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HomeMy WebLinkAbout700 Wolcott Springs RdEnvironmental Health Department P.O. Box 179 500 Broadway Eagle, CO 81631-0179 Phone: (970) 328-8730 Fax: (970) 328-7185 Permit Permit No. OWTS-022443-2021 Permit Type: OWTS Permit Work Classification: New Permit Status: Active Issue Date: 9/16/2021 Expires: 1/14/2022 On-Site Wastewater Treatement System Project Address Parcel Number 700 WOLCOTT SPRINGS RD, 194127400064 Owner Information Address John Mark & Laura Seelig Phone: Cell: Email: 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 Defina Construction, INC gary@definaconstruction. com (970) 376-6702OWTSPL-000140-20 21 Permitted Construction / Details: Install the new system exactly as depicted in the Kumar & Associates design dated, stamped and signed on June 24th, 2021 by David A Young, PE. This system is designed to accommodate the maximum daily flows for a 5 bedroom residence. This OWTS consists of one sewer line from the residence. A Valley Precast 1,500 gallon, two-chamber concrete septic tank with an effluent filter in the outlet tee will be used. A Tuf-Tite 6-Hole Distribution Box equipped with speed levelers will be accessible at grade. The STA consists of 4 rows of 25 Infiltrator Quick4 Plus Standard chambers for a total of 100. 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. 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 September 16, 2021 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 PERMIT 4.1.6(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 Thursday, September 16, 2021 1 *************************************************************************** APPLICATION FOR ON-SITE WASTEWATER TREATMENT SYSTEM (OWTS) PERMIT INCOMPLETE APPLICATIONS MAY NOT BE ACCEPTED (SITE PLAN MUST BE INCLUDED) FEE SCHEDULE APPLICATION FEE FOR NEW OWTS OR MAJOR REPAIRS $800.00 MINOR REPAIR FEE $400.00 Fee includes the design review, permitting and maintenance of OWTS records Make all checks payable to: Eagle County Treasurer Property Owner: _______________________________________Phone: ________________________ Owner Mailing Address: ________________________________ email: _________________________ Professional Engineer: __________________________________ Phone: ________________________ Applicant / Contact Person: ______________________________Phone: ________________________ Licensed Systems Contractor Name / Company: ___________________________________________ Contractor Mailing Address: _________________________________ Contractor License #:_______ Contractor Phone Number: ________________________ email: ______________________________ OWTS Permit Application is for: ____ New Installation ____ Alteration ____ Repair Tax Parcel Number: _________________________________ Lot Size: ________________________ Assessor’s Link: www.eaglecounty.us/patie/ Physical Address: _____________________________________________________________________ Legal Description: ____________________________________________________________________ Building Type: _____ Residential / Single Family _____ Residential / Multi Family _____ Commercial / Industrial Number of Bedrooms: ______ Number of Bedrooms: ______ Type of Use: _______________ *As of 06/27/2014, all systems require design by a Registered Professional Engineer. Type of Water Supply: ____ Private Well ____ Spring ____ Surface ____ Public If Public, Name of Supplier: ____________________________________________________________ Applicant Signature: ______________________________________Date:_______________________ **************************************************************************** Office Use Only: OWTS PERMIT # __________________ BUILDING PERMIT # ____________________ Amount Paid: ___________ Receipt #: ___________ Check #: ___________ Date: ______________ DEPARTMENT OF ENVIRONMENTAL HEALTH (970) 328-8755 FAX: (970) 328-8788 TOLL FREE: 800-225-6136 www.eaglecounty.us P.O. Box 179 500 Broadway Eagle, CO 81631 environment@eaglecounty.us John Mark & Laura Seelig Peter Van Dyke 970.376.8914 78 Stillwater, Edwards, CO 81632 jmseelig@gmail.com Kumar & Associates, Inc.970.945.7988 X X 5 X N/A 09.15.21 700 Wolcott Spring Rd. Wolcott, CO 81655 Defina Construction P.O. Box 4140, Eagle, CO 81631 970.376.6702 gary@definaconstruction.com Parcel 1 Wolcott Spring Parcels, Eagle County Parcel 1 Wolcott Spring Parcels, Eagle County, CO 35.04 Acres 970.306.8524 INSPECTION WORKSHEET (INSP-519056-2022) FOR EAGLE COUNTY GOVERNMENT OWTS-022443-2021Case Number:Case Module:Permit Management 08/30/2022 ApprovedInspection Status:Inspection Date: OWTS Final InspectionInspection Type:Inspector:Claire Lewandowski Job Address:Parcel Number:700 Wolcott Springs Rd CO 194127400064 Company Name NameContact Type Applicant Sunder Inc.Peter Van Dyke Contractor Defina Construction, INC Gary Defina Engineer KUMAR & ASSOCIATES Dave Young Owner John Mark & Laura Seelig CommentsPassedChecklist Item TrueSeptic Tank - Septic Tank True Received.Record Drawing - Record Drawing True Received. EHS has included their photos as