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Home My WebLink AboutOWTS Design Report 10.19.2024jfl?r'I'a fr{i.:i,li:.ir. i,r 129 CAINS LANE CaReoNroelE, CO 81623 970.309.5259 cARLA. oSTBERG@GMAIL. coM 8,10V 2 0 202'r ffiAt:tFtt:1. il q:r ii', r ,'i (l0l'rt,.:ililll i iil:\::. .llJ;";,.i.'1" F ttt"t'I{ : { r(}}{ri( :f ,'t'tai(;i October 19,2024 Project No. C1919 Randy Long a lwaysonelectric@hotm ai Lcom Subsurface lnvestigation and Onsite Wastewater Treatment System Design 2-Bedroom Residence + Future 2-Bedroom Accessory Dwelling Unit (ADU) 1010 Peterson Garfield County, Colorado Randy, CBO lnc. performed a subsurface investigation and completed an onsite wastewater treatment system (OWTS) design for the subject property. The property is located outside of Silt, in an area where OWTSs and wells are necessary. The property was recently subdivided and changed ownership. Updated information was not available on the Garfield County Assessor's website as of the time of this report. Parcel lD: 2177 -012-00-547 SITE CONDITIONS The property is currently undeveloped. A 2-bedroom residence is proposed and a future 2-bedroom ADU is contemplated. The property will be served by a private well. At the time of this design, the well had not been drilled. We have estimated the future well location on the site plan. The well must be greater than S0-feet from the proposed septic tank and greater than 1OO-feet from the proposed soil treatment area (STA). The proposed STA location has an approximate 1-2 percent slope to the southeast. The proposed area is vegetated with sparse native grasses. 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 October 3,2024 by digging two soil profile test pit excavations (Test Pits). A visual and tactile soil analysis was completed by Cada Ostberg at the time of excavation.l The materials encountered in Test Pit #1 consisted of light brown silt clay loam to 6.0-feet, underlain by moist silt clay loam to a maximum depth explored of 8.0-feet. No bedrock or groundwater was encountered. The materials encountered in Test Pit #2 consisted of light brown silt clay loam to 4.O-feet, underlain by I Carla Ostberg holds a Certificate of Attendance and Examination from the CPOW Visual and Tactile Evaluation of Soils Training. Page 2 moist silt clay loam 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 soil formed a ball and a ribbon 1 to 2-inches in length before breaking. Soil structure shape was blocky and consistence was firm. Soil texture was more smooth than gritty. The subsurface was investigated by CTL Thompson, Project No. GS6883.000-120 and is documented in a report dated September 3, 2024. Four Test Pits were excavated in the approximate location of the residence and garage. Groundwater was encountered in three of the Test Pits (TP1 4.5',fP2 3', TP3 6'). The soil is consistent with Soil Type 3, Silt Clay Loam, with moderate structure grade. A long-term acceptance rate (LTAR) of 0.35 gallons per square foot will be used to design the STA. The infiltrative area will be placed at approximate native grade to achieve separation to high seasonal groundwater, which we have estimated at 4-feet below native grade. Test Pit #1 / moisture observed at 6-feet :: 4. Ribbon between 1 and 2-inches Page 3 Backfill from Test Pit #1 Test Pit #2 Moist soils below 6-feet t Moist soils below 4-feet Page 4 .'