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Home My WebLink AboutOWTS Design 09.23.20212789 Riverside Parkway Grand Junction, Colorado 81501 Phone: 970-255-8005 Info@huddlestonberry.com September 23, 2021 Project#02293-0001 Lucky Seven LLC 336 Evergreen Drive Rifle, Colorado 81650 Attention: Mr. Javier Orozco Subject: OWTS Design 10991 CR 320 Rifle, Colorado Dear Mr. Orozco, At your request, Huddleston-Berry Engineering & Testing, LLC completed design of an Onsite Wastewater Treatment System (OWTS) for a single-family residence at 10991 CR 320 in Rifle, Colorado. 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, a garage structure occupied the northwest portion of the site. The remainder of the site was open and gradually sloping down towards the north. Site topography is shown on Figure 2. Vegetation consisted of weeds, grasses, and small to large trees. The site was bordered to the north by open land, to the west and east by residential properties, and to the south by CR 320. Subsurface Investigation In order to evaluate the subsurface conditions at the site, four test pits were excavated at the site. The locations of the test pits are shown on Figure 2. Copies of the test pit logs are included in Appendix A. As indicated on the logs, the subsurface conditions at the site were consistent. The test pits generally encountered 1.0 foot of loam above tan sandy loam soils with trace gravel and cobbles to the bottoms of the excavations. The soils were massive, structureless, and firm. Groundwater was not encountered in the subsurface at the time of the investigation. In general, HBET believes that the seasonal high groundwater elevation is deeper than 8.0 feet at this site. Onsite Wastewater Treatment System Seepage Bed Design The design of the absorption system generally follows the requirements of the Garfield County Department of Public Works as outlined in the Garfield County On-Site Wastewater Treatment System Regulations, effective July 2018. The proposed construction at the site is anticipated to include a three-bedroom home. 10991 CR 320 #02293-0001 09/23/21 Z:\2008 ALL PROJECTS\02293 - Lucky Seven LLC\02293-0001 10991 CR 320\200 - Geo\02293-0001 LR092321.doc 2 Based upon visual-tactile evaluation of the site soils in accordance with the regulations, a Long- Term Acceptance Rate (LTAR) of 0.5 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 = (6 persons)(75 GPD/person) = 450 GPD Soil Treatment Area = (450 GPD / 0. 5) = 900 Square Feet Adjusted Soil Treatment Area = (900 SF)(1.2)(0.7) = 756 Square Feet # of Quick4 Chambers = (756 / 12) = 63 Chambers; Use 64 Chambers System Installation The installation of the septic tank, plumbing lines, Infiltrators, etc. should be completed in accordance with the Garfield County On-Site Wastewater Treatment System Regulations and Infiltrator Systems, Inc. specifications. In addition, the following construction procedures are recommended:  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 the Garfield County Health Department 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. 10991 CR 320 #02293-0001 09/23/21 Z:\2008 ALL PROJECTS\02293 - Lucky Seven LLC\02293-0001 10991 CR 320\200 - Geo\02293-0001 LR092321.doc 3 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 09/23/21 3,203 ft 2789 Riverside Parkway Grand Junction, CO 81501 Project No.: 02293-0001 Date: 09/23/21 By: MAB 10991 CR 320 PARCEL#217720100010 FIGURE 2 - SITE PLANTEST PIT C.I. = 2 FT SCALE: 1" = 60' **NOTE:TANK AND BED LOCATIONS APPROXIMATE AND MAY SHIFT SOME DURING CONSTRUCTION BASED UPON SITE TOPOGRAPHY, OWNER PREFERENCE, AND/OR OTHER FACTORS AS LONG AS APPLICABLE SETBACKS ARE MET. ACTUAL LOCATION OF TANK AND BED WILL BE INDICATED ON AS-BUILT DRAWINGS.