The URL can be used to link to this page

Home My WebLink AboutSubsurface Investigation & OWTS Design 02.23.202133 FoUR WHEEL DRIVE RoAD CARBoNDALE, CO 41623 970.309.5259 CARLA.OSTBERG@GMAIL.COM sftr'îtc c()F¡ ÉiliL'r. r N G February 23,2021 Project No. 1589 Todd Cerrone tod d@garretconstruction.com Subsurface lnvestigation and Onsite Wastewater Treatment System Design 4-Bedroom Residence + 1 Future Bedroom Lot 5, Mountain Meadow Subdivision Garfield County, Colorado Todd, CBO lnc. performed a subsurface investigation and completed an onsite wastewater treatment system (OVV|S) design for the subject residence. The 2.'l1 1-acre property is located outside of Carbondale, in an area where OWTSs are necessary. Legal Description: Section: 11 Township: I Range: 88 Subdivision: MOUNTAIN MEADOWS AT PRINCE CK Lot: 5 2.111 ACRES Parcel lD: 2463-113-02-005 SITE CONDITIONS The property is currently undeveloped. A 4-bedroom residence is proposed The residence will be served potable water from a community water system. The water line will enter the property from the cul-de-sac off of Meadow Court and run along the proposed driveway. The water line will not come within 25-feet of any OWTS component. The proposed soil treatment area (STA) will be located to the west of the residence. The area has an approximate 3-4% slope to the north. The area was covered with snow at the time of our subsurface investigation but is an open field. There should be no traffic or staging of material over the future STA site to avoid compaction of soils prior to construction of the STA. SUBSURFACE The subsurface was investigated on February 8,2021 by digging two soil profile test pit excavations (Test Pits). A visual and tactile soil analysis was completed by Carla Ostberg at the time of excavation.l The materials encountered in the Test Pit #1 consisted of dark brown topsoil to 2.O-feet, underlain by medium brown sandy loam increasing rock content to a maximum depth explored of 7.O-feet. No bedrock or groundwater was encountered. ' Carla Ostberg holds a Certificate of Attendance and Examination from the CPOWVisualand Tactile Evaluation of Soils Training. Page 2 The materials encountered in the Test Pit #2 consisted of dark brown topsoil to 2.O-feet, underlain by medium to reddish brown sandy loam to a maximum depth explored of 7.O-feet. There was significantly less rock content in Test Pit#2. We are proposing the STA farther to the south for this reason. No bedrock or groundwater was encountered. A sample of the soil was taken from Test Pit#2 al3-feet below grade. Soil structure grade was moderate. The soilformed a balland a ribbon lessthan 1-inch in length before breaking. Soilstructure shape was blocky and consistence was friable. Soil texture was more gritty than smooth. STA sizing is based on SoilType2, Sandy Loam with moderate structure grade. A long term acceptance rate (LTAR) of 0.6 gallons per square foot will be used to design the OWTS. View of Test Pit #1 Êg'--årr¡&u-' . '* *ñ. Test Pit #1 backfill Page 3 Higher rock content with depth Test pit #1 in the foreground (#2 in to the south) Test Pit #2 Page 4 Test Pit #2 less rock content in Test Pit #2 Sieved sample DESIGN SPECIFICATIONS Desiqn