Loading...
HomeMy WebLinkAbout3.0 Staff Report BOCC 9.4.01,,1/n,*/ L ** t' ..Ie--J LL'a// ,',rii ur*l / 7/*tr4 REQUEST: uu ycrtu'L(tuJA ,P 4 ,'' l,il-n/7 4 *r'" ,*/ BOCC 9104101 PROJECTINF0RMATIoNANDSTAFFCoMMENTS APPLICANT: Review of the Proposed Blue Creek Ranch Wastewater iieatment Faciliry and Recommendation to the Colorado Department of Health and Environment' Water a;tt Control Division, per regulations22' Section 22.4 (2). Blue Creek Land Holdings, LLC The Blue Creek Ranch is a proposed PUD on an 82 acretract just to the south and east of the Catherir" Stor" roi"rr""tio, wrth Highway 82-and County Road 100, Extending from HrA;;y 82 to the Roaring Fork River (See Auached Map). The applicant proposes a working build out d;;;it?". this analysis of 40 single farnily homes' 6 affordable housing units and n ii"" iur.o/horr" UoitAng facilit| on the iite which results in a plant buJhg'fu"tor of 52 equivalent dwelling units' Theproposedmethodoftreafinentistoinitiallycollecteffluentinsingleorclustered septic tanks for solids removal. A gavitt se#1.wrll convey the tank effluent to a lift station that will p.*pi" , ";;t*; f*ifitY utilizing a Recirculating Filter System' The facility is designedto n*dt.20,000 guii* ner OaVStrich would handle any peak flows from an estimated 12,740GPD average daily flow' The.lift station is designed to accommod ate a24hour back-rrp fait,,rl si-o| 8e atea. -The proposed facilities are directly adjacent to, but Oo not lie within, tUe roO jeainooO plain witli the exception of required connecting pipes. A geotechnical ,ePort oi'* p."put"A for this project by HP Geotech of Glenwood Springs *tich indicates tirat much'of ine property and ftt-ltlllt:d site for the lift station and plant is subject to high ground water ievels' The construction of basements is not r.ro*.roea ana spEtiut r*. is advised in construction of any sub- surface structure. The potential for sint hotes and eroding subs!rugture is present in the general area. The pi"fit.a srte tras uO.q*t" access and setbacks from potential Ia3oiolrg uses as currently envisioned' The applicant proposes that the-ownership, operation and maintenance of the system will be turned over to u ho*"o*rr"r's associaiiorr. R proposed operations budget indicates twice weekly visits by a class D operator to inspect operations, periodic pumping of biosolids, u "upit l ro"*. fundand "tt*auv charge fol undeveloped lots to assist in funding prior to Uuifa-ort, and related operytiols costs for an estimated $40'73 per dwelling unit per montfr rn*g.. Cost for the facility is estimated at $250'000' or essentially S5000 per dwelling unit' B. II. Issues and Concerns A. Legal Process: To install a new sewage treatment facility and a lift station' an applicant irffiUoa io submit an Appl-ication for each to the Colorado Department of public Health ana rnvironment (CDPHE). The site applications are required to be reviewed by the county Board of Health, Board of county Commissioners and Planning Authority. fthel reviewers for this application include the Town of carbondale, carbondale Sanitation District, and Mid valley Metropolitan District. As the piurt u.ro lift station are to be constructed together i',p,o*i*ity-atthesametime,theyarebeingreviewedintandem. These entities are given three recommendation options; approval, disapproval and no "orrr-"nt.- ihe"charge to these reviewing entiiies is to address the following question: ..Ate the proposed facilities consistent with the Comprehen:,^u9-|lu,1nd anv other plans 6i trr" area, including the 201 facility Plan or 208 Water Quality Management Plan, as they affect water quality?" The recommendations made by local governments and entities are considered by the cDPHE in their approval ot deniulof the site applications' If thecDPFIE recommends denial of the propor.J site applicationi, that denial can be appealed to the Colorado Water Quality Control Commission' n: The current Garfield CountY Parcel in question as@ a recommended density for the Low Density Residential (10 acres perdwelling unit) yhi:l-Y:.*9^ry^'::l':l:{ ^,ilt ;ilT'J il:ffi ; rX ffi .;J.tur), 8 ;G-"o _y1l' n g units for a totar of 16. The proposed trJe farm and horse boarding operations would potentially .ourt as seueral additional units for the purposes of plant loading' This designation was applied to this area primarily-due to septic system - constraints (Plan, pug" rv-:l "These areas eithei have inadequate percolation ,ui.r, rrigr, grourrd *a'teror ulre underlain by the Eagle valley Evaporite formation." section III of the plan, 7.0 ..water and sewer seryices" provides guidance in ,.r.tut areas: (Plan, Section III, Pages 14 and 15) objective 7.1: "Development in_areas without existing central water and sewer service will be."q"ir.Oio provide adequate and safe provisions for these services before proj ect aPProval-" objective 7.2 "Development locatgd adjacent,to municipalities or sanitation districts with availabi. fupu"ity in their tentral water/sewer systems will be strongly encouraged to tie into these systems'" 2 C. objective 7.5 "Garfteld county will strongly discourage the proliferation of private water and sewer sYstems'" policy 7.4 "where I.s.D.S. is not feasible, Garfieldcounty will require a sewage disposal system approved by the State of Colorado'" UnderS.0,NaturalEnvironment'PolicyS'4*TheCountywillrequire development with ri;;;il"-rtrg. to uoor"s the issue through physical design in a way that will protecift"gti" *iUands and scenic resources-and protect floodplains from encroachment'" lliil,i,'.lio'ffiffirffiJffi;; ,oui. r'ai,i*,i, rot a'ea pe' dweiling unit is 2 acres. sit. 