrontc: PELs Page 3 of 15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY of fish present. The classification and Numeric Standards documents for each basin include a specification for appropriate hardness values to be used. Specifically, the regulations state that: The hardness values used in calculating the appropriate metal standard should be based on the lower 95% confidence limit ofthe -"* hardness value at the periodic low flow criteria as determined from a regression analysis of site-specific data' Where insufficient site-specific data exists to define the mean hardness value at the periodic low flow criteria, representative regional data shall be used to perform the regfession analysis. Where a regression analy;is is not appropriate, a site-specific method should be used. Hardness data for the Roaring Fork River near the point of discharge of the proposed Blue Creek Ranch wwTP were insufficient to conduct a regression analysis based on the- low flow' In the absence of a reglession analysis, the WQCD's altemative approach to calculating hardness was used' which involves computing a mean hardness' The mean hardness was computed to be 199 mg/l as caco, based on sampling conducted at Riverwatch sampling location 72 (Roaring Fork River at7-llBridge) located approximately 7 miles upstream of the proposed Blue creek Raich wwrp. This mean hardness from the Roaring Fork River and the formulas contained in the TVS were used to calculate the in-stream water quality standards for metals as shown in Table 3' Ambient Water Qualitv The wecD evaluates ambient water quality based on a variety of statistical methods as prescribed in Section 31.S(2)(aXU *a 31.8(2)@)(i)(Bi of the Colorado Department of Public Health and Environment water euarity contror commission Reguration No. i1. Ambient water quality is evaluated as part of this assessment to determine assimilative capacities' To conduct an assessment of the ambient water quality upstream of the Blue Creek Ranch WWTP' data were gathered from two sources. Data from the Riverwatch sampling location 72' located approximately seven miles upstream of the proposed Blue Creek Ranch WWTP' were used to determine ambient background concentration, foi pH, ternperature, dissolved oxygen, and hardness' Data were available for a period of record from ociober 1995 through February 2000' Data gathered at the WQCD sampling location oool44ll2708 (Roaring Fork fuver below Aspen)' located approximately twenty-five miles upstream of the propo..d Blue creek Ranch wwTP' provided background data on fecal coliform, ammonia, and metals. This WQCD sampling location was designated as sampling location 000144 until 1997, and later renumbered as wQCD sampling location l27og. These data were available for a period of record from octob er 1996 through April 2000. These data, which represent upstream ambient water quality, are summarized in Table 4' III. Water QuantitY The colorado Regulations speciff the use of low flow conditions when establishing water tualitl based effluent limitations, specifically the acute and chronic low flows' The acute low flow' referred PELs Page 4 of 15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY to as lE3, represents the one-day low flow recurring in a three-year interval' The chronic low flow' 30E3, represents the 30-day average low flow recurring in a three-year interval' Low Flow Analvsis To determine the low flows available to the proposed Blue Creek Ranch WWTP, a flow gage measurement immediately upstream of the proposed facility should be used. There are, however, no gage stations within 15 miles upstream or downstream of the proposed facility' Low flows were therefore determined using a comprehensive analysis of the flow balance of the Roaring Fork River performed by the weCD in 1998. As part of this analysis, the WQCD obtained Roaring Fork Riveidaily flow data from several USGS gage stations and then performed a flow balance throughout the basin to determine low flows at multiple discharge points and tributary Table 3 site-specific water Quality standards for the Proposed Blue creek Ranch wwTP Based on the Table Value Standards Contained in the Colorado Department of Public Health and Environment Water Quality Control Co foi Hardness as CaCO3:l99img/l Parameter In-Stream lfater Quatity Standard Formula Used Cadmiurn, Dissohed Troul 8.5 ugll pfftm(l ardn ess))-3 . E 2 6 ) Ctronic 1.9 wlr ,(r.z ri2 (tn ( n ardn ess)) - I . 