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HomeMy WebLinkAbout532 Amherst Dr - 211120407014Environmental Health Department P.O. Box 179 500 Broadway Eagle, CO 81631-0179 Phone: (970) 328-8730 Fax: (970) 328-7185 Permit Permit No. OWTS-022305-2021 Permit Type: OWTS Permit Work Classification: New Permit Status: Active Issue Date: 9/2/2021 Expires: 12/30/2021 On-Site Wastewater Treatement System Project Address Parcel Number 532 AMHERST RD, GYPSUM AREA,211120407014 Owner Information Address Jeremy Cossette Phone: Cell: (970) 471-9347 Email: valleybuilder@ymail.com Inspections: For Inspections Call: (970) 328-8755 Engineer Phone Email Kumar & Associates, Shane Mellow (970) 945-7988 smello@kumarusa.com Contractor License Number Phone Email Legacy Classicford79@gmail.com(970) 274-0743OWTSPL-000154-20 21 Permitted Construction / Details: Install the new system exactly as depicted in the Kumar and Associates design dated March 26th, 2021, stamped and signed on March 30th, 2021 by David A Young, PE. This system is designed to serve the maximum daily flow for a 5 bedroom residence with a 2 bedroom ADU for a total of 7 bedrooms and a toilet with a sink in the shop building. This OWTS consists of 2 sewer lines, one from the residence and one from the shop building. A Valley Precast 2,000 gallon, two-chamber septic tank with an effluent filter in the outlet tee will be used. A Valley Precast 8-Hole Distribution Box equipped with flow equalizers will be accessible at grade. The STA will consist of seven trenches of 15 Infiltrator Quick 4 Plus Standard chambers for a total of 105. Be sure to encase the sewer pipe with larger diameter Schedule 40 PVC pipe and seal at both ends anywhere it encroaches any of the setbacks as well as where it crosses the swale. 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 02, 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 2, 2021 1 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-523297-2023 Permit Number: OWTS-022305-2021 Inspection Date: 06/29/2023 Inspector: Weems, Kirk Permit Type: OWTS Permit Inspection Type: OWTS Final Inspection Work Classification: NewOwner:Valley Builders, Llc Job Address:532 AMHERST RD IVR Pin Number:194033 GYPSUM AREA, CO Project:<NONE> Parcel Number:211120407014 Contractor:Phone: (970) 471-6511 / Cell: (970) 471-6511Valley Excavation Inspection Status: Approved Inspection Notes Corrections from 06/27 Site visit were completed. System approved for backfill. Inspector Comments Added Item: Septic Tank A Valley Precast 2,000 gallon, two-chamber septic tank with an effluent filter in the outlet tee was installed. Added Item: Record Drawing Received 7/18/2023 from K&A. Added Item: Record Photos Received 7/18/2023 from K&A. Added Item: Site and Soil 06/23/23 - Soil appeared to be compacted in north bed, request engineer inspection for condition of soil for STA. 6/27/2023 - Corrections made. 06/29/2023 - Compacted soil scarified and infiltrators installed level. Added Item: Final Certification Letter Received 7/18/2023 from K&A. Added Item: General Plan 06/23/23 - Setback to drainage at SE corner of south bed was observed to be <25'. Measured approx 17'. 6/27/2023 - Corrections made. 06/29/2023 - South bed was reconfigured from 3 rows of 11 infiltrators to 4 rows of 9. This increased setback from drainage to meet regulation. Added Item: Soil Treatment Area (STA) Tuesday, July 18, 2023 For more information visit: http://www.eaglecounty.us Page 1 of 2 06/23/23 - Connection of serial beds was not to plan. Serial connection line was placed at both ends of beds. 6/27/2023 - Corrections made. 06/29/23 - Serial connections have been corrected, as well as lowering STA approx 12 inches to allow for proper flow from tank to field, and for proper serial distribution in STA. The STA consists of two beds, each with 4 rows, each row with 15 Infiltrator Quick 4 Plus Standard chambers and each row in the other bed with 12 Infiltrator Quick4 Plus Standard Chambers for a total of 108 chambers. The rows in the beds are connected using 4-inch SDR35 piping between Infiltrator Quick4 Plus All-In-One endcaps as depicted in the record drawing. The beds are serially connected with 4-inch SDR35 piping with minimum slope of 2%. Added Item: Identification of Systems Contractor Valley Excavation completed license process and was the installer for re-engineered system. Tuesday, July 18, 2023 For more information visit: http://www.eaglecounty.us Page 2 of 2 INSPECTION WORKSHEET (INSP-519097-2022) FOR EAGLE COUNTY GOVERNMENT OWTS-022305-2021Case Number:Case Module:Permit Management 11/18/2022 DisapprovedInspection Status:Inspection Date: OWTS Final InspectionInspection Type:Inspector:Claire Lewandowski Job Address:Parcel Number:532 Amherst Rd Gypsum Area, CO 211120407014 Company Name NameContact