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HomeMy WebLinkAbout1142 Summit Trl - 210716302002Environmental Health Department P.O. Box 179 500 Broadway Eagle, CO 81631-0179 Phone: (970) 328-8730 Fax: (970) 328-7185 Permit Permit No. OWTS-024637-2022 Permit Type: OWTS Permit Work Classification: New Permit Status: Active Issue Date: 7/11/2022 Expires: 11/14/2022 On-Site Wastewater Treatement System Project Address Parcel Number 1142 THE SUMMIT TRL, EDWARDS AREA,210716302002 Owner Information Address DCP Completed Gifted Trust/Drake Powell Phone: Cell: Email: drake.powell@assetliving.com Inspections: For Inspections Call: (970) 328-8755 Engineer Phone Email KUMAR & ASSOCIATES, Dave Young (970) 945-7988 dyoung@kumarusa.com Contractor License Number Phone Email Permitted Construction / Details: Install the new system exactly as depicted in the Kumar & Associates design dated April 4th, 2022, stamped and signed on April 5th, 2022 by David A Young, PE. This system is designed to accommodate the maximum daily flows for a 5 bedroom residence. The OWTS consists of one sewer line from the residence. The OWTS consists of a Valley Precast 1,500 gallon three-compartment septic tank (2,000 gallon total volume) with an ORENCO PF3005 submersible effluent pump and Biotube Vault installed in the third compartment, with floats set to pressure dose 104 gallons of effluent to the soil treatment area (STA). The STA consists of two rows of 22 Infiltrator Quick4 Plus Standard chambers in bed configuration for a total of 44 with distribution lines extending the length of the chambers set on a mounded sand filter. The sand filter consists on a gravel distribution cell 6 feet wide by 88 feet long, over a basal area of secondary sand 24 feet wide and 88 feet long, with additional area for edges sloped a minimum of 3 to 1. Distribution lateral size, orifice size, and orifice separation shall be exact to design. A swale may be necessary along the up slope side of the STA to deflect surface water away from the STA. Note: Gradation of the sand media use must be completed within one month prior to the installation and confirmed with the design engineer. If the sand does not conform to secondary or preferred sand media requirements, it cannot be used for the sand treatment media. An additional test pit immediately adjacent to the STA must be conducted and reviewed by the Design Engineer, prior to installation. Any changes required to the design must first be reviewed and approved by the Design Engineer and Eagle County Environmental Health Specialist. A licensed installer has not been identified. No person shall install, renovate, or repair an OWTS in Eagle County (EC) without a valid EC Systems Contractor License. Any person that conducts a business as a systems contractor without having obtained a valid license section commits a Class 1 petty offense as defined in section 18-1.3-503, C.R.S. Please notify the department when an installer is identified, prior to installation of the OWTS. Contact Eagle County Environmental Health and the design engineer well in advance of requesting inspections prior to backfilling any component of the OWTS. The design engineer is responsible for conducting all inspections necessary to certify the installation and assure the functionality of the system. System certification, along with photos and a record drawing is required to be submitted to and approved by Eagle County Environmental Health prior to the use of the system or occupancy of the dwelling. Monday, July 11, 2022 1 THIS PERIMT EXPIRES BY TIME LIMITATION AND BECOMES NULL AND VOID IF THE WORK AUTHORIZED BY THE PERMIT IS NOT COMMENCED WITHIN 120 DAYS OF ISSUANCE, OR BEFORE THE EXPIRATION OF AN ASSOCIATED BUILDING PERMIT Issued by: Environmental Health Department, Eagle County, CO Danielle Salinsky Date July 11, 2022 CONDITIONS 1. 2.ALL INSTALLATIONS MUST COMPLY WITH ALL REQUIREMENTS OF THE EAGLE COUNTY PUBLIC HEALTH AGENCY ON-SITE WASTEWATER TREATMENT SYSTEM REGULATIONS ADOPTED PURSUANT TO AUTHORITY GRANTED IN CR.S. 25-10-101, et seq., AS AMENDED 3.THIS PERMIT IS VALID ONLY FOR PERFORMING WORK ON OWTS ASSOCIATED WITH STRUCTURES WHICH HAVE FULLY COMPLIED WITH COUNTY ZONING AND BUILDING REQUIREMENTS CONNECTION TO, OR USE WITH, ANY DWELLING OR STRUCTURE NOT APPROVED BY THE ZONING AND BUILDING DEPARTMENTS SHALL AUTOMATICALLY BE A VIOLATION OF A REQUIREMENT OF THE PERMIT AND WILL RESULT IN BOTH LEGAL ACTION AND REVOCATION OF THE PERMIT4.1.6(A)(1) EAGLE COUNTY PUBLIC HEALTH AGENCY ON-SITE WASTEWATER TREATMENT SYSTEM REGULATIONS REQUIRES ANY PERSON WHO CONSTRUCTS, ALTERS OR INSTALLS AN ON-SITE WASTEWATER TREATMENT SYSTEM TO BE LICENSED Monday, July 11, 2022 2 Inspection Result Eagle County, Colorado P.O. Box 179 500 Broadway Eagle, CO Phone: (970) 328-8730 Fax: (970) 328-7185 IVR Phone: 1-866-701-3307 Inspection Number: INSP-524099-2023 Permit Number: OWTS-024637-2022 Inspection Date: 09/25/2023 Inspector: Salinsky, Danielle Permit Type: OWTS Permit Inspection Type: OWTS Final Inspection Work Classification: NewOwner:DCP Completed Gifted Trust/Drake Powell Job Address:1142 THE SUMMIT TRL IVR Pin Number:196553 EDWARDS AREA, CO Project:<NONE> Parcel Number:210716302002 Contractor:Phone: / Cell: Inspection Status: Approved Inspection Notes Inspector Comments Added Item: Septic Tank Inspected and verified 7/28/2023. aA Valley Precast 1,500 gallon three-compartment septic tank (2,000 gallon total volume) with an ORENCO PF3005 submersible effluent pump and Biotube Vault wqas installed in the third compartment, with floats set to pressure dose 104 gallons of effluent to the soil treatment area (STA). Added Item: Record Drawing Received 9/22/2023 from K&A. Added Item: Record Photos Received 9/22/2023 from K&A. Added Item: Site and Soil Inspected and verified 7/28/2023. Received 7/6/2022. Added Item: Final Certification Letter Received 9/22/2023 from K&A. Added Item: General Plan Received 7/6/2022. Added Item: Soil Treatment Area (STA) Monday, September 25, 2023 For more information visit: http://www.eaglecounty.us Page 1 of 2 Inspected and verified 7/28/2023. The STA consists of two rows of 22 Infiltrator Quick4 Plus Standard chambers in bed configuration for a total of 44 with distribution lines extending the length of the chambers set