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Home My WebLink AboutOWTS Design Report 02.24.2020Huddleston -Berry Engineering & Testing, LLC Porter Homes PO Box 2553 Grand Junction, Colorado 81502 Attention: Mr. Nate Porter RECEIVED GARFIELD COUNTY COMMUNITY DEVELOPMENT 2789 Riverside Parkway Grand Junction, Colorado 81501 Phone: 970-255-8005 Info@huddlestonberry.com February 24, 2020 Project#00287-0038 Subject: OWTS Design Shooting Building Branded Rock Canyon Ranch DeBeque, Colorado Reference: Geotechnical Investigation, Branded Rock Canyon Ranch, DeBeque, Colorado by Huddleston -Berry Engineering & Testing, LLC for Porter Homes, February 15, 2020. Dear Mr. Porter, At your request, Huddleston -Berry Engineering & Testing, LLC completed design of an Onsite Wastewater Treatment System (OWTS) for a new shooting building at the Branded Rock Canyon Ranch near DeBeque, Colorado. The building will include a bathroom for users of the shooting range. The site location is shown on Figure 1 — Site Location Map. A site plan is included as Figure 2. Site Description At the time of the investigation, the site was open and fairly flat. Site topography is shown on Figure 2. Vegetation included grasses, weeds, brush, and trees. The site was bordered to the north and south by open land, to the west, by hills rising to the west, and to the east by a small stream. Subsurface Investigation As discussed in the referenced report, the soils at the site consisted of 1.0 foot of topsoil above brown, moist, medium dense silt to a depth of 5.0 feet. Below the silt, brown, moist, medium dense silty sand with gravel extended to the bottom of the excavation. Groundwater was not encountered in the subsurface at the time of the investigation. The location of the test pit is shown on Figure 2. A copy of the test pit log is included in Appendix A. Branded Canyon Ranch #01178-0124 02/22/20 Huddleston -Berry Engineering Sr Testing. LLC Onsite Wastewater Treatment System In order to evaluate the soils for Onsite Wastewater Treatment, percolation testing was conducted in the test pit in accordance with Garfield County regulations. The percolation rate in the native soils ranged from 7 to 10 minutes -per -inch. The percolation testing data are included in Appendix B. In accordance with Garfield County regulations, a percolation rate of between 5 to 60 minutes - per -inch is required for soils to be deemed suitable for onsite wastewater treatment. Therefore, based upon the results of the percolation testing, HBET believes that the native soils are suitable for onsite wastewater treatment. In addition to the percolation rate of the subsurface materials, the seasonal high groundwater elevation is an important factor in determining the suitability of the site for Onsite Wastewater Treatment Systems. For OWTS suitability, the seasonal high groundwater elevation should be at least four feet below the bottom of the proposed absorption bed. As discussed previously, groundwater was not encountered at the time of the investigation. In general, based upon the results of the subsurface investigations, HBET believes that the seasonal high groundwater level is deeper than 10.0 feet below the existing grade at this site. Seepage Bed Design The design of the absorption system generally follows the requirements of the State of Colorado and Garfield County. Based upon information provided to HBET, the maximum daily use of the facility will consist of eight persons. Based upon the soil percolation rate, a Long Term Acceptance Rate (LTAR) of 0.80 will be utilized for the absorption field design. Infiltrator Systems Quick4 Standard Chambers are proposed. The daily flow of the sewage disposal system is calculated