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Home My WebLink AboutOWTS Design,l29 C¡lt¡s L¡rur CnReoNonLE,CO A1623 970.309.5259 CARLA. oSrBERG@GMAIL. coM sltt"rl( -r ( :()lÌsttr¡.,1.I :\.{t December 19,2021 Project No. C1654 Kevin Hoffman kevin. h. hoffman@qmail. com Onsite Wastewater Treatment System Design &Bedroom Residence + 1-Bedroom Attached Apartment 998 Huebinger Drive Garñeld County, Colorado Kevin, CBO lnc. performed a subsurface investigation and completed an onsite wastewater treatment system (OWTS) design for the subject residence. The 2.839-acre property is located outside of Glenwood Springs, in an area where OWTSs are necessary. Legal Description: Section: 2 Township: 7 Range: 89 Subdivision: WESTBANK RANCH PUD #4 RESUB Lot 37 Parcel lD: 239502406037 SITE CONDITIONS A 3-bedroom, single-family residence presently exists on the property and is served by an existing OWTS. The OWTS consists of a 1000-gallon, two-compartment concrete septic tank followed by an lnfiltrator@ chamber system. Garfield County Individual Sewage Disposal System Permit2742 documents this system. The system was sized to accommodate 3 bedrooms. The permit received final approval on July 28, 1997. A 1-bedroom apartment is being added to the residence. There is a need to upgrade the OWTS to accommodate this addition. The existing OWTS will be abandoned and replaced with the OWTS proposed in this design. The residence is cunently served potable water from a community water system. The water line enters the southeast comer of the residence. The water line will not come within 25-feet of any OWTS component. The proposed soiltreatment area (STA) location to the northwest of the residence has an approximate ten percent slope to the northeast. The area is vegetated with native grasses and sage. There should be no traffic or staging of material over the future STA site to avoid compaction of soilspriorto construc{ion of the STA It should be noted that no survey was provided to create the síte plan. GPS coordinates and a Google Earth image were used to create the site plan. Placement of existing and proposed features and components may not be accurate. The northwestem property line has been verified on the properly. Page2 Photos and measurements of property line to the northwest SUBSURFACE Hepworth-Pawlak Geotechnical, Inc. Subsoil Study for Foundation Design and Percolation Testing report dated December 6, 1996, Job No. 196 584 is enclosed. Three percolation tests were conducted, and a soíl profile test pit excavated. Percolation tests were conducted at47 % inches in depth, 52lzinches in depth, and 50 inches in depth with results of I minutes per inch (MPl), 10 MPl, and 10 MPl, respectively. The Profile Pít consisted of topsoíl to 1-foot, underlain by clay and sand (silty, scattered gravel, occasional cobble, stiff, loose to medium dense, slightly moist, light reddish brown, slightly porous and calcareous, angular siltstone/sandstone fragments) to 7.O-feet, underlain by clay (silty, sandy, stiff, slightly moist, reddish brown, slightly to moderately porous, slightly to moderately calcareous) to a maximum depth explored of 9.0- feet. No bedrock or groundwater was encountered. While the soil investigation was performed many yearc ago, the location of the testing is in the proposed STA location and the area remains undisturbed. Results are relevant for design purposes. Current regulation I h Page 3 does require a m¡nimum of TWO soil profile pit excavations. Prior to construction, an addit¡onal test pit must be excavated, and this office must be called to verify soils are consistent with those described in the Hepworth-Pawlak rêport Based on the information presented in the Hepworth-Pawlak report, soils align with Soil Type 2. We are sizing the