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HomeMy WebLinkAboutOWTS Design Report 09.23.2019DESIGN REPORT ON-SITE WASTEWATER TREATMENT SYSTEM (OWTS) TBD CR 237 TRACT 10 SILT, COLORADO GARFIELD COUNTY September 23, 2019 Prepared By: Kenneth J. Brotsky, P.E. 558 Rio Oso Lane Grand Junction, CO 81507 (970)216 8861 I. INTRODUCTION: This Report has been prepared at the request of Clayton Homes, representative for the above referenced property. This Report addresses the design of an On -Site Wastewater Treatment System to serve a proposed residence. Public sewer service is not available. The procedures used in this report follow the "Garfield County On -Site Wastewater Treatment System Regulations". II. SOILS AND PERCOLATION TEST: The site is a fairly flat, high desert area, with ground slopes generally about 2% to the southwest The site is heavily vegetated with grass and salt brush. A test hole was dug in the general area of the proposed OWTS. The upper 6" of soil is loamy, clay topsoil. From 6 to 18" there is grey, silty, clay. Below this layer to 96" is a gravelly, silty, gravelly, clay. This layer is a sedimentary matrix of minus 2" gravel and silty clay, with some rocks up to about 24" in size. Percolation rate is 23 minutes per inch. A Long Term Acceptance Rate of 0.7 gallons per square feet per day will be used for design. A 4 row bed of infiltrators will be used. The bottom of the absorption bed will be set at 26" below the existing grade at the southwest corner of the bed. III. SYSTEM DESIGN: A. Estimated Sewage Flow: The proposed house will be 4 bedroom. 4 x 150 = 600 gallons per day B. Septic Tank Use a 1,250 gallon tank. C. Absorption Bed: The absorption bed size is calculated as follows: A = 600/.7 858 sq. ft. Adjustment Factors: Table 5.2 Method of Application is gravity Factor 1.2 Table 5.3 Type of Distribution is Chambers Factor 0.70 Bed Size required is 858 x 1.2 x 0.70 = 720 Sq. Ft. Total Number of chambers required is 720/12 = 60.1 units Use bed configuration, with 4 rows and 15 chambers per row for a total of 60 chambers. "641 wo KENNETH J. BROTSKY,.PE'0a: ;'"'j No. 18843 PERCOLATION TEST DATA TABLE ADDRESS:75D- 57-772Aer DATE 9 -t HOLE DEPTH /z: 56 TIME Za DROP RATE AVE. £L 50 -6 sni 5 yq9 .57z t %z z 4/ D \-.- `- '' LArly CLA7 Tee) /25 0/L fina "18" 3,e.4 eL# f 1L G moi -c' r 41P - 9� S '�' RAva c r�� C'G Ay � M jtf U \ 6 ei 0 Z G573" z 3%z y3/� zsAA ze D E P T H ., ,z - Zy u - 3''-" ydn- COo°- 2Z' - D \-.- `- '' LArly CLA7 Tee) /25 0/L fina "18" 3,e.4 eL# f 1L G moi -c' r 41P - 9� S '�' RAva c r�� C'G Ay � M jtf U \ 6 ei 0 RATE SLOWER THAN 60 MPI Al RATE FASTER THAN 5 MPI SLOPE GREATER THAN 30% /u HSWT DEEPER THAN 4 FT. BEDROCK LESS THAN 4 FT. 4/ FLOODPLAIN /1 Z ON-SITE WATER J '� REPAIR AREA 5 GWT ---r HSWT HOLE LOCATION DIAGRAM COMMENTS: TESTED BYrd 41,4- SIGNATURE �/z apo CL _70 MOO sc- USE END PLATE ON EACH ROW VENT/INSPECTION PORTS SEE DETAIL. 4 RQD. QUICK 4 INFILTRATORS —4 ROW S, 15 EACH ROW = 60 TOTAL r>~ _ I , Ir-=- r r REPLACEMENT AREA y PLASTIC OR HDPR LID • FLAT OR DOMED • FASTEN TO RISER T 24" DIAMETER HDPE RISER I LD DETAIL FINISH GRADE mi -j FASrEN TO TANK •TANK WALL TANK COVER TANK RISER DETAIL SegeeW DA/ e 7R/cc N 3/, "Nola5 PIPE All 72AYo/e BaTTDiLY DF / /P/LT?97.02 D/2/LL 2 - lz11 /-rbc/Fs 3'x[//2 FCO //'/ B 'Tram VE/v/i /.5PECrrew %o€r 1250 GALLON SEPTIC TANK SEE NOTES. ) CLEANOUT 0 o --1- \--SEE MANIFOLD DETAIL PROPOSED HOUSE 4 BEDROOM SET BOTTOM OF INFILTRATORS 26" BELOW EXISTING GRADE AT SOUTHWEST CORNER OF THE BED NORTH SCALE: 1" =20' TorOrllausk: FOUNDATION 100.0 4ACILFII.I. win; ?.TPAsMIAAEAL, L 4" PVC CLEANOUT ! RISERS' q%In SEPTIC TANK VENT,INSPECTION TUBE I �S QUICK 4 INFILTRATORS 4 ROWS ,15 EACH ROW FLOW -LINE PROFILE SCHEMATIC NOT TO SCALE COYER - = 60 TOTAL SET BOTTOM OF INFILTRATORS 26" BELOW EXISTING GRADE AT SOUTHWEST CORNER OF THE BED • ournormenuI>11C • [RAPSUOVER DIFu.TRRTORS • 1 . ----� _l' SET BOTTOM OF INFILTRATORS ' 32" BELOW EXISTING GRADE. AT SOUTHWEST CORNER • OF BED 1 NOTES 1. Contact Engineer for inspections at the following times: (Allow at least 24 hours advance notice). (Engineer will coordinate inspection time with Garfield County) . 1) When installation of the infiltrators, piping, and septic tank is complete but not covered, and ready for final inspection. Engineer is Kenneth J. Brotsky (970) 216-8861 2. The pipe from the house plumbing to the septic tank and from the tank to the absorption bed shall be 4 inch diameter, SUR 35, PVC sewer pipe. The pipe shall be laid at a minimum slope of 1/4 inch per foot. 3. INFILTRATOR units to be installed per manufacturers recommendations. Units to be "Quick 4". Geo -textile landscaping fabric shall be draped over the Infiltrators as shown. 4. The septic tank shall be a 1,25 0 gallon, 2 -compartment tank approved by Garfield County. 5. All construction shall be in accordance with Garfield County On -Site Wastewater Treatment System Regulations", most current edition. 6. Any changes to the layout on these drawings must have the approval of the Engineer prior to construction. Any unauthorized changes may have to be corrected. Any costs for redrawing of plans required because of unauthorized changes may be back charged to the installer. 7. Installer responsible for calling for "Locates". 8. An OWTS Permit must be obtained from Garfield County priorto starting installation of system. SITE PLAN, DETAILS, & NOTES ON-SITE WASTEWATER TREATMENT SYSTEM (OWTS) TBD - CR 237 TRACT 10 SILT, COLORADO GARFIELD , COUNTY Cant 11 1110 1111,.. 1 i11, 1