Calculations: AverageDesignFlow=TSGPDx2people/bedroomx3Bedrooms+150GPD(4thandSthbedrooms)=600 GPD LTAR = 0.6 GPD/SF 600 GPD / 0.6 GPD/SF x 1.0 (gravity trenches) x 0.7 (chambers) = 700 SF The OWTS design is based on 4-bedrooms in the proposed residence plus 1-future bedroom foratotal of 5-bedrooms. An average daily wastewater flow of 600 GPD will be used. Page 5 For the purposes of this OWTS design, Benchmark Elevation at grade 6379' has been established as 100' (Finished Floor). CBO lnc. should be notifìed of any discrepancies or problems with grade elevations of proposed components during installation of the OWTS. The 4-inch diameter SDR-35 sewer line exiting the residence must have a double-sweep clean out and a minimum 2o/o grade to the septic tank. The system installation must include a 1S0O-gallon, two-compartment poly lnfiltrator@ septic tankwith an effluent filter on the outlet tee. A concrete septic tank may be substituted, if desired. Risers must bring the manhole lids to grade for access. lf more than one riser is added to the septic tank, an extension handle must be installed on the effluent filter. Effluent will gravity flow to a distribution box, and then to four gravelless chamber trenches. The distribution box must be accessible from grade and must have flow equalizers, or similar product, installed on each outlet pipe in the distribution box to assure equal flow to each trench. Each trench will consist of 15 'Quick 4' Standard Plus lnfiltrator@ chambers for a total of 720 square feet of infiltrative area. There must be at least 4-feet of undisturbed soil between each trench. lnspection ports must be installed at the beginning and end of each trench. Ports may be cut to grade and placed in sprinkler boxes for access. COMPONENT SPECIFICATIONS The component manufacturers are typical of applications used by contractors and engineers in this area. GBO lnc. must approve alternative components prior to installation of the OWTS. Requests must be submitted, in writing, to our office for approval prior to installation. Component technical data sheets are available upon request. Construction must be according to Garfield County On-Site Wastewater Treatment System Regulations, the OWTS Permit provided by Garfìeld County Building Department, and this design. OWTS Component Minimum Elevation Primary Tank lnlet lnvert 97' (6376') Approx. horizontal distance 10' / min 2o/o fall / min. 2.5" lall Distribution Box 96' (6375') Approximate horizontal distance 93' / min. 1%fall lmin. 1'1.625" Íall lnfiltrative Surface 95' (6374') Approx. horizontal distance to furthest trench 34' lmin.1o/ofall / min. 4.25" fall 3OMPONENT IMANUFACTURER I/IODEL NO.ICOMMENTS Septic Tank llnfiltrator@ M-1530-2CP l1 500-9allon, 2-compartment lpolv septic tank Biotube Effluent Filter lorenco@ lFull Size Effluent Filter and lhousinq Tank Risers and Lids lorencoo lDouble-walled PVC Risers and Iio.1z+" diameter) I Distribution Box lPolvLok lDistribution box, flow lequalizers, risers, lid Chambers llnfiltrator@ Standard Plus 160 'Quick 4' Standard Plus lChambers Page 6 INSTALLATION CONTRACTOR CBO lnc. expects that the installer be experienced and qualified to perform the scope of work outlined