well.Record Photos - Record Photos TrueSite and Soil - Site & Soil True Received from K+A Inc. Dated November 16, 2022. Stamped signed and dated by David A. Mellow Final Certification Letter - Final Certification Letter True The proposed Tuftite 6-hole distribution box was changed to a Polylok 7-hole distribution box. General Plan - General Plan TrueSoil Treatment Area (STA) - Soil Treatment Area (STA) True Eagle County licensed contractor Gary Defina completed the inspection. Identification of Systems Contractor - Identification of Systems Contractor November 17, 2022 Page 1 of 1P.O. Box 179, 500 Broadway, Eagle, CO 81631-0179 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 November 16, 2022 Sunder, Inc. Attn: Peter VanDyke P.O. Box 1393 Edwards, Colorado 81632 (mpetervandyke@gmail.com) Project No. 20-7-655.02 Permit No. OWTS-022443-2021 Subject: Certification of Onsite Wastewater Treatment System, Proposed Seelig Residence, Parcel 1, Wolcott Springs, 700 Wolcott Springs Road, Eagle County, Colorado Dear Peter: 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 our agreement for professional services to Sunder, Inc. dated October 28, 2020. We previously designed the OWTS for the residence as submitted in our report dated June 24, 2021, Project No. 20-7-655.02. The system was designed for five bedrooms. The system was installed by Defina Construction under Permit No. OWTS-022443-2021. At this time, the OWTS will only serve a 2-bedroom building located as shown on Figure 1. We performed our evaluation on August 30, 2022. The OWTS components observed included: sewer line, cleanout, septic tank, effluent line, distribution box 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 visit are included with this report. Pictures of the installation of the septic tank were provided by Defina Construction. The distance locations to the septic tank shown on Figure 1 were made by taping. The proposed Tuftite 6-hole distribution box was changed to a Polylok 7-hole distribution box. This change is acceptable to us. It is our opinion that the OWTS was installed in general conformance with the above referenced design, and no shallow confining soil layer exists as assumed in our original design. The observations and recommendations presented above are based on our site observations and our experience in the area. We make no warranty either express or implied. Alterations to the system or improper backfill and site grading could affect the operation and effectiveness of the OWTS. Kumar & Associates OWTS PHOTOGRAPH LOG PROPOSED SEELIG RESIDENCE PARCEL 1, WOLCOTT SPRINGS 700 WOLCOTT SPRINGS ROAD EAGLE COUNTY, COLORADO Project No. 20-7-655.02 Photograph 1: Sewer line exiting residence and entering septic tank. Photograph 2: Valley Precast 1,500-gallon, two-chamber septic tank. (Photograph provided by installer) OWTS PHOTOGRAPH LOG PROPOSED SEELIG RESIDENCE PARCEL 1, WOLCOTT SPRINGS 700 WOLCOTT SPRINGS ROAD EAGLE COUNTY, COLORADO Project No. 20-7-655.02 Photograph 3: Effluent line leaving septic tank. Effluent filter in outlet. Photograph 4: PolyLok 7-hole distribution box with levelers not yet in outlets. OWTS PHOTOGRAPH LOG PROPOSED SEELIG RESIDENCE PARCEL 1, WOLCOTT SPRINGS 700 WOLCOTT SPRINGS ROAD EAGLE COUNTY, COLORADO Project No. 20-7-655.02 Photograph 5: Effluent line to soil treatment area (STA). Photograph 6: Soil treatment area (STA) with observation ports. 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 ONSITE WASTEWATER TREATMENT SYSTEM DESIGN PROPOSED SEELIG RESIDENCE PARCEL 1, WOLCOTT SPRINGS 700 WOLCOTT SPRINGS ROAD EAGLE COUNTY, COLORADO PROJECT NO. 20-7-655.02 JUNE 24, 2021 PREPARED FOR: SUNDER, INC. ATTN: PETER VanDYKE P. O. BOX 1393 EDWARDS, COLORADO 81632 (mpetervandyke@gmail.com) Kumar & Associates, Inc. Project No. 20-7-655.02 TABLE OF CONTENTS INTRODUCTION ...................................................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 1 - SUBSURFACE CONDITIONS ................................................................................................. - 1 - OWTS ANALYSIS .................................................................................................................... - 3 - DESIGN RECOMMENDATIONS ............................................................................................ - 3 - SOIL TREATMENT AREA................................................................................................... - 4 - OWTS COMPONENTS ......................................................................................................... - 5 - 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 – USDA GRADATION TEST RESULTS FIGURE 3 – SOIL TREATMENT AREA CALCULATIONS FIGURE 4 – SOIL TREATMENT AREA PLAN VIEW FIGURE 5 – SOIL TREATMENT AREA CROSS SECTION ATTACHMENTS VALLEY PRECAST 1,500 GALLON, TWO-CHAMBER SEPTIC TANK DETAIL TUF-TITE 6-HOLE DISTRIBUTION BOX Kumar & Associates, Inc. Project No. 20-7-655.02 INTRODUCTION This report provides the results of an onsite wastewater treatment system (OWTS) design for the proposed Seelig residence to be located on Parcel 1, Wolcott Springs, 700 Wolcott Springs Road, Eagle County, Colorado. The purpose of the report is to provide design details for the OWTS in accordance with the 2018 Eagle County Environmental Health Department Onsite Wastewater Treatment System Regulations and the Colorado Department of Public Health and Environmental Regulation #43. The services were performed as part of our agreement for professional services to Sunder, Inc. dated October 28, 2020. PROPOSED CONSTRUCTION The proposed residence will be a single-family structure located on the site as shown on Figure 1. The residence will have five-bedrooms. The OWTS will be designed for a total of 5 bedrooms. The proposed soil treatment area (STA) for the OWTS will be located to the northeast of the residence as shown on Figure 1. Water service will be provided by an onsite well to be drilled approximately located as shown on Figure 1. The route of the water supply line from the well to the residence has not been designed at the time of this report. If proposed construction is different than that described, we should be contacted to re-evaluate our design recommendations. SITE CONDITIONS The lot is vacant with the exception a viewing deck located in the southeast corner of the building envelope. The parcel is about 35 acres in size and located on moderately steep, north- facing hillside terrain above Wolcott Springs Road. The proposed building site and STA are located in the northwest portion of the parcel and the building site topography is shown on Figure 1. The ground surface at the building site has slope grades ranging from about 15 to 30%. The slope continues down from the residence to the area of the planned STA. Vegetation consists of sagebrush, grass and weeds. There is a natural drainage that trends generally from south to north located about 300 feet west of the planned STA that was not flowing water at the time of our field exploration. No other water features were observed on the site. SUBSURFACE CONDITIONS The field exploration for the OWTS was conducted on May 20, 2021. Five profile pits (Profile Pits 1 through 5) were excavated with a trackhoe at the approximate locations shown on Figure 1 to evaluate the subsurface conditions at the planned soil treatment area for the OWTS. The pits were logged by a representative of Kumar & Associates. Logs of the profile pits are provided below. - 2 - Kumar & Associates, Inc. Project No. 20-7-655.02 Log of Profile Pit 1 Depth USDA Classification 0-3’ TOPSOIL; organic Loam, firm, moist, dark brown. 3’-4½’ CLAY LOAM; strong blocky structure, stiff, moist, brown. 4½’-5’ CLAYSTONE SHALE BEDROCK; medium hard, slightly moist, gray. • Bottom of pit @ 5 feet. • No groundwater or redoximorphic features observed at time of pit excavation. Log of Profile Pit 2 Depth USDA Classification 0-2½’ TOPSOIL; organic Loam, firm, moist, dark brown. 2½’-3’ CLAYSTONE SHALE BEDROCK; medium hard, slightly moist, gray. • Bottom of pit @ 3 feet. • No groundwater or redoximorphic features observed at time of pit excavation. Log of Profile Pit 3 Depth USDA Classification 0-2’ TOPSOIL; organic Loam, firm, moist, dark brown. 2’-6’ CLAY LOAM; gravelly, strong blocky structure, very stiff, moist to slightly moist, brown to pale brown. • Disturbed bulk sample obtained from 4 to 5 feet. • Bottom of pit @ 6 feet. • No groundwater or redoximorphic features observed at time of pit excavation. Log of Profile Pit 4 Depth USDA Classification 0-3’ TOPSOIL; organic Loam, firm, moist, dark brown. 3’-7’ CLAY LOAM; strong blocky structure, stiff to very stiff, moist to slightly moist, brown. • Bottom of pit @ 7 feet. • No groundwater or redoximorphic features observed at time of pit excavation. Log of Profile Pit 5 Depth USDA Classification 0-2’ TOPSOIL; organic Loam, firm, moist, dark brown. 2’-6½’ CLAY LOAM; strong blocky structure, stiff to very stiff, moist to slightly moist, brown. 6½’-8’ CLAYSTONE SHALE BEDROCK; medium hard, slightly moist, gray. • Disturbed bulk sample obtained from 4 to 5 feet. • Bottom of pit @ 8 feet. • No groundwater or redoximorphic features observed at time of pit excavation. - 3 - Kumar & Associates, Inc. Project No. 20-7-655.02 The soils encountered in profile pits, below about 2 to 3 feet of organic topsoil, consisted of nil to 4½ feet of Clay Loam overlying claystone shale bedrock down to the pit depths of 3 to 8 feet. Hydrometer and gradation analyses were performed on a disturbed bulk sample of the soils from Profile Pit 5 from 4 to 5 feet depth with the results provided on Figure 2. The tested sample (minus No.10 size sieve fraction) classifies as Clay Loam per the USDA system. No free water was encountered in the pits nor indications of seasonal high groundwater were observed at the time of the pit excavations. Based on the subsurface conditions and laboratory testing, the soils at the STA have been classified as Type 3 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.35 gallons per square foot per day. OWTS ANALYSIS Based on the site