on a mounded sand filter. The sand filter consists on a gravel distribution cell 6 feet wide by 88 feet long, over a basal area of secondary sand 24 feet wide and 88 feet long, with additional area for edges sloped a minimum of 3 to 1. Added Item: Identification of Systems Contractor JV Excavating was the licensed installer. Monday, September 25, 2023 For more information visit: http://www.eaglecounty.us Page 2 of 2 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email: kaglenwood@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado September 20, 2023 Pure Design Studio Attn: Millie Aldrich P.O. Box 527 Wolcott, Colorado 81655 millie@puredesign-studio.com Project No. 20-7-595.02 Permit No. OWTS-024637-2022 Subject: Certification of Onsite Wastewater Treatment System, Proposed Powell Residence, Lot 7, Block 2, Filing 36, Cordillera, 1142 Summit Trail, Eagle County, Colorado Dear Millie: A representative of Kumar & Associates observed the installation of the Onsite Wastewater Treatment System (OWTS) for the residence at the subject site as required by the Eagle County Environmental Health Department. Our observations and recommendations are presented in this report. The services are supplemental to Kumar & Associates agreement for professional services to Pure Design Studio dated February 21, 2022. We previously designed the OWTS for the residence as submitted in our report dated April 4, 2022, Project No. 20-7-595.02. The system was designed for five bedrooms. The OWTS was installed by Meadow Mountain Homes under Permit No. OWTS-024637-2022. We performed our as-built evaluations on June 16 and July 27 and 28, 2023. The OWTS components observed included: sewer line, cleanout, septic tank, effluent line, pump, control panel and soil treatment area (STA) and the locations of these components. The installation and locations of the system components were verified as shown on Figure 1. Pictures of the OWTS components made during the site visits are included with this report. The distance locations to the septic tank shown on Figure 1 were made by taping. On June 16, 2023, two profile pits (Profile Pits 1 and 2) were excavated to verify the subsoil conditions to adjacent the east and west sides of the STA and located as shown on Figure 1. The soils encountered were similar to the soils previously encountered in the area and below about 1 to 2 feet of organic topsoil, consisted of about 1 to 2 feet of gravelly Clay Loam. In both Profile Pits, hard basalt rock was encountered at 3 feet depth and practical digging refusal was encountered at 4 feet depth. No free water was encountered in the pits nor indications of seasonally high groundwater were observed at the time of excavation. On June 21, 2023, a sample of the secondary sand media was obtained and the results of gradation analysis test are attached. On July 28, 2023, after power had been supplied to the pump, a pump performance test was performed with adequate pump pressure observed. Lot 6 P r o p e r t y L i n e P r o p e r t y L i n eS u m m i tT r a i l8910 89208920893089306' @ 0% Asphalt Drive Prop os e d 5 Be dr o o m Resi de nce 1142 S u m mit Tr ail Lot 7, Bl oc k 2, Fili n g 3 6, C or diller a FFE 8936.5' Garage FFE 8934.5' FFE 8924.5' FFE 8924.5' FFE 8936.5' Patio Deck (above) (25.9')(2%) 26 323432893032 8930 28 26 2422343289302826242236 36343228 164' @ 4%2 0 ' @ 4% 26.8' 33.2' 34' @ 4% 34.5'2628 30 32 3 4 382:1 32.4' FFE 8934.5' Inlet Rim El. 33.5' 25.9' 2% 12'-0" Inlet Rim El. 23.0' 2:1Elec t r ic /Cab le /Gas Cover Storage 12" inlet invert out 8" HDPE storm=20.5' Daylight 8" storm 19.5' 30'@3.3% slope install rock rip rap at outlet 12" inlet invert out 8" HDPE storm=31.5' Daylight 8" storm 29.0' 98'@1% slope install rock rip rap at outlet Kumar & Associates GRADATION ANALYSIS TEST LABORATORY TEST REPORT DATA Laboratory Client: Location / Plant: Sample / Product: Sample Date: Lab Test Date: Job Number: SIEVE SIEVE OPENING IN MILLIMETERS PERCENT PASSING THRU SIEVE 3"75 100.0 1.5 37.5 100.0 3/4"19 100.0 3/8"9.5 100.0 No. 4 4.75 100.0 No. 8 2.36 81.0 No. 16 1.18 64.0 No. 30 0.6 45.0 No. 50 0.3 19.0 No. 100 0.15 6.0 No. 200 0.075 2.0 GRADATION RESULTS COMPARED TO PREFERRED AND SECONDARY SAND FILTER SPECIFICATIONS Value Units Preferred Sand Value Pass / Fail Preferred Sand Secondary Sand Value Pass / Fail Secondary Sand 1.06 millimeters 0.196 millimeters 0.25 to 0.60 FAIL 0.15 to 0.60 PASS 5.39 unitless ratio < or = 4.0 FAIL < or = 7.0 PASS 2.0 millimeters < or = 3 PASS < or = 3 PASS Effective Size - D10 - Diameter that 10 percent of the sample is finer than. Kumar Glenwood Springs Pure Design Studio Western Slope Materials - Silt Secondary Sand 06/21/2023 Uniformity Coefficient (D60 / D10) Percent passing thru #200 Sieve 06/21/2023 20-7-595.02 Parameter D60 - Diameter that 60 percent of the sample is finer than. 0 10 20 30 40 50 60 70 80 90 100 0.01 0.1 1 10 100Percent Passing SieveDiameter of Particle in Millimeters Plot of Gradation Analysis 3"1.5"3/4"3/8"#4#8#30#50#100#200 #16 OWTS PHOTOGRAPH LOG POWELL RESIDENCE LOT 7, BLOCK 2, FILING 36, CORDILLERA 1142 SUMMIT TRAIL EAGLE COUNTY, COLORADO Project No. 20-7-595.02 Photograph 1: Sewer line exiting residence, cleanout, and Valley Precast 1,500-gallon, 3 chamber septic tank. Photograph 2: Pump installed in the third chamber of the septic tank. OWTS PHOTOGRAPH LOG POWELL RESIDENCE LOT 7, BLOCK 2, FILING 36, CORDILLERA 1142 SUMMIT TRAIL EAGLE COUNTY, COLORADO Project No. 20-7-595.02 Photograph 3: 1.5” Schedule 40 effluent transport line to soil treatment area (STA). Photograph 4: Soil treatment area (STA): Infiltrator Quick4 Plus chambers distribution cell over sand filter. OWTS PHOTOGRAPH LOG POWELL RESIDENCE LOT 7, BLOCK 2, FILING 36, CORDILLERA 1142 SUMMIT TRAIL EAGLE COUNTY, COLORADO Project No. 20-7-595.02 Photograph 5: Control panel. 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email: kaglenwood@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado PRELIMINARY ONSITE WASTEWATER TREATMENT SYSTEM DESIGN PROPOSED POWELL RESIDENCE LOT 7, BLOCK 2, FILING 36, CORDILLERA 1142 SUMMIT TRAIL EAGLE COUNTY, COLORADO PROJECT NO. 20-7-595.02 APRIL 4, 2022 PREPARED FOR: PURE DESIGN STUDIO ATTN: MILLIE ALDRICH P. O. BOX 527 WOLCOTT, COLORADO 81655 (millie@puredesign-studio.com) Kumar & Associates, Inc. Project No. 20-7-595.02 TABLE OF CONTENTS INTRODUCTION ...................................................