in this design. The installer must review this design thoroughly and coordinate with our office in advance of installation. Any additional conditions in this design or county permit must be completed and documented prior to flnal approval of the OWTS installation. Communication between the installer and this office is expected throughout the installation. INSTALLAT¡ON OBSERVATIONS CBO lnc. must view the OWTS during construction. The OWTS observation should be performed before backfill, after placement of OWTS components. Septic tanks, distribution devices, pumps, dosing siphons, and other plumbing, as applicable, must also be observed. CBO lnc. should be notified 48 hours in advance to observe the installation. ln an effort to improve the accuracy of the record drawing, we request that the installer provide a sketch of the installation, including path of the sewer lines, water line installation (if applicable), septic tank location, STA location, and measurements from building corners or another fixed objects on the property. This sketch is most easily provided on Sheet W2.0 of the OWTS Design Packet. Photographs of the installation and final cover are also requested to supplement our installation documentation. REVEGETATION REQUIREMENTS An adequate layer of good quality topsoil capable of supporting revegetation shall be placed over the entire disturbed area of the OWTS installation. A mixture of native grass seed that has good soil stabilizing characteristics (but without taproots), provides a maximum transpiration rate, and competes well with successional species. No trees or shrubs, or any vegetation requiring regular irrigation shall be placed over the STA. Until vegetation is reestablished, erosion and sediment control measures shall be implemented and maintained on site. The owner of the OWTS shall be responsible for maintaining proper vegetation cover. OPERATION INFORMATION AND MAINTENANCE The property owner shall be responsible for the operation and maintenance of each OWTS servicing the property. The property owner is responsible for maintaining service contracts for manufactured units, alternating STAs, and any other components needing maintenance. Geo-fabrics or plastics should not be used over the STA. No heavy equipment, machinery, or materials should be placed on the backfilled STA. Machines with tracks (not wheels) should be used during construction of the STA for better weight distribution. Livestock should not graze on the STA. Plumbing fixtures should be checked to ensure that no additionalwater is being discharged to OWTS. For example, a running toilet or leaky faucet can discharge hundreds of gallons of water a day and harm a STA. lf an effluent fllter or screen has been installed in the OWTS, we recommend this filter or screen be cleaned annually, or as needed. lf the OWTS consists of a pressurized pump system, we recommend the laterals be flushed annually, or as needed. The homeowner should pump the septic tank every two years, or as needed gauged by measurement of solids in the tank. Garbage disposal use should be minimized, and non-biodegradable materials should not be placed into the OWTS. Grease should not be placed in household