below and a plan and profile of the absorption system are shown on Figure 3. Average Daily Flow = (8 persons)(5 GPD/person) = 40 GPD Soil Treatment Area = (40 GPD / 0.8) = 50 Square Feet Adjusted Soil Treatment Area = (50 SF)(1.0)(0.7) = 35 Square Feet # of Quick4 Chambers = (35 / 12) = 3 Chambers **For conservatism, use a single trench with 6 chambers** System Installation The installation of the septic tank, plumbing lines, Infiltrators, etc. should be completed in accordance with Garfield County and Infiltrator Systems, Inc. specifications. In addition, the following construction procedures are recommended: C:\HBEI\Projecl Files \2020\ 01178-0124 Branded Rock\200 - Geo\01178-0124 LR022420.doc 2 Branded Canyon Ranch #01178-0124 02/22/20 Huddleston -Berry &oaring F Testing. LLC • The septic tank and distribution box should be placed level over native soils that have been scarified to a depth of 8 to 12 inches, moisture conditioned, and recompacted to a minimum of 95% of the standard Proctor maximum dry density, within ±2% of optimum moisture content. However, up to 3 -inches of washed rock or pipe bedding passing the 1 -inch sieve may be used as a leveling course under the septic tank and/or distribution box. • The bottoms of trenches and backfill around the septic tank and distribution box which will support sewer or effluent lines should be compacted to at least 90 percent of the standard Proctor maximum dry density, within ±2% of optimum moisture content. Pipe bedding should have a maximum particle size of 1 -inch. • Vehicular or heavy equipment traffic and placement of structures should not encroach within 10 feet of the septic tank or distribution box. Inspection Schedule Huddleston -Berry Engineering & Testing LLC should be retained to monitor the construction of the OWTS. The following schedule of observation and/or testing should be followed: ■ Observe the absorption bed excavation prior to placement of Infiltrator chambers. ■ Observe placement of the septic tank, distribution box, and all connecting sewer and effluent lines prior to backfill. Verify proper fall between inverts. ■ Observe and verify installation of the absorption bed prior to placement of cover and backfill. In conformance with Garfield County regulations, HBET will be required to provide Garfield County with documentation certifying that the OWTS was placed in conformance to the plan and profile and Garfield County regulations. General Notes The OWTS design was based upon the results of the subsurface investigation and on our local experience. The design is valid only for the proposed construction We are pleased to be of service to your project. Please contact us if you have any questions or comments regarding the contents of this report. Respectfully Submitted: Huddleston -Berry Engineering and Testing, LLC Michael A. Berry, P.E. Vice President of Engineering C:\H13B9Wroject Files\2020\01178-0124 Branded Rock\200 - Geo \01178-0124 LR022420.doc 3 FIGURES Go ;,: de Earth leml 20 40 FIGURE 1 Site Location Map A GENERALIZED SYSTEM PROFILE SITE PLAN 11 SCALE: 1" = 30' A TEST PIT C.I. =2 FT \ \ \ \ \ \ \ 30. \ \ f f l I 1 TP-1 SG I ,1 NEW BUILDING V I I WATER TINE: EIIiCASE 2D' MIN 5CH 40 PVC PIP T' to. :N IS WITHIN 90 FT INSPECTION POR I Ili I 1% STA e � 24.15. I •*� a• C TANK WITH ! MINIMUM 500 I ! INFILTRATOR SYSTEMS GALLON CAPACITY /! ! 111 QUICK4 STANDARD C h / ! l \% i 4-INCH DIAMETER SEWER AND ! 5 \ EFFLUENT PIPS. MEETING ASTM / / R PAIR AREA . D1785, SCF4FERI E 40 OR SDR 35 / / / ; =:. I \ ,/ • ; t' . -J A S3 3.'010 V DIRT ROAD ,Z�'�+[� SAO t ~' ,.W ' ��4,0if Al E,- �'• - * ' WATER LINE IN WHERE WATER LINE F EFFLUIVTI.T2.'ES � I I j "USE SWEEP 90'S OR TWO 45'S AT 90 DEGREE BENDS"Vi SHOOTING STRUCTURE NOT TO SCALE RISERS (AS NECESSARY) H THAT LIDS ARE AT OR ABOVE FINISHED GRADE INFILTRATOR OUICK4 CLE NWT STANDARD CHAMBERS IA F T HIM. COVER IZ FAS MIM. - k. °r FxL I ON EFallENI L111E5 EST. 6.0 - �:F'.