conditions and profile pit evaluations, the evaluated area should be suitable for a conventional infiltration disposal system. There is adequate elevation difference from the proposed ground floor of the residence down to the STA for gravity flow of the sewer effluent. The STA will consist of chambers in a trench configuration based in the Loam soils. The STA will be sized for five bedrooms (eight persons) and an average daily flow of 75 gallons per person, and an LTAR of 0.35 gallons per square foot per day for the natural Clay Loam soils. The effluent will gravity flow from the residence to the septic tank for primary treatment and then gravity flow to the STA for dispersal and final treatment. The STA will consist of four trenches with Infiltrator Quick 4 Plus Standard chambers. Equal distribution will be provided to the chambers and trenches by a distribution box. A 100 feet minimum setback is required for the STA from the onsite well located to the west of the STA. The route of the planned water supply line to the residence is currently not known, but appears to be adequately away from the OWTS. The required setback of the water line from the septic tank is 10 feet, 5 feet for sewer and effluent lines, and 25 feet from the STA. We should be notified for additional recommendations if the waterline is within these minimum setbacks. DESIGN RECOMMENDATIONS The 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, we should be contacted to re-evaluate our design recommendations. - 4 - Kumar & Associates, Inc. Project No. 20-7-655.02 SOIL TREATMENT AREA • The STA will consist of four trenches with 25 Infiltrator Quick 4 Plus Standard chambers placed in each trench (100 chambers total) in the native soils. Equal distribution will be provided to the trenches by a distribution box. • The STA was sized based on an LTAR of 0.35 gallons per square feet per day. • Each chamber was allowed 12 square feet of area. A 30% reduction of the STA size was applied for use of Infiltrator chambers in a trench configuration. The total STA design size is 1200 square feet. Soil treatment area calculations are shown on Figure 3. • A minimum of four feet of undisturbed soil between trenches is required. • Trench cut depths should be a maximum of 2 feet deep to provide a minimum 4 feet of vertical separation to the bedrock. • The trenches should be oriented along ground contours to minimize soil cut and cover. • The base and sidewalls of the trench excavations should be scarified prior to the chamber placement. • A minimum of 12 inches and a maximum of 24 inches of cover soil should be placed over the chambers. • Backfill should be graded to deflect surface water away from the STA and should be sloped at 3 horizontal to 1 vertical or flatter. A swale to divert surface water flow away from the STA may be needed along the upslope side. • 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 chamber end caps. Install ports at each end of the trench. 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 STA must be a minimum of 100 feet from the onsite well. • The STA must be a minimum of 10 feet from any property line. • The STA must be a minimum of 5 feet from the septic tank. • The STA must be a minimum of 25 feet from any potable water supply lines. • The STA must be a minimum of 20 feet from the residence. • A plan view of the STA is presented on Figure 4 and a cross section of the STA is presented on Figure 5. - 5 - Kumar & Associates, Inc. Project No. 20-7-655.02 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. Septic Tank • A Valley Precast 1,500 gallon, two-chamber septic tank should be used for primary treatment and dosing to the STA. A detail of the tank is provided as an attachment. • An effluent filter should be installed in the tank outlet tee. • The tank must be a minimum of 50 feet from the onsite well. • The tank must be a minimum of 5 feet from the residence. • 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. Schedule 40 PVC pipe is required beneath any driveway surfaces. • The sewer pipe should be sloped between 2% to 4% to help limit disturbance of solids in the tank and potential 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 pipes 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. - 6 - Kumar & Associates, Inc. Project No. 20-7-655.02 • Install cleanout pipes within 5 feet of the building foundation, where the sewer pipes bend 90 degrees or more and every 100 feet of sewer pipe. • 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 other sewer lines exiting the building. Effluent Transport Piping • The effluent transport pipe should be 4-inch diameter SDR35 piping sloped at a 2% minimum to flow from the septic tank to the distribution box and from the distribution box to each trench. Piping should extend at least 6 inches into the top knockout provided in the Infiltrator end caps and be screwed in place. Splash plates should be installed beneath the inlet piping to help limit scouring of the infiltrative soil surface in the chambers. • 