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Home My WebLink AboutOWTS Plans129 Cains Lane Carbondale, CO 81623 970.309.5259 carla.ostberg@gmail.com February 25, 2023 Project No. C1787 Scott Dillard scottdillardrealtor@gmail.com Subsurface Investigation and Onsite Wastewater Treatment System Design 4-Bedroom Residence 144 CR 111 Garfield County, Colorado Scott, CBO Inc. performed a subsurface investigation and completed an onsite wastewater treatment system (OWTS) design for the subject residence. The 5.01-acre property is located outside of Carbondale, in an area where OWTSs and wells are necessary. Legal Description: Section: 3 Township: 8 Range: 88 A TR IN LOT 18 SEC 3 & LOT 1 SEC 10. Parcel ID: 2463-034-00-033 SITE CONDITIONS The property is currently developed with a 4-bedroom residence. The residence is served by an existing OWTS. The permit (enclosed) was provided by Garfield County Community Development Department. The subject OWTS consists of one 1250-gallon, two-compartment concrete septic tank followed by a soil treatment area (STA). There is limited information on the permit regarding the STA. Through camera work on December 13, 2022 we observed a perforated pipe extending approximately 33’ past the existing septic tank. Individual Sewage Disposal System (ISDS) Permit 1363 documents the system. The system was designed to accommodate a 4-bedroom residence. The permit received final approval on May 9, 1984. There is a desire to upgrade the OWTS to serve the newly remodeled 4-bedroom residence. The residence is served by a private well on the property. The well is located to the north of the residence. The well is located greater than 50-feet from the proposed septic tank and greater than 100- feet from the proposed STA. The STA location has an approximate 20% slope to the west. The proposed area is vegetated with native grasses and sparse trees. 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 1, 2023 by digging one soil profile test pit excavation (Test Pit). Only one Test Pit was excavated because we didn’t want to disturb any of the existing OWTS components. There were also materials staged in the area making finding an additional Test Pit location Page 2 difficult. A visual and tactile soil analysis was completed by Carla Ostberg at the time of excavation.1 The materials encountered in Test Pit #1 consisted of dark brown (frozen) sandy loam topsoil to 2-feet, underlain by medium brown sandy loam to maximum depth explored of 7.0-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 less than 1-inch in length before breaking. Soil structure shape was blocky and consistence was friable. Soil texture was more gritty than smooth. The soils were 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. View of Test Pit #1 location Looking toward house (south) Test Pit #1 Backfill 1 Carla Ostberg holds a Certificate of Attendance and Examination from the CPOW Visual and Tactile Evaluation of Soils Training. Page 3 Sieved sample Ribbon less than 1-inch DESIGN SPECIFICATIONS The existing septic tank will be abandoned by pumping the tank and removing it or crushing the top, bottom, and sides and filling in the void with onsite materials. The existing STA will be abandoned in place. Design Calculations: Average Design Flow = 75 GPD x 2 people/bedroom x 3 Bedrooms + 75 GPD (4th Bedroom) = 525 GPD LTAR = 0.6 GPD/SF 525 GPD / 0.6 GPD/SF = 875 SF 875 SF x 0.8 (pressure-dosed trenches) x 0.7 (chambers) = 