'orrt uiis *i.,ro proiably not allow 41 selarate lots to be subdividedfromthislarger32acreparcel,,equiringaPUDtoallowtheproject proponents to approachihe density levels proposed' TheapplicantproposestoenterintoaPIIDprocessforthedevelopmentofthe oarcel that will facilitate weighing ttrese-and-other issues in the overall approval ffii]r;.'t# ililu[| t u, .[*.Jtry iointined the maximum probable densitv allowedundertheunderlyingzoning,subjecttoothersrteconstraintsand considerationr, *hi.h i' uppiop'iatJ oiv ana -tgfl:::'""fl1r3::::.,",1evaluatine se' orchard or 'ff:-Y#'*li f.., o", dwelling unit i consloerauorls' w'ru* r' .vPrv'rr-* "'-iu,i""s and costs' The approval of the p"i""ti"t effluent levet-'T:"T:Lt^?:f:- onrr rrecrmenr facilitv do notin a4yr : The parcel in as the III. StaffComments' l.TheparcelinquestionresidesinalocationwheretheComprehensivePlanand the Zoning Resolution ur. ,."*i"r,ril;;;;;fl*-,11. comprehensive Plan, based on soil and ground water constrain=ti, suggests minimum 10 acre lots in an effort to recogniz. r.s.o.s. constraints r."* g.i*dwater and subsurface issues as well as to preserve the agricultot-"f u'a.1t"'":t **""I:of this corridor' and not pto*ot" urban gto*th levels outside of urban seruces areaa' 2. The comprehensive Plan also identifies a broader area of concern dealing with water q*ritv irru.s and speciuiun"",io" to river frontage' The underlying concern ir Jil#ffi;;ffi;*tstreams and rivers mav be approached cumulatively, impactingnl*.ffi ;i'."*r ura rrrlo of special districts, should there be u piofii.iu,ion-of smatler, private wastewater systems' There is also an underlying;;;;.* that privateGl;;, "'d facilities managed by homeowner's associations have had an *.";;'il;il;J track record of maintenance and comPliance' the Permitting Process' 3.TheapplicantsowngeotechnicalleportstatesthatthesitecontainsEagle Valley Evaporite tpi,e"T),'ugg"to further study by a hydrologist for areas along the river and flood fiil6"#"+;, and states *Giound water level typically appears shallow thr"rgd;itre prqect area. Field sprinkler and flood irrigation could be contributilfi" the shaiow groundwater condition' Due to the shallow water level and flrtl;;g;;uir, it r,ill probably n9t be practical to protect below grade areas from *.tttil and hydrostatii pressure buildup. by use of an underdrain system. (... ) gasemenil?""ft may not be -feasible' Potential groundwater impacts on proposed development should be Juated as part of the site specific building study."(Page 7) 4.TheCDPHEreviewandapprovalprocessprimarilyfocusesonthetreatment plant itself, the lift station, and what will be discharged into the river environment' It is less ,orr.-.a *iit, the collection system, which in this case is part of the overall system with the individual septi; tanki acting as solid settling vaults prior to effluent reachirrg i't. pi*, itself. taking an overview of the entire system therefore falls on the countY' 5. county staffhave not had the opportunity to evaluate the proposal from an engineering standpoint, or a water q*ltt standpoint, by. in-house staffor external consultants *,th that';;.rirr..*p.rtir.. we wiil rely primarity on cD?HE evaluation fo, *uto-q11tflty issuls but note that in their report on preliminary effluent limits cDpm ;iates that at lowest flows the ratio of discharge to river volume is 1:6065 ul}dtmt "assimilative capacities aJ9 extremely large" (page 1) and later in discussing loading along the reach considering uptT"* 111^.,^ downstream discha-rgZrs "the-ambient water quality backpround concentrattons used in the mass-balance equation account foi poliutantslf concern contributed by upstream ,o*,",, and thus it was-not necessary to model upstream dischargers together with the Sir. Ct".t Ranch WWTP when determining available assimilativ" "upurlii", in the Roaring Fork River. Because of the signifrcant dilution available i.tutir" to the sizJof the dischargers of concern' downstream dischargers were not found to affect the assimilativi capacity calculations for the Roaring Fork River near the proposed Blue creek Ranch 'w'wT?>" (Page 9) 6. The applicant has explored the potential for consolidation into the treatment facility at the Ranch at ioaring Foik and has been told that their loading would trigger a threshoiJtnat woutA iequire system expansion at a cost of $7500+ per dwelling unit, and in addition.