4 e u ) Hexavalent ChromiunL Dissolved Acute 16 wl Numeric standards provided, formula not applicable Chronic l1 wlr Numeric standards provided, formula not applicable Copper, Dissolved Acute 34 ugA ;7T-.E4TT@6*dn ess)) - I' 4 6 3 4 ) Chronic 2l ugA ;f0f5 45On ( h ardn ess)) - I . 4 6 5 ) Lead, Dissolved Acute 291 ug/l W)-2.8736) Chronic 10i ugA F? 0-rfu *drrss))-5 . I 67 ) Nickel, Dissolved Acute 1 561 ug/l ;I0FtrI-*ness))+3.33) Chronic 161 wll /0.20-(Inffardn e ss) )+ I . o 6 ) Seleniurn, Dissolved Acute 20 ugA Numeric standards provided, formula not applicable Chronic 5.0 ugll Numeric standards provided, formula not applicable Silver, Dissolved Acute 6.6 ug/l [z t tn tn ardn e ss)) - 7 . 2 I ) Trout 0.25 i \gl "el .72Cn(hardness))-I o.5I ) Zinc, Dissolved Acute 210 ugA ,TO.8A73(tn( Chronic 190 ugA W))+0.7614) PELs Page 5 of 15 Draft BlueCreekRanchwwTPPreliminaryEffluentLimits PEl-Garfield CountY confluences. Based on this analysis, the estimated low flows for the proposed Blue creek Ranch WWTP are presented in Table 5. Draft PELs Page 6 of l5 Ambient Water Quali$ for the pt'pot"A Btrlu Ctttk YT ;;;;;;*-;ili;Ranch wwrP. Thisdatacoversthepcriodof rccordof l0/e5 through 2/00' t !rrnrrr I H=i:IE;Ili; ;;;rffi';;;?; was used where thcre was no dctectablc amount because thc geomctric mean of one y ncn samPle rEsultD wErE rrurr-wrvr" 'rrv t for summarization and avcraging purposes' ;#;;;"r*." *,n wecD procedures, ambient water quality is not determined using non-detect data detcction levels are greater than the in-stream standards' Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY ,, ,* -""rr .rr*"ary, June, July, and october, the acute low flow exceeded the chronic low flow' In accordance with WQCD standard procedures, the acute low flow was set equal to the chronic low flow for these months. IV. Technical AnalYsis Low flows and in-stream background data evaluated in sections II and III are ultimately used to determine the assimilative capacity of the Roaring Fork River near the proposed Blue creek Ranch WWTP for pollutants of concern. For all parameters except ammonia, it is the WQCD's approach to conduct a technical analysis of stream assimilation "upu.ity using the lowest of the monthly low flows (referred to as the annual low flowj as calculated rnJhe low flow analysis' For ammonia' it is the standard procedure of the wecD to ietermine assimilative capacities for each month using the monthly low flows calculated in the low flow analysis, as the regulations allow the use of seasonal flows when establishing assimilative capacities' The WQCD's standard analysis consists of steady-state, mass-balance calculations for most pollutants and modeling forpoltutants such as ammonia. The mass-balance equation is usedby the wecD to calculate the maximum allowable concentration ofpollutants inthe.eflluent, and accounts for the upstream concentration of a pollutant, critical low flow (minimal dilution)' effluent flow and the watei quality standard. The mass-balance equation is expressed as: Qz Q,: Upstream low flow (lE3 or 30E3) b.i.r: Au"ruge daily effluent flow (design capacity) pr: Downstream flow (Q, + Qr) it, : In-stream b ackground pollutant concentrations Mr: Calculated max=imum allowable effluent pollutant concentration Mr:Maximum allowable in-stream pollutant concentration (water quatity standards) Low Flows for the Roaring MtOt- MrOt Mz = ---=-=- Draft PELs Page 7 of 15 pollutants that are modeled as if mass is conierved and there is no degradation' whereas non- conservative pollutants degrade and sometimes are created within a receiving stream depending on stream conditions. A more detailed discussion of the technical analysis for these parameters is provided in the Pages that follow. Pollutants of Concern The following pouutants were identified by the wecD as pollutants of concern for this facility: o BOD5 o TSS o Percent removal o Oil and Grease .pH oDO o Fecal Coliform o Total Residual Chlorine o Ammonia. There are no in-stream water quality standards for BOD5, TSS, percent removal' and oil and grease for the Roaring Fork fuver. Thus, assimilative capacities were not determined for these parameters in this section and an antidegradation review for these parameters was not conducted in Section V' However, the evaluation of applicable limitations for these pollutants can be found in Section VI' Regulatory AnalYsis. During assessment of the