HomeMy WebLinkAbout340 Cordillera Wy - 210712203016 - OWTS-11-15-13750Work Classification: NewPermit PO BOX 532 AVON CO 81620- Address Owner Information Permit Status: Active Project Address 210712203016 Permit Type: OWTS Permit Permit NO. OWTS-11-15-13750 Expires: 12/30/2016 Issue Date: 4/22/2016 Parcel No. 340 CORDILLERA WY Private Wastewater System Environmental Health Department P.O. Box 179 500 Broadway Eagle, CO 81631-0179 Phone: (970)328-8755 Fax: (970)328-8788 Phone: (970)470-2361 Cell: Inspection For Inspections call: (970) 328-8755 Inspections: IVR OWTS Final Inspection 095 PhoneEngineer(s) (970)945-7988HP GEOTECH Contractor(s)Phone Primary ContractorLicense Number JV Excavating (970)390-6564 Yes33-16 Moving Mountains Trucking No47-15 ROBERT & BARBARA KEDROWSKI Permitted Construction / Details: Install the OWTS exactly as depicted on the HP Geotech design report and drawings stamped, signed and dated by David A. Young on July 24, 2015. System is designed for a three bedroom residence. System consists of installing a 1,000 gallon Valley Precast two compartment septic tank with effluent filter on the outlet tee and 750 square feet of soil treatment area (prior to 30% adjustment for using chambers) via the installation of 44 Infiltrator Quick 4 Plus chambers placed in two, shallow, serially connected trenches with 22 chambers in each trench. Be sure to install inspection portals atop the first and last chambers in each trench and to scarify the soil prior to chamber placement. Do not install in wet or frozen ground. Contact the design engineer at least 48 hours in advance to conduct all inspections necessary to certify the system and to prepare the necessary as-built drawings. System certification along with the as-built drawings and photos are required to be submitted to, and approved by, Eagle County Environmental Health prior to the use of the system or occupancy of the dwelling. Office Copy April 22, 2016 Issued by: Environmental Health Department, Eagle County, CO Date Terri Vroman CONDITIONS: 1. THIS PERMIT 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 2. ALL INSTALLATIONS MUST COMPLY WITH ALL REQUIREMENTS OF THE EAGLE COUNTY INDIVIDUAL SEWAGE DISPOSAL SYSTEM REGULATIONS ADOPTED PURSUANT TO AUTHORITY GRANTED IN C.R.S. 25-10-101, et seq., AS AMENDED 3. THIS PERMIT IS VALID ONLY FOR CONNECTION TO 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. CHAPTER IV, SECTION 4.03.29 REQUIRES ANY PERSON WHO CONSTRUCTS, ALTERS OR INSTALLS AN INDIVIDUAL SEWAGE DISPOSAL SYSTEM TO BE LICENSED DEPARTMENT OF ENVIRONMENTAL HEALTH (970) 328-8755 FAX: (970) 328-8788 TOLL FREE: 800-225-6136 www.eaalecounty.us EAGLE COUNTY P.O. Box 179 500 Broadway Eagle, CO 81631 www.eaglecounty.us :j::F:ic;k;::%1c:k 1::1•:k:k 1:;k 1:*1: 1:*<:*:k:k***:k>k;k:t:,k1:***:k*:k:k*>k*1c***1: 1::k*: 1c;k:k1::k Jc*:k*:k* **1:*:r 1t:k 1: J7 **:: **:k-;!::k PERMIT APPLICATION FOR ON -SITE WASTEWATER TREATMENT SYSTEM OWTS PERMIT # /j-/4;_ - 13:ZL-'50 BUILDING PERMIT # r INCOMPLETE APPLICATIONS WILL NOT BE ACCEPTED (SITE PLAN MUST BE INCLUDED) FEESCHEDULE APPLICATION FEEZ$800D_00MTOR REPAIR FEE 800.00 MINOR REPAIR FEE 400.00 This fee includes esign Review and Final Inspection Review. An additional fee -of $135.00 may apply for review of resubmitted plans_ Make all remittance payable to: Eagle County Treasurer. --- Property Owner: ,&Z aP�Z Phone: 3?0 OV BZ 4'7D 0361 Mailing Address: P O- ,t3®Lr 53 Z At," �-1AO 1 email rya-, Registered Professional Engineer: AT aeQ /�G� Phone: %�yZfA Applicant or Contact Person: � �Vol�S�i Phone: ��r'* 236; Licensed Contractor Company J°V F_�X m0a4 )1"b License # Contractor's Name: �� )Ayt e C Phone: In Mailing Address: ED& _ LD emaily e 2_ aw ak, ki Q �?Qqma,,_mn Permit Application is for: P/ New Installation Alteration Repair Location of Proposed On -site Wastewater Treatment System: Tax Parcel Number: tom( /0 ?- l02 20 w D / �Lot Size: Z. S acl-e-5 Assessor's Link: www.eaglecounty.us/patie/ Physical Address: 3y0 4o o-41111" Attach Legal Description Building Type: PI/ Residential / Single Family Number of Bedrooms: Residential / Multi Family Number of Bedrooms: Commercial / Industrial 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 0,- Public If Public, Name of Supplier: a" � (/0) S Applicant Signature: Office Use Only r Amount Paid: �o�_ Receipt #: �999�heck #: 11917 Date: ✓,ue�t e��i�"` )D August 3, 2016 Mr. Bob Kedrowski PO Bod 532 Avon, CO RE: Final approval of septic permit OWTS-11-15-13750; Tax parcel #210712203016; Property location: 340 Cordillera Way, Cordillera area Mr. Kedrowski: This letter is to inform you that the above-referenced septic permit has been inspected and finalized. This permit was approved and sized for a total capacity for 3 bedrooms. Additional information about the maintenance your septic system needs can be accessed through web site links provided on the Environmental Health Department’s home page at http://www.eaglecounty.us/envHealth/ Be aware that changes in the use of your property or alterations of your building may require commensurate changes to, or relocation of, your septic system. Landscape features, trees with tap roots, irrigation systems and parking areas above the drain field can cause premature system failure. It is equally important that you notice and immediately repair dripping faucets and hissing toilets as this will certainly cause the system to fail. By following a few simple guidelines, like avoiding grease or other additives down the drain and making sure your septic tank is on a pumping schedule, your system has been designed to last for many years. If you have any questions regarding this information, please contact us at (970) 328-8755 and reference the OWTS septic permit number. Sincerely, Terri Vroman Administrative Technician IV cc: OWTS electronic permit folder Energov electronic file HP Geotech – Project113 141B DEPARTMENT OF ENVIRONMENTAL HEALTH (970) 328-8755 FAX: (970) 328-8788 TOLL FREE: 800-225-6136 www.eaglecounty.us RAYMOND P. MERRY, REHS Director �tecr, HEPWORTH-PAWLAK GEOTECHNICAL June 30, 2016 KED Development ATTN: Bob Kedrowski P.O. Boa 532 Avon, Colorado 81620 kedrowskibuilders(7a,amail.com Hepworth-Pawlak Geotechnical, Inc. 