490 SF The OWTS design is based on 4-bedrooms. An average daily wastewater flow of 525 GPD will be used. For the purposes of this OWTS design, Benchmark Elevation has been established as 100’ as the existing sewer line exiting the residence. CBO Inc. should be notified of any discrepancies or problems with grade elevations of proposed components during installation of the OWTS. OWTS Component Minimum Elevation Primary Tank Inlet Invert Approximate horizontal distance 63’ / min. 2% fall / min. 15.75” fall Automatic Distributing Valve Approximate horizontal distance 42’ / min. 1% rise / min. 5.25” rise Infiltrative Surface Approximate horizontal distance 22’ to furthest trench / min. 1% fall / min. 2.75” fall *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. We explored the existing sewer line from the residence to the existing septic tank with a camera and the sewer line was found to be in good condition. A clean out is present near the foundation of the residence. A new 4-inch SDR-35 sewer line will tie into the exiting sewer line with a wye fitting. The sewer line must have a minimum 2% grade to the septic tank. 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 65 gallons each pump cycle, allowing approximately 7 gallons of drain back. The control panel for the pump must be located within line of sight Page 4 of the septic tank. We recommend Valley Precast out of Buena Vista be contracted for start-up of the pumping system. Pump Table Dose Range Max = 138.25 gal. (525 GPD x 25% + 7 drain back) Min. 35 gal. (7 gal x 4) + 7 gal drain back Dose Setting 65 gallons/dose 7 gallons drain back (63’ / 1.5” diameter pump line) Float Separation 1500 gallon 2-compartment Valley Precast concrete septic tank 6.5” on/off float separation Pump Criteria 15.6 gallons per minute (GPM) 21.5 feet total dynamic head (TDH) Effluent will be pumped through a 1.5-inch diameter pump line from the pump chamber to an Orenco® automatic distributing valve (ADV), model 6404. This pump line must have a minimum 1% 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 four gravelless chamber trenches, each with 11 ‘Quick 4’ Plus Standard Infiltrator® chambers, for a total of 44 chambers and 528 square feet of infiltrative area. There must be at least 4-feet of undisturbed soil between each trench. Effluent will be pressure dosed to 1.5-inch diameter laterals, which must be hung with zip ties from the underside of the chambers. Laterals will have 5/32-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 2-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. Inspection 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. 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. COMPONENT MANUFACTURER MODEL NO. COMMENTS Septic Tank Valley Precast Item # 1500T-2CP-HH 2-compartment concrete septic tank with high head pump Pump Orenco® PF300511 ½ HP 120 Volt Biotube ProPak Pump Package Orenco® BPP30DD Vault, Filter, Control Panel (demand dose) Tank Risers and Lids Orenco® Double-walled PVC Risers and Lids (24” diameter) ADV Orenco® V6404A 1.5” Inlet and Outlets ADV Riser and Lid Orenco® Double-walled PVC Risers and Lids (30” diameter) Orifice Shields Orenco® OS150 1.5 inch diameter (8 total) Page 5 Flushing Assembly Orenco® 1.5” diameter (2) 45° or 90° long sweep only (4 total) Chambers Infiltrator® 44 ‘Quick 4’ Plus Standard chambers 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.garfield-county.com/environmental-health/filesgcco/sites/16/OWTS-Application-Complete- Packet-Dec.