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HomeMy WebLinkAboutAs-built Report & Drawing 09.14.2020September 14, 2020 William Rice T & T LLC Po Box 1252, Carbondale, CO, 81623 "BillRice" billrice@sopris.net RE: AS -Constructed Report—Onsite Wastewater Treatment System (OWTS), T & T, Commercial Storage Facility, 0544 C.R. 100, Garfield County, Colorado SE Job No. 18197.01 Parcel Number: 2393-353-02-002 Dear Bill: Pursuant to County requirements, this letter provides documentation that the new Onsite Wastewater Treatment Systems (OWTS) recently installed at the above referenced site is in compliance with the permitted design. Sopris Engineering inspected the excavations, soils, materials and the installation of the system components at various times during construction, prior to final backfill and after all installations was completed. The system constructed on site was designed and built to serve the needs of a commercial storage facility currently under construction by IRMW of Colorado, Inc. The installed system was designed with a maximum treatment capacity of 200 gallons per day. Sopris Engineering performed site visits to inspect and document the as -constructed conditions of the new OWTS in coordination with the contractor, Gavin Griffiths, Mountain Works. The as -constructed conditions and installation of the new OWTS components is in compliance with Garfield County Regulations; the recommendations and specifications delineated on the civil OWTS design plan, Cl-OWTS Plan, and Design Report, dated 04-08-2020, by Sopris Engineering. The design criteria and system sizing information is summarized below. An As -constructed OWTS record drawing is attached delineating the As -built descriptions and location of the OWTS components. Summary Design Criteria The OWTS was designed for maximum treatment capacity of 200 gallons per day based on the estimated daily wastewater flow based on base fixture counts for the '/z baths per unit and additional employee population usage in accordance with Table 6-2 values, Section 43.6, A.4. The proposed site improvements included the construction of a 3840 S.F. commercial building structure that has four'/z bath restrooms. The as -constructed OWTS includes an installed 1000 gallon 2-compartment concrete septic tank with concrete risers and lids installed at the surface. The tank was installed with an inlet sanitary tee and an outlet effluent filter sanitary tee. A gravity SDR-35 sewer pipe, with a two-way cleanout, adjacent to the warehouse facility structure, to the tank was installed. The soil treatment unit (STU) consists of two leaching chamber trenches that provide 240 S.F. of total absorption area. The septic tank effluent is distributed by gravity via a 4" distribution pipe routed to a concrete distribution box with individual 4" pipes connected to the head end cap on each chamber trench. Observation ports with caps are installed on each terminal end chamber unit. 