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. • Schedule 40 PVC pipe is required underneath driveway surfaces and should be provided with at least 48 inches of soil cover, and be insulated on top and sides with 2-inch thick rigid foam insulation board. • All 90-degree bends should be installed using a 90 degree long-sweep or by using two 45-degree elbows. Distribution Box • The distribution box will be used to equally divide effluent flow between the trenches. We recommend the Tuf-Tite 6-Hole Distribution Box since it is easily accessible from ground surface for maintenance. A copy of the distribution box detail is provided as an attachment to this report. • The distribution box outlet pipes should be equipped with Tuf-Tite speed levelers for ease of initial setup and adjustment over time. - 7 - Kumar & Associates, Inc. Project No. 20-7-655.02 • The distribution box should be a minimum of 18 inches below grade with risers and an access lid at or above grade. • The distribution box must be accessible from ground surface for inspection and maintenance per the State guidelines. • The effluent line from the septic tank should be directed downward into the distribution box with a 90-degree elbow inside the box. • The distribution box must be installed level on a compacted road base subgrade to ensure equal effluent distribution. If settlement of the distribution box occurs, unequal effluent distribution may take place which could cause hydraulic overload of one of the trenches and potential failure. The distribution box should be monitored periodically, and the speed levelers should be adjusted as necessary for levelling. • The ground surface above and around the distribution box should be graded to drain away surface water to prevent standing water near the distribution box which could freeze or cause settlement. 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. 20-7-655.02 • 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 soils 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, distribution box and STA at least annually for problems or signs of failure. • The effluent filter for the tank should be cleaned at least annually by spray washing solids into the first chamber of the septic tank. • The septic tank should be pumped and cleaned 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 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, profile pit evaluations and soil texture analysis, the proposed construction and our experience in the area. Variations in 7698.267694.707692.307689.607687.717685.7135.043 ACRESTEST HOLETEST HOLEWHITE RIBBONINDICATES ALATHE FOUND18" CMPDITCHDITCHEDGE OFROADWAYPHONE PEDESTALEVERGREENTREEEVERGREENTREEPARCEL 1WOLCOTT SPRINGS ROAD (50' R.O.W.)TRAVIS CREEK SUBDIVISION FILING No. 1FOUND A No. 5 REBARWITH A 11_2" ALUMINUM CAPP.L.S. No. 23508(ELEVATION = 7700.00')FOUND A No. 5 REBARWITH A 11_2" ALUMINUM CAPP.L.S. No. 23508(ELEVATION = 7687.18')S 82°41'30" E - 31.20'∆=17°22'20"R=597.96'T=91.35'L=181.30'ChB=N88°37'20"EChL=180.61'N 79°56'10" E - 144.63'N 00°00'00" E - 1213.98'∆=14°27'30"R=547.96'T=69.51'L=138.28'ChB=n87°09'55"eChL=137.91'PH40801 inch = ft.GRAPHIC SCALEKumar & Associates SILT COBBLES COARSE GRAVEL MEDIUMMEDIUMV. FINE SAND CLAY FINE CO.FINEV. CO.CO.FINE Kumar & Associates Kumar & Associates Kumar & Associates Notes: &KDPEeUssKoXOGEeLQstDOOeGOeYeOoQDsFDULILeGJUoXQGsXUIDFe&oQFUetesDQGPD\EeXseGDsDOeYeOLQJFoXUseLI QeFessDU\ &DUesKoXOGEetDNeQE\tKeFoQtUDFtoUtoDYoLGFoPSDFtLoQoItKeQDtLYesoLOsLQtKetUeQFKDUeDs7KeEDseDQGsLGeZDOOsoI tUeQFKe[FDYDtLoQssKoXOGEesFDULILeGSULoUtoFKDPEeULQstDOODtLoQ $OOSLSLQJsKoXOGKDYeDUDtLQJoI6'5oUstUoQJeU &KDQJestotKLsGesLJQsKoXOGQotEePDGeZLtKoXtFoQsXOtDtLoQDQGDSSUoYDOE\.XPDU $ssoFLDtes 5eIeUtotKe(DJOe&oXQt\2QsLte:DsteZDteU6\steP5eJXODtLoQsIoUotKeUDSSOLFDEOesSeFLILFDtLoQs Infiltrator Quick 4 Plus Standard Chamber Installed Level Scarify bottom and sides of trench prior to chamber placement. Excavate 36" Wide Trench Approx. Existing Grou n d S u r f a c e 12" min. 24" max. Cover Soil Graded to Deflect Surface Water Native Soil 4' Min. Undisturbed Soil Between Trenches Kumar & Associates Notes 1.Chambers should be installed level on a scarified ground surface. Concrete sand may be used as a leveling course if necessary. 2.Care should be taken by the contractor to avoid compaction of the native soils in the trench areas. The base and side walls of trench excavations should be scarified prior to chamber installation. 3.Changes to this design should not be made without consultation and approval by Kumar & Associates. Tough Problem Providing a simple, reliable, and permanent means for dividing septic tank effluent flow. TUF-TITE Solution A strong, stable, permanent, non-corrosive Tuf-Tite Distribution Box, with a Tuf-Tite Speed Leveler in each outlet. Snap-in pipe seals They’re patented. Simply insert your PVC pipe and push it through the flexible, polyethylene Tuf-Tite seal. Pipes fit watertight. Installation couldn’t be easier. TTuuff--TT iittee®® DDiissttrriibbuuttiioonn BBooxx.. 