facility, nearby facilities, and receiving stream water quality, no additional parameters were identified as pottrrt*t, of concern. It should be noted that cyanide and metals are not evaluated as part of PELs development because it is the WQCD's approach to ensure control of cyanide and metals through a pretreatment program, if necessary, versus through wastewater treatment. Blue creek Ranch wwTP: The proposed Blue creek Ranch wwTP will be located near the town of Mulford in the Southwestern-most corner of Garfield County, specifically, the NW quarter of the SE quarter of Section 31, Township 7 South, Range 87 West of the 6ft P'M' The proposed design capacity of the facility is 0.02 MGD (0.03 r cfs). The proposed wastewater treatment is a mechanical wastewater treatment process. The technical analysei tt ut follow include assessments of the assimilative capacity based on this proposed design capacity' Nearby Sources An assessment of nearby facilities based on EPA's Permit Compliance System (PCS) database found 5l dischargers in the Garfield county area. Because of its proximity to Eagle and Pitkin counties (within five miles upstream) facilities in these counties were assessed also' t*t:ll"l^1"ji:111i:: r i- ^^r6frnh llrtrn Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY For non-conservative parameters and ammonia, the mass-balance equation is not as applicable and thus other approaches are considered where appropriate' Note that conservative pollutants are :#il;:"".,#t"" related operations and thus had no pollutants of concem in common with Draft PELs Page 8 of 15 BlueCreekRanchwwTPPreliminaryEffluentLimits PEl-Garfield CountY proposed Brue creek Ranch wwrp. other facilities discharged to different watersheds or were located more than twenty miles from the proposed Blue creek Ranch wwTP and thus were not considered to be of relevance to this analysis' The nearest dischargers were: . The uialvalley Metropolitan District wwTP (CoG584007), located 4 miles upstream nearthetownofElJebel,dischargesdirectlyintotheRoaringForkRiver.Afewmiles farther upstream the Basalt Sanitation District wwTP (co0021491), which services the townofBasalt,alsodischargestotheRoaringForkRiver' . The Ranch at Roaring ro.kt (coc5840S1j discharges to the Roaring Fork River approximately two miles downstream and the Town of carbondale wwTP (coc584050) discharges four miles downstream of the proposed Blue creek Ranch WWTP. The arnbient water quality background concentrations used in the mass-balance equation account for pollutants of concern contributed by upstream sources, and thus it was not necessary to model upstream dischargers together with the Blue creek Ranch wwTP when determining available assimilative capacitie, ii tr," Roaring Fork River. Because of the significant dilution available relative to the size of the dischargers of concern, downstream dischargers were not found to affect the assimilative capacity calculations for the Roaring Fork River near the proposed Blue creek Ranch WWTP. Based on available information, there is no indication that non-point sources were a significant source of pollutants of concern. Thus, non-point sources were not considered in this assessment' BOD5. TSS, and Percent RemoYal:'There are no in-stream water quality standards forBoD" TSS' and percent r"*ouuIf* th.E*irrg Fork River. Thus, assimilative capacities for these parameters were not calculated. Oil and Grease: There are no in-stream water quality standards for total oil and grease for the Roaring Fork River. Thus, assimilative capacities for totat oil and grease were not calculated' pH: The pH of a stream measures the intensity of the acidity or alkalinity of the stream' when pH falls outside of the neutral range, it can be harmful to aquatic life' To determine assimilative capacities of a stream for pH, the buffering capacity of lhe riceiving stream and its interaction with the discharge contributions would need to be assessed in a complex evaluation' An evaluation of pH data available for the Roaring Fork River near the proposed Blue creek Ranch wwTP found that the 15,h percentile value was well above the minimum in-stream water quality standard and the 85fr percentile value was well below the maximum in-stream water quality standard' Because only limited data are available and because ambient water quality data indicate that no further controls are needed to meet in-rt** pH standards, a complex