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-94S-7988 Fax: 970-945-8454 Email: hpgeo@hpgeotech.com Job No. 113 141 B Permit No. OWTS-11-15-13750 Subject: As -Built Evaluation of On -site Wastewater Treatment System, Proposed Residence, Lot 4, Filing 1, The Divide at Cordillera, 340 Cordillera Way, Eagle County, Colorado Dear Mr. Kedrowski: As required by Eagle County Environmental Health Department regulations, Hepworth- Pawlak Geotechnical observed the installation of the Onsite Wastewater Treatment System (OWTS) for the proposed residence at the subject site. Our observations and recommendations are presented in this report. The services are supplemental to our proposal for geotechnical services to KED Development dated May 7, 2013. We designed the OWTS for the residence and presented our recommendations in a report dated July 24, 2015, Job No. 1 l 3 141 B. We also observed additional profile pits for the OWTS design and submitted our findings in a report dated November 10, 2015. The profile pit evaluations verified the soil assumptions for our design. We performed our As -Built site evaluation on June 21, 2016. The installation and locations of system components were verified as shown on Figure 1. The installer was JV Excavating. The OWTS components observed included: cleanout, sewer lines, septic tank, effluent filter, effluent transport pipe. Infiltrator chambers, inspection ports, serial connection piping and the locations of components. The sewer lines, septic tank, and soil treatment area configurations were modified slightly from our design due to the terrain; however, this will not alter the effectiveness of the OWTS. Photographs of the OWTS installation are provided in the attached Photograph Log. It is our opinion that the OWTS was installed in general conformance with our July 24, 2015 design. Job No. 113 14113 KED Development June 30, 2016 Page 2 The observations and recommendations presented above are based on our site observations and our experience in the area. We make no warranty for the system either expressed or implied. Alterations to the system, improper backfill, improper use and site grading could affect the operation and effectiveness of the OWTS. Please feel free to contact us if you have any questions regarding this letter. Sincerely, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Jason A. Deem Project Geologist Reviewed by: CQr,0O�;� David A. Young, P.E" ' d e G Q Attachments: Figure 1 5 •6-Ae*- �an OWTS As-- h Log cc: Eagle County Environmental Health Department (enyironment@ea&lecoW1y,uO ]oh No. 113 14111 ^ E 9 SOIL TREATMENT AREA CONSISTING OF TWO ROWS OF 22 INFILTRATOR 4 QUICK 4 PLUS STANDARD CHAMBERS O IN EACH ROW (44 CHAMBERS TOTAL), O O O O PP-1 O P-3 O Oil, n O 1,000 GALLON, TWO CHAMBER VALLEY PRECAST SEPTIC TANK g • . , , , M .$ + 4 ! F # WITH AN EFFLUENT FILTER \ "+ INSTALLED IN THE OUTLET TEE -P-2 .. a PP-2 rqm• � O O 0 CLEANOUT�,i 0 PROP05E � \� THREE; \ BEDROOM \ RESIDENCE O' O Legend ■ Profile Pit APPROXIMATE SCALE P-1 1 INCH 40 FEET � Percolation Test Hole 113 141 BteCh LOT 4, FILING 1, THE DIVIDE AT CORDILLERA FIGURE 1 HEPWORTH-PAWLAKGEOTECHNICAL OWTS AS -BUILT SITE PLAN OWTS AS -BUILT PHOTOGRAPH LOG LOT 4, FILING 1, THE DIVIDE AT CORDILLERA 340 CORDILLERA WAY, EAGLE COUNTY, COLORADO NNE 21, 2016 A Job No.113Id1B Photograph 1: Cleanout at residence and backfilled sewer line. Photograph 2: 1,000 gallon, two chamber Valley Precast septic tank. Photograph 3: Sewer line running into septic tank. Photograph 4: 1,000 gallon, two chamber Valley Precast septic tank with uninstalled risers. OWTS AS -BUILT PHOTOGRAPH LOG LOT 4, FILING 1, THE DIVIDE AT CORDILLERA 340 CORDILLERA WAY, EAGLE COUNTY, COLORADO JUNE 21, 2016 Photograph 5: Effluent transport Iine and first trench of STA with Infiltrator Quick 4 Plus chamber. Photograph 6: Second chamber of septic tank with uninstalled effluent filter. Photograph 7: View facing east of STA trenches with Infiltrator Quick 4 Plus chambers and inspection port. Photograph S: View facing east of STA trenches with Infiltrator Quick 4 Plus chambers. Job No. 1 13 141 Q OWTS AS -BUILT PHOTOGRAPH LOG LOT 4, FILING 1, THE DIVIDE AT CORDILLERA 340 CORDILLERA WAY, EAGLE COUNTY, COLORADO JUNE 21, 2016 Photograph 9: View facing west of STA with Infiltrator Quick 4 Plus chambers and inspection ports. Job No_ 113 141 B fne- �0'�� cmtiil: hn.,c„%1 hh�•aurcch.o mi ONSITE WASTEWATER TREATMENT SYSTEM DESIGN PROPOSED RESIDENCE LOT 4, FILING 1, THE DIVIDE AT CORDILLERA 340 CORDILLERA WAY EAGLE COUNTY, COLORADO JOB NO. 113 141B JULY 24, 2015 PREPARED FOR: KED DEVELOPMENT ATTN: BOB KEDROWSKI P.O. BOX 532 AVON, COLORADO 81620 bbkedroivski.ng amai1.cum Parker 303-841-7119 0 Colorado Sprin, S 7 19-633-5561 Si1: erthorne 97i1_�1�,,ti_ 1yti� TABLE OF CONTENTS INTRODUCTION................................................................ BACKGROUND INFORMATION ................................. PROPOSED CONSTRUCTION................................................................ SITE CONDITIONS................................ ................................ SUBSURFACE CONDITIONS ................................. PERCOLATION TESTING ................................. .2- OWTSANALYSIS............................................................... DESIGN RECOMMENDATIONS ................................ SOIL TREATMENT AREA ................................. OWTS COMPONENTS ................................. .................... 3 - .............- 4 - OWTS OPERATION AND MAINTENANCE ................................ OWTS HOUSEHOLD OPERATION : 6 - ............................ OWTSMAINTENANCE........................................................................................: 6- 7- OWTS CONSTRUCTION OBSERVATION .................... LIMITATIONS ................................. FIGURES FIGURE 1 - OWTS SITE PLAN FIGURE 2 - USDA GRADATION ANALYSIS FIGURE 3 - PERCOLATION TEST RESULTS FIGURE 4 - SOIL TREATMENT AREA CALCULATIONS FIGURE 5 - SOIL TREATMENT AREA PLAN VIEW FIGURE 6 - SOIL TREATMENT AREA CROSS SECTION ATTACHMENT VALLEY PRECAST SEPTIC TANK DETAIL Job No. 113 141 B INTRODUCTION This report provides the results of an onsite wastewater treatment system (OWTS) design for the proposed residence to be located on Lot 4, Filing 1, The Divide at Cordillera, 340 Cordillera Way, Eagle County, Colorado. The purpose of this report was to provide design details for the OWTS in accordance with the 2014 Eagle County Onsite Wastewater Treatment System Regulations and the Colorado Department of Public Health and Environment's Regulation #43. The services were supplemental to our proposal for geotechnical engineering services to KED Development dated May 7, 2013. BACKGROUND INFORMATION Hepworth-Pawlak Geotechnical, Inc. (HP Geotech) previously performed a subsoil study for foundation design at site, and submitted our findings in a report dated June 30, 2013, Job No. 113 141A. PROPOSED CONSTRUCTION The residence will be a two-story structure over a walkout basement located on the site as shown on Figure 1: The OWTS soil treatment area (STA) will be located north northeast and downslope of the residence. The residence will have three bedrooms. If proposed construction is different than that described, we should be contacted to re-evaluate our design recommendations. SITE CONDITIONS The site was vacant at the time of our field exploration. The proposed building is in the southwest part of the lot as shown on Figure 1. The ground surface slopes moderately to steeply down toward the north-northwest. Vegetation consists of scattered evergreen and juniper trees, sagebrush, grass and weeds. A fairly well incised, dry drainage channel trends through the lower part of the lot and below the proposed OWTS. A 25 feet setback Job No. 113 141 B -2- is required from dry ditches to the STA. Water service will be provided to the residence by a public water supply system. SUBSURFACE CONDITIONS The field exploration was conducted by on July 9, 2015. Two profile pits (PP-1 and PP- 2) and three percolation test holes (P-1, P-2 and P-3) were excavated at the approximate locations shown on Figure 1 to evaluate the subsurface conditions and to perform percolation testing. The soils encountered consisted of about % to 1'/z feet of topsoil overlying Silt Loam the depth explored, 8 feet. No free water was encountered in the pits at the time of excavation and the soils were typically moist. A hydrometer and gradation analyses was performed on a disturbed bulk sample of the soils from Profile Pit 1 with the results provided on Figure 2. The tested sample classifies a Silt Loam with gravel and cobbles per the USDA system. Based on the subsurface conditions and laboratory testing, the soils have been classified as Soil Type 2 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.6 gallons per square foot per day. Bedrock was encountered in the borings at the residence at depths of 15 feet or more. No free water was encountered in the borings when drilled in May 2013. PERCOLATION TESTING Percolation tests were performed in the three test holes (P-1, P-2 and P-3) on July 10, 2015. Percolation test rates ranged from 6 to 12 minutes per inch (mpi) with an overall average of percolation rate 8.7 mpi. Percolation test procedures outlined in Regulation #43 were not utilized and the results were only used for comparison of the soil profile pit evaluations. The percolation test results are provided on Figure 3. OWTS ANALYSIS The base of the soil treatment trenches will be located in Silt Loam (Soil Type 2) and no bedrock, groundwater or evidence of seasonal shallow groundwater was encountered in Job No. 113 141 B -3- the profile pits to the depths explored of 8 feet. Based on the profile pit evaluations and laboratory testing, the site is suitable for a conventional infiltration disposal system. The STA will be sized for three bedrooms using an LTAR of 0.6 gallons per square foot per day. The sewage will gravity flow to the septic tank for primary treatment then gravity flow to the STA for disposal and final treatment. The STA will consist of two trenches with Infiltrator chambers in a serial distribution network. 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. If conditions encountered during construction are different than those that are described in this report please contact us and we will re-evaluate our design recommendations. SOIL TREATMENT AREA • The treatment system will consist of two trenches with 22 Infiltrator Quick 4 Plus Standard chambers. • The STA was sized based on an LTAR of 0.6 gallons per square feet per day. • Each chamber was allowed 12 square feet of area and a 30% reduction in the STA was allowed per Eagle County regulations. The total STA is 528 square feet. Soil treatment area calculations are shown on Figure 4. • The base and sidewalls of the trench excavations should be scarified prior to 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 absorption area and should be sloped at 3 Horizontal to 1 Vertical maximum. A swale may be needed upslope of the STA to help divert surface water. Job No. 113 141 B • 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 absorption area as this may damage the system piping. • Four inch diameter inspection ports should be installed vertically into the knockouts provided in the Infiltrator end caps. Install vents at each end of each 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. • A plan view of the absorption area is provided on Figure 5 and a cross section of the absorption area is provided on Figure 6. 