STA based conservatively on Soil Type 2A. A long term acceptance rate (LTAR) of 0.5 gallons per square foot will be used to design the OWTS. DESIGN SPEGIFICATIONS The existing OWTS will be abandoned. The existing septic tank will be pumped and the sides, top, and bottom crushed and the remaining void filled with onsite material. The existing STA will be abandoned in place. Desion Calculations: Average Design Flow = 75 GPD x 2 people/bedroom x 4 Bedrooms = 600 GPD LTAR = 0.5 GPD/SF 600 GPD / 0.5 GPD/SF x 0.8 (pressure dosed trenches) x 0.7 (chambers) = 672 SF The ne¡v O1^,TS 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 has been established the sewer line exiting the residence as 100'. 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. 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 150O-gallon, two-compartment concrete septic tank with an effluent filter on the outlet tee. 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- The installation must include a 1S00-gallon, two-compartment lnfiltrator@ poly septic tank with an Orenco Biotube Effluent filter on the outlet tee, followed by a 500-gallon, lnfiltrator@ poly pump chamber with an Orenco@ ProPak pumping system and an Orenc@ PF3005 pump. The floats must be set to dose approximately 80 gallons each pump cycle, allowing for approximately 12 gallons of drain back into the pump chamber after each pump cycle. A pump curve is enclosed. The control panel for the pump must be located within line of sight of the septic tank. We recommend Valley Precast out of Buena Msta be contracted for start-up of the pumping system. OWTS Gomoonent Minimum Elevation Primary Tank lnlet lnvert Approximate horizontal distance 13' / min. 2o/o fall I min.3.25" fall Automatic Dístributing Valve (ADV)Approximate horizontal distance 113'l mín. 1% rise for drain back / min, 14.125" rise lnfiltrative Surface Approximate horizontal distance to furthest trench 32' I min.1o/otall / min. 4" lall Page 4 Table A 1.S-inch diameter Schedule 40 pump line must be installed from the pump to an Orenco@ automatic distributing valve (ADV), model6404. This pump line willcross the driveway. We recommend a minimum $chedufe 40 conduit to run underthe driveway. This pump line must have a minimum 1o/o gradefor 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 exísting the ADV remain vísible for future inspection and maintenance. Effluent will be pressure dosed through 1.S-inch diameter pipes to four trenches, each with 14 'Quick 4' Standard Plus lnfiltrator@ chambers, for a total of 56 chambers and 672 square feet of ínfiltrative area. There must be at least 4-feet of undisturbed soil between each trench, although we recommend 6-feet where feasible. 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 holes 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 contrac{ors 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 = 162 gal- (600 GPD x25o/" + 12 oal drain back) Min. 56 gal. (11 gal x 4) + 12 gal drain back Dose Setting 80 gallons/dose 12 gallons drain back (1'13' I 1.5" diameter pumo line) Float Separation 5O0-gallon lnfiltrator@ poly pump chamber 6" on/off float separation Pump Criteria 12.9 gallons per minute (GPM)25.6 feet totaldynamic head fiDH) COMPONENT MANUFAGTURER MODEL NO.GOMMENTS Septic Tank lnfiltrator@ Item # IM-1520-2CP 2-compartment poly seotic tank Effluent Filter Orenco@ 4-inch diameter full size effluent filter Pump Chamber lnfiltrator@ Item # |M-540-HH Pump chamber with high- head pump Pump Orenc@ PF3005111/'HP 120 Volt Biotube ProPak Pump Packaqe OrencoG)BPP3ODD Vault, Filter, Control Panel ldemand dose) Tank Risers and Lids Orenco@ Double-walled PVc R¡sers ancl Lids (24" diameter) ADV Orenco@ v64044 1.5" lnlet and Outlets ADV Riser and Lid Orenco@ Double-walled PVC Risers