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). Sub Surface Conditions and )bservation Subsurface soil investigations and USDA soil texture method tests were performed by Sopris Engineering in May, 2018. The soils in the area of the proposed absorption field were sampled and characterized by application of the 502 Main Street • Suite A3 • Carbondale, CO 81623 • (970) 704-0311 • Fax (970) 704-0313 SOPRIS ENGINEERING • LLC civil consultants Bill Rice, T & T LLC OWTS 0544 C.R. 100 SE Job No. 11174.01 September 14, 2020 USDA soil texture method analysis. A shallow and deep excavated pit was observed in the Easterly portion of the site adjacent to the proposed field location. The soils below 4 to 9 inches of mixed surface fill & topsoil consist of medium dense sandy silt loam with moderate granular to slightly blocky structure with some cobbles and gravels. The percentage of cobbles and gravels below 24 inches was less than 20% in the sandy silt loam to the 7 foot depth explored. The soil appears to be consistent across the easterly side of the relatively flat development envelope. The native soils sampled from 2-3 feet below the surface are characterized as a soil type 2 consisting of silt loam texture with moderate granular structure. This soil has an effective loading rate for conventional soil treatment of 0.60 gal/S.F./day for a level 1 conventional treatment system. The equivalent percolation rate is assumed to be approximately 16-25 minutes per inch. No free water was encountered in the excavations on site. Groundwater levels are expected to be well below 10 feet from the existing surface grades. The soils appear suitable for a conventional shallow absorption field consisting of gravelless infiltration chamber units. Design Flow The design flow is calculated as follows for low useage commercial facility onsite wastewater treatment system (OWTS) From the Regulation 43 usage Table 6-2 : Max. Design flow (Qd) = # of people x (avg.per capita and/or per base fixture flow-GPD) Each unit has 1/2 bath with single water closet (24.8 gpd) and Lavatory (8.4 gpd) Qd1=Base fixture load = (24.8 gpd + 8.4 gpd)=33.2 gpd x 4 units = 33.2 x 132.8 gpd; Qd2= Assume 1 additional daily worker per unit: 1 persons @ 15 gpd = 4 x 15 = 60 gpd; Qd=Qd1 + Qd2 = 132.8 + 60 = 192.8 gpd Total Design flow Qd = 200 gpd A 1,000 gallon 2-compartment concrete septic tank was installed with inlet and an outlet sanitary tee with an effluent filter. The tank accesses have concrete risers and T.R. lids installed at the finish surface grade. Treatment -Soil Treatment Unit/ Absorption System Design The treatment/absorption field is designed based on utilizing the effective Long Term Acceptance Rate (LTAR) for the native soils and the application of appropriate loading factors for a soil treatment unit system utilizing gravity distribution to gravelless chamber trenches. Long Term Acceptance Rate (LTAR), Wastewater Treatment Level 1; A(sf) = Qd x L.F.1 x L.F.2 .: A = Area; LTAR LTAR = 0.60 Gal/S.F./day for silt loam, soil type 2 Qd = flow (gal/day) = 200 gpd L.F.1=1.0 Table 10-2, Gravity application trenches L.F.2=0.7 Table 10-3, Chambers A(sf) = 200 gpd x 1.0 x 0.7 = 233 S.F. 233 S.F = 15.5chambers 0.60 Gal/S.F./day 15 S.F./Arc-36 Chamber (5'x3') Installed 16 Arc-36 chambers in two trenches, 40' long by 3' wide, with 8 chambers per trench and end caps. Inspection ports were installed on each end chamber at head and distal ends of each trench. Bill Rice, T & T LLC OWTS 0544 C.R. 100 SE Job No. 11174.01 September 14, 2020 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 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, p]ease call. Sincerely, SOPRIS ENGINEERING, LLC Paul E. Rutledge Design Engineer