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 1,000 gallon, two chamber Valley Precast septic tank is proposed for primary treatment. A copy of the tank detail is provided as an attachment to this report. • An effluent filter should be installed in the tank outlet tee. • 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 gravel or road base bedding material may be necessary to prevent tank damage during placement and act as a leveling course. • Install tank with 2 feet minimum cover soil for frost protection. Maximum tank soil cover depth is 4 feet. • The septic lids must extend to final surface grade and made to be easily located. Sewer Pipe • The sewer line from the residence to the septic tank should not be less than the diameter of the building drain and not less than 4 inches in diameter. J00 IVo. 115 141 d Gc�cPtech -5- • The sewer pipe should have a rating of SDR35 or better. • 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. We recommend 48 inches of soil cover over the sewer pipe in these areas and the pipe be insulated on top and sides with 2 inch thick blue foam insulation board. If adequate soil cover is not possible, we should be contacted for re-evaluation prior to installation. • The sewer pipe should be bedded in compacted % inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than 2'/s inches in diameter to help prevent settlement of the pipe. Sags could cause standing effluent to freeze and damage piping. • Install cleanout pipes within 5 feet of the building foundation, where the sewer pipe bends 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 and/or contractor 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 residence. Effluent Transport Piping • The effluent transport pipe should be 4 inch diameter SDR35 piping sloped at a 2% minimum to drain flow from the septic tank to the first 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 prevent scouring of the infiltrative soil surface in the chambers. Ge Ptech • Serial connections between the rows of should also consist of 4 inch diameter SDR35 piping sloped at a 2% minimum to drain to the next trench. Piping should extend at least 6 inches into the upper knockout provided in the Infiltrator end caps and be screwed in place. • The effluent transport pipe should be bedded in compacted 3/ inch road base or native soils provided that the native soils contain no angular rocks or rocks larger than 2%a inches in diameter to help prevent settlement of the pipe. Sags in the piping could cause standing effluent to freeze and damage. • A minimum 24 inches of cover soil should be provided over the effluent transport pipe. Paved areas, patios or other paved area or areas without vegetative cover may be more susceptible to freezing. We recommend 48 inches of soil cover over the pipe in these areas. If adequate cover soil is not possible the effluent pipe should be insulated on top and sides with 2 inch thick foam insulation board, and we should re-evaluate the proposed soil cover prior to installation. • The effluent pipe should be double encased with larger diameter Schedule 40 PVC pipe underneath driveway surfaces and be provided with at least 48 inches of soil cover and be insulated on top and sides with 2 inch thick foam insulation board. • All 90 degree bends should be installed using a 90 degree long -sweep or by using two 45 degree elbows. 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. goo ivo. i u 141ts GecPtech -7- • 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 household 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, effluent filter and soil treatment area at least annually for problems or signs of failure. • The effluent filter should be cleaned annually by spray washing solids into the first chamber of the septic tank. • 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 soil absorption area, which may shorten its life span. Jon IVo. 1IS 1411:3 C Pt@Ch • 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 an As -Built certification of the OWTS construction. We should be provided with at least 48 hour notice prior to the installer needing the As -Built 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 percolation test results, 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 cPtech M Regulations for a complete list of required setbacks. We recommend the OWTS components be surveyed by a Professional Colorado Land Surveyor and verified by H-P Geotech prior to the system permitting. Table 1 - Common Minimum Horizontal Setbacks from OWTS Components Water Lined Lake, Dry Wells Supply Occupied Ditch Irrigation Ditch Septic EAbsorption Line n Dwelling or Ditch, or Tank Lake Stream Gulch 100, 25' 20' 20' S0' 25' 5' Septic Tank 50' 10, S' 10, 50' 10, - Building Sewer 50' 10, 0' 10' S0' 10' - Please contact us for any necessary revisions or discussion after review of this report by Eagle County. If you have any questions, or if we may be of further assistance, please let us know Respectfully Submitted, HEPWORTH - PAWLAK�TECHNICAL, INC. Q�� a" Jason A. Deem Project Geologist Reviewed by: David A, JAD/ksw Job No. 113 141 B �'C�' rAech 0 r ;;. PROPOSED SOIL TREATMENTAREA `? CONSISTING OF TWO ROWS OF 22 INFILTRATOR QUICK 4 PLUS STANDARD CHAMBERS IN EACH ROW (44 CHAMBERS TOTAL). Cam) ■ PP-1 \ P-3 r PROPOSED 1,000 GALLON, TWO CHAMBER VALLEY PRECAST SEPTIC P-1 TANK WITH AN EFFLUENT FILTER ,I - Z INSTALLED IN THE OUTLET TEE 'sa �P-2 PP-2 / o i, U (a CLEANOUT toy o a o �` W "emu: a \ _..PROPOSEC� THREE n. aa, \ BEDROOM .RESIDENCE o \ Z <) ILI b� p O O % \ � 0 Legend ■ Profile Pit APPROXIMATE SCALE: P-1 1 INCH = 40 FEET A Percolation Test Hole 113 141 B Ge Ptech LOT 4, FILING 1, THE DIVIDE AT CORDILLERA HEPWORTH�PAWLAKGEOTECHNICAL OWTS SITE PLAN FIGURE 1 SIEVE ANALYSIS HYDROMETER ANALYSIS I U.S. STANDARD q10 q16 #30 I SIEVES u50 tt100 #270 1 TIME READINGS MIN 4 MIN 19 IN 60 MIN 435 MIN i I i i I I i z.oD 1.1s 100 90 sn 70 LD Z u Q 60 a F- Z � 50 w 40 30 20 10 0 .60 .30 .15 OS .037 .019 .009 .005 .002 .001 DIAMETER OF PARTICLE IN MILLIMETERS SAND VERY SILT CLAY COARSE COARSE MEDIUM FINE VERY FINE Grain Size (mE sing 2.00 1.18 0.60 0.30 0.15 0.053 Grain Size (mm) 0.025 0.018 0.011 0.008 M539 0:006 0.003 0.001 Particle Size Distribution Sand: 20% Silt: 66% Clay: 14% Classification: Silt Loam Location: Profile Pit 1 Depth: 3-4 feet Total Sample %Retained on #10 Sieve: 49% Note: Hydrometer and Sieve Analyses was performed on a bulk sample following screening of all material larger than the #t 0 size sieve (2.0 mm) per USDA guidelines. i 113 141 B i <3eVIt�� LOT 4, FILING 1, THE DIVIDE AT CORDILLERA i i rlE�w�oarN-aAVwEAKoeoTECNNicaLl USDA GRADATION TEST RESULTS FIGURE 2 OWTS ABSORPTION AREA CALCULATIONS In accordance with the current Eagle County Onsite Wastewater Treatment System Regulations, the soil treatment area was calculated as follows: CALCULATION OF OWTS DESIGN FLOW Q = (F)(B)(N) WHERE: Q = DESIGN FLOW F = AVERAGE FLOW PER PERSON PER DAY B = NUMBER OF BEDROOMS N = NUMBER OF PERSONS PER BEDROOM F= B= N= Q= CALCULATION OF OWTS SOIL TREATMENT AREA: MINIUMUMTREATMENTAREA=Q =LTAR WHERE: Q= LTAR = MINIMUM ABSORPTION AREA = REDUCTION FACTOR FOR CHAMBERS = MINIMUM ABSORPTION AREA WITH REDUCTION = AREA PER INFILTRATOR QUICK 4 STANDARD CHAMBER = TOTAL CHAMBERS NEEDED = NUMBER OF TRENCHES = CHAMBERS PER TRENCH = TOTAL NUMBER OF CHAMBERS AS DESIGNED = TOTAL SOIL TREATMENT AREA = 75 GALLONS PER DAY 3 BEDROOMS 2 PERSONS PER BEDROOM 450 GALLONS PER DAY 450 GALLONS PER DAY 0.6 GALLONS/FT2/DAY 750.0 SQUARE FEET 0.70 525 SQUARE FEET 12 SQUARE FEET 44 CHAMBERS 2 22 44 CHAMBERS 528 SQUARE FEET I 113 141 B I G wl-tech I LOT 4, FILING 1, THE DIVIDE AT CORDILLERA HEPwoRTH�PAwLAKGEOTECHNICAL SOIL TREATMENT AREA CALCULATIONS FIGURE 4 4" non -perforated SDR35 transport pipe sloped at 2% min. down to first trench Infiltrator Quick 4 Plus Standard End Plates NOT To SCALE 113141E 4 inch diameter PVC inspection port installed vertically into knockouts Provided in end caps. Install vents at each end of each trench. Removable lid to be placed on top of pipe. Pipe must stick up at least 8 inches above finished grade or be installed in a valve box at grade. Infiltrator Quick 4 Plus Standard Chambers installed level. Two rows of 22 chambers. 4" non -perforated SDR35 serial connection pipe 6' in. sloped at 2% between each row Transport piping should be in>atleast 6 inches into the upper knothe chamber end plates. Instaplates beneath inlet piping Prevent scouring of the infiltrative surface. Notes: 1. Chambers should be installed level on a scarified ground surface. 2. All piping should have a rating of SDR35 or stronger. 3. Changes to this design should not be made without consultation and approval by HP Geotech. LOT 4, FILING 1, THE DIVIDE AT CORDILLERA SOIL TREATMENT AREA PLAN VIEW FIGURE 5 ATTACHMENT VALLEY PRECAST SEPTIC TANK DETAIL Job No. 113 141B Item 0 1000T-2CP DESIGN NO7 c • Design per performance test per ASTM C1227 • Top surface area 46.25 ft' • fc ® 28 days; concrete = 6,000 PSI Min. Installation• • Tank to be set on 5" min. sand bed or pea gravel • Tank to be backfilled uniformly on all sides in lifts less than 24° and mechanically compacted • Excavated material may be used for backflll, provided large stones are removed • Excavation should be dewatered and tank filled with water prior to being put in service for installation with water table less than 2' below grade • Meets C1644-06 for resilient connectors • Inlet and Outlet identified above pipe • Delivered complete with internal piping • PVC or concrete risers available • Secondary safety screen available with PVC riser • Option of pump or siphon Installed E BURYter Table)ALLOWABLEEARTH FILL2. _ 0"3'-0"3'— N 0"4'_0"4' _ 0" 1000 Gallon Top Seam Two Compartment 1 Top View Rubber slant ction M Digging Specs Invert Dimensions Net Ca acit— __ P y Net Weight 13' Long x 8' WideFInletIOutlet Length Width Height Inlet Sidl Outlet Total Lid TankTotal 56=beloI 53" 111" 60" I 68" 687 gal I323 gal 1010 gal 2620 Ibs 9380 Ibs �12000 Ibs Water $ 28005 Co. Rd. 317 Wastewater (719) 395.6764 P.O. BCK925 T! VALLEY 0 systems Fax: (719) 385-3727 C081211 D PPYXAST, Inc. • service Website: www•valleyprecastoom Emall: ftorrtdesk@vaneyprecastcom tech HEPWORTH- PAWLAK GEOTECHNICAL Hepworth-Pawlak Centrchnical, Inc. 50,0 Cinutt\' R'wd 154 ( 1,1wooil Springs, Culonldo 81(i01 Phi me: 970-945-7988 Fax:970-945-8454 entail: hi,,rti@lhp�eotech"om SUBSOIL STUDY FOR FOUNDATION DESIGN PROPOSED RESIDENCE LOT 4, FILING 1, THE DIVIDE AT CORDILLERA 340 CORDILLERA WAY EAGLE COUNTY, COLORADO JOB NO. 113 141A JUNE 30, 2013 PREPARED FOR: KED DEVELOPMENT ATTN: BOB KEDROWSKI P.O. BOX 532 AVON, COLORADO 81620 bbkedrowskW,2mai1.com Parker 303-841-7119 0 Colorado Springs 719-633-5562 0 Silverthome 970-468-1989 TABLE OF CONTENTS PURPOSE AND SCOPE OF STUDY........................................................................ - 1 - PROPOSED CONSTRUCTION................................................................................. - 1 - SITECONDITIONS................................................................................................... - 2- SUBSIDENCE POTENTIAL..................................................................................... - 2- FIELDEXPLORATION............................................................................................ - 3- SUBSURFACE CONDITIONS.................................................................................. - 3- FOUNDATION BEARING CONDITIONS............................................................... - 4- DESIGN RECOMMENDATIONS............................................................................. - 4- FOUNDATION AND RETAINING WALLS......................................................... - 5- FLOORSLABS...................................................................................................... - 7 - UNDERDRAINSYSTEM...................................................................................... - 7- SITEGRADING.................................................................................................... - 8 - SURFACEDRAINAGE......................................................................................... - 8- LIMITATIONS.......................................................................................................... - 9- FIGURE 1 - LOCATION OF EXPLORATORY BORINGS FIGURE 2 - LOGS OF EXPLORATORY BORINGS FIGURE 3 - LEGEND AND NOTES FIGURES 4,5 and 6 - SWELL -CONSOLIDATION TEST RESULTS TABLE 1 — SUMMARY OF LABORATORY TEST RESULTS PURPOSE AND SCOPE OF STUDY This report presents the results of a subsoil study for a proposed residence to be located on Lot 4, Filing 1, The Divide at Cordillera, 340 Cordillera Way, Eagle County, Colorado. The project site is shown on Figure 1. The purpose of the study was to develop recommendations for foundation design. The study was conducted in accordance with our agreement for geotechnical engineering services to Ked Development dated May 7, 2013. A field exploration program consisting of exploratory borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils and bedrock obtained during the field exploration were tested in the laboratory to determine their classification, compressibility or swell and other engineering characteristics. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed building foundation. This report summarizes the data obtained during this study and presents our conclusions, recommendations and other geotechnical engineering considerations based on the proposed construction and the subsurface conditions encountered. PROPOSED CONSTRUCTION The proposed residence plan was conceptual at the time of our study. In general, the residence will be a two-story, wood frame structure over a walkout basement and located in the building envelope shown on Figure 1. The garage and basement floors are assumed to be slab -on -grade. Grading for the structure is assumed to be relatively minor with cut depths between about 4 to 12 feet. We assume relatively light foundation loadings, typical of the proposed type of construction. If building loadings, location or grading plans change significantly from those described above, we should be notified to re-evaluate the recommendations contained in this report. Job No. 113 141 A -2- SITE CONDITIONS The site was vacant at the time of our field exploration. The building envelope is in the eastern, uphill part of the lot on the inside curve of Cordillera Way as shown on Figure 1. The ground surface in the building envelope slopes moderately to steeply down toward the southwest. A fairly well incised, dry drainage channel flows through the lower part of the lot and below the building site. There is about 20 feet of elevation difference across the proposed building footprint. Vegetation consists of scattered evergreen and juniper trees. sagebrush, grass and weeds. SUBSIDENCE POTENTIAL Bedrock of the Pennsylvanian age Eagle Valley Evaporite underlies The Divide at Cordillera. These rocks are a sequence of gypsiferous shale, fine-grained sandstone/siltstone and limestone with some massive beds of gypsum. There is a possibility that massive gypsum deposits associated with the Eagle Valley Evaporite underlie portions of the lot. Dissolution of the gypsum under certain conditions can cause sinkholes to develop and can produce areas of localized subsidence. During previous studies in the area, several sinkholes were observed scattered throughout the Cordillera Development. These sinkholes appear similar to others associated with the Eagle Valley Evaporite in areas of the Eagle River valley. Sinkholes were not observed in the immediate area of the subject lot. No evidence of cavities was encountered in the subsurface materials; however, the exploratory borings were relatively shallow, for foundation design only. Based on our present knowledge of the subsurface conditions at the site, it cannot be said for certain that sinkholes will not develop. The risk of future ground subsidence on Lot 4 throughout the service life of the proposed residence, in our opinion, is low; however, the owner should be made aware of the potential for sinkhole development. If further investigation of possible cavities in the bedrock below the site is desired, we should be contacted. J00 IV 0. 113141A tech -3- FIELD EXPLORATION The field exploration for the project was conducted on May 21, 2013. 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 auger powered by a track -mounted CME-45 drill rig. The borings were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Samples of the subsoils were taken with a 2 inch I.D. spoon sampler. The sampler was driven into the subsoils at various depths with blows from a 140 pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils and hardness of the bedrock. Depths at which the samples were taken and the penetration resistance values are shown on the Logs of Exploratory Borings, Figure 2. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Graphic logs of the subsurface profiles encountered at the site are shown on Figure 2. Below about 1 foot of organic topsoil, stiff to very stiff, sandy silty clay with shale and gypsum fragments was. encountered to depths of about 14'/2 to 24% feet where medium hard to hard siltstone/claystone bedrock was encountered to the drilled depths of 20 to 25% feet. Laboratory testing performed on samples obtained during the field exploration included natural moisture content and density. Swell -consolidation testing was performed on relatively undisturbed drive samples of the clay soils and siltstone/claystone. The swell - consolidation test results, presented on Figures 4, 5 and 6, generally indicate the clay soils have low to moderate compressibility under relatively light surcharge loading and Job No. 113 141A Gt PtGCh wetting. The sample of clay with shale fragments from Boring 1 at 14'/z feet showed a low to moderate collapse potential (settlement under constant load) when wetted, and the sample of weathered siltstone/claystone from Boring 3 at 19 feet showed a low expansion potential when wetted under a constant light surcharge. The laboratory testing is summarized in Table 1. No free water was encountered in the borings at time of drilling or when checked 8. days later and the soils and bedrock materials were slightly moist to moist. FOUNDATION BEARING CONDITIONS The clay soils encountered at the site possess low bearing capacity for shallow spread footings and low to moderate settlement potential mainly when wetted. The settlement potential and risk of building distress must be considered in the building design and site development. To some extent, the building settlement and distress risk can be mitigated by use of a heavily reinforced and simple -shaped concrete foundation designed to span settlement areas and limit distortion of the building. Surface runoff, landscape irrigation, and utility leakage are possible sources of water which could cause wetting of the bearing soils. Presented below are recommendations for a shallow spread footing foundation. If the risk of settlement and distress is not acceptable to the owner, a deep foundation, such as drilled piers, that extends down into the bedrock should be used to support the building and likely the ground floor. DESIGN RECOMMENDATIONS Considering the subsurface conditions encountered in the exploratory borings and the nature of the proposed construction, the building can be founded with spread footings bearing on the natural clay soils with a settlement risk. The design and construction criteria presented below should be observed for a spread footing foundation system. JUo 1VO. 11J 141A CAE Ptech -5- 1) Footings placed on the undisturbed natural soils should be designed for an allowable bearing pressure of 1,500 psf. Based on experience, we expect initial settlement of footings designed and constructed as discussed in this section will be about 1 inch or less. There could be addition differential settlement on the order of 1 to 2 inches if the bearing soils become wetted. 