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Home My WebLink AboutOWTS Installation ObservationCBO Inc. 129 Cains Lane Carbondale, CO 81623 970.309.5259 carla.ostberg@gmail.com October 14, 2025 Project No. C1674 Chris Hjorth norskbuilders@gmail.com Onsite Wastewater Treatment System (OWTS) Installation Observations Lot 23, Stirling Ranch Garfield County, Colorado Permit SEPT-8286 Chris, CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on August 4 and August 22, 2025 for the subject property. Norsk Builders (you, the property owner) installed the system. The OWTS design is based on 6-bedrooms in the Main Residence and 2-bedrooms in a detached accessory dwelling unit (ADU(. An average daily wastewater flow of 975 GPD was used. The sewer lines exiting the ADU and Main Residence have 4-inch diameter SDR-35 sewer lines with double-sweep clean outs and a minimum 2% grade to the septic tanks. The system installation includes a 1000-gallon, two-compartment Infiltrator® poly septic tank with an Orenco® Biotube Effluent filter on the outlet to serve the ADU. A 2000-gallon, two-compartment Valley Precast concrete septic tank with an Orenco Biotube Effluent filter was installed to serve the Main Residence. A 500-gallon, single-compartment Infiltrator® poly pump chamber was installed with an Orenco® Pump Vault and an Orenco® PF3005 pump. The floats are set to dose 75 gallons each pump cycle. The control panel for the pump is located within line of sight of the septic tank. The filters in these septic tanks must be cleaned annually, or as needed. Valley Precast performed start up of the pumping system. We performed a squirt test, tested the pump and alarm floats, and cycled the ADV at the time of our August 22, 2025 visit. Effluent is 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 has a 1% grade for proper drain back into the tank after each pump cycle. The ADV is placed at a high point in the system in an insulated riser with access from grade. Effluent is pressure dosed through 1.5-inch diameter pipes to four gravelless chamber trenches, each with 19 ‘Quick 4’ Plus Standard Infiltrator® chambers, for a total of 76 chambers and 912 square feet of infiltrative area. There was at least 4-feet of undisturbed soil between each trench. Effluent is pressure dosed to 1.5-inch diameter laterals, which are hung with zip ties from the underside of the chambers. Laterals have 5/32-inch diameter orifices facing up, with the exception of the first and last orifices facing down for drainage. The orifices are placed 3-feet on center. Each lateral has a 90 degree ell facing up with a ball valve for flushing. Valves are placed in a valve box, accessible from grade, for access. Inspection ports are placed at the beginning and end of each trench. Ports are cut to grade and covered with a valve box for access. The OWTS was generally installed according to specifications. This observation is not a guarantee of workmanship and/or parts and materials. CBO Inc. should be notified if changes are made to the OWTS in the future. Any additional OWTS construction must be according to the county regulations. LIMITS: Observations are limited to components that are visible at the time of the inspection. The installer must have documented and demonstrated knowledge of the requirements and regulations of the county in which they are working. The quality of the installation is dependent on the expertise of the installer, soil type, and weather conditions. Please call with questions. Sincerely, CBO Inc. Carla Ostberg, MPH, REHS Pump Selection for a Pressurized System - Single Family Residence Project Hjorth 7 29 25 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 1.25 100 40 1.50 6404 35 40 2.00 8 0 40 1.50 4 76 40 1.50 5/32 3 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 26 17.8 1 4.9 2.8 1.7 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 2.2 1.9 3.7 0.2 0.0 0.6 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 10.6 6.1 0.0 8.0 10.6 14.1 gals gals gals gals gals gals 17.8 21.7 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: Garfield County Public Health 2014 Blake Ave. Glenwood Springs, CO 81601 Phone: (970) 945-6614 ext. 8150 For inspections, call: 970-945-6614 ext. 8150 and call the Design Engineer, if applicable Project Address: 0 Skipper Dr Carbondale, CO _ Parcel No.: _239129205023 Owner Name: Chris Hjorth Owner Phone: (970)-445-0777 Designed By: CBO Septic Consulting, Inc. Designer Phone: (970) 309-5259 Number of Bedrooms: _8_ Minimum Tank Capacity: 3,000-gallon Minimum Absorption: 910 ft 2 OWTS PERMIT KEEP AVAILABLE AT PROJECT SITE Permit Number _SEPT-8286_______________________________ Permit Type X New X Repair X Remodel/addition X Tank only Issue Date _10/04/2023____________________ Expiration Date_10/04/2024_________________ Permit Conditions: This OWTS Permit is approved on the condition of compliance with the report and design as submitted by CBO Septic Consulting, Inc. dated November 27, 2022. Changes to the design and permit must be approved by Garfield County Public Health and the designer prior to construction. The new OWTS will serve a new six-bedroom residence and a two-bedroom ADU. The system will consist of a new, two-compartment 2,000-gallon septic tank for the residence and a 1,000 gallon tank for the ADU set level with access to grade followed by a 500-gallon single-chamber pump chamber set level with access to grade and a high-head pump in the pump chamber. Effluent will be pumped to an automatic distributing valve set at the high point of the system that will distribute effluent to 912 ft2 of STA. The new STA will consist of four gravelless chamber trenches, each trench consisting of 19 chambers per trench (76 chambers total). Distribution laterals are to be 1 ½ inch Schedule 40 PVC, with 5/32-inch orifices 3-feet on center and the laterals ending in flushing valves at the distal end of the laterals. Laterals are to be hung from the underside of the chambers with zip- ties. The orifices are to be facing upward, except for the first and last orifice (which shall face downward for drainage purposes). Inspection ports are to be installed at each end of each trench. Maintain all setbacks and elevations as designed. Contact the designer and Garfield County Public Health at least 48 hours prior to requesting final inspection of the installed system prior to backfill. Agreement All installations must comply with all requirements of the Garfield County OWTS regulations including but not limited to the conditions specified above. In consideration of the issuance of the permit, the applicant hereby agrees to comply with all laws and regulations related to the zoning, location, construction, and erection of the proposed OWTS and associated structures for which this permit is granted. The applicant further agrees that if the above said regulations are not fully complied with in the zoning, location, erection, and construction of the above described OWTS and structure, the permit may then be revoked by notice from the Health Department and immediately become null and void. The issuance of a permit and specifications of terms and conditions therein will not constitute assumption of liability, nor create presumption that the local public health agency or its employees may be liable for the failure or malfunctioning of any system. Permit issuance will not constitute a certification that the system, the equipment used in the system, or any component used for system operation will ensure continuous compliance with the provision of the OWTS Act, the regulations adopted thereunder, or any terms and conditions of a permit. Permit Approval Plans and specifications for the proposed OWTS have been reviewed and are considered satisfactory. Permission is hereby given to the property owner(s) to perform the work indicated in accordance with the Garfield County OWTS Regulation. This Permit will expire 1 year from the date of issuance unless construction on the system has commenced. An "as-built" drawing must be submitted and inspection of the system must be completed by GCPH before final approval of the system will be issued. 10/04/2022 Issued By: Garfield County Environmental Health Department Date 832‐R‐13‐002