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The 6HD2 Distribution Box comes complete with a Regular Lid or an Inspection Port Lid, and 8 snap-in fittings of your choice. 9” S-35 S-40 P-10 14” 14” 9” 9” 2” Drop INSTALLATION IS JUST THIS SIMPLE 1.Position the Distribution Box on level virgin soil. Do not place box on a concrete slab. 2.Install the inlet pipe and outlet pipes. Be sure the bottoms of all pipes rest on virgin soil. 3.Level the Distribution Box and all pipes as needed. 4.Backfill the pipes to within two feet of the Distribution Box. Recheck the level of the box, then backfill up to the top lid ridge. 5.Install and adjust Tuf-Tite Speed Levelers. 6.Place lid on the Distribution Box and finish backfilling. Choice of Fittings S-35 Pipe Seal, for: ■ Sewer and Drain ■ SDR 35 ■ ASTM 3034 ■ Thin Wall ■ 1500 Lb. Crush S-40 Pipe Seal, for: ■ Schedule 40 ■ 4” Corrugated P-10 Plug, for unused holes Choice of Lids Regular Lid. Molded of rugged HDPE. Inspection Port Lid. For easy access and inspection. Accepts 4” riser pipes. Tuf-Tite Speed Levelers™ Control the flow of effluent from the Distribution Box. Simply insert a Speed Leveler into each outlet pipe. Rotate each Speed Leveler so the flow is distributed as desired. Available for 3” or 4” PVC pipe. ©2005 Tuf-Tite® Corporation Form 6HD2-4. Printed in USA Water-tight Lids and Risers by Tuf-Tite®Drainage and Septic Products Tuf-Tite®Corporation 1200 Flex Court Lake Zurich, Illinois 60047 6-Hole Distribution Box 6HD2 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 SEELIG RESIDENCE PARCEL 1, WOLCOTT SPRINGS TBD WOLCOTT SPRINGS ROAD EAGLE COUNTY, COLORADO PROJECT NO. 20-7-655 JANUARY 25, 2021 PREPARED FOR: SUNDER, INC. ATTN: PETER VANDYKE P. O. BOX 1393 EDWARDS, COLORADO 81655 mpetervandyke@gmail.com Kumar & Associates, Inc. ® Project No. 20-7-655 TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY ....................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 2 - FIELD EXPLORATION ............................................................................................................ - 2 - SUBSURFACE CONDITIONS ................................................................................................. - 2 - FOUNDATION BEARING CONDITIONS .............................................................................. - 3 - DESIGN RECOMMENDATIONS ............................................................................................ - 4 - FOUNDATIONS .................................................................................................................... - 4 - FOUNDATION AND RETAINING WALLS ....................................................................... - 5 - FLOOR SLABS ...................................................................................................................... - 6 - UNDERDRAIN SYSTEM ..................................................................................................... - 7 - SITE GRADING ..................................................................................................................... - 7 - SURFACE DRAINAGE ......................................................................................................... - 8 - LIMITATIONS ........................................................................................................................... - 8 - FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURE 4 - SWELL-CONSOLIDATION TEST RESULTS FIGURE 5 - GRADATION TEST RESULTS TABLE 1- SUMMARY OF LABORATORY TEST RESULTS Kumar & Associates, Inc. ® Project No. 20-7-655 PURPOSE AND SCOPE OF STUDY This report presents the results of a subsoil study for the proposed Seelig residence to be located on Parcel 1, Wolcott Springs, address TBD Wolcott Springs Road, 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 Sunder, Inc. dated October 28, 2020. Evaluation of potential geologic hazard impacts on the site are beyond the scope of this study. A field exploration program consisting of exploratory borings was conducted to obtain information on the general 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 Design plans for the residence had not been developed at the time of our report preparation. We understand the building will likely be a one and two-story structure wood-frame structure over a walkout basement level located in the area of our Exploratory Borings 1 and 2 shown on Figure 1. Ground floors are planned to be slab-on-grade. Grading for the structure is assumed to be relatively minor with cut depths between about 3 to 10 feet. We expect relatively light foundation loadings, typical of the proposed type of construction. When building location, grading and loading information have been developed, we should be notified to re-evaluate the recommendations presented in this report and perform additional analyses as needed. - 2 - Kumar & Associates, Inc. ® Project No. 20-7-655 SITE CONDITIONS The subject parcel was vacant and covered with about 3 inches of snow at the time of our field exploration. The parcel is about 35 acres in size and located on moderately