Type Contractor Legacy German Nevarez Engineer Kumar & Associates Shane Mellow Owner Valley Builders, Llc Jeremy Cossette CommentsPassedChecklist Item False Outlet tee was not installed. Risers were not installed.Septic Tank - Septic Tank False Soil Structure has been compromised. A new site inspection and design must be submitted for review and approval before changes are made. A pre-installation inspection must be scheduled with Eagle County after the redesign is submitted. Site and Soil - Site & Soil False Approved design was not followed. Changes were not approved and do not meet OWTS Regulations. General Plan - General Plan False Soil treatment area does not follow the engineered design and does not meet OWTS Regulation requirements. 4 rows of infiltrator chambers were installed in a bed configuration and not trenches as designed. Three rows of infiltrator chambers only had 13 chambers in the row instead of 15, and one row only had 12 chambers instead of 15. Three trenches that were installed did not maintain 4 feet of separation between trenches. The end of the "bed" was greater than four feet deep. Soil Treatment Area (STA) - Soil Treatment Area (STA) False Must confirm that a licensed installer completed the work. Legacy Excavation listed as the installer was not onsite at either inspection. Identification of Systems Contractor - Identification of Systems Contractor November 18, 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 July 17, 2023 Jeremy Cosette P. O. Box 4987 Eagle, Colorado 81631 jeremy@valleybuilders.net Project No. 20-7-293.02 Permit No. OWTS-022305-2021 Subject: Certification of Onsite Wastewater Treatment System, Proposed Residence, Lot 12, Hardscrabble Subdivision, 532 Amherst Road, Gypsum, Colorado Dear Jeremy: 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 you dated November 17, 2020. We previously designed the OWTS for the residence as submitted in our revised report dated June 7, 2023, Project No. 20-7-293.02. The system was designed for seven bedrooms. The OWTS was installed by Valley Excavation under Permit No. OWTS-022305-2021. We performed our as-built evaluations on June 21, 22 and 27, and July 1, 2023. The OWTS components observed included: sewer line, cleanout, septic tank, effluent line, 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 sewer line was previously installed and buried and pictures were not found. The distance locations to the septic tank shown on Figure 1 were made by taping. The second bed of the STA was changed during installation from 3 rows of 15 chambers to 4 rows of 12 chambers to better fit setbacks. The overall number of chambers was increased from 105 to 108 chambers. It is our opinion that the OWTS was installed in general conformance with the above referenced 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 RESIDENCE LOT 12, HARDSCRABBLE SUBDIVISION 532 AMHERST ROAD GYPSUM, COLORADO Project No. 20-7-293.02 Photograph 1: Cleanout at sewer line exiting residence. Photograph 2: Valley Precast 2,000-gallon, two-chamber septic tank and effluent line exiting tank. OWTS PHOTOGRAPH LOG PROPOSED RESIDENCE LOT 12, HARDSCRABBLE SUBDIVISION 532 AMHERST ROAD GYPSUM, COLORADO Project No. 20-7-293.02 Photograph 3: Effluent filter at tank outlet. Photograph 4: Both beds of soil treatment area (STA) with observations ports. Beds are connected on far end of picture and first (upper) bed is on the left. OWTS PHOTOGRAPH LOG PROPOSED RESIDENCE LOT 12, HARDSCRABBLE SUBDIVISION 532 AMHERST ROAD GYPSUM, COLORADO Project No. 20-7-293.02 Photograph 5: First bed of STA with effluent pipe entering. Photograph 6: Serial connection from first bed (right) to second bed (left). 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 RE-DESIGN PROPOSED RESIDENCE LOT 12, HARDSCRABBLE SUBDIVISION 532 AMHERST ROAD GYPSUM, EAGLE COUNTY, COLORADO PROJECT NO. 20-7-293.02 JUNE 7, 2023 PREPARED FOR: JEREMY COSSETTE P. O. BOX 4987 EAGLE, COLORADO 81631 (jeremy@valleybuilders.net) Kumar & Associates, Inc. Project No. 20-7-293.02 TABLE OF CONTENTS INTRODUCTION ...................................................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 1 - SUBSURFACE CONDITIONS ................................................................................................. - 1 - OWTS ANALYSIS .................................................................................................................... - 2 - DESIGN RECOMMENDATIONS ............................................................................................ - 3 - SOIL TREATMENT AREA................................................................................................... - 3 - OWTS COMPONENTS ......................................................................................................... - 4 - OWTS OPERATION AND MAINTENANCE.......................................................................... - 6 - OWTS HOUSEHOLD OPERATION .................................................................................... - 7 - OWTS MAINTENANCE ....................................................................................................... - 7 - 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 2,000 GALLON, TWO-CHAMBER SEPTIC TANK DETAIL Kumar & Associates, Inc. Project No. 20-7-293.02 INTRODUCTION This report provides the results of an onsite wastewater treatment system (OWTS) re-design for the proposed residence to be located on Lot 12, Hardscrabble Subdivision, 532 Amherst Road, Gypsum, 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 design revision was done due to failure to properly install the original design dated March 26, 2021. The services are supplemental to our agreement for professional services to Jeremy Cossette dated November 17, 2020. PROPOSED CONSTRUCTION The residence will be a two-story structure with a partial walkout basement located on the lot as shown on Figure 1. The residence will be five-bedrooms with a basement level finish floor elevation of 6825.3 feet. A two-bedroom auxillary dwelling unit (ADU) will be above the attached garage. In addition, a shop building will also be attached to the OWTS. The shop building will have a sink and toilet. The OWTS will be designed for a total of 7 bedrooms. The proposed soil treatment area (STA) for the OWTS will be located to the south of the residence as shown on Figure 1. Water service is provided by public water supply from the curb stop on Amherst Road in the northwest corner of the property, located as shown on Figure 1. The route of the water supply line from the water valve to the residence is roughly designed and appears to be well outside of any setbacks to the OWTS. If proposed construction is different than that described, we should be contacted to re-evaluate our design recommendations. SITE CONDITIONS The lot was vacant with about four inches of snow on the site at the time of field exploration in January 2021. Amherst Road bounds the lot on the east and north, see Figure 1. The terrain is moderately sloping down to the southwest at grades from about 8 to 10%. Several dry drainages run through the site converging near the southwest corner of the property. Vegetation consists of sagebrush, grass and weeds. SUBSURFACE CONDITIONS The field exploration for the OWTS was conducted on January 21, 2020. Two profile pits (Profile Pits 1 and 2) were excavated with a mini-excavator at the approximate locations shown - 2 - Kumar & Associates, Inc. Project No. 20-7-293.02 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. Log of Profile Pit 1 Depth USDA Classification 0-3” TOPSOIL; organic Loam, firm, slightly moist, dark brown. 3”-8’ SILT LOAM; moderately blocky structure, stiff, slightly moist to moist, tan to brown, slightly gypsiferous. • 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. Log of Profile Pit 2 Depth USDA Classification 0-3” TOPSOIL; organic Loam, firm, slightly moist, dark brown. 3”-5’ SILT LOAM; moderately blocky structure, stiff, slightly moist, tan to brown. 5’-8’ SANDY LOAM; moderately blocky structure, stiff, slightly moist, grayish brown, very gypsiferous. • Disturbed bulk sample obtained from 5 to 6 feet. • Bottom of pit @ 8 feet. • No groundwater or redoximorphic features observed at time of pit excavation. The soils encountered in profile pits, below about 3 inches of organic topsoil, consisted of about 5 to 8 feet of Silt Loam, and in Profile Pit 2 overlying about 3 feet of Sandy Loam, to the pit depths of 8 feet. Hydrometer and gradation analyses were performed on a disturbed bulk sample of the soils from Profile Pit 1 from 4 to 5 feet depth with the results provided on Figure 2. The tested sample (minus No.10 size sieve fraction) classifies as Silt 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 2 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.60 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. - 3 - Kumar & Associates, Inc. Project No. 20-7-293.02 The STA will consist of chambers in a bed configuration based in the natural soils. The STA will be sized for seven bedrooms (12 persons) and an average daily flow of 75 gallons per person, and an LTAR of 0.60 gallons per square foot per day for the natural Silt Loam soils. Our re-design incorporated a portion of the previously installed chambers/bed configuration. The effluent will gravity flow from the residence and shop building to the septic tank for primary treatment and then gravity flow to the STA for dispersal and final treatment. The STA will consist of two beds, one with four and one with three rows of Infiltrator Quick 4 Plus Standard chambers. Equal distribution will be provided to the chambers and beds by serial distribution. A 25 feet minimum setback is required for the STA from all dry drainages. The drainage to the north will be redirected farther north and west to outside the required setback. 