The URL can be used to link to this page

Home My WebLink AboutEngineer Report.pdfNovember 10, 2014 William Rice POB 1252, Carbondale, CO 81623 billrice@a sopri.s.net Ty Rice POB 398, Carbondale, CO 81623 RE: AS -BUILT, On-site Wastewater Treatment System (OWTS), Ty Rice Residence, 268 Rose Ln, Garfield County, CO SE Job No. 13184.01, Parcel No: 239335300017. Dear Gentleman: Pursuant to County requirements, this letter provides documentation that the new Onsite Wastewater Treatment Systems (OWTS) recently installed at the abovefer ed siteils, iare in comandpliance m twi itiothn of the permitted design. Sopris Engineering inspected the excavations, so system components at various times during construction, P pandor snal built ackfito serve the needs of thelsingle ations were completed. The system constructed on site was designed family residential structure located at 268 Rose Lane east of Carbondale. The install e eeraresidei.is to inspect tial system was designed for a maximum 4 -bedroom residence. Sopris Engineering perform the as built conditions of the constructed system. We haveicoordinated dinndate our efforts rtof the winew OWT�oving contractor that constructed the system. The as built conditions components is in compliance with Garfield County Regulations; the recommendations and spec ifications delineated on the civil design plans, C-1-OWTS and C-2 OWTS Details, dated August 18, 2013, by P Engineering. The design criteria and system sizing information is summarized el stow. Td As-built nt OWT our S treatment bed has been constructed in the exact location per the designplans survey stakeout. Desi n Criteria and As built System Component Installation and Sizing stems. The The system was designed based on the design criteria 3-compartment pproved for use of septic tank withta total of 1500 gallon eon septic ile sand filters (GSF) sy OWTS includes the installation of a 1500 gallon capacity in the primary and secondary tank chambers. The Bio tube vault. The effli int is equally pressure a simplex effluent pump assembly installed with an Orencodistribution es connected distributed across the treatment/absorption GSF field vithi�o-way cleanout has bividual custom eetnanstall d from n the house to the at the head of each GSG row. A Gravity sewerpipe tank. The design average flow for a 4 bedroom residence is 600 gpd and the F e k flow is 900 gpd calculated by the equivalent 4 bedroom residential population with a Peaking The Eljen In -Drain Geotextile Sand Filter (GSF) System was sized based upon the average assumed percolation rate calculated in the standard absorption area equation. 502 Main Street • Suite A3 • Carbondale, CO 81623 • (970) 704-0311 • Fax (970) 704-0313 SOPRIS ENGINEERING • LLC civil consultants AS -BUILT, OWTS Rice Residence, 268 Rose Ln SE Job No. 13184.01 November 10, 2014 Page 2 A (S.F.) = (Qd *(t) 1) x Plf: where: A = Absorption Area S.F. 5 Qd = flow (gal/day) = 900 t = time in minutes per inch = 10 mpi Plf = 0.8 for secondary treatment Qd = 540 gpd A= 900 *10) 1 x0.8=455 sq. ft. 5 An area reduction of 20% is allowed for a dosed treatment system. A(reduction 20%) = A x 0.8 = 455 x 0.8 = 364 S.F. GSF field. A total of 28 Eljen In -Drain units (7 units per bedroom) were installed in a single bed with 4 rows of 6 to 7 in - drain units per row, plus a fifth row extension with 2 units over approximately 365 S.F. sand basil area of select sand 24" deep. A Valley precast three chamber 1500 gallon concrete septic was installed with an attached a 500 gallon dosing chamber equipped with a simplex pump Biotube vault dosing assembly and associated piping and controls. Ribbed PVC risers were installed over the access openings with lids at the surface. The tank is tested watertight, installed level, bedded and backfilled with class 6 base material. Two way cleanouts are installed on the sewage pipe off the exterior wall of the residence and accessory buildings. The septic tank effluent is pressure dosed from the pump chamber to a manifold pipe at the head of each In -Drain rows via a 1.25" discharge pipe installed with a continuous slope to allow drain back to the tank. The effluent is equally pressure dosed through 1.25 -inch custom perforated distribution laterals running the length of the treatment bed rows installed on top of the installed In -drain units. The pipe has 3/16 -inch orifices drilled every 2 feet oriented upward to spray onto the orifice shield 12 -inch HDPE half pipes. Ball valves from each pair of rows are housed in a valve box installed on each end corner of the field. A piezometer monitoring well pipe riser with threaded cap was installed near the head end corners of the field. Sub Surface Conditions and observation A subsurface soil investigation was conducted by HP GEOTECH on April 19, 2014 (HP report dated 4-25- 14, job # 114 123A). An 8 -foot deep profile pit and three percolation test holes were prepared approximately 28 to 30 inches deep to calculate percolation rates and to confirm the onsite soils are suitable for conventional absorption systems. The average rate was determined to be 7 MPI. The fastest measured rate was 8 MPI and the slowest rate was 6 MPI. 10 MPI is used for design. The subsoils below about 1 1/2 feet of topsoil consist of siltly sandy gravel with cobbles and small boulders (USDA: extremely gravelly sand Soil type 1). No free water was observed in the profile pit or evidence of a seasonal high water table at the time of excavation and the soils were moist. The soils are suitable for conventional shallow absorption beds. 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 AS -BUILT, OWTS Rice Residence, 268 Rose Ln SE Job No. 13184.01 November 10, 2014 Page 3 good operating condition and suitable vegetative cover is established on the fields. The components of the OWTS system should 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 2 - 4 years. 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, ple Sincerely, SOPRIS ENGINEERING, LLC Paul E. Rutledge Design Engineer