. I Backfill from Test Pit#2 Moist soils below 4-feet DESIGN SPECIFICATIONS Desiqn Calculations: Average Design Flow = 75 GPD x 2 people/bedroom x 4 Bedrooms = 600 GPD LTAR = 0.35 GPD/SF 600 GPD / 0.35 GPD/SF = 't714.3 SF x 0.8 (pressure dosed trenches)x 0.7 (chambers) = 960 SF The OWTS design is based on 4-bedrooms. An average daily wastewater flow of 600 GPD will be used For the purposes of this OWTS design, Benchmark Elevation at grade 5364' has been established as 100'(Finished Floorof the 2-bedroom residence). The elevation of the Finished Floorof the future 2- bedroom ADU will be at approximately 5362'. 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. The 4-inch SDR-35 sewer line exiting the residences must have a double-sweep clean out and a minimum 2o/o grade to the septic tank. Any area subject to traffic must be minimum Schedule 40 sewer lineorconduit. lfthesewerlinefromtheproposedsteel buildingexceedsl0O-feetinlength,an OWTS C nt Minimum Elevation Primary Tank lnlet lnvert Approximate horizontal distance 97' I min.2%fall I min.24.25" fall Automatic Distributing Valve Approximate horizontal distance 41' I min. 1% rise I min. 5.125" rise lnfiltrative Surface Approximate horizontal distance 37' to furthest trench / min. 1 % fall to STA / min. 4.625" fall The system installation will include a 1500-gallon, two-compartment Valley Precast concrete septic tank with an Orenco@ Biotube Pump Vault and an Orenco@ PF3005 pump in the second compartment of the septic tank. The floats should be set to dose approximately 66 gallons each pump cycle, allowing Page 5 approximately 4 gallons of drain back. The control panel for the pump must be located within line of sight of the septic tank. An electrician will be responsible for wiring the pumping system and the contractor will be responsible for connecting the plumbing. This office should be contacted for start-up of the system to verify its functioning and to perform a squirt test prior to use of the system. Pum Table Effluent will be pumped through a 1 .5-inch diameter pump line from the pump chamber to an Orenco@ automatic distributing valve (ADV), model 6605. This pump line must have a minimum 1oh grade for proper drain back into the tank after each pump cycle. The ADV must be placed at a high point in the system in an insulated riser with access from grade. Screened rock must be placed below the ADV to support the ADV and to assure the clear pipes exiting the ADV remain visible for future inspection and maintenance. Effluent will be pressure dosed through 1.5-inch diameter pipes to five gravelless chamber trenches, each 16 'Quick 4' Plus Standard Low Profile lnfiltrator@ chambers, for a total of B0 chambers and 960 square feet of infiltrative area. There must be at least 4-feet of undisturbed soil between each trench. The chambers must be set at approximate native grade in order to achieve a minimum 4-foot separation from the infiltratfue area to high seasonal groundwater, which we have estimated at 4' feet below native grade in the area of the proposed STA. Backfilling over the trenches and re' grading will be necessary. Effluent will be pressure dosed to 1.S-inch diameter laterals, which must be hung with zip ties from the underside of the chambers. Laterals will have 5132-inch diameter orifices facing up, with the exception