HomeMy WebLinkAboutOWTS Design Specs129 CAINS LANE
CARBoNDALE,CO 416'23
970.309.5259
CARLA.OSTBERG@GMAIL.COM
stt¡"t'I(. (:(>s.sI rf .'t tN(i
December 12,2022 Project No. C1715
Kim Ochko
kimôoou ldconstruction.com
Subsurface lnvestigation and Onsite Wastewater Treatment System Design
1-Bedroom Accessory Dwelling Unit (ADU)
4362 CR 100
Garfield County, Colorado
Kim,
CBO lnc. performed a subsurface investigation and completed an onsite wastewater treatment system
(OWTS) design for the subject residence. The 19.03-acre property is located outside of Carbondale, in
an area where OWTSs and wells are necessary.
Legal Description: Section: 30 Township: 7 Range: B7 A TR lN THE SW1/4 OF THE NE1/4
Parcel lD: 239130100027
SITE CONDITIONS
The property is currently developed with a 3-bedroom residence on the northern portion of the property
A 1-bedroom ADU is proposed on the southern portion of the property. This design addresses the
OWTS that will serve the proposed ADU.
The ADU will be served by a well located on the neighboring property to the west. The address of the
neighboring property is 4266 CR 100, Parcel lD 2391-301-00-028. The well is located greater than 50-
feet from the proposed septic tank and greater than 1O0-feet from the proposed soil treatment area
(srA).
A dry ditch bisects the property. This ditch is no longer in use and should be filled in on the property to
be rendered inoperable in the future.
Page2
The proposed soil treatment area (STA) location has an approximate 25-30% slope to the west. The
proposed area is vegetated with Pinion trees and native grasses. The property lines to the south and
west should be located to assure the minimum required 10-foot setback is met.
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 August 6,2022 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 Test Pit #1 consisted of dark brown topsoil to 1-foot, underlain by tan
calcareous clay matrix to a maximum depth explored of 7.O-feet. No bedrock or groundwater was
encountered.
The materials encountered in Test Pit #2 were consistent with those encountered in Test Pit #1. Test Pit #2
was excavated to a maximum depth explored of 7.O-feet. No bedrock or groundwater was encountered.
A sample of the soil was taken from Test Pit #1 at 3-feet below grade. Soil structure grade was
moderate. The soilformed a ball and a ribbon less than 1-inch in length before breaking. Soil structure
shape was blocky and consistence was friable. Soil texture was more smooth than gritty.
The soils are consistent with Soil Type 2 with moderate structure grade. A long-term acceptance rate
(LTAR) of 0.6 gallons per square foot will be used to design the STA.
DESIGN SPECIF¡CATIONS
Desiqn Calculations:
Average Design Flow = 75 GPD x 2 people/bedroom x 2 Bedrooms = 300 GPD
LTAR = 0.6 GPD/SF
300 GPD / 0.6 GPD/SF = 500 SF
500 SF x 1.0 (gravity, trenches) x 0.7 (chambers) = 350 SF
Although the ADU will have only 1-bedroom, Garfield County OWTS Regulation requires sizing be based
on a minimum design flow for 2-bedrooms. The OWTS design is based on 2-bedrooms. An average
daily wastewater flow of 300 GPD will be used.
For the purposes of this OWTS design, Benchmark Elevation at grade 6547.5' has been established as
100' (Finished Floor). CBO lnc. should be notified of any discrepancies or problems with grade
elevations of proposed components during installation of the OWTS.
*Elevations are based upon standard OWTS installation practices. Component elevations may change during
installation due to site conditions. Minimum grade refers to piping between components.
' Carla Ostberg holds a Cerlificate of Attendance and Examination from the CPOW Visual and Tactile
Evaluation of Soils Training.