and Lids (30" diameter) Page 5 Construction must be according to Garfield County On-Site Wastewater Treatment System Regulations, the owTs Pennit provided by Garfield county Building Department, and this design. INSTAL¡-ATION GONTRACTOR CBO lnc. expects that the installer be experienced and qualified to perform the scope of work ouüined in this design. The installer must review this design thoroughly and coordinate with our office in advance of installation. Any additional e¡nditions in this design or county pennit 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 perfonned before backfill, after placement of OWTS components. Septic tanks, distribution devices, pumps, dosing siphons, and other plumbing, as applícable, must also be observed. CBO lnc. should be notified 48 houri 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.O of the OWTS Design Packet. Photographs of the installation and final cover are also requested to supplement our instãllation documentation. REVEGETATION REOUIREMENTS An adequate layer of good quality topsoil capâble 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 witñ successional species. No trees or shrubs, or any vegetation requiring regular inigation 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 theproperty. The property owner is responsible for maintaining service contracts for manufactured units, alternatíng 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 exampb, ã running toilet or leaky faucet can discharge hundreds of gallons of water a day and harm a STA. Orif¡ce Shields Orenc@ os150 1.5 inch diameter (72 total) Flush¡ng Assembly Orenco@ 1.5" cliameter lz) 45" or 90" long sweep only(4 total) Chambers Inf¡ltrator@ Standard PIus 56 Standard Plus'Quick 4' chambers Page 6 lf an effiuent 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 nonùiodegradable 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 Oì^/TS. The OWTS is engineered for domestic waste only. 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 accolding 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.Reviewed By: (ø¡'tü tsthrug Carla Ostberg, MPH, REHS Romeo A. Baylosis, PE Shosi 1 0F 4w1.0Designed by: CBODatet 12h912021by: RBDDReviewêdDrawn by:Hoffman Residence998 Huebinger DriveGarlield County, ColoradoProjectNumber: C1654N_zSCALE: I = 50'=0-STA-\.or.*r"LINESEPTICTANKSADDITIONAL TEST PITREQUIRÊD PRIOR TOINSTALLATIONWATER LINE ENTERSSOUTHEAST CORNER OF HOUSERESIDENCEWITH AN ATTACHED1-BEDROOM APTTHE LOCATION OF PROPOSED IMPROVEMËNTS SHOWN ARENOl THE RËSULT OF A FROPÊRW SURVEY. 'T}IE LOCATIONSARE APPROXIMATE. IT IS THE HOMEOWNERS' DUTY fOENSURE ALL CONSTRUC'TION AND IMPROVÊMÉNT LOCATIONSARE ACCURATE. PROPERTY LINÊS AND SE'IBACK DISTANCËSSHOULO BE CONFIRMËD PRIOR TO EXCAVATION, SCALEDFOR PRINTING ON 1'I"17 PAPER,DRAWNGS MUST BË USED INCONJUNCTION WITH DESIGNLETTER DATED 121 1 gI2O21w2.0CBO lnc-f29 Cains LaneCarbondal6, Colorâdo 81 623Phone 970.309.5259carla.ostborg@gmâil.ôom Sheet 2 0F 4w2.0ooSBEDROOMRESIDENCEWITH I.BEDROOMATÎACHED APT\\15OO-GALLON z.COMPARTMÊNT POLY SEPTICPLACE PUMP LINE IN MIN. SCHEDULE 40CONDUITUNDER DRIVEWAYAPPROX. LOCATION OF EXISTINGSTA TO BE ABANDONED. TANK FOLLOWED BYAsOO-GALLON POLY\ putr¡p cg¡NeeR wrrH AN oRENco puMprNcSYSTËM, RISERS AND LIDS TO GRADEHoffman Residence998 Huebinger DriveGârfield County, ColoradoPrcject Number C1654loártet 121ßno2'lloeslgneo uy: cgoI Reviswed by: RBlDrawn by: DDCBO lnc.129 Cains LansCarbondale, Colorâdo 81623PhonÊ 970.309.5259carla.ostberg@gmail,comPROPERTYFLUSHING VALVE ATEND OF EACH LATERAL4' DIA SDR.35 INSPECTION PORT ATBEGINNING ANÐ END OF EACH TRENCH4 TRENCHES EACH WTH 14 'QUICK 4' CHAMBERS = 5 CHAMBERS= 672 SF.I,5" DIA SCH4O PVC SUSPENDED LATÉRALS WITH 5/32" DIAORIFICES 3' O,C. FACING UP, FIRST AND LAST ORIFICES FACINGDOWN FOR