-`1 Hyl in}.{_ :}.{•}.?.; �•.v •?•}t:St::: �`}•'::• ..: ' ••, TO 0.0 FT eii.}+'fF • �; ti`�. EST. 2A FT _} sxi 4.0 FT MAX, 1.0 FT MRI. COVER- SE41C TANK GENERALIZED TRENCH PROFILE NOT TO SCALE INFILTRATOR SYSTEMS QUICK COVER SOIL; NATIVE SOILS OR OTHER SUITABLE STANDARD CHAMBERS OPSOIL- GRADE TO CARRY SURFACE WATER AWAY FROM BED. EI: I� • '11 I-- I= ONWOVEN. NEEDLE PUNCHED, GEOTEXTILE/ FABRIC IMMEDIATELY ABOVE CHAMBERS MINIMUM SETBACKS (UNITS =FT) VEILS WATER LINE GATED PIPE LINED DITCH FLOODED FIELDS LAKE, STREAM, UNLINED DITCH DWELLING UNOCCUPIED BALDINGPREPERTY LIRE '" ''1 """ '"^` 50 10 10 10 10 50 ID 5 ID """" "' Ivo 25 25 l0 25 50 20 5 10 ,NES ' 50 10 10 10 10 50 -+ •+ 10 Project No.: 01178-0124 Date: 02/24/20 By: MAB 1 ._ Huddleston-Berry Engineering & Tcsring, LLC 2789 Riverside Parkway Grand Junction, CO 81501 BRANDED ROCK CANYON SHOOTING BUILDING FIGURE 2 - SITE PLAN AND DETAILS "OTHER SETBACKS NOT LISTED HERE SHOULD BE IN ACCORDANCE WITH GARFIELD COUNTY OWTS REGULATIONS APPENDIX A Typed Test Pit Log GEOTECH BH COLUMNS 01178-0124 BRANDED ROCK.GPJ GINT US LAB.GDT 2114/20 1 v a L l 1 1 I 1 I. Ln I 1 I 1 r l i w a 1 1 1 1 I na Lit 1 p DEPTH a (ft) DATE STARTED 1/28/20 COMPLETED 1/28/20 GROUND ELEVATION — TEST PIT SIZE EXCAVATION CONTRACTOR Client GROUND WATER LEVELS: EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry LOGGED BY SD CHECKED BY MAB AT END OF EXCAVATION dry NOTES AFTER EXCAVATION -- * `'w„ Huddhston-Beery Engineering & Testing, LLC TEST PIT NUMBER TP -1 g �2789 Riverside Parkway PAGE 1 OF 1 €' Grand Junction, CO 81501 ` 970-255-8005 • CLIENT Porter Homes PROJECT NAME Branded Rock Canyon Ranch PROJECT NUMBER 01178-0124 PROJECT LOCATION DeBeque, CO : '.1 .. r.= GRAPHIC •' ' :r : LOG :-,-...:•:_--:.:...:-.'.--Z r Z Bottom of test plt at 10.0 feet. Silty SAND with Gravel (SM), brown• moist, medium dense ***Lab Classified GB2 SILT (ML), brown, moist, medium dense ***Lab Classified GB1 MATERIAL DESCRIPTION SILT with Organics (TOPSOIL) ry W -, m SAMPLE TYPE NUMBER RECOVERY % (RQD) BLOW COUNTS (N VALUE) POCKET PEN. (tsf) DRY UNIT WT. (Pu) c' MOISTURE CONTENT (%) z co LIQUID LIMIT ATTERBERG LIMITS z co o PLASTIC LIMIT zPLASTICITY INDEX CO -.I(%) FINES CONTENT APPENDIX B Percolation Testing Results PERCOLATION TESTING Project No. 01178-0124 Project Name: Branded Rock Ranch Location DeSeque, CO Testing Conducted By: Pit Dimensions: Length Water Level Depth: Sam Dinterman SOIL PROFILE Depth Description Test Pit No. TP -1 Date: 1/29/2020 Supervising Engineer: M. Berry ; Width Not Encountered X : Depth 10.0 ft Remarks 0-1 ft SILT with Organics (TOPSOIL) Change (in.) 1-5 ft SILT (ML), brown, moist, medium dense 5-10 ft Silty SAND with Gravel (SM), brown, moist, medium dense 2.25 10 6 1 15 7 1 Test Number: 1 Top of Hole Depth: 3 ft Diameter of Hole 8 -in. Depth of Hole: 20 -in. Time (min.) Water Depth (in.) Change (in.) 0 2.75 5 5 2.25 10 6 1 15 7 1 20 8 1 25 8.75 0.75 30 9.5 0.75 35 10.25 0.75 40 10.875 0.625 45 11.5 0.625 50 12 0.5 55 12.5 0.5 60 13 0.5 Rate (min/in): 10 Average Percolation Rate (min/in): Test Number: 2 Top of Hole Depth: 6 ft Diameter of Hole: 8 -in. Depth of Hole: 19 -in. Time (min.) Water Depth (in.) Change (in.) 0 3 5 6.25 3.25 10 8 1.75 15 9.5 1.5 20 10.75 1.25 25 11.625 0.875 30 12.75 1.125 35 13.5 0.75 40 14.25 0.75 45 15 0.75 50 15.75 0.75 55 16.375 0.625 60 17 0.625 Rate (min/in): I 7 Test Number: Top of Hole Depth: Diameter of Hole: Depth of Hole: Time (min.) Water Depth (in.) Change (in.) Rate (min/in):