OWTS Gomoonent Minimum Elevation
Primary Tank lnlet lnvert Approximate horizontal distance 25' / min. 2% fall I
min. 6.25" fall
Distribution Box Approximate horizontal distance 9' / min. 1% fall I
min. 1.125" fall
lnfiltrative Surface Approximate horizontal distance 19' / min. 1% fall
to STA / min. 2.375" fa[
Page 3
The 4-inch 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 1OO0-gallon, two-compartment lnfiltrator@ poly septic tank with an
Orenco@ Biotube effluent filter on the outlet tee. Other state-approved septic tank may be used. 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 three 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 bed.
Each trench will consist of 10 'Quick 4' Standard Plus lnfiltrator@ chambers for a total of 30 chambers
and 360 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.
CBO Inc. 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 the jurisdiction's adopted On-Site Wastewater Treatment System
Regulations, the OWTS Permit, and this design.
PERM¡T APPLICATION INSTRUCTIONS
An OWTS Permit Application must be submitted to Garfield County Environmental Health Department.
https://www.qarf¡eld-county.com/environmental-health/filesqcco/sites/16/OWTS-Aoplication-Comolete-
Packet-Dec.-2019.pdf. lf the OWTS Permit Application will be submitted with a Building Permit
Application, it should be submitted directly to Garfield County Building Department.
All questions regarding permit submission can be directed to Garfield County Environmental Health
Department, 970-945-661 4 xBl 50.
COMPONENT MANUFACTURER MODEL NO.GOMMENTS
Septic Tank lnfiltrator@ tM-1060-2CP 1000-gallon, 2-
:ompartment seotic tank
Risers and Lids Orenco@ Double-walled PVC
risers and lids
Effluent Filter Orenco@ 4-inch diameter Fullsize
Distribution Box Polylok Distribution box, lids,
rises, and (3)flow
equalizers
Chambers lnfiltrator@ Standard Plus 30'Quick 4' lnfiltrator@
ohambers
Page 4
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 final approval of the OWTS installation. Communication between the installer and this office is
expected throughout the installation.
INSTALLATION 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 OWïS 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 seruice 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 additional water 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 filter 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 OWT$. The OWTS is engineered for domestic waste
only.
Page 5
ADDITIONAL CONSTRUCTION NOTES
lf design includes a pump, weep holes must be installed to allow pump lines to drain to minimize risk of
freezing. The pump shall have an audible and visual alarm notification in the event of excessively high-
water conditions and shall be connected to a control breaker separate from the high-water alarm breaker
and from any other control system circuits. The pump system shall have a switch so the pump can be
manually operated.
Excavation equipment must not drive in the excavation of the STA due to the potential to compact soil.
Extensions should be placed on all septic tank components to allow access to them from existing grade.
Backfill over the STA must be uniform and granular with no material greater than minus 3-inch.
LIMITS:
The design is based on information submitted. lf soil conditions encountered are different from conditions
described in report, CBO lnc. should be notified. All OWTS construction must be according to the county
regulations. Requirements not specified in this report must follow applicable county regulations. The
contractor should have documented and demonstrated knowledge of the requirements and regulations of
the county in which they are working. Licensing of Systems Contractors may be required by county
regulation.
Please call with questions.