-2019.pdf. If 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, 970-945-6614 x8150. INSTALLATION CONTRACTOR CBO Inc. 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 Inc. 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 Inc. should be notified 48 hours in advance to observe the installation. In 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. Page 6 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. If an effluent filter or screen has been installed in the OWTS, we recommend this filter or screen be cleaned annually, or as needed. If 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 CONSTRUCTION NOTES If the 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. If soil conditions encountered are different from conditions described in report, CBO Inc. 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 Inc. Carla Ostberg, MPH, REHS Pump Selection for a Pressurized System - Single Family Residence Project GCC Lofts, LLC / 144 CR 111 Parameters 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 1.25 63 40 1.50 6404 22 40 1.50 10 0 40 1.50 4 44 40 1.50 5/32 2 5 None 0 inches feet inches feet inches feet feet inches feet inches inches feet feet inches feet Calculations Minimum Flow Rate per Orifice Number of Orifices per Zone Total Flow Rate per Zone Number of Laterals per Zone % Flow Differential 1st/Last Orifice Transport Velocity Before Valve Transport Velocity After Valve 0.68 23 15.6 1 2.3 2.5 2.5 gpm gpm % fps fps Frictional Head Losses 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 1.7 0.9 3.2 0.3 0.0 0.3 0.0 0.0 feet feet feet feet feet feet feet feet Pipe Volumes Vol of Transport Line Before Valve Vol of Transport Line After Valve Vol of Manifold Vol of Laterals per Zone Total Vol Before Valve Total Vol After Valve 6.7 2.3 0.0 4.7 6.7 6.9 gals gals gals gals gals gals 15.6 21.5 gpm feet 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 300 Net Discharge (gpm) PumpData PF3005 High Head Effluent Pump 30 GPM, 1/2HP 115/230V 1Ø 60Hz, 200V 3Ø 60Hz PF3007 High Head Effluent Pump 30 GPM, 3/4HP 230V 1Ø 60Hz, 200/460V 3Ø 60Hz PF3010 High Head Effluent Pump 30 GPM, 1HP 230V 1Ø 60Hz, 200/460V 3Ø 60Hz PF3015 High Head Effluent Pump 30 GPM, 1-1/2HP 230V 1Ø 60Hz, 200/230/460V 3Ø 60Hz Legend System Curve: Pump Curve: Pump Optimal Range: Operating Point: Design Point: WSECTION CORNERFOUND STONE310211DEED=S39°39'24"E 793.04'N40°11'13"W 792.62'S17°24'31"E 314.81'DEED=N17°00'00"W 315.33'DE E D = S 2 2 ° 5 4 ' 1 4 " W S22 ° 2 6 ' 0 4 " W 1 5 5 . 7 1 'S02°13'38"W 25.74'DEED=S02°41'48"W18.31'N41°35'42"W 73.12'DEED=N42°03'39"W 64.55'N65°34'03"W 196.56'N52°49'W61.90'N41°27'03"W 79.33'N21°24'20"W 246.81'N31°26'W22.94'N10°22'16"W58.89'N04°30'14"W47.86'N13°03'23"E 92.33'N10°22'16"W58.89'BASIS OF BEARINGSN87°46'10"E 355.80'S50°08'00"W 4.62'DEED=S50°36'06"WS21°20'58"E 220.08'DEED=N20°52'53"W 219.26'EXCEPTIONPARCELBOOK 601 PAGE 210FENCELINEWIRE FENCELINEFENCELINEPAVEDDRIVEWAYTWO - STORY FRAME HOUSEW/WALK-OUT BASEMENT& GARAGE144 COUNTY ROAD 111CARBONDALE2'± WIDE DITCH(SUBJECT TO EASEMENT)24"CMP15"PAVED ROADWAYA.K.A PRINCE CREEK ROADCOUNTY ROAD111ROADWAY EASEMENTBOOK 600 PAGE 708(HATCHED AREA)SSCMP144 PRINCE CREEKADDRESS SIGN12"CMP 12"CMP309.16'49.50'S04°13'33"E 117.93'S24°42'41"E 99.86'S14°30'49"E 348.71'S14°58'54"W41.55'PAVEDAUTOCOURTEEPAVERS BOUL D E R SCONCRETE EDGINGPATHGRAVELPARKINGSPOTSPACONCRETEWALLSCONCRETEPATIOHVAC