evaluation ofthe assimilative capacity for pH is not warranted for this facility' PELs Page 9 of 15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY -, ,r. ,*t"t1ity of dissolved oxygen in receiving streams is critical for aquatic life' ffi.;;;,i", "i"rg*ic matter and nitrification within receiving streams are generally the causes of depletion of DO in receiving waters' For a non-conservative parameter like DO, a simple mass balance cannot be used to determine assimilative capacity. Instead, Do background, stream flow, 5-day biochemical-oxygen demand and ammonia loading, stream dimensions] temperature, and estimates of effluent DO may be incorporated into models such as the Streeter-Ph"lp, DO model or STREAMDO to simulate the impact of the proposed Blue Creek Ranch WWTP discharge' An evaluation of Do data available for the Roaring Fork River near the proposed Blue creek Ranch wwTPfoundthatthel5epercentilevaluewaswellabovetheminimumin-streamwaterquality standard. Because only limited data are available and because arnbient water quality data indicate that no further controls are needed to meet in-stream standalds for DO, modeling was not conducted as part of this evaluation and no further discussion of Do is provided' chlorine: The mass-balance equation was used to determine the assimilative capacity for chlorine' There are no point sources discharging total residual chlorine within one mile of the proposed Blue creek Ranch wwrp. Because chrorine is rapidly oxidized, in-stream levels ofresidual chlorine are detected only for a short distance below u ,our"L. Ambient chlorine was therefore assumed to be zero. using the mass-balance equation provided in the beginning of Section IV, the acute and chronic low flows set out in Section III, the chlorine background concentration of zero as discussed above' and the in_stream standards for chlorine shown in Section II, assimilative capacities for chlorine were calculated. The data used and the resulting calculations of the allowable discharge concentration, Mr' are also set forth below. Fecal coriform: There are no point sources discharging fecal coliform within one mile of the proposed Blue creek Ranch wwrp. Thus fecal coliform assimilative capacities were evaluated separatelY. It is the standard approach of the WQCD to perform a mass-balance check to determine if fecal coliform standards are exceeded. And, as is standard WQCD procedure' the checks are only conducted on the chronic 10w flows as set out in Section IIi. Using the mass-balance equation provided in the beginning of Section IV, the background concentration for fecal coliform contained in Section II, and the in-itream standards for fecal coliform shown in Section II' checks for fecal Draft M , (ug/l) PELs Page 10 of l5 Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY coliform were conducted. The data concentration, Mr, are also set forth used and the resulting calculations of the allowable discharge below. Ammonia: Ammonia is present in the aqueous environment in both ionized and un-ionized forms' It is the un-ionized form which is toxic and which is addressed by water quality standards' The proportion of total ammonia present in un-ionized form in the receiving stream is a function of the upstream and effluent ammonia concentrations, and the pH and temperature ofthe receiving stream and of the effluent, combined. The colorado Ammonia Model (cAM) is a software proglam designed to project the downstream effects of ammonia and the ammonia assimilative capacities available to each discharger based on upstream water quality and effluent discharges. To develop data for the CAM, an in-stream water quality study must be tonducted of the upstrlam receiving water conditions, particularly the pH and corresponding temperature, over a period of at least one year' There were no data in the Roaring Fork fuver near the proposed Blue creek Ranch wwTP that could be used as adequate input data for the CAM' Therefore, the WQCD standard procedure is to rely on default values for the allowable chronic concentrations of in-stream total ammoniq which are provided in the colorado Total Maximum Daily Load and wasteload Allocation Guidance and the CD4S Summary of Rationale General Permitfor Domestic Wastewater Treatment Facilities that Discharge to Receiving Waters with a Chronii Low Flow: Design Flow Ratio of 100: I or Greater' Note that acute values are not provided in these sources