DRAINAGE COVERED WITH ORIFICE SHIETDS1.5' DIA SCH-40 DISTRIBUTION LINES TO EACHTRENCHEXISTING SEPTIC TANKTO BÊ ABANOONEDBM 100'4" DIA SDR.35 SEWERPIPE WTH CLEANOUTMIN 2% FALL TO TANKADV MODEL 6404 AT HIGH POINTACCESSIBLE AT GRADE1.5'DIA SCH.4O PUMP LINÊ,(MIN 1% DRAIN BACK TO TANK)NffiSCALE: 1" = 20'-0' Sheet 3 0F 4w3.01A1912021by: CBOby:by: RBDDHofünan Resldence998 Huebinger DriveGarff eld County, ColoradoProjsctNumber: C1654ÎRATORGRAVÉLLESS QUlcK.4'CHAMBER (4'x 3')ENI' PLAÎEDIA SCH-40DISÎR¡BUÎION LINÊ 1OEÀCH TRENCII1.5',DIA SCH-40EFFLUENÍ PIPË FROMDtq sDR.35INSPECfIONPORlADV WTH ACCESS AT4' maxLGRADEsotLPLACED IN IOP PORT2'minl. OF CHAMBER END PLAÍES\-olstareurorl r-rNE rooIHER TRENCH (4TOTAL)L¡MITEXCAVATIONSUSPEND LATERAIS WTHZIP.ÍIES IO UNDERSIOEOF CTIAMBÊRS,outcK{'DIASDR€s INSPÊCTONCHAMEER(4r3)PORT AT BËêINNING ANDEND OF EACH TRENCHSURFACÊEND EACH LATERAL IN A 90' LONGSWEEPING ELI FACING UP WIÍH A BALLVALVE IN A VALVE BOX ACCÊSSIBLÊ A1GRAI]EI.5" DIA SCH4O PVC SUSPENDEO LAÎERALwllH 5r3u DtA oR|FICES Al3' O.C. FACtNcUP. FIRST AND LASI ORIFICES FACE OOW{WÍTII AN ORIFICE SHIELD FOR DRAINAGE¡4\CHAMBER IRENCH SEClloN\?_nlrtfæoË4lEEE-JBsqS* ftrNA,v4,Hsr¡u rLus"t*cVALVË ECCENTRIC TOCÊNTER OF VALVESMALL VALVE COVÊRBOX OR IRRIGATONVALVE BOX À1 GRADE30'DIAMETER PVC10'DIAVALVE 8OXWITH SECUREO LIOI,5'PVC SLIP X MALEPIPE THREADADAPTERW/CAPRISERDIA BALLCAP OR IHREADEDVALVECLEÀNOUT ASSEMBLY1.5" DIA SCH.40 PVCLONG SWEEP 90'ELBOWCOMPACTDIS'ÍRIBUTINGVALVE ASSEMBLYBASE fO SUPPORIBOXPIPE CUt 10FITFROMÊND CAPUSE HOLE SAWTOCI,JT IHRU TOP OFPUMPINGJ.S DtA SCH-40PVC INLÊÍANDOUTLETS't.5i DtA scH40 PVCSUSPENDED LATERALEND(Ð.llsieEgllsrsL!$EfcH AMBERA AUTOMATIC OISIRIAUÌNG\?r---.BrñiEVAIIE DÊTAIL/ÀFLUS}IING VALVE OETAIL\3,r--rtræC8O lnc.129 Cains LânaCarbondalê, Colot'ado 81623Phone 970.309.5259carla.ostberg@gmâ¡l,com Pump Selection for a Pressurized System - Single Family Residence Project 998 Huebinger Drive Parameters 300Discharge Assembly Size Transport Length Beforô Valve Transport Pipe Class Transport Line Size Distributing Valve Model Transport Length After Valve Transport Pipe Class Transport P¡po Size Max Elevation Lift Manifold Length Manifold Pipe Class Manifold Pipe Size Number of Laterals per Cell Lateral Length Laleral P¡pe Class Lateral Pípe Size Orifice Size Orifìce Spacing Residual Head Flow Meter Add-on' Friction Losses Calculations 1.50 113 40 1.50 6404 32 40 1.50 15 0 40 1.50 4 56 40 1.50 5132 3 5 None 0 feet inches inches feet inches feet feet inches feet inches inches feet feet inches Íæl 250 100 I oolt -o doo c og cl 6 oF 200 50 Minimum Flow Rate per Orifice Numbsr of Orifices per Zone Total Flow Rate per Zone Number of Laterals per Zone oÁ Flow Differential lsvLast Orif¡ce Transport Velocity Before Valve Transport Velocity Afier Valve Frictional Head Losses 0.68 19 12.9 1 2.O 2.ø 2.O 50 gpm 9pm o/o Os þs 00 feet feet feet feet fêet feet fe€t feet 0.5 1.2 2.6 0.4 0.0 0.2 0.0 0.0 gâls gals gals gals gals gals Loss through Discharge Loss in Transport Before Valve Loss through Valve Loss in Transport ãfter Valve Loss in Manifold Loss in Lalerals Loss lhrough Flowmeter Add-on'Fdclion Lossês Pipe Volumes s10 15 20 25 Net Discharge (gpm) 30 35 40 PumpData Vol of Transport Line Before Valve Vol of Transport L¡ne After Vâlve Vol of Man¡fold Vol of Laterals per Zone Totia¡Vol Before Valve Total VolAfterValve 11.9 3.4 0.0 5.9 11.9 9.3 PF3005 High Head Efluent Pump 30 GPM, 1/2HP 1T5nsOV 1Ø 6OHz,2OOV 3Ø 6OHz PF3007 High Hêad Effiuent Pump 30 GPM,3/4HP 23OV 1Ø6OHz,2OOí46OY 3Ø 60Hz PF301O High Head Emuent Pump 30 GPM, lHP 23OY 1Ø 6OHz.2OO|46OY 3Ø 6OHz PF30l5 High Head Effuent Pump 30 GPM, 1-ll2HP 23OV 1Ø 6OHz,2OO|23O|46OV 3ø 6OHz gpm feet I I \ System Curve: - Pump Curve: *' Pump Opt¡mal Range:- i\ operat¡ng Point êJ o Des¡gn Po¡nt: sY$'tÈ1Ml;