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 1 - SUBSURFACE CONDITIONS ................................................................................................. - 2 - OWTS ANALYSIS .................................................................................................................... - 2 - DESIGN RECOMMENDATIONS ............................................................................................ - 3 - SOIL TREATMENT AREA................................................................................................... - 3 - OWTS COMPONENTS ......................................................................................................... - 4 - OWTS OPERATION AND MAINTENANCE.......................................................................... - 7 - OWTS HOUSEHOLD OPERATION .................................................................................... - 7 - OWTS MAINTENANCE ....................................................................................................... - 8 - OWTS CONSTRUCTION OBSERVATION ............................................................................ - 8 - LIMITATIONS ........................................................................................................................... - 8 - FIGURES FIGURE 1 – OWTS SITE PLAN FIGURE 2 – SOIL TREATMENT AREA CALCULATIONS FIGURE 3 – SOIL TREATMENT AREA PLAN VIEW FIGURE 4 – SOIL TREATMENT AREA CROSS SECTION FIGURE 5 – DISTRIBUTION LINE CLEANOUT DETAIL ATTACHMENTS VALLEY PRECAST 1,500 GALLON, THREE-CHAMBER SEPTIC TANK DETAIL ORENCO PF3005 PUMP PERFORMANCE CURVE Kumar & Associates, Inc. Project No. 20-7-595.02 INTRODUCTION This report provides the preliminary results of an onsite wastewater treatment system (OWTS) design for the proposed residence to be located on Lot 7, Block 2, Filing 36, Cordillera, 1142 Summit Trail, Eagle County, Colorado. The purpose of this report was to provide design details for the OWTS in accordance with the 2018 Eagle County Onsite Wastewater Treatment System Regulations and the Colorado Department of Public Health and Environment’s Regulation #43. The study was performed as part of our agreement to Pure Design Studio dated February 21, 2022. BACKGROUND INFORMATION We previously prepared a subsoil study for foundation design of the residence and submitted our findings in a report dated December 31, 2020, Project No. 20-7-595. Information from that report has been considered in the preparation of the OWTS design. Profile Pits have not been excavated at the time of this report due to considerable snow cover on the site. Soil classification for the preliminary design is based on the borings from the previous subsoil study which encountered shallow bedrock. Profile pits need to be excavated and subsoils further evaluated to finalize the OWTS design prior to construction. PROPOSED CONSTRUCTION The residence will be a five-bedroom single-family structure with an attached garage located on the lot as shown on Figure 1. The residence will have a walkout basement with a finish floor elevation of 8,924.5 feet. The OWTS will be designed for a total of 5 bedrooms. The proposed OWTS soil treatment area (STA) will be located to the east of the residence. Water service will be provided to the residence by the public water supply from Summit Trail and the water service line will likely go along the driveway alignment. If proposed construction is different than that described, we should be contacted to re-evaluate our final design recommendations. SITE CONDITIONS The lot was vacant at the time of field exploration and the ground surface appeared mostly natural. The terrain is relatively flat in the uphill, northwest part of the building envelope. In the area of the proposed residence and proposed STA, the terrain slopes moderately steep down to the southeast at a grade of about 20%. Vegetation on the lot consists oak brush, sagebrush, grass and weeds. No surface water features were observed in the near vicinity of the lot. We are not aware of any nearby water wells. - 2 - Kumar & Associates, Inc. Project No. 20-7-595.02 SUBSURFACE CONDITIONS The field exploration for the subsoil study was conducted on October 20, 2020. Two exploratory borings were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. The borings were advanced with 4 inch diameter continuous flight augers powered by a truck- mounted CME-45B drill rig. The borings were logged by a representative of Kumar & Associates. Log of Boring 1 Depth USDA Classification 0-½’ TOPSOIL; organic loam, firm, slightly moist, dark brown. ½’-1’ SANDY CLAY; moderate blocky structure, stiff, slightly moist, dark brown. 1’-12’ WEATHERED SANDSTONE; hard, slightly moist, tan. 12’-31’ BASALT FLOW; clayey, hard to very hard, slightly moist, dark brown. • Bottom of boring @ 31 feet. • No free water or redoximorphic features observed at time of pit excavation. Log of Boring 2 Depth USDA Classification 0-2’ TOPSOIL; organic loam, firm, slightly moist, dark brown. 2’-4’ SANDY CLAY; moderate blocky structure, stiff, slightly moist, dark brown. 4’-10’ WEATHERED BASALT AND ASH; clayey, sandy, hard to very hard, slightly moist, tan and brown 10’-26’ BASALT FLOW; clayey, hard to very hard, slightly moist, dark brown. • Bottom of boring @ 26 feet. • No free water or redoximorphic features observed at time of pit excavation. Based on the subsurface conditions encountered at the site and laboratory testing, the near surface soils the site have been classified as Type 4 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.20 gallons per square foot per day for the Clay soils. OWTS ANALYSIS Based on the site conditions, our previous subsoil study information and our experience in the area, the clay soils are expansive and tend to swell when wetted. Based on these considerations and the presence of shallow bedrock, we recommend a mounded sand wastewater treatment system for proper treatment of the effluent. The system will consist of chambers in a bed configuration overlying a sand filter placed on the native ground surface. The STA will be sized five bedrooms (eight persons) using