2) The footings should have a minimum width of 20 inches for continuous walls and 24 inches for isolated pads. 3) Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 42 inches below exterior grade is typically used in this area. 4) Continuous foundation walls should be reinforced top and bottom to span local anomalies such as by assuming an unsupported length of at least 14 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) The topsoil and any loose or disturbed soils should be removed and the footing bearing level extended down to the firm natural soils. The exposed soils in footing area should then be moistened and compacted. 6) A representative of the geotechnical engineer should observe all footing excavations prior to concrete placement to evaluate bearing conditions. FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pcf for backfill consisting of the on -site soils. Cantilevered retaining structures which are separate from the residence and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed Job No. 113 141A Ge Pttech MrSIB on the basis of an equivalent fluid unit weight of at least 45 pcf for backfill consisting of the on -site soils. Backfill should not contain vegetation, topsoil or oversized rock. 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. A relatively well graded granular soil compacted to at least 98% of standard Proctor density could be used to help reduce the settlement potential of deep backfill. The lateral resistance of foundation or retaining wall footings will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.35. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 300 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 rob No. 113 141A GecPtech -7- should be compacted to at least 95% of the maximum standard Proctor density at a moisture content near optimum. FLOOR SLABS The natural on -site soils, exclusive of topsoil, can be used to support lightly loaded slab - on -grade construction provided the risk of settlement and distress, mainly from wetting of the bearing soils is acceptable to the owner. To reduce the effects of some differential movement, non-structural 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 -site soils devoid of vegetation, topsoil and oversized rock. UNDERDRAIN SYSTEM Although free water was not encountered during our exploration, it has been our experience in the area that local perched groundwater can develop during times of heavy precipitation or seasonal runoff. Frozen ground during spring runoff can create a perched condition. We recommend below -grade construction, such as retaining walls, crawlspace and basement areas, be protected from wetting and hydrostatic pressure buildup by an underdrain system. Jou INO. Ili 141A c- Ptech The drains should consist of drainpipe placed in the bottom of the wall backfill surrounded above the invert level with free -draining granular material. The drain should be placed at each level of excavation and at least 1 foot below lowest adjacent finish grade and sloped at a minimum 1 % to a suitable gravity outlet. 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 1% feet deep. An impervious membrane, such as 20 mil PVC liner, should be placed below the drain in a trough shape and attached to the foundation wall with mastic to prevent wetting of the bearing soils. SITE GRADING The risk of construction -induced slope instability at the site appears low provided cut and fill depths are limited. We assume the cut depths for the basement level will not exceed one level, about 12 feet. Fills should be limited to about 8 to 10 feet deep. Embankment fills should 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 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. This office should review site grading plans for the project prior to construction. SURFACE DRAINAGE Keeping the bearing soils dry will be critical to prevent excessive differential settlement of the building. 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. OD INO. 115 141A ,'9tech Q 2) Exterior backfill should be adjusted to near optimum moisture and compacted to at least 95% of the maximum standard Proctor density in pavement and slab areas and to at least 90% of the maximum standard Proctor density in landscape areas. 3) The ground surface surrounding the exterior of the building should be sloped to drain away from the foundation in all directions. We recommend a minimum slope of 12 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. Free -draining wall backfill should be capped with at least 2 feet of the on - site soils to reduce surface water infiltration. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. 5) Vegetation that requires regular heavy irrigation, such as sod, and sprinkler heads should not be located within 10 feet of the building. Xeriscape should be used to help minimize wetting below the building from irrigation. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 1, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified at the exploratory borings and variations in the subsurface conditions may not become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. doo rvo. its ivin Cie Ptech MU111 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 the recommendations presented herein. We recommend on -site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Steven L. Pawlak Reviewed by: Daniel E. Hardin, P.E. / SLP/ksw JUD 1VU. I" 141A C3e�'cPitech BORING 1 BORING 2 BORING 3 ELEV.= 111' ELEV.= 100' ELEV.