Design Calculations OWTS GENERAL NOTES: 1 1 The design flow is calculated as follows for low useage commercial facility onsite wastewater 1. THE OWTS AS SHOWN ON THE PLAN AND THE DETAILS WERE DESIGNED BY SOPRIS treatment system (OWTS) ENGINEERING. From the Regulation 43 usage Table 6-2 : Max. Design flow (Qd) = # of people x (avg.per capita and/or per base fixture flow-GPD) 2. THE EXISTING/ PROPOSED LOT CONDITIONS AND SURVEY/PLAT INFORMATION SHOWN BY Each unit has z bath with single water closet (24.8 gpd) and Lavatory (8.4 gpd) SOPRIS ENGINEERING. Qd1=Base fixture load = (24.8 gpd + 8.4 gpd)=33.2 gpd x 4 units = 33.2 x 132.8 gpd; 3. PRIMARY OWNER NAME AND ADDRESS: T & T LLC, PO BOX 1252, CARBONDALE CO 8162.3 ACCESS EASEMENT 20' WIDE Qd2= Assume 1 additional daily worker per unit: 1 persons @ 15 gpd = 4 x 15 = 60 gpd; BOOK 905 PAGE 347 REC #464338 Qd=Qd1 + Qd2 = 132.8 + 60 = 192.8 gpd 4. SITE ADDRESS: 0544 COUNTY RD 100, CARBONDALE, CO 81623 I Total Design flow Qd = 200 gpd 5. Legal Summary: Quarter: SE Section: 35 Township: 7 Range: 88 Subdivision: IRMW LLC' 1 EXISTING ROADWAY COVERED BY EASEM ENT PARCEL 1 Lot: 1B AS PER KMINOR SUBDIVISION PLAT RECEPTION NUMBER 893462. Septic Tank Design: PV 7s ,� •. ?7 4 • •? • %2020-09-14•.: �� O '•• ••, a,� 2, AN ,, REC. NO. 237727 (BOOK 383 PAGE 558 1 1 1 ) Installed a 1000 gallon, two compartment concrete septic tank with an effluent filter outlet 6. Parcel Number: 2393 353 02 002 RIO sanitary tee in the second chamber. Tank installed with sealed concrete risers and lids to the 7. GARFIELD COUNTY SEPTIC PERMIT #: SEPT 10 19 5983, ISSUED :April 2020 GRANDEfinish grade surface. \ TRAIL 8. CONTRACTOR: Gavin Griffiths, Mountain Works P.O. Box 3260, Basalt, CO 81621 1 Sub Surface Conditions and Testing: °, , .. <��"., C� 4', 'Oh1AL. V 1� 970-948-4177 (C). 970-927-0985 (0), griffithsgavin@hotmail.com " Subsurface soil investigations and USDA soil texture method tests were performed by Sopris ! -� INSTALLED 2-COMPARTMENT 1000 GALLON CONCRETE SEPTIC Engineering in May, 2018. The soils in the area of the proposed absorption field were sampled TANK (VALLEY PRECAST ITEM-1000T-2CP-W/T.R. LID) and characterized by application of the USDA soil texture method analysis. The soils were INITIALS DATE DESIGNED BY DRAWN BY CHECKED BY I tested to determine the hydraulic loading rate and to confirm the appropriate absorptive - INSTALLED INLET SANITARY TEE & OUTLET EFFLUENT FILTER 1 ` X 2 WAY CLEANOUT ASSEMBLY WITH (2) 24" DIA. BY 24" DEEP CONCRETE RISERS W/ LIDS. surface suitable for conventional absorption systems in native soils. A shallow and deep excavated pit was observed in the Easterly portion of the site adjacent to the proposed field 1 I 1 1 1 1 I I _ CONCRETE DISTRIBUTION BOX WITH - PROTECT OWTS FIELD AREA FROM location. The soils below 4 to 9 inches of mixed surface fill & topsoil consist of medium dense BAFFLE INSTALLED LEVEL ON VEHICULAR TRAFFIC OR ANY sandy silt loam with moderate granular to slightly blocky structure with some cobbles and I COMPACTED BASE DISTURBANCE BY PLACEMENT OF gravels. The percentage of cobbles and graves! below 24 inches was less than 20% in the sandy INSTALL RISERS AND LID TO SURFACE CONCRETE BARRIERS OR BOLLARDS silt loam to the 7 foot depth explored. The soil appears to be consistent across the site the 20.00'BUILDING easterly