UNIT(TYPICAL)40.3'8.0'44.5'10.1'17.7'23.5'24.3'34.2' 15.5'7.0'7.4'23.6'24.0'18.4'GRAVELPARKINGSPOTDECKMAILBOX5.081± ACRESOWNERJEREMY D. MORRISPARCEL NO. 246303400023RECEPTION NO. 823551OWNERNIESANIK INVESTMENT LLCPARCEL NO. 246303400048RECEPTION NO. 938724OWNERSUSAN C. REEDPARCEL NO. 246303400032RECEPTION NO. 383651OWNERETTA L. HOLGATEPARCEL NO. 246303400025RECEPTION NO. 241067OWNERCHARLES P. VERMEYENREVOCABLE TRUSTPARCEL NO. 246303400030RECEPTION NO. 85588232.0' WITNESS CORNERSET NO. 5 REBAR & 1-1/4"BLUE PLASTIC CAPWC TNC PLS382155.0' WITNESS CORNERSET NO. 5 REBAR & 1-1/4"BLUE PLASTIC CAPWC TNC PLS3821510.0' WITNESS CORNERSET NO. 5 REBAR & 1-1/4"BLUE PLASTIC CAPWC TNC PLS38215FOUND NO. 5 REBARFOUND NO. 5 REBAR &1-1/2"ALUMINUM CAPLS15710FOUND NO. 5 REBAR &1-1/2"ALUMINUM CAPLS15710FOUND NO. 5 REBAR &1-1/4"YELLOW PLASTIC CAPLS-ILLEGIBLEAPPARENT EASEMENT FOROVERHEAD TELEPHONE LINESAPPARENT EASEMENT FOROVERHEAD POWER POLES &OVERHEAD POWER LINES85.3'(TIE)217.1'(TIE)63306335634063456350635563606365637063756380 SWPOWER POLEGUY ANCHORSEPTIC TANK LIDWELLSATELLITE DISHOVERHEAD TELEPHONE LINEOVERHEAD ELECTRIC LINE FENCE LINETELEPHONE PEDESTALLEGENDSURVEYOR'S CERTIFICATIONA PARCEL OF LAND SITUATED IN LOT 18 OF SECTION 3 AND LOT 1OF SECTION 10, TOWNSHIP 8 SOUTH, RANGE 88 WEST OF THE 6TH PMCOUNTY OF GARFIELD, STATE OF COLORADOPARCEL NO. 246303400033IMPROVEMENT SURVEY PLATW/PARTIAL TOPOGRAPHY TRUE NORTH COLORADO LLC.A LAND SURVEYING AND MAPPING COMPANYP.O. BOX 614 - 386 MAIN STREET UNIT 3NEW CASTLE, COLORADO 81647(970) 984-0474www.truenorthcolorado.comPROJECT NO: 2021-224DATE:December 19, 2022DRAWNRPKSURVEYEDMANSHEET1 OF 1TRUENORTHA LAND SURVEYING AND MAPPING COMPANY40'20'80'SCALE: 1" = 40'NFURNISHED PROPERTY DESCRIPTION:0NOTICE: ACCORDING TO COLORADO LAW YOU MUST COMMENCE ANYLEGAL ACTION BASED UPON ANY DEFECT IN THIS SURVEY WITHIN THREEYEARS AFTER YOU FIRST DISCOVER SUCH DEFECT. IN NO EVENT MAY ANYACTION BASED UPON ANY DEFECT IN THIS SURVEY BE COMMENCED MORETHAN TEN YEARS FROM THE DATE OF CERTIFICATION SHOWN HEREON.NOTES:1.BASIS OF BEARINGS FOR THIS SURVEY IS A BEARING OF N87°46'10"E ALONG THE NORTH PROPERTY LINEBETWEEN A FOUND REBAR & 1-1/4" YELLOW PLASTIC CAP LS-ILLEGIBLE AND A FOUND REBAR & 1-1/2"ALUMINUM CAP LS15710S38215 AS SHOWN HEREON.5.THIS IMPROVEMENT SURVEY PLAT DOES NOT CONSTITUTE A TITLE SEARCH BY TRUE NORTH COLORADO, LLC FORALL INFORMATION REGARDING EASEMENT, RIGHTS-OF-WAY AND/OR TITLE OF RECORD, TRUE NORTHCOLORADO, LLC. RELIED UPON TITLE COMMITMENT NO. BAR64003962 ISSUED BY LAND TITLE GUARANTEECOMPANY, EFFECTIVE DATE: JANUARY 22, 2021.6.ELEVATIONS SHOWN HEREON ARE BASED ON GROUND SURVEY GPS OBSERVATIONS UTILIZING THECONTINUOUS OPERATING REFERENCE STATIONS (CORS) THROUGH THE MESA COUNTY RTVRN NETWORK BROADCASTING NORTH AMERICAN VERTICAL DATUM (NAVD88) YIELDING AN ON-SITE BENCHMARK ELEVATION OF6366.83 ON THE FINISH FLOOR OF THE HOUSE.7.CONTOUR INTERVAL EQUALS 1 FOOT.SET NO. 5 REBAR & 1-1/4" ORANGEPLASTIC CAP TNC PLS38215UNLESS OTHERWISE NOTED Garfield County, CO Developed by Account Number R090046 Par cel Number 246303400033 Acr es 5 Land SqFt 0 T ax Ar ea 009 2019 Mill Levy 80.9940 Physical Addr ess 144 111 C OUNTY RD C ARBONDALE 81623 O w ner Addr ess GC C L OFTS LL C 852 HANDY DRIVE C ARBONDALE C O 81623 2019 Total Actual Value $645,430 Last 2 Sa les Date Pr ice 3/31/2021 $1,025,000 4/20/2005 $475,000 Date created: 2/15/2023 748 ft Overvi ew Legend Parcels Roa ds Parcel/Account Number s Owner Na me Lakes & River s County Boundar y Line