and thus are not evaluated as part of this assessment. Using the mass-balance equation provided in the beginning of Section IV, the acute and chronic low flows set out in Section III, the mean ammonia background concentration shown in Section II' and the in-stream standards found in the Colorado Total Maximum Daily Load and Wasteload Allocation Guidanceand the cDpS summary of Rationale General Permitfor Domestic lrastewater Treatment Facilities that Discharge to Receiving waters with a chronic Low Flow: Design Flow Ratio of t 00: t or Greaterfor M], assimilative capacities for chronic total ammonia were calculated' The data used and the resulting calculations of the allowable discharge concentration, M2, are contained in Table 6. V. Antidegradation Review As set out in The Basic standards and Methodologies of Surface Yl/ater, Section 3l '8(2)O), an antidegradation analysis is required except in cases *h"." the receiving water is designated as "IJse protected.,, Note that ..LJse protected" waters are waters "that the Commission has determined do M 2 (#/100 ml) M 3 (#/100 ml) M t (#/100 ml) 'arameter PELs Page 11 of15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY not warrant the special protection provided by the outstanding waters designation or the antidegradation review process" as set out in Section 31.8(2Xb). The antidegradation section of the regulation became effective in December 2000, and therefore antidegradation considerations are applicable to the proposed Blue Creek Ranch WWTP permit issuance. According to the Classification and Numeric Standards for Upper Colorado River Basin and North Platte River (Planning Region l2), stream segment COUCRFO3 is Undesignated' Thus, an antidegradation review-is required for this segment if new or increased impacts are found to occur. The ratio of the low flow of the Roaring Fork River to the design flow of the proposed Blue Creek Ranch wwTp is 6065: I . Section 3 I .8 (3)(c) specifies that the discharge of pollutants should not be considered to result in significant degradatio, of th" reviewable waters if the ratio of the low flow of the receiving water to the facility flow is greaterthan 100:1. Thus, condition 31.8(3Xc) of the regulations is met and no further antidegradation evaluation is necessary' VI. RegulatorY AnalYsis Regulation 62, the Regulations for Effluent Limitations, includes effluent limitations that apply to all discharges of wastewater to State waters, with the exception of storm water and agricultural return flows. ih"r. regulations are applicable to the proposed Blue Creek Ranch WWTP discharge' Table 7 contains a summary of these limitations. Table 6 Monthly Assimilative Capacities for Ammonia on at the ProPosed Blue Creek Ranch the Roaring Fork River WWTP Parameter Q r kfs)"Q z'Gfs)Q s (cfs)Mt Mj M2 NHr, Tot (mg[) Jan 2.39 U.UJ I 239.U5 |O.UUUY I 0.70 5,390 NH3, Tot (mgA) Feb 239 U.UJ I 2J9.U3 t O.UUUY I 0.60 4,619 NHr, Tot (mg/l) Mar 239 U.UJ I '239.UJ t O.UUUY I 0.40 3,077 NH3, Tot (mgA) Apr 227 U.UJ I zz l .tJ3l 0.0uu9l 0.40 2,92i NHr, Tot (mg/l) May t8E U.UJ I I EU.UJ I 0.ouuv I 0.30 1,814 NH3, Tot (mg/l) JLtn 365 0.03I 365.03I 0.0009r 0.30 3,522 NHr, Tot (mg/l) Jul 333 U.UJ I 333.UJ I 0.0uu9l 0.30 3,213 NH3, Tot (mgA) Aug 296 O.U3I 296.O3 L O.OUU9I 0.30 2,856 NH3, Tot (mg/l) Sep 307 O.U3I JU /.UJ I U.UUUY I 0.30 2,962 NH3, Tot (mg/l) Oct 290 U.UJ I 29U.U3 t O.UUUY I 0.30 2,798 NH3, Tot (mgA) Nov 301 U.UJ I 30l.u3l 0.00091 0.30 2,904 NHr, Tot (mg/l) Dec 26s 0.03I 265.1J'31 U.UUUY I 0.50 4,267 PELs Page 12 of 15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield CountY In addition to these regulations, the State has developed the Procedure for Selection of Fecal Coliform Limitations permit Conditions that specifies a 30-day average limit of 6,000 colonies per 100 ml and a 1-day average limit of 12,000 colonies per 100 ml when the ratio of the receiving stream flow to design flow is gteater than ten to one' PELs Page 13 of l5 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield County Specific Limitations Table 7 for the Discharge of Wastes Parameter 7-Day Average 30-Day Average fnstuntaneous Maximum BOD5 45 mll 30 mg/l NA TSS, mechanical plant 45 mg/l 30 mgll NA TSS, aerated lagoon I l0 mg/l 75 mgll NA TSS, non-aerated lagoon 160 mg/l 105 mg/l NA BOD5 Percent Removal 8s% TSS Percent Removal 8s% Total Residual Chlorine 0.5 mgll pH 6.0-9.0 su range Oil and Grease l0 mg/l Note that