of the first and last orifices facing down for drainage. Orenco@ Orifice Shields may be placed under each downward-facing orifice. The orifices must be placed 3-feet on center. Each lateral must end in a 90 degree ell facing up with a ball valve for flushing. Valves may be placed in a valve box, accessible from grade, for access. lnspection ports must be placed at the beginning and end of each trench. Ports may be cut to grade and covered with a valve box 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. Dose Range Max = 154 gal. (600 GPD x25o/o + 4 oal drain back) Min. 48 gal. (11 gal x 4) + 4 gal drain back Dose Setting 66 gallons/dose 4 gallons drain back (41' I 1.5" diameter oump line) Float Separation 1 500 gallon 2-compartment Valley Precast concrete septic tank 6.5" on/off float separation Pump Criteria 14.9 gallons per minute (GPM)17.4 feet total dynamic head (TDH) COMMENTSMANUFACTURERMODEL NOCOMPONENT Septic Tank Valley Precast Item # 1500T-2CP-HH ^^-^^-a*^^t ^^^^-^+^ 1500-gallon, two- septic tank with high head pump PF300511%HP 120 Volt Pump Orenco@ Page 6 Construction must be according to the jurisdiction's adopted On-Site Wastewater Treatment System Regulations, the OWTS Permit, and this design. PERMIT APPLICATION INSTRUCTIONS An OWTS Permit Application must be submitted to Garfield County Environmental Health Department https://www.qarfield-countv.com/environmental-health/filesgcco/sites/16/OWTS-Aoplication-Complete- 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 xB1 50. 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. IN STALLATION 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 REQU IREMENTS Biotube ProPak Pump Packaqe Orenco(9 BPP3ODD Tank Risers and Lids Orenco@ Double-walled PVC Risers and Lids (24" diameter) ADV Orenco@ v6505A 1.5" lnlet and Outlets ADV Riser and Lid Orenco@ Double-walled PVC Risers and Lids (30" diameter) Orifice Shields Orenco@ os150 1 .5 inch diameter (10 total) Flushing Assembly Orenco@ 1.5" diameter 2) 45" or 90" long sweep only 5 total) Chambers lnfiltrator@ B0 'Quick 4' Low Profile chambers 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 Page 7 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 propefi. 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 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 OWTS. The OWTS is engineered for domestic waste only. ADDITIONAL GONSTRUCTION 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. Page 8 Please call with questions Sincerely, CBO lnc. #;p'{a Carla Ostberg, MPH, REHS K-CROINK P.tl. Ilox t4o CO 8r ,17t',. z 5 tr. o 57 a f kat'hav I a. ru r&4pou r loo[. trrm ReviewedBy: Kachayla R. Cronk, P.E. Colorado License No. 61440 Pump Selection for a Pressurized System - Single Family Residence Project 1010 Peterson Lane Parameters 1.25 41 40 1.50 6605 ea 40 1.50 4 0 40 1.50 5 64 40 1.50 st32 a 5 None 0 Calculations 100 300 Discharge Assembly Size Transport Length Before Valve Transport Pipe Class Transport Line Size Distributing Valve Model Transport Length After Valve Transport Pipe Class Transport Pipe Size Max Elevation Lift Manifold Length Manifold Pipe Class Manifold Pipe Size Number of Laterals per Cell Lateral Length Lateral Pipe Class Lateral Pipe Size Orifice Size Orifice Spacing Residual Head Flow Meter 'Add-on' Friction Losses inches feet inches feet inches feet feet