*"*.rrt, to reac-h the nearest lift station would cost at teast szoo,ooo, o, u, additional $4000 Pef {we}ing unit equivalent' Assuming that the "ort of th. system and the indiviaua septic tanks is approximat.f, SiOOO per dweliing,roit u. proposed, a Ranch at Roaring Fork alternative could double the cost per unit. -Given the potential and likely market niche these lots uiJ J*"ff ings are likely to be targeted at, that is not an insurmountuUf. ,ort tt"eshojd despite ihe statemint by the applicant that this cost differential represents economic unviabilrty. However, as the Ranch at Roaring 4 Fork is a private System, there is no assurance that the homeowner's association would uppror" that expansion. The applicant also approached Mid Valley about a service expansion and they were told it ut ro plans exist to extend down valley at this time. There is no indicat'ion that discussions were held about Mid valley managing the facilitY, however' 7. There is an existing dwelling and at least one existing I'S'D'S' system at present on the p6.f ."ffre appiicant states that the dwelling will remain but fails to state whether the existingi.S.O.S. will be taken out of commission and integrated into the r.rr ryrG*. Verbal communication with the engineer indicates that it will be tied in' fV. Conclusions and Findines 1. Staff finds that a consolidation with the Ranch at Roaring Fork system is not supported Uy any evidence that water quality would be enhanced by such consolidatior,, oi by any preliminary conc"*t by CDPFIE. To burden the applicant with the *"..tuirty of negotiations with a private facility T'by u homeowner's association and the cJsts involved would be unfair, and while this finding doesn't address the issue of proliferation,-such consolidation would still result in a private system subject to maintenance by a homeowner's association' 2. Stafffinds that should the proposed facility meet the water quality standards set by CDPHE, and an apparent iack of concern about cumulative loading by that agency on this stretct of tt" Roaring Fork River, that baring evidence to the conffary water quality issues and impacts on the river should not preclude upprouul if itre proposed standards aie met. CDPIIE comments appear to suggest that Total t ta*i*um Daily Load standards for the Roaring Fork River are not an issue for this aPPlication' 3. Stafffinds that the overall system as proposed does not address significant issues p.o, io effluent reaching the lift itationand pl1nt, nor does itaddress specific flood plain and *etland. issues at the lift siation and plant site. Pipes will need to "ror, .-d.r flood plain areas, facilities are ploposed right on lhe edge of the flood plairl and no site specific information is given about vegetation' habitat' hydrolory, "ir,if impact and other riverbank and riparian concerns' The site adjoins a live steam with valuable riparian characteiistics and sits in a wooded area with mature trees. While not reasons to recommend denial' these concerns trigger the suggested conditions below' 4. Stafffinds that the applicant has met the intent of those aspects of the comprehensive plan thif require care and attention to groundwater issues and soils issues at ftris particulariite in seeking to construct a State Approved sev/er system to rnitigate site constraints for development. The proposal does not address the isslue of proliferation of smaller, private sewer systems, or suggest management structures and monitoring that might alleviate that concern' 5 V. Recommendations and Conditions Staffrecommends approval of the proposed site applications with the following comments to be forwarded to the applicant, the CDPHE and the other partners in the review Process- 1. That the facility only be approved if it can meet all water qualitystan9tlt f* ihe Roaring Fork Riveiand uoy "ot r"*s by public wastewater facilities both upstream and downstream. 2. Thatthe applicant completes a site specific ludy.for the lift station and plant by a qualified iire, hyarofogist and engineer addressing all site concerns but ,p."iii"uffy addressing pipJocations and foundation issues where pipes must cross under the 100 ye"ar flood plain, ground water issues, channelization and bank erosion and site disturbance issues' 3. That the applicant specifies that any existing I.S.D'S' systems now existing on the parcel be de-commissioned and reclaimed,ind that existing dwellings will be integrated into the proposed system' 4. That the applicant specifies that the "individual or clustered septic tanks" which are an integral part of the proposed system be totally non-discharging . except to the gfavity fed sewer lines, specifies design standards for those septic tanks that meet ground water "or,""*., and show that such tanks will be constructed to allow for visual inspection of their continued integriU to be non- discharging over time. Further, thl applicantvill specit/ that the individual or clustered septic tanks shall be the resfrnsibility of ihe homeowner's association to periodicuily ir.p"tt and repair and maintain as necessary' 5. That the applicant show that the gravity fed sewer lines are designed in such a way as to totally r.rirt irfilt utio, *d exfiltration over time, and a proposed -"thodolorytoperiodicallyverifftheintegrityofthepipingsystem' 6