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. SOIL TREATMENT AREA • The STA will consist of seven rows in two beds with 15 Infiltrator Quick 4 Plus Standard chambers placed in each row (105 chambers total) in the native soils. Equal distribution will be provided to the beds by serial distribution. • The STA was sized based on an LTAR of 0.60 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. A 20% increase of the STA size was applied for the use of beds. The total STA design size is 1260 square feet. Soil treatment area calculations are shown on Figure 3. • A minimum of 12 feet of undisturbed soil between beds is required. • The bed cut depths should be a maximum of 4 feet deep. • The beds should be oriented along ground contours to minimize soil cut and cover. - 4 - Kumar & Associates, Inc. Project No. 20-7-293.02 • The base and sidewalls of the bed excavations should be scarified prior to the chamber placement. • A minimum of 12 inches and a maximum of 36 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 row. 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. • Rows within a bed should be connected by 4-inch diameter SDR35 piping attached in the side knockouts in the end caps. Splash plates should be installed beneath the inlet piping to help limit scouring of the infiltrative soil surface in the chambers. • The serial distribution pipe between the beds should be 4-inch diameter SDR35 piping sloped at a 2% minimum to flow from the first bed to the second bed. 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 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. • The STA must be a minimum of 25 feet from any drainages or dry gulches. • A plan view of the STA is presented on Figure 4 and a cross section of the STA is presented on Figure 5. 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. 20-7-293.02 Septic Tank • A Valley Precast 2,000 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 5 feet from the residence and shop. • The tank must be a minimum of 10 feet from any potable water supply lines. • The tank must be a minimum of 10 feet from any drainages or dry gulches. • 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 lines 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 pipes should have a rating of SDR35 or stronger. Schedule 40 PVC pipe is required beneath any driveway surfaces. • The sewer pipe should be encased with larger diameter Schedule 40 PVC pipe and sealed at both ends anywhere it encroaches of setbacks. • The setback from the sewer lines to any dry gulch, drainage, or subsurface drain is 10 feet. • The sewer pipes 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 24 inches of cover soil should be provided over the sewer pipes. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost and we recommend 36 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. 20-7-293.02 • 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 locations shown on Figure 1 are considered conceptual. We assume that there will be only one sewer line exiting the residence and one exiting the shop building. 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 buildings. 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 first bed of the STA. 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. 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 - 7 - Kumar & Associates, Inc. Project No. 20-7-293.02 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 STA. • Do not irrigate the area on top of or directly upgradient of the STA 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. • 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 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. - 8 - Kumar & Associates, Inc. Project No. 20-7-293.02 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 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 monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to our design. It is our opinion that the designed location of the OWTS components does not violate any setback requirements of the current Eagle County Regulations. Below is a table of common minimum horizontal setbacks to OWTS components. Refer to the Eagle County Regulations for a complete list of required setbacks. We recommend the OWTS components be surveyed by a Professional Colorado Land Surveyor. Table 1 - Common Minimum Horizontal Setbacks from OWTS Components Wells Water Supply Line Occupied Dwelling Lined Ditch Lake, Irrigation Ditch, Stream Dry Ditch or Gulch Septic Tank STA 100’ 25’ 20’ 10’ 50’ 25’ 