inches feet inches inches feet feet inches feet Poo Il. !aF t't!oI .c Et! olt ot- 250 200 150 50 PumpData 5 10 15 20 25 Net Discharge (Spm) 30 35 40 Minimum Flow Rate per Orifice Number of Orifices per Zone Total Flow Rate perZone Number of Laterals per zone % Flow Differential 1st/Last Orifice Transport Velocity Before Valve Transport Velocity After Valve Frictional Head Losses 0.68 22 14.9 1 J. I 2.4 2.4 gpm gpm fps fps Loss through Discharge Loss in Transport Before Valve Loss through Valve Loss in Transport after Valve Loss in Manifold Loss in Laterals Loss through Flowmeter 'Add-on' Friction Losses Pipe Volumes 1.6 0.6 5.4 0.5 0.0 0.4 0.0 0.0 feet feet feet feet feet feet feet feet 0 0 nd Vol of Transport Line Betore Valve 4.3 Vol of Transport Line After Valve 3.9 Vol of Manifold 0.0 Vol of Laterals perZone 6.8 Total Vol Before Valve 4.3 Total Vol After Valve 10.7 gals gals gals gals gals gals PF3005 High Head Effluent Pump 30 GPM, 1/2HP 1151230V 1A 60Hz,20OV 3A 60Hz PF3007 High Head Effluent Pump 30 GPM, 3/4HP 230V 1@ 60H2, 200/460V 30 60Hz PF3010 High Head Effluent Pump 30 GPM, 1HP 230V 1@ 60H2, 200/460V 3@ 60Hz System Curve: - Pump Cun/e:""'" Pump Optimal Range, - operating Point, O o Design Point: tquirements PF3015 High Head Effluent Pump 30 GPM, 1-1l2HP 230V 1@ 60H2,20012301460V 3@ 60Hz I nJ: 17.4 feet INFILTRATOR END PLATE CHAMBER (4'x 3') GRAVELLESS'OUICK.4' LOW PROFILE mtn. 1.5' DIA SCH.4O DISTRIBUTION LINE TO EACH TRENCH '1,5" DIA SCH-40 PUIVP LINE FROM PUMP CHAMEER 4' DrA SDR-35 SEWER LrNE (MtN 2% SLOPE TO TANK) SCREENED ROCK OR SAND FOR BEDDING 24't\,,ilN. 3" tvtN. FINISHED GRADE ADV WITH ACCESS AT GRADF PLACED IN TOP PORT OF CHAMBER END PLATES DISTRIBUTION LINES TO OTHER TRENCHES (5 TOTAL) FILL TO RAISE GRADE OVER CHAMBERS DIA SDR-35 INSPECTION PORT GRAVELLESS'QUICK-4' LOW PROFILE CHAMBER (4'x 3') SCARIFY SURFACE I't\,flN. /A TRENCH DETAIL\9r-ffi3 4' DIA SDR-35 INSPECTION PORT AT AND END OF EACH TRENCH END EACH LATERAL IN A 90'LONG SWEEPING ELL FACING UP WITH A BALL VALVE IN A VALVE BOX ACCESSIBLE AT GRADE 1.5' DIA SCH-40 PVC SUSPENDED LATERAL WTH 5i32' DIA ORIFICES FACING UP, SPACED 3' O.C. FIRST AND LAST ORIFICES FACE DOWN WITH AN ORIFICE SHIELD FOR DRAINAGE SLIP-ON PVC DO NOT GLUE INSULATED TRACER WRE 4' DIA SDR.35 SEWER LINE COMPACT SOIL BASE TO SUPPORT BOX USE HOLE SAW TO CUT THRU TOP OF END PLATE SMALL VALVE COVER BOX OR IRRIGATION VALVE BOX AT GMDE TO 4''l' minJNATIVE LIMIT OF EXCAVATION SUSPEND LATERALS WTH ZIP.TIES TO UNDERSIOE OF CHAMBERS PVC PIPE CUT TO FIT rA CHAMBER IRENCH SECTION\r,-rftffi CBO lnc. 129 Cains Lane Carbondale, Colorado 81623 Phone 970.309.5259 carla.ostberg@gmail.com w3.0Long Residence '1010 Peterson Lane Garfield County, Colorado ProjectNumber: C1919 bale: 'lol19l2o24 tesisneo oy: ceo heviewed bv: KC prawn uV: oo Sheet 3 0F 4 DESIGN PROPOSED 2.BEDROOM RESIDENCE + FUTURE 2.BEDROOM ADU 75 GPD x 2 PERSONS/BEDROOM x 4 BEDROOMS = 600 GPD WASTEWATER FLOW = 600 GPD USE ,I5OO GALLON, TWO.COMPARTMENT CONCRETE SEPTIC TANK WITH AN ORENCO PUMPING SYSTEM IN THE SECOND COMPARTMENT SOIL TREATMENT AREA (STA): LONG TERM ACCEPTANCE RATE (LTAR) = 0.35 GAL/ SF 600 SF / 0.35 GALiSF = 1714 SF X 0.8 (PRESSURE DOSED TRENCHES) X 0.7 (CHAMBERS) = 959 SF 959 SF / 12 SF/CHAMBER = MlN. 80 'QUICK 4' LOW PROFILE CHAMBERS SOIL PROFILE TEST PIT NO. 1 SOIL PROFILE TEST PIT NO. 2 