drains. Loading from a water softener should not be discharged into the OWTS. No hazardous wastes should be directed into the OWTS. Mechanical room drains should not discharge into the OWTS. The OWTS is engineered for domestic waste only. Page 7 ADDITIONAL CONSTRUCTION NOTES lf design includes a pump, weep holes must be installed to allow pump lines to drain to minimize risk of freezing. The pump shall have an audible and visual alarm notification in the event of excessively high water conditions and shall be connected to a control breaker separate from the high water alarm breaker and from any other control system circuits. The pump system shall have a switch so the pump can be manually operated. Excavation equipment must not drive in excavation of the STA due to the potential to compact soil Extensions should be placed on all septic tank components to allow access to them from existing grade Backfill over the STA must be uniform and granular with no material greater than minus 3-inch. LIMITS: The design is based on information submitted. lf soil conditions encountered are different from conditions described in report, CBO lnc. should be notified. All OWTS construction must be according to the county regulations. Requirements not specified in this report must follow applicable county regulations. The contractor should have documented and demonstrated knowledge of the requirements and regulations of the county in which they are working. Licensing of Systems Contractors may be required by county regulation. Please call with questions. Sincerely, CBO lnc. te)"(a-}*fu,^-g Carla Ostberg, MPH, REHS CBO lrþ.33 FflrWh6êl DriE RodCsrbof, dâle, Cdffi do 81 623Phone 970.919.5259cârla.o6ib€lg@gma¡¡-com#f:4w+TP2., BUITTINGENVEL0PE /,oet/-\-TPf---¿:írIøwffit@@/ı+UruREBEDROOMRESIDENCE+)-t^NOTE: WATERLINE TO FOLLOWIr--7DRIVEWAY/-STALOT 52.777* ACNTjI--1TGerrone ResidneceLot 5, irountah M€adow Subd¡vlsionGerfi eld Co{¡nty, ColoradoPþjoctNwnbeñ C1589Wi O2l'lBÍñ21DræYnDesignedRe\ri€wedby: DDby: CBOby: RBw1.0Sh€Bt 1 0F4NLOT 8SCALE: 1 = SOlfLOT 6/lLINE\----ofr-t----THE LOCATIO¡I OF PROPOSED MPROVEÂIENTS¡ STIOYVN ARE f{OT THERESULT OFA PROPERTYSIJRVEY. THE LOCATE,NS ARE APPROX¡M^"IE. TT ETHE HOMEOWN€RS' DUTY TO ENSTJRE AIT CONSTRT,,CTIOI{ ANDIMPROVÉMËNT LOCATþNS ARE ACCIIRATE. PROPERTY LINES AA¡DSETBACK DISIANCE]S S}IOLÍ.¡' BÊ CONFIRMED PRIOR TO EXCAVATIOI{.SCALED FORPRNTINGON If X ITPAFERDRAWNGS MUST BE USED INCONruNCTION WITH DESIGNLETTER DATED 02123/2021ASITE PLAN\rr--ï'ïã.d'l,vz.0 CBO lnc.3Í¡ FolfWheel Drir/o RoadCaòondals, Cdorado 81623Phone 970.309.5259carla.ostborg@gmail.comSCALE:1'= 2O4'NroGerrone ResidneceLot 5, Mountain Meadow SuHivisionGarñ€ld County, ColoradoProject Numbd: C1589Dalei o2123m21De*¡ned by: CBOR€viewed b],: RBDrewn bS DDTNVTLOPI /,/IBUILDINGw,"{\,\F6tt65'MIN+TOSTA20'MtN-HoÛSËTP2ffi--4'DIA SDR35 SEWER LINETO EACH TRENCH(MIN, 1% SLOPE TO TRENCH)II-+Shee( 2 0F 4w2.0TPl+s86'20'04E ßo.2+,LOT 52.777* ACRESMIN TO PROPERTY LINELINE'QUICK-4' CHAMBER TRENCHES.- 4 TRENCHES WITH 15 CHAMBERS PER TRENCHFORATOTAL OF 60 CHAITIBERSAND720 SF.4'DIASDR-3s INSPECTION PORT ATaeerNrurnènHe_!:NÐ oF EAcH TRENcHDISTRIBUTION BOXWITH ACCESS AT GRADE---->-<r-_-100'(FF 63791INO.sßEtsARêtgR/,Næ?LJ,6ÍTCñrc P¿s38215Io,DIA SDR.35 SEWER PIPEWITH DOTJBLE SWEEP CLEA¡¡OUTMIN 2% FALL TO TANKITWO-COIIIPARTMENTÞ-SEPnC TANK WTH EFFLUENT SCREEN/L-6¡6,tI4' DtA SDR-35(MrN. 1% FALLIIt CBO lnc.