steep, north/northwesterly facing hillside terrain above Wolcott Springs Road. The proposed building site is located in the north-central portion of the parcel and the building site topography is shown on Figure 1. The ground surface at the building site has slope grades ranging from about 20 to 30%. Elevation difference across the assumed building area is about 10 to 12 feet. There is a natural drainage that trends generally from south to north located about 175 feet west of the building site that was not flowing water at the time of our field exploration. Vegetation consists of native grass and weeds with sagebrush and scattered pinon trees. FIELD EXPLORATION The field exploration for the project was conducted on November 11, 2020. Three 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 track- mounted CME 45 drill rig. The track rig was needed due to the moderately steep terrain. The borings were logged by a representative of Kumar & Associates. Samples of the subsoils and bedrock were taken with a 2 inch I.D. spoon sampler. The sampler was driven into the subsoils and bedrock 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 encountered, below about ½ to 2 feet of organic topsoil, consisted of from nil to about 9½ feet of intermixed gravel and sandy clay with cobble soils overlying hard to very hard, siltstone/claystone shale bedrock that extended down to the maximum depth explored of 20 feet. - 3 - Kumar & Associates, Inc. ® Project No. 20-7-655 The gravel and clay soils contained possible boulders, were very stiff/dense and were encountered only at Boring 2. Laboratory testing performed on samples obtained from the borings included natural moisture content and density, and gradation analyses. Results of swell-consolidation testing performed on relatively undisturbed drive sample of the sandy clay with gravel soils, presented on Figure 3, indicate low to moderate compressibility under conditions of loading and wetting and a moderate expansion potential when wetted under a constant 1,000 psf surcharge. The shale bedrock was too hard to obtain undisturbed samples for swell-consolidation testing. Results of gradation analyses performed on a small diameter drive sample (minus 2-inch fraction) of the clayey gravel subsoils are shown on Figure 4. The laboratory testing is summarized in Table 1. No groundwater was encountered in the borings at the time of drilling or when checked 28 days later. The subsoils and bedrock were slightly moist. FOUNDATION BEARING CONDITIONS At assumed excavation depths, the subgrade is expected to transition from the shale bedrock in the deeper cut areas to the gravel and clay with cobble soils in the shallow cut areas. The hard to very hard bedrock materials possess moderately high bearing capacity, and based on its hardness and our experience in the area, probably does not possess a swell potential. The gravel and clay soils have moderate bearing capacity; however, the clay portion of the soils possess an expansion potential when wetted. Spread footings should be feasible for foundation support of the building with some risk of differential movement due primarily to the assumed variable bearing conditions and especially if the clay portion of the bearing soils were to become wetted. To reduce the risk of differential settlement, the footings should bear entirely on the hard to very hard shale bedrock. We understand the building location is planned to be moved to the south to the apparent shallower bedrock area to limit the need for sub-excavation to the bedrock. It may be feasible to use imported structural fill consisting of aggregate base course below subexcavated areas to re-establish design footing bearing elevation and can be further evaluated - 4 - Kumar & Associates, Inc. ® Project No. 20-7-655 at the time of the foundation excavation if desired. The depth of structural fill below footings should be limited to 5 or 6 feet to reduce the potential for settlement of deeper fill areas. 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 entirely on the hard to very hard shale bedrock or on a limited depth of properly placed and compacted structural fill placed on the bedrock. The design and construction criteria presented below should be observed for a spread footing foundation system. 1) Footings placed on the undisturbed hard to very hard bedrock and/or properly placed and compacted structural fill should be designed for an allowable bearing pressure of 3,000 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 18 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 48 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be well reinforced top and bottom to span local anomalies such as 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) All topsoil, soil, and any loose disturbed materials should be removed and the footing bearing level extended down to the hard to very hard shale bedrock. If structural fill is placed below the footings the structural fill should consist of CDOT Class 2, 5 or 6 aggregate base course compacted to at least 98% standard Proctor density at a moisture content within about 2% of optimum. The structural - 5 - Kumar & Associates, Inc. ® Project No. 20-7-655 fill should extend beyond the edges of the footings a distance equal to at least ½ the depth of the fill below the footing. 