an LTAR of 0.8 gallons per square foot per day for imported “secondary sand media”. The STA basal area of the sand will be sized for Soil Type 4 with an LTAR of 0.20 gallons per square foot per day. - 3 - Kumar & Associates, Inc. Project No. 20-7-595.02 The sewage will gravity flow from the residence to the septic tank for primary treatment and then be pressured-dosed on a regular basis to the STA for dispersal and final treatment. Pressure dosing is necessary for the sand treatment system. DESIGN RECOMMENDATIONS The preliminary design recommendations presented below are based on the proposed construction, the site and subsurface conditions encountered, and our experience in the area. A layout of the proposed OWTS components is provided on Figure 1. If conditions encountered during construction are different than those that are described in this report, please contact us to re-evaluate our design recommendations. Profile Pit evaluations should be done at the STA for final design of the system. SOIL TREATMENT AREA • The STA will consist of 2 rows of 22 Infiltrator Quick 4 Plus Standard chambers in a bed configuration placed on imported secondary sand media. The sand media should be a minimum 12 inches thick and be placed on the native ground surface. A pressure distribution system will be used to disperse the effluent to the chambers on a regular basis. • The distribution cell was sized based on an LTAR of 0.80 gallons per square foot per day for secondary sand media. The basal area was sized using an LTAR of 0.20 gallons per square foot per day for Soil Type 4 for the natural Clay soils. • A 30% reduction of the STA size was applied for use of Infiltrator chambers. The proposed distribution cell will be 6 feet wide by 88 feet long (528 square feet). • The minimum basal area of the mound is 88 feet long by 24 feet wide (2112 square feet). • Soil treatment area calculations are shown on Figure 2. • Vegetation should be removed and the ground surface scarified to at least 3” deep prior to the sand placement. • Distribution lines, consisting of 1.5-inch diameter, Schedule 40 piping, with ⅛-inch diameter orifice holes drilled at 4-foot centers near the center of the Infiltrators, should be installed along the complete length of the chambers, see Figure 3. The distribution lines should be suspended approximately 2 inches from the top surface of the infiltrators by pipe ties. The orifice holes should face up toward the infiltrator surface above. • An ⅛-inch hole should be drilled on the bottom of each end of the distribution pipe to allow for complete drainage of the distribution line following pressure dosing. Install splash plates below drain holes. - 4 - Kumar & Associates, Inc. Project No. 20-7-595.02 • The sand bed should be oriented along ground contours to minimize soil cover. • Sand filter material should extend one foot horizontally from the perimeter of the chamber bed and then be sloped at 3 horizontal to 1 vertical maximum in all directions. • The sand filter media should meet the requirements of the current Eagle County OWTS Regulations for “secondary sand media”. ASTM C33 concrete sand is suitable for the filter media. A sample of the sand filter media should be obtained within one month prior to installation of the system for gradation analyses testing by us or the gradation test results of the sand provided to us for approval. • The sand filter material shall be placed in lifts not exceeding 10 inches thick. Each lift shall be track or bucket compacted until settlement ceases. • A minimum of 10 inches and a maximum of 24 inches of cover soil should be placed over the chambers. The cover soil should include 6 inches of topsoil. • Backfill should be graded to deflect surface water away from the STA and should be sloped at 3 horizontal to 1 vertical or flatter. This may require a swale along the up-slope side of the STA. • Disturbed soil should be re-vegetated as soon as possible with a native grass mix. No trees, shrubs or other plants with deep roots should be planted on or near the STA as this may damage the system piping. • Four-inch diameter inspection ports should be installed vertically into the knockouts provided in the Infiltrator end caps. Install ports at each corner of the bed. The inspection port piping should be screwed into the top to the chambers and should not extend down to the ground surface inside the chambers. The inspection ports should extend at least 8 inches above the finished ground surface or be protected in a valve box at finished grade. • The minimum setback from the STA to the water service supply line is 25 feet. Where the water line encroaches on the setback, the water line must be encased with larger diameter Schedule 40 PVC pipe in a watertight manner throughout the encroachment. • A plan view of the STA is presented on Figure 3 and a cross section of the STA is presented on Figure 4. • Cleanouts are required at the end of the distribution line. See Figure 5 for the cleanout detail. OWTS COMPONENTS Recommended OWTS components provided below are based on our design details and our experience with the specific component manufacturers. Equivalent components may be feasible but need to be approved by us prior to construction. - 5 - Kumar & Associates, Inc. Project No. 20-7-595.02 Septic Tank • A 1,500 gallon, three-chamber septic tank (2,000 gallons total) will be used for primary treatment and dosing to the STA. The first two chambers of the tank will be utilized for treatment and settling, and the third chamber of the tank will contain the dosing pump. A detail of the tank is provided as an attachment to the report. • A submersible effluent pump enclosed in a Biotube Pump Vault will be installed in the third chamber. • The tank must be a minimum of five feet from the residence and from the STA. The tank must be a minimum of 10 feet from any potable water supply lines. • The tank must be set level. The excavation bottom must be free of large rocks or other objects that could damage the tank during placement. A road base or gravel bedding material may be needed to prevent tank damage during placement and act as a leveling course. • The tank lids must extend to final surface grade and made to be easily located. • Install the tank with 2 feet minimum cover soil for frost protection. Maximum tank soil cover is 4 feet. Sewer Pipe • The sewer line to the septic tank should not be less than the diameter of the building drains and not less than 4 inches in diameter. • The sewer pipe should have a rating of SDR35 or stronger. • The sewer pipe should be sloped between 2% to 4% to help limit disturbance of solids in the tank and the potential for sewage bypass of the first chamber of the tank. If a steeper slope is needed, this can be accomplished with vertical step-downs in the sewer line. • A minimum 36 inches of cover soil should be provided over the sewer pipe. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost and we recommend 48 inches of soil cover over the sewer pipe in these areas, and the pipe be insulated on top and sides with 2-inch-thick blue foam insulation board. If adequate soil cover is not possible, we should be contacted for re-evaluation prior to installation. • The sewer pipe should be bedded in compacted ¾ inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than 2½ inches in diameter to help prevent settlement of the pipe. Sags in the pipe could cause standing effluent to freeze and damage the piping. • Install cleanout pipes within 5 feet of the building foundation, where the sewer pipe bends 90 degrees or more and at every 100 feet of sewer pipe. - 6 - Kumar & Associates, Inc. Project No. 20-7-595.02 • All 90-degree bends should be installed using a 90-degree long-sweep or by using two 45-degree elbows. • The sewer line location shown on Figure 1 is considered conceptual. We assume that there will be only one sewer line exiting the residence. It is the responsibility of the owner/contractors to locate all sewer line exit locations and connections to the septic tank. We should be notified if there are more than one sewer line exiting the building. Effluent Transport Piping • The effluent transport pipe should be 1.5-inch diameter Schedule 40 piping sloped at a 2% minimum to drain to the STA. • The effluent transport pipe should be bedded in compacted ¾ inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than 2½ inches in diameter to help prevent settlement of the pipe. Sags could cause standing effluent to freeze and damage to the piping. • A minimum 18 inches of cover soil should be provided over the effluent transport pipe. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost. We recommend 48 inches of soil cover over the effluent pipe and insulation with at least 2 inches of rigid foam insulation in these areas. If adequate cover soil is not possible, we should re-evaluate the condition prior to installation. • The effluent pipe should be encased with larger diameter Schedule 40 PVC pipe underneath driveway surfaces and be provided with at least 48 inches of soil cover and be insulated on top and sides with 2-inch-thick foam insulation board. • All 90-degree bends should be installed using a 90 degree long-sweep or by using two 45-degree elbows. • The minimum setback from the effluent line to the water supply line is 5 feet. Where the water line encroaches on the setback and crosses the effluent line at the driveway, either the water line or the effluent line must be encased with larger diameter Schedule 40 PVC pipe in a watertight manner throughout the encroachment. Effluent Pumping System • An Orenco PF3005, 115-volt, submersible effluent pump with a 1.5-inch diameter discharge assembly, or equivalent, will be required for the effluent pumping. • The maximum effluent transport distance from the pump discharge to the STA estimated to be 60 feet. • The elevation difference from pump discharge to the STA is estimated to be 4 feet of drop. - 7 - Kumar & Associates, Inc. Project No. 20-7-595.02 • The pump should be enclosed in an Orenco Biotube Pump Vault for effluent filtering and protection of the pump from vibration. • An equivalent pump must be capable of operating at 20.0 gallons per minute at 4.1 feet of total dynamic head. A pump performance curve is provided as an attachment to this report. • The floats should be set to provide a dose volume of approximately 104 gallons. The actual dose volume will be about 104 gallons in the transport line. To achieve the desired dose volume, the upper (“ON”) and lower (“OFF”) floats should be set approximately 10½ inches apart. • The flow differential between the first and last orifices is estimated to be 2.0%. • The high-water alarm float should be placed approximately 3 inches above the “ON” float in the dose tank. The high-water alarm must be wired on a separate electrical circuit from the pump. • An ⅛-inch diameter weep hole should be drilled in the effluent transport line prior to exiting the dose tank so the transport line can drain after each pumping cycle. OWTS OPERATION AND MAINTENANCE The OWTS will require periodic inspection and maintenance to function properly. A properly designed, installed and maintained system can greatly increase its lifespan. The level of maintenance will vary depending on the complexity of the system and water use habits of the residents. We recommend that an OWTS Operation and Maintenance (O&M) Manual be developed. Depending on the complexity of the system, a contract with an OWTS maintenance provider may be prudent. Below are some basic recommendations for the OWTS O&M. OWTS HOUSEHOLD OPERATION • Use of high efficiency water fixtures is recommended to decrease the hydraulic load on the OWTS system. • Fix plumbing leaks immediately as this may cause a hydraulic overload of the soil absorption system. • Do not irrigate the area on top of or directly upgradient of the soil absorption field as this may cause a hydraulic overload. • Do not dispose of household waste down drains as this may clog or damage OWTS components. Examples of household waste includes: dental floss, cotton swabs, coffee grounds, paper towels, feminine products and many other kitchen and bath items. • Use of kitchen garbage disposals is not recommended. If a garbage disposal is utilized, kitchen wastewater should be screened thoroughly. Many kitchen solids are not decomposed in the septic tank and may cause increased tank pumping frequency. - 8 - Kumar & Associates, Inc. Project No. 20-7-595.02 • Do not dispose of household chemicals, greases, oils, paints, hot