LIGHT BROWN SILry CLAY LOAM LIGHT BROWN SILTY CLAY LOAM EST. HIGH SEASONAL GROUNDWATER EST. HIGH SEASONAL GROUNDWATER LIGHT BROWN, MOIST SILTY CLAY LOAM LIGHT BROWN, MOIST SILry CLAY LOAM 0 INSTALL FLUSHING VALVE ECCENTRIC TO CENTER OF VALVE BOX /:\FLUSHING VALVE DETAIL\y Z\ SETBACK CHART 10' LID t.c 1.5" 90" VALVE BOX WITH SECURED SLIP X MALE PIPE THREAD W/CAP 1.5'BALL VALVE SCH-40 PVC LONG SWEEP END CAP 2 t.c SCH-40 PVC SUSPENDED 5 FUU I TFcUo LEGEND t7l silty cray bam 30' DIAMETER PVC RISER (INSULA FROM PUMPING SYSTEM /A AUTOMATIC DISTRIBUTING\91-i6r6ffi MI DISTRIBUTING VALVE ASSEMBLY NO GROUNDWATER OR BEDROCK ENCOUNTERED DURING EXCAVATION 10 DIA SCH.4O VALVE DETAIL PVC INLET AND OUTLETS CBO lnc. 1 29 Cains Lane carbondale, Colorado 81623 Phone 970.309.5259 carla.ostberg@gmail.com w4.0Long Residence 1010 Peterson Lane Garfield County, Colorado Project Number: C1919 STATO WATER COURSE 50' STA TO WELL 100' STA TO HOUSE 20' SEPTIC TANK TO WATER COURSE 50' SEPTIC TANK TO WELL 50' HOUSE TO SEPTIC TANK 5' OWTS COMPONENTS AND PHYSICAL FEATURFS MINIMUM REQUIRED SFTBACK Dale: 1011912024 Designed by: CBO Reviewed by: KC Drawn by: DD PROXII\4ATE PROPOSED SETBACK N/A 153' 5J N/A 232' 11', Sheet 4 0F 4 N Fs SCALE: 1 = 50'=0" DRAWINGS MUST BE USED IN CONJUNCTION WITH DESIGN LETTER DATED 1011912024 .10.o' D.li?k{r tubr. aghr oI wa9 & It..pron,{o 67a-aa 2-BEDROOM CALL 811 FOR UTILITY LOCATES w1 .0 ADU THE LOCATION OF PROPOSED IMPROVEMENTS SHOWN ARE NOT THE RESULT OF A PROPERTY SURVEY, THE LOCATIONS ARE APPROXII\,IATE. IT IS IHE HOMEOWNERS' DUTY TO ENSURE ALL CONSTRUCIION AND IMPROVEMENT LOCATIONS ARE ACCURAIE. PROPERry LINES AND SETBACK DISTANCES SHOULD BE CONFIRMED PRIOR TO EXCAVATION. SCALFD FOR PRINTING ON 1 1'X 17" PAPER. x-X-X ,0.0 hkr, Roddtar FlPrer! d Baok t)at, Pq 917 ri SITE PLAN CBO lnc. 129 Cains Lane Carbondale, Colorado 81623 Phone 970.309.5259 carla.ostberg@gmail.com ED ILDING \Jsoq c') C\c\ a oO WELL LOCATION RESIDENCE TP1 X 2 STA LINE 2A.o td?dtnh t nr FAs.Dt.,l A Long Residence 1010 Peterson Lane Garfield County, Colorado Project Number: C1919 Sheet 1 0F 4 destal li Electric Metero CBO Inc. 129 Cains (n o * t! \)\os a . {(ot ""il"Fs' A 4" DIA SDR-35 SEWER PIPE WITH CLEANOUT MIN 2Ol" FALL TO TANK 1 sOO-GALLON 2-COMPARTMENT SEPTIC TANK WITH AN - * ORENCO PUMPING SYSTEM IN THE SECOND COMPARTMENT RISERS AND LIDS TO GRADE*---i-, io . i s x Fence Y_ X-^-r zc LINE 1.5" DIA SCH-40 DISTRIBUTION LINES TO EACH TRENCH 4" DIA SDR-35 INSPECTION PORT AT BEGINNING AND END OF EACH TRENCH X X ,-X x- SETBACK Found+5 Rebarand. 1-1/4" Orange Plastic Cap Stqmped. "PROP CORNER PLS 36572" X -X w2.0 N SCALE: 1" = 30L0" Date: 1011912024 Designed by: CBO Reviewed by: KC Drawn by: DD FUTURE 2 BEDROOM ADU 98'= FF 5362' 89.6 tl E@sement2O.0 lrtigdtion Lirte Irtigdtion (rypical) o- PROPOSED STEEL BUILDING TP1 rP2 2-BEDROOM RESIDENCE BM 100'= FF 5364'o. Long Residence '1010 Peierson Lane Garfield County, Colorado Project Number: C1919 DIA ORIFICES 3'O.C. FACING UP. FIRST AND LAST ORIFICES FACING (MIN 1% DRAIN BACK TO TANK) ,1.5' DIA SCH.4O PUMP EACH WITH 16'OUICK4'LOW PROFILE CHAMBERS = 80 = 960 SF. 1.5' DIA SCH-40 PVC SUSPENDED LATERALS WITH ADV MODEL 6605 AT HIGH POINT ACCESSIBLE AT GRADE/l FOR DRAINAGE COVERED WITH ORIFICE SHIELDS FLUSHING VALVE AT END OF EACH LATERAL Colorado 81623 Phone 970" r"\ PROPOSED OWTS Sheet 2 0F 4