Sincerely,
CBO lnc
(p,r,(",*- t*óx,'.6
Carla Ostberg, MPH, REHS
CBO lnc.129 Cains LaneCarbondale, Colorado 81623Phone 970.309.5259car¡a.ostberg@gma¡l.comII1/IIIPROPERTYLINE,*¿Ðo(,_t_rlILaoooeOchko Residence4362 CR 100Garfield County, ColoradoProjectNumben C1772Dale:12n2no22Designed by: CBODrawn by: DDw1 .0Sheet 1 0F 4Il¡liTPxtlII---T----INak)(o,ADUiRENDERIDRYTNoPERABLE)DITCHtlYI,l\ILEACHFTELDII,t,lII,IITO,ItIlI;oo)!DII,IIII,!oa(oIIIIIIoHçQIIISEPTICTANKN20' INçRË55, EçRESS & UTTLT'IY'//E4Sã¡-.'[Nf REC. NO.46 77 7.tIt-]_,ì$.r-r--ifrÏffi1P¡tll.m¡T--]:l;li:lSCALE: I = 50'=0"C9UNTYR9ADLOO I.(uNK¡\roWN RIçrff - oT -u)Ay W IDn{)cENTElr QUARTEI? OF SECT¡ON 30BOIIILIIIJTOUND 3" çAß.CO tsRASS CA?"7963"THE LOCATION OF PROPOSED IMPROVEMENTS SHOWN ARENOTTHE RESULT OF A PROPERry SURVEY. THE LOCATIONSARE APPROXIMAIE. IT IS THE HOIVEOWNERS' DUTY TOENSURE ALL CONSTRUCTION AND IMPROVEMENT LOCATIONSARE ACCURATE. PROPERTY LINES AND SETBACK DISTANCESSHOULD BE CONFIRMED PRIOR TO EXCAVATION. SCALEDFOR PRINTING ON 11" X 17" PAPER.DRAWINGS MUST BE USED INCONJUNCTION WITH DESIGNLETTER DATED 1 2I'I 2I2O?2
CBO lnc.129 Cains LaneCarbondale, ColoEdo 81623Phone 970.309.5259carla.ostberg@gmail.comTP\Z'.--J10',,Ochko Residence4362 CR 100Garfield County, ColoradoProjectNumþer: C1772Dale:121212022Designed by: CBODrawn by: DDSheet 2 0F 4w2.0u,I,I\\-weLLI\I,%7ôII\IIIIIIzIIIIlIIIIII1 OOO-GALLON, TWO.COMPARTMENTSEPTIC TANK WITH EFFLUENT SCREEN-'i I4" DIA SDR.35 SEWER LINE TO STAIIIIlIIIIIIIIl!(MtN. 1% FALL TO STA)-¿' I I4' DIA SDR-35 DISTRIBUTION LINE TO EACH TRENCH(MlN. 1 7o SLOPE TO TRENCH)IIIIIIIIlIIIIIeoctloþIIIIIIII1-BEDROOM ADU'QUICK-4' CHAMBER TRENCHES.3 TRENCHES WITH 1O CHAMBERS PER TRENCHFOR A TOTAL OF 30 CHAMBERS AND 360 SF./././4'DIA SDR-35 INSPECTION PORT ATL/\i\/ 30'uTrLrTYIIBEGINNING AND END OF EACH TRENCH-t4" DIA SDR-35 SEWER PIPE WITH CLEANOUTMIN 2% FALL TO TANKt'lDrsrRrBUTroN Box IWITH ACCESS AT GRADE IIII,IIIIIII10'!!!,_t_J____iÍ_,LINE/^PROPOSED OWTS
CBO lnc.129 Cains LaneCarbondale, Colorado 81623Phone 970.309.5259carla.ostberg@gmail.com-INF¡LTUTOR,/ eno eure'QUtCK4,4" ÐIA SDR-35 DISTRIBUTIONLINE TO EACH TRENCH(MIN- I% SLOPE TO TRENCH)CHAMBER (4'x 3')4'DIA SDR-35EFFLUENT PIPE FROMSEPTIC TANKDISTRIBUTION BOXWITHDIA SDR.35GMDEìNSPECTIONPORIPLACED IN4',TOP PORT OFCHÁIVBER ENDPLATES4'sotL2'LIMITDIA SDR-35 INSPECIIONEXCAVATIONPORTAT BEGINNING ANDEND OF EACH TRENCH'oulcK4'SCARIFYCHAMBER (4'x3')/:\CHAMBER'IRENCH PLAN\.r,-¡T1r@/ìCHAMBER'IRENCH SECÎON\é/-træFINISHED GRADEVALVE COVERBOX OR IRRIGATIONVALVE BOX AT GRADEBOX AND COVER BROUGHT TO GRADECAP OR THREADED24"CONCRETECLEANOUf ASSEMBLY4'DIA SDR.35 SEWER LINE(MtN 2% SLOPE TO TANK,MtN. 10lo TO STA)FtNs-HÉD-Gffii-COMPACTMSE TO SUPPORTBOXPVC PIPE CUTTOFITSCREENEDUSE HOLE SAWTOCUT THRU TOP OFOR SAND FORBEDDING3" tvtN.BAFFLE ORANGLED PIPETO BE USEDEND8" l\¡lN.AT INLETÃINSPECÎON PORT DEÍAIL\91-ear@A'IRENCH DETAIL\.t/---'fñrr5æÃDIS]RIBUTON BOX DETAIL\?