side of the relatively flat development envelope. STORAGE il�� ENVELOPE I ! i1 10I *IT2E/ I I _ s ,0'UTILITyEASEM TOP PERIMETER OF FIELD SURFACE MOUNDED 3" ABOVE SURFACE GRADES The native soils sampled from 2-3 feet below the surface are characterized as a soil type 2 / ST _/ / consisting of silt loam texture with moderate granular structure. This soil has an effective UNIT 1 STORA ISToRGI _ o STORAGE INSTALLED 4" RISER PIPE INSPECTION PORTS W/ loading rate for conventional soil treatment of 0.60 gal/S.F./day for a level 1 conventional V NIT CAPS (TYP. EACH END CHAMBER) treatment system. The equivalent percolation rate is assumed to be approximately 16-25 3En -- minutes per inch. No free water was encountered in the excavations on site. Groundwater UNIT�` INSTALLED "CHAMBER END CAP Q�r 40 levels are expected to be well below 10 feet from the existing surface grades. The soils appear WAREHOUSE/SHO' FA ITV STRUCTURE ��-- ON ALL END CHAMBERS suitable for a conventional shallow absorption field consisting of gravelless infiltration chamber F.F.= 6214+/-MIN. 2" AB` E EXIST. GRADW-1--� \/ units. I 1/2 BATH PER UNI , 4 EMPLO` . ES 10' -Soil Treatment Unit/Absorption System Design: '4- ITreatment • I PP-1 A _ treatment/absorption field is designed based on utilizing the effective Long Term The IP Acceptance Rate (LTAR) for the native soils and the application of appropriate loading-6213 for a soil treatment unit system utilizing gravity distribution to gravelless chamber trenches. The 4" PVC GRAVITY SEWERABSORPTION/TREATMENT FIELD / new treatment system and absorption field consist of gravity distribution of septic tank effluent PIPE. 2%SLOPE±,BED&/ via a distribution box to individual chamber trenches with treatment across the scarified native 16 ARC-36 CHAMBERS IN 2 TRENCHES WITH PP-2BACKFILL W/CLASS 68 CHAMBERS PER TRENCH FOR A TOTAL / soil absorptive surface. 'RIS ENGINEERING, CIVIL CONSULTANTS1 502 MAIN STREET CARBONDALE, CO 81623 (970) 704-0311 FAX: (970)-704-0313 / ABSORPTION AREA OF 240 S.F. / Long Term Acceptance Rate (LTAR) 04" PVC EFFLUENT PIPE @ MIN. 1%, SCHD-40 OR 4" PVC DISTRIBUTION PIPE, / / Wastewater Treatment Level 1; loading rate for silt loam is (0.60 gal./S.F./day) for soil type 2.; BEDDED & BACKFILLED W/ CLASS-6 INSTALLED INTO UPPER END / Loading factors; (Table 10-2, Gravity application trenches = 1.0) and PENETRATION OF END CAP (TYP.) / / (Table 10 3, gravelless chambers = 0.7) \ / / A(sf) = Qd .: A = Area; / LTAR LTAR = 0.60 Gal/S.F./day for silt loam / / Qd = flow (gal/day) = 200 gpd / L.F.1=1.0 Gravity Distribution *� / / L.F.2=0.7 Chambers / / A(sf) = 200 x 1.0 x 0.7 = 233 S.F. LECTRIC ASSOCIATION, INC M MID CONTINENT COAL AND COKE CO. i50 PAGE 454 AS REC #304903 ♦ & `� CESS EASEMENT BENEFITING JD THE NIESLANIK PROPERTIES NO. 89115 % / gpd \ / 0.60 Gal/S.F./day • i ��JJ// / Number of quick-4 chambers: / / 233 S.F = 15.5 chambers, Used 16 Arc-36 chambers w O \ / 15 S.F./Chamber DATE Iwo i . Installed 16 Arc-36 chambers in two trenches 40' long by 3' wide with two end caps as •' ` delineated on the plan. The septic tank effluent will be gravity discharge to a distribution box with two 4" distribution pipe routed to the head of each chamber row from the D-box. 1 / / 4 � / /' / o / 4000 Gallon Top Sears Item # Two Compartment 1000T-2CP / / / FSD- �i,• Top Oe • _ - -._ �• ..