5’ Septic Tank 50’ 10’ 5’ 10’ 50’ 10’ - Building Sewer 50’ 5’ 0’ 10’ 50’ 10’ - Kumar & 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\tKeFoQtUDFtoUtoDYoLGFoPSDFtLoQoItKeQDtLYesoLOsLQtKeEeGDUeDs7KeEDseDQGsLGeZDOOsoI EeGe[FDYDtLoQssKoXOGEesFDULILeGSULoUtoFKDPEeULQstDOODtLoQ $OOSLSLQJsKoXOGKDYeDUDtLQJoI6'5oUstUoQJeU &KDQJestotKLsGesLJQsKoXOGQotEePDGeZLtKoXtFoQsXOtDtLoQDQGDSSUoYDOE\.XPDU $ssoFLDtes 5eIeUtotKe(DJOe&oXQt\2QsLte:DsteZDteU6\steP5eJXODtLoQsIoUotKeUDSSOLFDEOesSeFLILFDtLoQs Infiltrator Quick 4 Plus Standard Chamber Installed Level Scarify ground surface prior to chamber placement. Excavate 12' Wide Bed Approx. Existing Ground S u r f a c e 12" min. 36" max. Cover Soil Graded to Deflect Surface Water Native Soil 12' Min. Undisturbed Soil Between Beds Excavate 9' Wide Bed 4' Diameter Non-Perforated SDR35 Transport Pipe Sloped at 2% Min. Infiltrator Quick 4 Plus All-in-One 12 End Cap at Ends of Each Row 4" Diameter SDR35 Pipe Connecting End Caps at Both Ends of Rows, Typical All End Caps 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. 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 RESIDENCE LOT 12, HARDSCRABBLE 532 AMHERST ROAD GYPSUM, EAGLE COUNTY, COLORADO PROJECT NO. 20-7-293.02 MARCH 26, 2021 PREPARED FOR: JEREMY COSSETTE P. O. BOX 4987 EAGLE, COLORADO 81631 (valleybuilder@ymail.com) Kumar & Associates, Inc. Project No. 20-7-293.02 TABLE OF CONTENTS INTRODUCTION ...................................................................................................................... - 1 - PROPOSED CONSTRUCTION ................................................................................................ - 1 - SITE CONDITIONS ................................................................................................................... - 1 - SUBSURFACE CONDITIONS ................................................................................................. - 1 - 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 – 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 2,000 GALLON, TWO-CHAMBER SEPTIC TANK DETAIL VALLEY PRECAST 8-HOLE DISTRIBUTION BOX Kumar & Associates, Inc. Project No. 20-7-293.02 INTRODUCTION This report provides the results of an onsite wastewater treatment system (OWTS) design for the proposed residence to be located on Lot 12, Hardscrabble Subdivision, 534 Amherst Road, Gypsum, 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 Jeremy Cossette dated November 17, 2020. PROPOSED CONSTRUCTION The residence will be a two-story structure with a partial walkout basement located on the lot as shown on Figure 1. The residence will be five-bedrooms with a basement level finish floor elevation of 6825.3 feet. A two-bedroom auxillary dwelling unit (ADU) will be above the attached garage. In addition, a shop building will also be attached to the OWTS. The shop building will have a sink and toilet. The OWTS will be designed for a total of 7 bedrooms. The proposed soil treatment area (STA) for the OWTS will be located to the south of the residence as shown on Figure 1. Water service is provided by public water supply from the curb stop on Amherst Road in the northwest corner of the property, located as shown on Figure 1. The route of the water supply line from the water valve to the residence is roughly designed and appears to be well outside of any setbacks to the OWTS. If proposed construction is different than that described, we should be contacted to re-evaluate our design recommendations. SITE CONDITIONS The lot was vacant with about four inches of snow on the site at the time of field exploration. Amherst Road bounds the lot on the east and north, see Figure 1. The terrain is moderately sloping down to the southwest at grades from about 8 to 10%. Several dry drainages run through the site converging near the southwest corner of the property. Vegetation consists of sagebrush, grass and weeds. SUBSURFACE CONDITIONS The field exploration for the OWTS was conducted on January 21, 2020. Two profile pits (Profile Pits 1 and 2) were excavated with a mini-excavator at the approximate locations shown - 2 - Kumar & Associates, Inc. Project No. 20-7-293.02 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. Log of Profile Pit 1 Depth USDA Classification 0-3” TOPSOIL; organic Loam, firm, slightly moist, dark brown. 3”-8’ SILT LOAM; moderately blocky structure, stiff, slightly moist to moist, tan to brown, slightly gypsiferous. • 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. Log of Profile Pit 2 Depth USDA Classification 0-3” TOPSOIL; organic Loam, firm, slightly moist, dark brown. 3”-5’ SILT LOAM; moderately blocky structure, stiff, slightly moist, tan to brown. 