tub water or water softener backwash in household drains. A separate drywell, if feasible, may be necessary for hot tub water or water softener backwash disposal. • Limit the use of bleach as this may harm useful bacteria in the septic tank and soil absorption system. • Liquid dishwasher and clothes washer detergent is recommended for households served by an OWTS. Clay substances used as fillers in powder detergents may result in clogging of the soil absorption system. • The effluent in septic tanks can freeze during extended periods of non-use in cold weather. We recommend that a tank heater be installed in this system to help prevent freezing. OWTS MAINTENANCE • Inspect the septic tank, pump, pump vault filter and STA at least annually for problems or signs of failure. • The filter should be cleaned annually by spray washing solids into the first chamber of the septic tank. • The septic tank should be pumped and cleaned about every 3 to 5 years depending on use. Longer pumping intervals may increase the amount of solids that reach the STA, which may shorten its life span. • Pumping of the septic tank should take place when the level of the sludge and scum layers combined take up 25 to 33% of the capacity of the first chamber of the tank. OWTS CONSTRUCTION OBSERVATION The Eagle County Environmental Health Department requires that the designer of the system provide a record drawing and certification of the OWTS construction (As-Built inspection). We should be provided with at least 48-hour notice prior to the installer needing the inspections. Prior to issuance of our certification letter, we require observation of all system components prior to backfill. The As-Built inspection will include a pump test for the system. The number of site visits required for the inspection will depend on the installer’s construction schedule. LIMITATIONS We have conducted this design in accordance with generally accepted engineering principles and practices in this area at this time. We make no warranty either expressed or implied. The recommendations provided in this report are based on the site conditions, the proposed construction, assumed subsurface conditions and our experience in the area. Additional profile pit evaluations should be done at the soil treatment area prior to construction. Lot 6 P r o p e r t y L i n e P r o p e r t y L i n e Lot 8 S u m m i t T r a i l 8890 89008910 891089208920893089306' @ 0% Asphalt Drive Prop ose d 5 Be dr o o m R esi d e nce 1142 S u m mit Tr ail Lot 7, Bl oc k 2, Fili n g 36, C or diller a FFE 8936.5' Garage FFE 8934.5' FFE 8924.5' FFE 8924.5' FFE 8936.5' Patio Deck (above) (25.9')(2%) 26 24 8930 32323432893032 8930 28 26 2422343289302826242236 36343228 164' @ 4%2 0 ' @ 4% 26.8' 33.2' 34' @ 4% 34.5'2628 30 32 34 382:1 32.4' FFE 8934.5' Inlet Rim El. 33.5' 25.9' 2% 12'-0" Inlet Rim El. 23.0' 2:1Ele c t r ic /Cab le /Ga s Electric/ Cable/ Gas Cover Storage 12" inlet invert out 8" HDPE storm=20.5' Daylight 8" storm 19.5' 30'@3.3% slope install rock rip rap at outlet 12" inlet invert out 8" HDPE storm=31.5' Daylight 8" storm 29.0' 98'@1% slope install rock rip rap at outlet Kumar & Associates Kumar & Associates Kumar & Associates NATIVE SOILS REMOVE VEGETATION AND SCARIFY UPPER 3" OF GROUND SURFACE PRIOR TO SAND PLACEMENT INFILTRATOR QUICK 4 PLUS STANDARD CHAMBERS EXISTING G R O U N D S U R F A C E SAND FILTER PLACED ON EXISTING GROUND SURFACE 4" DIAMETER OBSERVATION PORT 6.0' 8.0' 10" COVER SOIL. 3:1 MAX. SLOPE. 24.0' MINIMUM BASAL WIDTH 1.0' MIN SAND FILTER UNDER CHAMBERS Kumar & Associates Notes: 1.Chambers should be installed level on top of minimum 1 foot of concrete sand. The ground surface should be scarified prior to sand placement. 2.Care should be taken by the contractor to avoid compaction of the native soils in the bed area. 3.Changes to this design should not be made without consultation and approval by Kumar and Associates. Kumar & Associates NOT TO SCALE NRWHV AOO SLSLQJ ILWWLQJV DQG YDOYHV VKRXOG EH SFK  39C ,QVWDOO GLVWULEXWLRQ OLQH FOHDQRXWV DW WKH HQG RI HDFK GLVWULEXWLRQ OLQH Pump Selection for a Pressurized System - Single Family Residence Project 20-7-595.02 / 1142 Summit Trail Parameters Discharge Assembly Size Transport Length Transport Pipe Class Transport Line Size Distributing Valve Model Max Elevation Lift Manifold Length Manifold Pipe Class Manifold Pipe Size Number of Laterals per Cell Lateral Length Lateral Pipe Class Lateral Pipe Size Orifice Size Orifice Spacing Residual Head Flow Meter 'Add-on' Friction Losses 1.50 66 40 1.50 None -4 3 40 1.50 2 88 40 1.50 1/8 4 5 None 0 inches feet inches feet feet inches feet inches inches feet feet inches feet Calculations Minimum Flow Rate per Orifice Number of Orifices per Zone Total Flow Rate per Zone Number of Laterals per Zone % Flow Differential 1st/Last Orifice Transport Velocity 0.43 46 20.0 2 2.0 3.2 gpm gpm % fps Frictional Head Losses Loss through Discharge Loss in Transport Loss through Valve Loss in Manifold Loss in Laterals Loss through Flowmeter 'Add-on' Friction Losses 1.2 1.6 0.0 0.0 0.2 0.0 0.0 feet feet feet feet feet feet feet Pipe Volumes Vol of Transport Line Vol of Manifold Vol of Laterals per Zone Total Volume 6.9 0.3 18.6 25.9 gals gals gals gals Minimum Pump Requirements Design Flow Rate Total Dynamic Head 20.0 4.1 gpm feet 0 5 10 15 20 25 30 35 40 0 50 100 150 200 250 300 Net Discharge (gpm) PumpData PF3005 High Head Effluent Pump 30 GPM, 1/2HP 115/230V 1Ø 60Hz, 200V 3Ø 60Hz Legend System Curve: Pump Curve: Pump Optimal Range: Operating Point: Design Point: 5020 County Road 154 Glenwood Springs, CO 81601 phone: (970) 945-7988 fax: (970) 945-8454 email: kaglenwood@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado SUBSOIL STUDY FOR FOUNDATION DESIGN PROPOSED RESIDENCE LOT 7, BLOCK 2, FILING 36, CORDILLERA 1142 SUMMIT TRAIL EAGLE COUNTY, COLORADO PROJECT NO. 20-7-595 DECEMBER 31, 2020 PREPARED FOR: TOM GRANT 2413 ROBERT BROWNING AUSTIN, TEXAS 78723 (tgrant@empirecommunities.com) Kumar & Associates, Inc. ® Project No. 20-7-595 TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY ....................