æ Four Wh6d Drire Rædcarbondals, Colorado 81ô23Phone 970.309.5259€rla.Gtberg@gm¡l.m,-INFILRG/ eroeureUfi4SDRSSffiClr rrBER (J ¡ 3)LINË TO EACH'TRËNCH(MrN. r%sLoFEroTRÉNCH}f tlAsDRsEFIUffi ffi FROìINOE: HNTAN SMllOilINSTATTATION BETMEN ZA¡TD 3DlmMtilmxwmOIA SDR¡sATGMDEttsPEcllotPORTPTICED N10P POtrOFC¡AMBER ENDPUESE'rsoLTWITilsvATtd{SCARFYffi({¡E)M SDRë INSPECIIOIACHAMBER'IRENCH SECÏON\á,rePORT AT ffiGINNING NDEþ OF ACH NENCH^CHAMBER 'IRENCH PLAN\rrreFINISHED GRADEcqrRaümRmmvew sox af GtuoESUP€N PI/CDO NOTGLIJEüPffißRæÐMOUTSMYINSULATEDTRACERWREFINISHED GRADÊ4'DIA SDR-35 SEWERPVC PFE CUTfO(MlN 2% SLOPE lO lAtlKMrN. r% lo sTA)BOXUSE HOLE SÀW TOCÚ ßRUtrGFITSÊWÊR LINEOR SANO FORBEDDING3'MtN-TO TANK8'MtN.A INSPECIION PORT DEÎAIL\),-rtE/ãCLEAN OUT DETAIL\1,re/A IRENCH DETAIL\9r-15CffiERf}PERffiH¿Cerrone ResidneceLot 5, Mountain Meadorv SubdMslonGarñeld County, ColoradoProþc{ Numben C1589llaø, oz!23no2ttes¡sned ¡v: ceolRev¡ewed by RBlDram bV: DDw3.0Sheet 3 0F 4 CBO lm33 FurWheel Driw RoadCarbondals, Colorado 81623Phonê 970.309.5259€rla.ostberg@m¡1.æm4.AEDROO¡I RESIDEI{CE + ,I FUTURE BEDROOM75 GPD x 2 PERSOT¡SiBEDROOM x 3 BEDROOMS + 150 GPD (4th ând 5ürSTATO WÂ'TER @URSE50N/ASTA TO WELL't0ûN/ASTA TO HOI.JSEN4gSEPT|C TANK TO WATER COIJRSE50N/ASEPTIC TA}.¡I(TO WEI-L50'N/AHOUSETO SEPTICTANK5'5'OWTS COMPONENTS AM)PHYSICAL FEATURESMINIMIJIú REQUIREDSEÎBACKAPPROXIMATE PROPOSEDSETBACKBEDROOMS)WASTEWATERFLOW=6{þ GPDTANK:MIN, 15OO GALLONSUSE I$(}GALLON, IWOCOMPARTMENT SEPTIC TANKSOIL TREATMET.IT ARÊA (STA):LoNG TERM ACCEFTÌANCE RATE (LTAR) = 0.6 GAU SFCALCUTA'ÍED STA = Q/LTAR = 600 / 0.6 = lmo SFGRAVÍYT, IRENCHES = 1000 SFXoí.o È f000 SFCHAMBERS = 1000 SF X 0.7 = 700 SF / 12 SF / CIIAMBER = 59 CHAMBERSFOUR GPAVELLESS CTIAMEER TRENCHES15 'QUICK 4 CHAMBERS IN EACH ÎRENCHTOTAL 60 'OUICK 4' CHAMBERSSOIL PROFILE TEST PTT NO. ISOIL PROFILE TEST PIT NO,2-0_,|:,-3-1DARK BROWN TOPSOILDARK BROWN TOPSOILMEDIUM BROWN SANDY LOAMMEDIUM TO REDDISH BROWN SAI{DYLOAM (LESS ROCK @NTENT WTHDEPTII THAN TEST PTT fi)FuuE-tsÈUoBOXAND COVER BROUGHT TO GRADE567I9t0MEDIUM BROWN SAI.¡DY LOAM WTHINCREASING ROCK CONTENT wlTHDEPIHCOl,lCRË'fE uD-*::..LEGENDF<l top€dl1:.:l $mYl: J bÊmffiãÑ-NO GROUNDWATER OR BEDROCK ENCOUNTEREI)DURING EXCAVATIONBAFFLE ORA¡¡GLED PIPETO BE USEDAT INLËTASOILS LOGADIS]RIBUIION BOX DEIAIL\r,-niErouTtEIs[-ooooCerrone ResidneceLot 5, Mountain M€ådow Subd¡visbnGarfield County, ColoradoPmjec{ Numbên C1589Oelet 02t23m21Der¡riIl€d by: CBOReviewed by: RBDrawby DDw4.0Sheet 4 0F 4 sHuTRUE NORTH COLOMDO LLC.TODD & ANNIE CERRONEw*GM@-f Ee@ruø5ruffi&TRUENORTH- cotoR^Do -AIIMPROVEMENT & TOPOGRAPHIC SURVEYLOT 5 - MOUNTAIN MEADOWS AT PRINCE CREEKSECTION 11, TO\AAISHIP 8 SOUTH, RANGE 88 WEST OF THE 6TH PMCOUNTY OF GARFIELD, STATE OF COLORADOLOT 8INTECINDN 4.tu.'wjffiL!tsÁlEr ¡ !:5'LOT 6SURVEY NOTES:LOT 4'-----."SURVEYORS CERTIFICATION9MewwwEedde@M@E@I.ill-!l:dda¡Ð.&i&),..-I)..'T'*",-1",-.::: --.: '.-* ' .:.-1.- .---. - -. .- - rBILILDÍNÇ'..- ' tNvÉLoPÉì^""*''*"r/:g----'*---v"-- -/- --._..,,/_.....LOT 52.777! ACRES