5’-8’ SANDY LOAM; moderately blocky structure, stiff, slightly moist, grayish brown, very gypsiferous. • Disturbed bulk sample obtained from 5 to 6 feet. • Bottom of pit @ 8 feet. • No groundwater or redoximorphic features observed at time of pit excavation. The soils encountered in profile pits, below about 3 inches of organic topsoil, consisted of about 5 to 8 feet of Silt Loam, and in Profile Pit 2 overlying about 3 feet of Sandy Loam to the pit depths of 8 feet. Hydrometer and gradation analyses were performed on a disturbed bulk sample of the soils from Profile Pit 1 from 4 to 5 feet depth with the results provided on Figure 2. The tested sample (minus No.10 size sieve fraction) classifies as Silt 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 2 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.60 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. - 3 - Kumar & Associates, Inc. Project No. 20-7-293.02 The STA will consist of chambers in a trench configuration based in the natural soils. The STA will be sized for seven bedrooms (14 persons) and an average daily flow of 75 gallons per person, and an LTAR of 0.60 gallons per square foot per day for the natural Silt Loam soils. The effluent will gravity flow from the residence and shop building to the septic tank for primary treatment and then gravity flow to the STA for dispersal and final treatment. The STA will consist of seven trenches with Infiltrator Quick 4 Plus Standard chambers. Equal distribution will be provided to the chambers and trenches by a distribution box. A 25 feet minimum setback is required for the STA from all dry drainages. The drainage to the north will be redirected farther north and west and the existing drainage will be regraded after installation 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. SOIL TREATMENT AREA • The STA will consist of seven trenches with 15 Infiltrator Quick 4 Plus Standard chambers placed in each trench (105 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 0.60 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 1260 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 3 feet deep. • 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. - 4 - Kumar & Associates, Inc. Project No. 20-7-293.02 • 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 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. • The STA must be a minimum of 25 feet from any drainages or dry gulches. • A plan view of the STA is presented on Figure 4 and a cross section of the STA is presented on Figure 5. 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 2,000 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 5 feet from the residence and shop. • The tank must be a minimum of 10 feet from any potable water supply lines. • The tank must be a minimum of 10 feet from any drainages or dry gulches. • 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 - 5 - Kumar & Associates, Inc. Project No. 20-7-293.02 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 lines 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 pipes should have a rating of SDR35 or stronger. Schedule 40 PVC pipe is required beneath any driveway surfaces. • The sewer pipe should be encased with larger diameter Schedule 40 PVC pipe and sealed at both ends anywhere it encroaches of setbacks. • The setback from the sewer lines to any dry gulch, drainage, or subsurface drain is 10 feet. • The sewer pipes 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 24 inches of cover soil should be provided over the sewer pipes. Paved areas, patios or other areas without vegetative cover may be more susceptible to frost and we recommend 36 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. • 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 locations shown on Figure 1 are considered conceptual. We assume that there will be only one sewer line exiting the residence and one exiting the shop building. 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 buildings. - 6 - Kumar & Associates, Inc. Project No. 20-7-293.02 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 Valley Precast 8-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 flow equalizers for ease of initial setup and adjustment over time. • 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. - 7 - Kumar & Associates, Inc. Project No. 20-7-293.02 • The distribution box must be installed level on a minimum 12 inches of 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. • 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. - 8 - Kumar & Associates, Inc. Project No. 20-7-293.02 • 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 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. Kumar & 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 ground surface prior to chamber placement. Excavate 36" Wide Trench Approx. Existing Ground Surf 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.