� Our keno ri View - / 20' UTILITY EASEMENT• EXCHANGE AGREEMENT• / / REC. NO. 891195 '.r :stall Tonle to So set 6a 5" min: sand Ton or Pet bookt al°"sito °� °°6"`"�`° �'a�'°"�r d e omm�iaaem campaTtaad �.° ,ad ul9rfd he "sed for emovel,tl prodded large stone. ore • '57avatl°n Should be dewatered and '0 V TrF �.. `.. � j l ` H• - - - - - z c ) 5 II /cP CENTERED OVER EXISTINGput / WATERLINE SERVICING /' IRMW PARCEL 1B / 20 GRAPHIC 0 10 20 SCALE 40 80 ' Tank filled with rater prier to being 1n for • water C 4se06 for•relaa1•nt with oter tobte lees them 2' below erode •• °°"nett«. above pqe *lot and Outlet ie with Delivered complete with internal Ping En/0 or concrete risers ava0able se a da y eatery s r w o vname Rubber to BOOT Bodoni • Option of pymp or siphon inetolled ®Qi / ^r X` (IN FEET)1 inch = 20 ft. ALL0WM6kE 6t,RY an Water i� � fr/30 HOLY CROSS EASEMENT ATER TRBLE WABLEWA3EIt EARTH FLE E2' 6} REC. NO. 889895 ° - P - DLL 1' POSITIONED OVER EXISTING OVERHEAD LINE 2' 3 D' Section iOr DRY 4' - a' Z Digging Specs Invert Dimensions Net Capacity Ne! Weight 13' Long x 8' Wide Inlet Outlet Length Vlldth Haight Intel Side Outlet Total Lid "fork Total 56" below inlet 56' 53" 111" 80' 68" 687 gal 323 gal 1010 gal 2620 Ibs 9380 Ibx 12000 the ` EM PLAN - Wider & R+� see -ale 23005Ctx Rio 317 W VALLEY ;; F 37z7 ov81211 J Ill 0 Q „ Q , iac• • seats: cn • w - 11 ' ` -r F" h:Ct.d ht4b k " ..,._._' qqnnu F -- r i - sue,. ri 4 ; x r 1, ` s _. .44_ ' h _ CROWN FIELD TRENCH TO DIVERT SURFACE WATER 4" PVC INLET PORT t, LOT 1B - STORA TY RD 100, CARE ELD COUNTY, COLORA :WATER TREATMEN. RUCTED OWTS RECORD D ra aka.: , a 'Iv r �- - \�+ r` _`.• -1 IN END CAP 6' MIN y A, - : 3' MIN `,; BACKFILL WITH SCREENED ,<EVEGATAI!0N :.� a � ONSITE SOILS FREE OF ROCKS IN EXCESS NATIVE, YARD OR LANDSCAPED SURFACE S TOPSOIL LAYEP ��\\A.-.,\\\\\ z = I- -CONSTI ; , ` j o®""' ' OF 3"DIAMETER OR USE 3 4 TO 1 5 / " SCREENED ROCK ` /. 12"-36" \\� ./ J Lu DQ v) DISTRIBUTION BOX LID \/� U LD O Q � AT GROUND SURFACE T PAR 0544 CI tr 3�...}' " RISER SECTION BAFFLE N\�\�\\� \/ /. �/� , FILTER FABRIC LEACHING CHAMBERi �%� 12" \/�� w I- _:. 6" MIN. 4" DISTRIBUTIONCO EXCAVATED MATERIAL COMPACTED BACKFILL LAYER NATURAL ONSITE •SOILS a rc4' r , GRAVITY LINE FROM SEPTIC TANK FREE OF ROCKS TO 90% STANDARD PROCTOR /\\/\/\/\/\\' „/ , \ \ \ \ \ \ �/ `i`i``'`/ ( , \ / 6" Z i SCARIFY/TILL BOTTOM SURFACE TO A DEPTH UN.I`.)), d EARITH SzIL11 Q OF 3" LOAM SOIL. 4" SOLID PVC GRAVITY N' 4" MIN. NOTE: ALL CHAMBERS IN EACH TRENCH MUST BE INSTALLED ON LEVEL 1 U A O T JT�� TIO �O� DISTRIBUTION PIPES (TYP.) \� \4� \. 4 SUITABLE BACKFILL OR GRADE OVER 3" ASTM-33 FILTER SAND LEVELING COURSE. l l 1 1 TO ABSORPTION FEILD INVERT INhul-CLASS 6 ROAD BASE MAXIMUM DEPTH OF TRENCHES NOT TO EXCEED 36" BELOW PROPOSED SURFACE GRADES. INLET AND END CAPS ARE TO BE INSTALLED ON EACH Q 8" AGREGATE BASE COURSE COMPACTED SUBGRADE END CHAMBER ROW. IF EXCESSIVE LARGE COBBLES OR BOULDERS ARE COMPACTED SUBGRADE ENCOUNTERED IN ANY PART OF THE EXCAVATION, OVER EXCVATE AND DATE: SEPT 14, 2020 TRENCH CROSS-SECTION FOR BACKFILL WITH SAND OR SUITABLE SCREENED NATIVE SOILS. JOB NO. 11174.01 DISTRIBUTION BOX DETAIL SDR-35.26 OR SCHD-40 PIPES CHAMBER TRENCH CROSS SECTION DETAIL N.T.S. N.T.S. N.T.S. G:\2011\11174\CIVIL\CIVIL DWGS\DE\11174-AC-OWTS RECORD DWG.DWG - Sep 14, 2020 - 1:01pm SHEET C1