/r-1O CHNBERS PERTRENCH-¿OUTLETSooooOchko Residence4362 CR 100Garfield Couniy, ColoradoProjectNumber: C1772lDale: 1211212022lo"s¡sn"¿ ¡v' ceolDrawn bv: DDw3.0Sheet 3 0F 4
CBO lnc.129 Cains LaneCarbondale, Colorado 81623Phone 970.309.5259€rla.ostberg@gma¡l.comDESIGNl-BEDROOM ACCESSORY DWELLTNG UNtT (AOU) / S|ZE FOR MtN.2 BEDROOMS(75 GPD x 2 PERSONS/BEDROON¡ x 2 BEDROOMS)WASTEWATER FLOW = 300 GPDSTATO WATER COURSE1 00'N/ASTA TO WELL100'108'STA TO HOUSE20'40'SEPTIC TANK TO WATER COURSE100'N/ASEPTIC TANK TO WELL50'129'HOUSE TO SEPTIC TANK5'22',OWTS COIUPONENTS ANDPHYSICAL FEATURESIVIINIMUM REQUIREDSETBACKAPPROXIMATE PROPOSEDSETBACKTANK:MIN. lOOO GALLONSUSE lOOO.GALLON, TWO-COMPARTMENT SEPTIC TANKSOIL TREATMENT AREA (STA):LoNG TERM ACCEPTANCE RATE (LTAR) = 0.6 cAU SFCALCULATED STA = CYLTAR = 3OO / 0.6 = 5OO SFGRAVITY, TRENCHES = 500 SF X 1.0 = 500 SFCHAMBERS = 500 SF X 0.7 = 350 SF / 12 SF / CHAMBER = 30 CHAMBERSTHREE GRAVELLESS CHAMBER TRENCHES1O'OUICK 4'CHAMBERS IN EACH TRENCHTOTAL 30 'QUICK 4' CHAMBERSSOIL PROFILE TEST PIT NO. 1SOIL PROFILE TEST PIT NO.20124678910DARK BROWN TOPSOILDARK BROWN TOPSOILTAN CALCAREOUS CLAY MATR¡XTAN CALCAREOUS CLAY MATRIXSLIP-ON PVCDO NOT GLUEINSULATEDTRACERWIREFINISHED GRADENO GROUNDWATER OR BEDROCK ENCOUNTEREDDIJR¡NG EXCAVATION4" DIASEWER LINELEGENDFl topso¡ltil :ilñ"ï;TO TANKHOUSE^SOILS LOG\rr-"-18æTACI,EAN OIJT DETAIL\é/--.1ıñf*Ochko Residence4362 CR 100Garfield County, ColoradoProjectNumber: C1772Dafe:1211212022Designedby: CBODDDrawnby:w4.0Sheet 4 0F 4
G# [#;tfåï"råi;:_"Map Viewer* Well Constructed¡ Final Permitfl CountyLegend:1\- 1"'lLocationNotes585 0 292 585 Feetl: 3,508tlThis product is for ¡nformational purposes and may not have been prepared for, or be su¡table for legal,engineer¡ng, or survey¡ng purposes. Users of this ¡nformation should rev¡ew or consuft the prímary data and¡nformation sources to ascertain the usability of the information.Date Prepared: 1211312022 12:.21:.58 PM
G)qPublic"nef" Garfield County, CO
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f] Parcels
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¡ I Lakes&Rivers
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$904,000 Last2Sales
Date Price
2/tB/2O7e $O
ro/8/t996 $O
Account R111930 Physical 43627OOCOUNTYRD 2ol9TotalActual
Number Address Value
