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Home My WebLink AboutOWTS Installation Report 03.16.2026March 16, 2026 502 Main Street • Suite A3 • Carbondale, CO 81623 • (970) 704 -0311 • Fax (970) 704 -0313 S OPRIS E NGINEERING • LLC civil consultants Broadhurst, Christopher J & Tamara Marie PO Box 1132, Carbondale, CO 81623 C/O Jeff Parrington President, Tally Ho Construction www.tallyhoconstruction.com "jeff" <jeff@tallyhoconstruction.com > RE: As-Constructed Report –Onsite Wastewater Treatment System (OWTS), Broadhurst Residence, 1420 County Road 107, Carbondale, CO, Garfield County, Colorado SE Job No. 35041 .01 Parcel No: 239322300114 . Garfield County OWTS Permit No. SEPT-9232 Dear Jeff and Chris: Pursuant to County requirements, this letter provides documentation that the Onsite Wastewater Treatment System (OWTS) components recently installed at the above referenced site is in compliance with the permitted design and all punchlist items that were addressed pursuant to Garfield County EHD final inspection comments dated 9 -04-25. Sopris Engineering inspected the excavations, soils, materials and the installation of the system components during construction, prior to final backfill and after all installations were completed. The installed OWTS was designed and constructed to serve the new garage/shop with a ½ bath facility with a 2-bedroom small apartment ADU . Sopris Engineering performed site visits to inspect and document the as-constructed conditions of the OWTS. Inspections were coordinated with the property owner and the Contractor, Tally Ho Construction, that installed the new system components. The as -constructed conditions and installation of the new OWTS components is in compliance with Garfield County Regulations; the recommendations and specifications delineated on OWTS permit/construction plan “C1-OWTS-Plan”, dated 05-01-2025, prepared by Sopris Engineering. with previously submitted survey plat information, architectural site plan, GIS and aerial mapping. The design criteria and system sizing information is summarized below. The As-Constructed OWTS conditions, design criteria and components installed are delineated on the attached AC OWTS Record Drawing, dated 03-16-26. Summary Design Criteria The OWTS is designed for a treatment capacity of 300 gallons per day based on the design wastewater flow to serve a minimum 2-bedroom residence in accordance with Table 6-2 values, Section 43.6, A.4. The OWTS utilizes a 1,000 gallon two -compartment reinforced plastic septic tank installed with sealed ribbed PVC access risers. The new 1,000 gallon 2-compartment septic tank was installed with appropriate sanitary tees, outlet effluent filter with risers and lids at the surface. A gravity schedule-40 sewer pipe section with two-way cleanout was installed between the tank inlet on the gravity sewer line adjacent to the accessory structure and an additional intermediate cleanout was installed as shown on the record drawing. The soil treatment area (STA) consists of leaching chamber rows in a single bed that provide 350 S.F. of total absorption area. The septic tank effluent is gravity discharged through a 4-inch schedule-40 pipe installed at a minimum 1.5% slope, to the STA via a distribution box. The effluent is equally distributed from the distribution box via 4” distribution pipes connected to the head end cap of each chamber trench. Observation ports with caps are installed on the proximal and distal ends of each chamber trench. The design is in compliance with the current County regulations with design calculations based on the soil type, texture and structure with an appropriate long term acceptance rate (LTAR). The designed system meets all required setbacks and has been installed within the general location indicated on the attached C1-AC OWTS record drawing. AC Report-Broadhurst Residence 1420 County Rd 107, Carbondale, CO SE Job No. 35041 .01 March 16, 2026 Page2 Design Flow The design flow is calculated as follows for the minimum design capacity of an equivalent 2-bedroom residential dwelling. The OWTS is designed for a treatment capacity of 300 gallons per day based on the design wastewater flow in accordance with Table 10-1 values, Section 43.6, A.4. Regulation 43: Minimum population based on 2 bedrooms at 2 person s per bedroom equating to 4 persons. The Design flow is calculated based on residential usage of 75 gal/person/day, No PF Max. Design flow (Qd)gallons/day = (# of people) x (avg. flow) gal/person/day. Design flow Qd = 4*75=300 gpd Sub Surface Conditions and Testing A subsurface soil investigation and site assessment was performed by Sopris Engineering on April 17, 2025. The soils in the proposed field envelope area were sampled and characterized by application of the USDA visual/tactile soil texture method analysis from samples in two profile pits. The soils below approximately 6 inches of topsoil consist of medium dense silt loam texture soil with slightly blocky to granular structure to the profile pit depth of 8 feet. The soils contain less than 5% scattered gravel or rock content to the 8-feet depth explored below the surface grades. No free water was encountered in the pit excavations. No evidence of seasonal high ground water or redox conditions was observed in the profile pits. Seasonal high Groundwater levels are expected to be below 20 feet from the existing surface grades on the moderatley sloped terrain. The native soils sampled from 2 -3 feet below the surface, in the vicinity of the proposed field, are characterized as a soil type 2 consisting of silt loam texture with blocky granular structure. This soil has an effective loading rate for conventional soil treatment of 0.6 Gal/S.F./day for a level 1 conventional treatment system. The equivalent percolation rate is assumed to be 20 -30 minutes per inch. The soils are suitable for a shallow conventional absorption field consisting of gravelless infiltration chamber units. Long Term Acceptance Rate (LTAR): Receiving Wastewater Treatment Level 1; LTAR; (Table 10 -1 Soil type 2 loading rate for a silt loam is (0.6 gal./S.F./day); Design Flow; Qd = flow (gal/day) = 450 gpd Loading factors; (Table 10-2, Gravity application Bed, L.F.1 = 1.2) (Table 10-3, Gravelless chambers, L.F.2 = 0.7) STU absorption treatment area; A = Area S.F.; A(sf) = Qd x L.F.1 x L.F.2 .: A(sf) = 300 gpd x 1.2 x 0.7 = 420 S.F. LTAR 0.6 Gal/S.F./day Number of ADS ARC-36 chambers 5'x3'x12"chambers: 420 S.F. = 28 chambers; Use 30 chambers 15 S.F./Chamber Installed 30 Arc chambers in 1 bed with 3 trenches 50' long by 3' wide with 10 chambers units per row plus two end caps as delineated on the plan. The septic tank effluent is gravity distributed to the head of each chamber row via individual distribution pipes from a distribution box. AC Report-Broadhurst Residence 1420 County Rd 107, Carbondale, CO SE Job No. 35041 .01 March 16, 2026 Page3 OWS Operation and Maintenance Ownership of the system and responsibility for maintenance and repair will remain with the property Owner. The Owner is encouraged to retain the services of qualified personnel to inspect the OWTS and to perform all maintenance and repairs necessary to ensure that the system components are maintained in good operating condition and suitable vegetative cover is established on the fields. The components of the OWTS system should be inspected within 30 days of being placed into operation and should been inspected and maintained bi-annually. The tank, absorption field and other system components should be visually inspected bi-annually for debris, damage, leaks, or other potential problems. In general, for a properly utilized system, septic tanks should be pumped every 3 - 5years. The effluent filter should be cleaned every six months and at the time of pumping. Absorption fields should be maintained with suitable vegetative cover and kept free of root invasive plants. Positive surface drainage away from the absorption field should be maintained. If you have any question or need any additional information, please call. Sincerely, SOPRIS ENGINEERING, LLC Paul E. Rutledge Yancy Nichol, PE Design Engineer Principal 3/16/2026