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 1 - FIELD EXPLORATION ............................................................................................................ - 2 - SUBSURFACE CONDITIONS ................................................................................................. - 2 - FOUNDATION BEARING CONDITIONS .............................................................................. - 3 - DESIGN RECOMMENDATIONS ............................................................................................ - 3 - FOUNDATIONS .................................................................................................................... - 3 - FOUNDATION AND RETAINING WALLS ....................................................................... - 4 - FLOOR SLABS ...................................................................................................................... - 5 - UNDERDRAIN SYSTEM ..................................................................................................... - 6 - SURFACE DRAINAGE ......................................................................................................... - 6 - LIMITATIONS ........................................................................................................................... - 7 - FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURES 4 and 5- SWELL-CONSOLIDATION TEST RESULTS TABLE 1- SUMMARY OF LABORATORY TEST RESULTS Kumar & Associates, Inc. ® Project No. 20-7-595 PURPOSE AND SCOPE OF STUDY This report presents the results of a subsoil study for a proposed residence to be located on Lot 7, Block 2, Filing 36, Cordillera, Eagle County, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for the foundation design. The study was conducted in accordance with our agreement for geotechnical engineering services to Tom Grant dated October 8, 2020. A field exploration program consisting of exploratory borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils and bedrock obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The proposed residence will be a one or two story structure possibly over a walkout basement level with attached garage and located generally as shown on Figure 1. Ground floors could be structural over crawlspace or slab-on-grade. Grading for the structure is assumed to be relatively minor with cut depths between about 2 to 10 feet. We assume relatively light foundation loadings, typical of the proposed type of construction. If building loadings, location or grading plans change significantly from those described above, we should be notified to re-evaluate the recommendations contained in this report. SITE CONDITIONS The subject site was vacant at the time of our field exploration. The ground surface is relatively flat in the uphill, northwest part of the building envelope sloping moderately steep down to the southeast at a grade of about 20 percent. Vegetation consists of sagebrush, oak brush, grass and weeds. - 2 - Kumar & Associates, Inc. ® Project No. 20-7-595 FIELD EXPLORATION The field exploration for the project was conducted on October 20, 2020. Two exploratory borings were drilled at the locations shown on Figure 1 to evaluate the subsurface conditions. The borings were advanced with 4 inch diameter continuous flight augers powered by a truck- mounted CME-45B drill rig. The borings were logged by a representative of Kumar & Associates, Inc. Samples of the subsoils were taken with 1⅜ inch and 2 inch I.D. spoon samplers. The samplers were driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils and hardness of the bedrock. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface conditions encountered at the site are shown on Figure 2. The subsoils consist of about ½ to 2 feet of topsoil overlying loose to medium dense sand and clay to between 1 and 4 feet deep underlain by weathered sandstone in Boring 1 and clayey basalt and ash in Boring 2 to between 10 to 12 feet in depth. Basalt rock was encountered below the sandstone and ash to the maximum explored depth of 31 feet. Laboratory testing performed on samples obtained from the borings included natural moisture content and gradation analyses. Results of swell-consolidation testing performed on a relatively undisturbed drive sample of the clay, presented on Figure 4, indicate low to moderate compressibility under existing moisture conditions and light loading and a moderate expansion potential wetted. Results of swell-consolidation testing performed on a relatively undisturbed drive sample of the weathered basalt and ash, presented on Figure 5, indicate low to moderate compressibility under conditions of loading and wetting. The laboratory testing is summarized in Table 1. No free water was encountered in the borings at the time of drilling and the subsoils and rock were slightly moist to moist. - 3 - Kumar & Associates, Inc. ® Project No. 20-7-595 FOUNDATION BEARING CONDITIONS The upper clay soils encountered in the borings possess a swell potential when wetted. The underlying weathered sandstone and weathered basalt rock possess a moderate bearing capacity and typically low settlement potential. At assumed excavation depths, we expect the subgrade will consist of sandstone and basalt/ash rock. Spread footings bearing on the sandstone and basalt/ash rock should be feasible for foundation support of the proposed building with a risk of movement due to variable bearing conditions across the different materials. The effects of differential movement can be limited by heavily reinforcing the foundation. The foundation excavation should be evaluated for expansive soils which should be removed from below foundation and slab areas and replaced with compacted structural fill. DESIGN RECOMMENDATIONS FOUNDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, we recommend the building be founded with spread footings bearing on the sandstone and basalt/ash rock below expansive clay soils. The design and construction criteria presented below should be observed for a spread footing foundation system. 1) Footings placed on the undisturbed sandstone and basalt/ash should be designed for an allowable bearing pressure of 2,500 psf. Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be about 1 inch or less. 2) The footings should have a minimum width of 16 inches for continuous walls and 2 feet for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 42 inches below exterior grade is typically used in this area. - 4 - Kumar & Associates, Inc. ® Project No. 20-7-595 4) Continuous foundation walls should be heavily reinforced top and bottom to span local anomalies, such as across material transitions, by assuming an unsupported length of at least 12 feet. Foundation walls acting as retaining structures should also be designed to resist lateral earth pressures as discussed in the "Foundation and Retaining Walls" section of this report. 5) Topsoil, expansive clay and any loose disturbed soils and rock should be removed and the footing bearing level extended down to the undisturbed natural soils or rock. The exposed soils in footing area should then be moistened and compacted. If water seepage is encountered, the footing areas should be dewatered before concrete placement. Structural fill should be a non-expansive granular material such as CDOT Class 6 road base compacted to at least 98% of standard Proctor density at near optimum moisture content. 6) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions. FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 50 pcf for backfill consisting of the on-site predominantly granular soils. Cantilevered retaining structures which are separate from the residence and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 40 pcf for backfill consisting of the on-site predominantly granular soils. The backfill should not contain topsoil or oversized (plus 6-inch) rocks. All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. An underdrain should be provided to prevent hydrostatic pressure buildup behind walls. - 5 - Kumar & Associates, Inc. ® Project No. 20-7-595 Backfill should be placed in uniform lifts and compacted to at least 90% of the maximum standard Proctor density at a moisture content near optimum. Backfill placed in pavement and walkway areas should be compacted to at least 95% of the maximum standard Proctor density. Care should be taken not to overcompact the backfill or use large equipment near the wall, since this could cause excessive lateral pressure on the wall. Some settlement of deep foundation wall backfill should be expected, even if the material is placed correctly, and could result in distress to facilities constructed on the backfill. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.45. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 375 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be a granular material compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The on-site clay soils possess an expansion potential and slab heave could occur if the clay subgrade soils become wetted. Exposed clay subgrade should be evaluated for expansion potential and removed as needed and replaced with compacted structural fill. Crawlspace construction could also be used to avoid slabs bearing on expansive soils. To reduce the effects of some differential movement, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. The requirements for joint spacing and slab reinforcement should be established by the designer based on experience and the intended slab use. A minimum 4 inch layer of free-draining gravel should be placed beneath basement level slabs to facilitate drainage. This material should consist of minus 2-inch aggregate with at least 50% retained on the No. 4 sieve and less than 2% passing the No. 200 sieve. - 6 - Kumar & Associates, Inc. ® Project No. 20-7-595 All fill materials for support of floor slabs should be compacted to at least 95% of maximum standard Proctor density at a moisture content near optimum. Required fill should consist of granular soils devoid of vegetation, topsoil and oversized rock. We recommend vapor retarders conform to at least the minimum requirements of ASTM E1745 Class C material. Certain floor types are more sensitive to water vapor transmission than others. For floor slabs bearing on angular gravel or where flooring system sensitive to water vapor transmission are utilized, we recommend a vapor barrier be utilized conforming to the minimum requirements of ASTM E1745 Class A material. The vapor retarder should be installed in accordance with the manufacturers’ recommendations and ASTM E1643. UNDERDRAIN SYSTEM Although free water was not encountered during our exploration, it has been our experience in the area and where clay soils are present that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a perched condition. We recommend below-grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free-draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1% to a suitable gravity outlet. If rigid PVC drain-pipe is used, which we recommend, the pipe slope can be reduced to a minimum ½%. Free-draining granular material used in the underdrain system should contain less than 2% passing the No. 200 sieve, less than 50% passing the No. 4 sieve and have a maximum size of 2 inches. The drain gravel backfill should be at least 1½ feet deep and covered with filter fabric such as Mirafi 140N or 160N. SURFACE DRAINAGE The following drainage precautions should be observed during construction and maintained at all times after the residence has been completed: 1) Inundation of the foundation excavations and underslab areas should be avoided during construction. - 7 - Kumar & Associates, Inc. ® Project No. 20-7-595 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90% of the maximum standard Proctor density in landscape areas. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. Free-draining wall backfill should be covered with filter fabric and capped with about 2 feet of the on-site finer graded soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Landscaping which requires regular heavy irrigation should be located at least 5 feet from foundation walls. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and TABLE 1 SUMMARY OF LABORATORY TEST RESULTS Project No. 20-7-595 SAMPLE LOCATION NATURAL MOISTURE CONTENT NATURAL DRY DENSITY GRADATION PERCENT PASSING NO. 200 SIEVE ATTERBERG LIMITS UNCONFINED COMPRESSIVE STRENGTH SOIL TYPE BORING DEPTH GRAVEL SAND LIQUID LIMIT PLASTIC INDEX (%) (%) (ft) (%) (pcf) (%) (%) (psf) 1 1 5.6 121 Weathered Sandstone 7 12.6 112 Weathered Sandstone 2 4 14.6 100 43 Clay with Basalt Fragments 7 24.7 102 Weathered Ash