the TSS limitations shown above vary based on the t1pe ofwastewater treatment processes used at the facility. The Regulations for Effluent Limitations waive the 85 percent removal requirements for TSS where waste stabilization ponds, both aerated and non-aerated, are used as the principal process for treating domestic wastes. VII. Preliminary Effluent Limits The regulations require the use of the most stringent effluent limit forpermit limitations. Thus, the PELs reflected in Table 8 include the most stringent of the following:o Water quality-based effluent limits as discussed in the technical analysis contained in Section fV o ADBELs as discussed in the antidegradation review provided in Section V ' Effluent limits prescribed by the regulations based on the regulatory analysis provided in Section VI. BOD,(m/l)45 (7-day average), 30 (30-day average) BOD, (percent removal)85 (30-day average) rSS (mg/l)45 (7-day average), 30 (30-day average) TSS (percent removal)85 (30-day average) Oil and Grease (mg/l)10 (maximum) pH (s.u.)6.5 -9.0 (minimum-maximum) Fecal Coliform (organisms/l00 ml)I 2,000 (7 -day average), 6,000 (3 O-day average) Total Residual Chlorine (mg/l)0.5 (maximum) PELs Page 14 of15 Draft Blue Creek Ranch WWTP Preliminary Effluent Limits PEl-Garfield County The Procedure for Selection of Fecal Colifurm Limitations Permit Conditions specifies that the 7- day average limit must be calculated as two times the 30-day average limit. Note that limitations for ammonia were not necessary for this facility because the assimilative capacity of the receiving water, as discussed in Section IV, is large enough to establish total ammonia effluent concentrations for all months at 30 mgll. Because treated sanitary sewage effluent is not expected to have a total ammonia concentration greater than 30 mg/I, no additional allocations were determined as per WQCD procedure. VIII. References Colorado Total Maximum Daily Load and Wasteload Allocation Guidance, CDPHE, WQCD, November 1991. Classification and Numeric Standards for Upper Colorado River Basin and North Platte River (Planning Region l2), Regulation No.33, CDPHE, WQCC, November 30,1999. The Basic Standards and Methodologies for Surfoce Water, Regulation 3.1, CDPHE, WQCC, November 8, 2000. Procedurefor Selection of Fecal Coliform Limitations Permit Conditions, CDPHE, WQCD, 1976. Regulationsfor Effluent Limitations, Regulation 62, CDPHE, WQCC, November 9, 1998. CDPS Summary of Rationale General Permitfor Domestic Wastewater Treatment Facilities that Discharge to Receiving Waters with a Chronic Low Flow:Design Flow Ratio of 100:t or Greater, CDPS Permit COG-584000, Statewide, CDPHE, September 14,1994. PELs Page 15 ofl5 Draft P.O. Box 19OB 10O5 Cooper Ave. Glenwood Springs, co 81602 (97O) 945-s7OO (970) 945-1253 Fax Erraffr ggnng Cor{ rllLTAtrls RECEIVEDJUNOs2OOI' June 6, 2001 Mr. Mark Bean Garfield County Building and Planning 109 Eighth Street, suite 303 Glenwood Springs, CO 81601 RE: Blue Creek Ranch Site Application Dear Mark. Attached for your review and comment by the Board of County Commissioners and the Health Department is a Site Application and supporting documentation for a central wastewater treatment facility at the Blue Creek Ranch property near Catherine Store in unincorporated Garfield County. This Site Application is being submitted to you in accordance with Colorado Department of Public Health and Environment Regulations No 22 5 22.4 (2) Generally, this application proposes an on-site system comprised of septic tanks at individual structures, collection lines, manholes, a pump station, and a force main collection system. The wastewater will be treated by centralized recirculating sand filter (RSF) treatment facility, which will discharge to the Roaring Fork River. I have provided two original copies of the signed Site Application with this submission. We would ask that the County and the County Health Department sign both copies where indicated on Page 14 of the Site Application submittal, and return one copy to our office. Please feel free to contact me during your review of this Site Application tf you have any questions or require further information. Very truly yours, Zancanella and Associates, lnc. BY luUc^.*l-n-C-s^-=t.'s.. C\\ q Thomas A. Zancanella, P.E. #20481 cc: Robert Cumming, Jr. Scott Miller, Esq. Z.'20000.001 29 B I ue Creek Ranch\siteapp\S ite Apphcation Cover Letter. doc AN]D ASSOCtareS, N(.