** WATER LINE LAST CHANCE DITCH NEW HOME REPAIR AREA MINIMUM 1,000 GALLON TANK STA 53405330532053505322532453265328533253345336533853425344534653485352TP-1 TP-3 TP-2 TP-4 ~48' 64' 12' ~20' (10' MIN) ~78'~20' ~9' ~70'6" ~53' ~171'6" ~117' ~205' ~240' NEW DRIVEWAY ~78' ~46' ~31' ~24' ~25'~132' EXISTING STRUCTURES 09/23/21 2789 Riverside Parkway Grand Junction, CO 81501 Project No.: 02293-0001 Date: 09/23/21 By: MAB MINIMUM SETBACKS (UNITS = FT) **OTHER SETBACKS NOT LISTED HERE SHOULD BE IN ACCORDANCE WITH GARFIELD COUNTY OWTS REGULATIONS **USE SWEEP 90'S OR TWO 45'S AT 90 DEGREE BENDS** DETAIL AREA SCALE: 1" = 20' 10991 CR 320 PARCEL#217720100010 FIGURE 3 - SEPTIC SYSTEM DETAILS 64' 12' 5' MIN 20' MIN 4-INCH DIAMETER SEWER AND EFFLUENT PIPE MEETING ASTM D1785, SCHEDULE 40 OR SDR 35 DISTRIBUTION BOX THAT ENSURES EVEN DISTRIBUTION OF EFFLUENT SEPTIC TANK WITH MINIMUM 1,000 GALLON CAPACITY WATER LINE INFILTRATOR SYSTEMS QUICK4 STANDARD CHAMBERS NEW HOME INSPECTION PORTS 5' MIN GENERALIZED SYSTEM PROFILE GENERALIZED BED PROFILE COVER SOIL; NATIVE SOILS OR OTHER SUITABLE TOPSOIL. GRADE TO CARRY SURFACE WATER AWAY FROM BED. NONWOVEN, NEEDLE PUNCHED, GEOTEXTILE FABRIC IMMEDIATELY ABOVE CHAMBERS INFILTRATOR SYSTEMS QUICK4 STANDARD CHAMBERS 09/23/21 APPENDIX A Typed Test Pit Logs 1.0 7.0 Loam Sandy Loam, trace gravel and cobbles, tan, massive, structureless, firm Bottom of test pit at 7.0 feet. NOTES GROUND ELEVATION LOGGED BY SD EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry AT END OF EXCAVATION dry AFTER EXCAVATION --- TEST PIT SIZE EXCAVATION CONTRACTOR Hi-River GROUND WATER LEVELS: CHECKED BY MAB DATE STARTED 5/19/21 COMPLETED 5/19/21 DEPTH(ft)0.0 2.5 5.0 SAMPLE TYPENUMBERPAGE 1 OF 1 TEST PIT NUMBER TP-1 CLIENT Lucky Seven LLC PROJECT NUMBER 02293-0001 PROJECT NAME 10991 CR 320 PROJECT LOCATION Rifle, CO GENERAL BH / TP / WELL 02293-0001 CR 320 RIFLE USDA.GPJ GINT US LAB.GDT 9/23/21Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 GRAPHICLOGMATERIAL DESCRIPTION 1.0 8.0 Loam Sandy Loam, trace gravel and cobbles, tan, massive, structureless, firm Bottom of test pit at 8.0 feet. NOTES GROUND ELEVATION LOGGED BY SD EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry AT END OF EXCAVATION dry AFTER EXCAVATION --- TEST PIT SIZE EXCAVATION CONTRACTOR Hi-River GROUND WATER LEVELS: CHECKED BY MAB DATE STARTED 5/19/21 COMPLETED 5/19/21 DEPTH(ft)0.0 2.5 5.0 7.5 SAMPLE TYPENUMBERPAGE 1 OF 1 TEST PIT NUMBER TP-2 CLIENT Lucky Seven LLC PROJECT NUMBER 02293-0001 PROJECT NAME 10991 CR 320 PROJECT LOCATION Rifle, CO GENERAL BH / TP / WELL 02293-0001 CR 320 RIFLE USDA.GPJ GINT US LAB.GDT 9/23/21Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 GRAPHICLOGMATERIAL DESCRIPTION 1.0 3.0 Loam Sandy Loam, trace gravel and cobbles, tan, massive, structureless, firm Bottom of test pit at 3.0 feet. NOTES GROUND ELEVATION LOGGED BY SD EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry AT END OF EXCAVATION dry AFTER EXCAVATION --- TEST PIT SIZE EXCAVATION CONTRACTOR Hi-River GROUND WATER LEVELS: CHECKED BY MAB DATE STARTED 5/19/21 COMPLETED 5/19/21 DEPTH(ft)0 1 2 3 SAMPLE TYPENUMBERPAGE 1 OF 1 TEST PIT NUMBER TP-3 CLIENT Lucky Seven LLC PROJECT NUMBER 02293-0001 PROJECT NAME 10991 CR 320 PROJECT LOCATION Rifle, CO GENERAL BH / TP / WELL 02293-0001 CR 320 RIFLE USDA.GPJ GINT US LAB.GDT 9/23/21Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 GRAPHICLOGMATERIAL DESCRIPTION 1.0 3.0 Loam Sandy Loam, trace gravel and cobbles, tan, massive, structureless, firm Bottom of test pit at 3.0 feet. NOTES GROUND ELEVATION LOGGED BY SD EXCAVATION METHOD Trackh/Backhoe AT TIME OF EXCAVATION dry AT END OF EXCAVATION dry AFTER EXCAVATION --- TEST PIT SIZE EXCAVATION CONTRACTOR Hi-River GROUND WATER LEVELS: CHECKED BY MAB DATE STARTED 5/19/21 COMPLETED 5/19/21 DEPTH(ft)0 1 2 3 SAMPLE TYPENUMBERPAGE 1 OF 1 TEST PIT NUMBER TP-4 CLIENT Lucky Seven LLC PROJECT NUMBER 02293-0001 PROJECT NAME 10991 CR 320 PROJECT LOCATION Rifle, CO GENERAL BH / TP / WELL 02293-0001 CR 320 RIFLE USDA.GPJ GINT US LAB.GDT 9/23/21Huddleston-Berry Engineering & Testing, LLC 2789 Riverside Parkway Grand Junction, CO 81501 970-255-8005 GRAPHICLOGMATERIAL DESCRIPTION