6) A representative of the geotechnical engineer should observe all footing excavations and test structural fill compaction on a regular basis 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 55 pcf for backfill consisting of the on-site predominantly granular soils and well broken bedrock. 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 50 pcf for backfill consisting of the on-site predominantly granular soils and well broken bedrock. The backfill should not contain predominantly clay soils, 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. 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 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. Use of a select granular backfill material, such as aggregate base course, and increasing compaction to 98% standard Proctor density could be done to reduce the backfill settlement. - 6 - Kumar & Associates, Inc. ® Project No. 20-7-655 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 predominantly 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 subgrade soils were to become wet. Slab-on-grade construction may be used provided precautions are taken to limit potential movement and the risk of distress to the building is accepted by the owner. If slab on grade construction is planned, all potentially expansive soil should be removed below slab areas to reduce the risk of floor slab movement and distress. A positive way to reduce the risk of slab movement, which is commonly used in the area, is to construct structurally supported floors over crawlspace. 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. 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 can consist of the on- - 7 - Kumar & Associates, Inc. ® Project No. 20-7-655 site predominantly granular soils devoid of clay soils, topsoil and oversized (plus 6-inch) rock or of imported CDOT Class 5 or 6 aggregate base course. UNDERDRAIN SYSTEM Although groundwater was not encountered during our exploration, it has been our experience in the area where clay soils are present and bedrock is shallow that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can also 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 4 inch dimeter PVC 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 ½% to a suitable gravity outlet. 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 2 feet deep and extend to above any seepage in the adjacent cut face, and be covered in filter fabric such as Mirafi 140N or 160N. SITE GRADING The risk of construction-induced slope instability at the site appears low provided the building is located as generally planned and cut and fill depths are limited. We assume the cut depths for the basement level will not exceed one level, about 10 to 12 feet. Embankment fills should be limited to about 8 to 10 feet deep and be compacted to at least 95% of the maximum standard Proctor density near optimum moisture content. Prior to fill placement, the subgrade should be carefully prepared by removing all vegetation and topsoil and compacting to at least 95% of the maximum standard Proctor density. The fill should be benched horizontally into the portions of the hillside exceeding 20% grade. Permanent unretained cut and fill slopes should be graded at 2 horizontal to 1 vertical or flatter and protected against erosion by revegetation or other means. Steeper permanent unretained cuts - 8 - Kumar & Associates, Inc. ® Project No. 20-7-655 into bedrock may be feasible and can be evaluated if desired. The risk of slope instability will be increased if seepage is encountered in cuts and flatter slopes may be necessary. If seepage is encountered in permanent cuts, an investigation should be conducted to determine if the seepage will adversely affect the cut stability. 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. 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. This may require a swale on the uphill side. 4) Free-draining wall backfill should be capped with filter fabric and about 2 feet of the on-site finer graded soils to reduce surface water infiltration. 5) Roof downspouts and drains should discharge well beyond the limits of all backfill. 6) 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 7698.26 7694.70 7692.30 7689.60 7687.71 7685.71 Kumar & Associates Kumar & Associates Kumar & Associates Kumar & Associates Kumar & Associates TABLE 1 SUMMARY OF LABORATORY TEST RESULTS Project No. 20-7-655 SAMPLE LOCATION NATURAL MOISTURE CONTENT NATURAL DRY DENSITY GRADATION PERCENT PASSING NO. 200 SIEVE ATTERBERG LIMITS UNCONFINED COMPRESSIVE STRENGTH SOIL OR BEDROCK TYPE BORING DEPTH GRAVEL SAND LIQUID LIMIT PLASTIC INDEX (%) (%) (ft) (%) (pcf) (%) (%) (psf) 1 2 9.3 119 Siltstone/Claystone Shale 2 2 5.6 123 46 26 28 Clayey Sandy Gravel 4 12.4 115 74 Sandy Clay with Gravel