ParcelNumber 239L3O7OOO27 CARBONDALE 81623
Acres t9 OwnerAddress OCHKO,STEVEN M & KIMBERLY
LandSqFt 0 D
TaxArea 011 43ó2COUNTYROAD100
2019 M¡ll Levy 79J760 CARBONDALE CO 81ó23-8809
D ate cr eated: 12 / 5 / 2022
Last Data Uploaded: 12/5/20222:05:4O AM
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1215122,10:28 AMqPublic.net - Garfield County, CO - Property Record Card: R1'11930G)qPublic,net-" Garfi eld County, COSummaryAccountParcelProperty AddressLegal Descript¡onAcresLand SqFtTax AreâMillLevySubdivisionR111930239130tO002743ó2 1OO COUNTY RD, CARBONDALE,CO 8T623Section: 30Townshîp: 7 Range:87 ATR lN THE SW1/4 OFTHE NE1/4. 19.03 ACRE519.03ott79.7760OCH KO, STEVEN lv1 & KIMBERLY D43ó2 COUNry ROAD 100cARBONDALE CO 81ó23-8809View MapOwnerLandUnitTypeSquâre FeetBuildinesBuilding#SINGLE FAM.RES.-LAND - 1112 (RESIDENTIAL PROPERTY)UUnitsBuildingTypeAbstract Codes / (Property Type)Arch¡tectural StyleStor¡esFrameActual Year BuiltBasementAreâFinish BasementAreaGross LivingAreaTotal Heated SqFtBedroomsBathsHeating FuelHeatingTypeAir ConditioningRæf TypeRoofCover77SFRSI NGLE FAM.RES-IMPROVEMTS-1212 (RESIDENTIAL PROPERTY)2 STRY/BsM2WOOD FRAMEt994I,296t,!52¿,+ö33,67532.75GASHOTWATERNONERIDGE FRMEPREFAB METhttps://qpublic.schneidercorp.com/Application.aspx?ApplD=1038&LayerlD=22381&PageTypelD=4&PagelD=9447&KeyValue=R111930114
1215122, 10:28 AMActual ValuesAssessed ValuesAssessed YearLand AssessedI mprovement AssessedTotal AssessedTax HistoryTax YearTaxes BilìedClick here to view the tåx lnformation for this Þarcel on the Gãrfreld CountvTreasurer's website.TransfersSale DateDeed TyDeut8/2019AGREEMENTto/8/1996Plat5/4/7994WARRANTY DEED4/74/7994Plat4/ul7994RESOLUTION5/19/1980RESOLUTIONqPublic.net - Garfield County, CO - Property Record Card: R11'19302422sizs,oòô.oo$ó79,000.00$904,000.002022$15,ó40.00$,17,7e,o.oo$ó2,830.00202!2020$4,732.44$5,r56.72Reception Number917743499346462746467773467777304058BôÕk -0995-04000901-04958?8-776548-922202t$225r000:oo$ó79,000.00$904,O0O.O0202t$1ó,090.00$48r55O:Oo$64,640.O02079$4,774.482020$235:000:0_0í64L,2Q.OO$a76,2Æ.002020$1ó,800.00$j.s:8:o,oo$ó2,ós0.0020ta$4,429.48Sale Price$o$o$o$o$o$o$o$o$o$o$o6/16/79783/15/7977tol75/7972t2124/19624/77/7953AFFIDAVITneLease o¡ rÑHedfiÀNcË rÀDEATH CERTIFICATEQU!rcLAtM DFEDWARRANTY DEEDry2870!1287OO2H?17L82407512-805iiá-eos5t2-806346-329269-40Propefi Related Public DocumentsClick here to vîew Prooertv Related Public DocumentsPhotoshttps://qpublic.schneidercorp.comiApplication.aspx?ApplD=1038&LayerlD=22381&PageTypelD=4&PagelD=9447&KeyValue=R1119302t4
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