= 119' 0 0 5 26/12 19/12 18/12 =1 WC=26.0 WC=22.3 5 DD =103 DD=98 DD=102 10 22/12 9/12 27/12 10 m LL tv' LPL L CL L m 0 15 19/1z 14/6,20/1 28/12 WC=12.7 WC=17.4 15 DD=95 DD=105 20 16/12 50/2 26/12 WC=11.9 20 DD=117 25 37/12 35/12 25 Note: Explanation of symbols is shown on Figure 3. H 113 141A �" C� l LOGS OF EXPLORATORY BORINGS Figure 2 HEPWORTHPAWLAK GEOTECHNICAL LEGEND: ® TOPSOIL; organic sandy clayey silt, moist, black. CLAY (CL); sandy, silty, shale fragments, stiff to very stiff, slightly moist to moist, mixed brown, gypsum pieces, low plasticity. SILTSTONE/CLAYSTONE BEDROCK; medium hard to hard, slightly moist, gray -brown. Eagle Valley Evaporite. Relatively undisturbed drive sample; 2-inch I.D. California liner sample. 26/12 Drive sample blow count; indicates that 26 blows of a 140 pound hammer falling 30 inches were required to drive the California sampler 12 inches. NOTES: 1. Exploratory borings were drilled on May 21, 2013 with 4-inch diameter continuous flight power auger. 2. Locations of exploratory borings were measured approximately by pacing from features shown on the site plan provided. 3. Elevations of exploratory borings were measured by hand level and refer to Boring 2 as elevation 100', assumed. . 4. The exploratory boring locations and elevations should be considered accurate only to the degree implied by the method used. 5. The lines between materials shown on the exploratory boring logs represent the approximate boundaries between material types and transitions may be gradual. 6. No free water was encountered in the borings at the time of drilling or when checked 8 days later. Fluctuation in water level may occur with time. 7. Laboratory Testing Results: WC = Water Content (%) DID = Dry Density (pcf) 113 141A LEGEND AND NOTES I Figure 3 M c 0 a 2 E 0 U 3 A! Moisture Content = 16.4 percent Dry Density = 103 pcf Sample of: Sandy Silty Clay From: Boring 1 at 4 2 Feet Compression upon wetting U.7 0 1 2 3 6 7 8 0.1 1.0 10 APPLIED PRESSURE - ksf Moisture Content = 12.7 percent Dry Density = 95 pcf Sample of: Sandy Silty Clay with Shale Fragments From: Boring 1 at 14 z Feet 1.0 10 APPLIED PRESSURE - ksf Compression upon 100 100 113 141A I.ieCh I SWELL -CONSOLIDATION TEST RESULTS I Figure 4 HEPWORTH-PAWLAK GEOTECHNICAL 0 0 1 0 N N 0- 2 E 0 3 0.1 1.0 10 100 APPLIED PRESSURE - ksf Moisture Content = 22.3 percent Dry Density = 102 pcf Sample of: Sandy Silty Clay From: Boring 3 at 4 Feet O 0 C O m 1 a E 0 U 2 No movement upon wetting 0.1 1.0 10 100 APPLIED PRESSURE - ksf 113 141A G h SWELL -CONSOLIDATION TEST RESULTS Figure 5 HEPWORTH�PAWLAK GEOTECHNICAL n a K 4 0 0 0 C m 0 x w 1 0 O N P 2 0- E O U Moisture Content = 17.4 percent Dry Density = 105 pcf Sample of: Sandy Silty Clay From: Boring 3 at 14 Feet No movement upon U. 1 1.0 10 100 APPLIED PRESSURE -ksf a Moisture Content = 11.9 percent Dry Density = 117 pcf Sample of: Weathered Siltstone/Claystone From: Boring 3 at 19 Feet upon wetting 1.0 10 APPLIED PRESSURE - ksf 100 113 141A I G6Ch1.1@GI^t I SWELL -CONSOLIDATION TEST RESULTS I Figure 6 HEPWORTH-PAWLAK GEOTECHNICAL I z k § \ ] < LU z co § §w �—o $§§ \§\ } \ / / _ cn � _ j _§ * \ 4 � ( b 0 /a / O ) § { O e al G } / . + } / «7¥ OW \§2 §! E \ �- j ( )\ Z zzow §}§k 0 i� §�G © E / & f j / \ §§2 - c m t m {00 « \ § N § e / F9�— m r c'fAech G I=** 4 HEPWORTH-PAWLAK GEOTECHNICAL November 10, 2015 KED Development Attn: Bob Kedrowski P.O. Box 532 Avon, Colorado 81620 (bbkedrowski @ gmai l.co m) Hepworth -Pa hk Geutechntcal, Inc. 5020 County RoAd 154 GIC11W wLl Springs, Cnlnr dt) 81601 Phone: 970.945-7988 Fax: 970.945-8454 email: 11PgC4)@1)Pgcotec11 aim Job No. 113 141 B Subject: Supplement to Onsite Wastewater Treatment System Design, Proposed Residence, Lot 4, FiIing 1, The Divide at Cordillera, 340 Cordillera Way, Eagle County, Colorado. Dear Mr. Kedrowski: As requested by the Eagle County Environmental Health Department, we are providing additional subsoil information to supplement our Onsite Wastewater Treatment System (OWTS) design for the proposed residence dated July 24, 2015, Job No. 113141B. Additional comments regarding the subsoil conditions encountered at the site are provided below. The field exploration was conducted by on July 9, 2015. Two profile pits (PP-1 and PP-2) were excavated with a mini-trackhoe at the locations shown on Figure 1 of the above referenced OWTS design report. The soils encountered consisted of about 1/2 to 1' z feet of topsoil overlying Silt Loam that extended down the depths explored of 8 feet. No free water was encountered in the pits at the time of excavation and the soils were typically moist. Logs of the profile pits are provided below. Log of Profile Pit 1 Depth IUSDA Classification 0-6" TOPSOIL; silt loam with organics, loose, slightly moist, dark brown. 6"-8' SILT LOAM; with gravel and cobbles, moderate blocky structure, medium dense, moist, li ht brown, red and gray. Disturbed bulk sample obtained roar 3 to 4 eet. • Bottom of pit @ 8 feet. • No free water was encountered during excavation. Log of Profile Pit 2 Depth USDA Classification 0-18" TOPSOIL; silt loam with organics, loose, slightly moist, dark brown. 18"-8, SILT LOAM; with gravel and cobbles, moderate blocky structure, medium dense, moist, light brown, red and gray. • Bottom of pit @ 8 feet. • No free water was encountered during excavation. Parker 303-841-7119 9 Colorado Springs 719-633-5562 • Silverthorne 970-468-1989 KED Development November 10, 2015 Page 2 A hydrometer and gradation analyses was performed on a disturbed bulk sample of the soils from Profile Pit 1 with the results provided on Figure 2 of our OWTS design report. The tested sample classifies a Silt Loam with gravel and cobbles per the USDA system. Based on the subsurface conditions and laboratory testing, the soils have been classified as Soil Type 2 per State regulations, which equates to a long-term acceptance rate (LTAR) of 0.6 gallons per square foot per day which was used for the design. During our previous subsoil study for foundation design, bedrock was encountered in the borings at the residence location at depths of 15 feet or more. No free water was encountered in the borings when drilled in May 2013. Feel free to contact us if you have any questions or require additional information. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. "rO \ Vl� Jason A. Deem Project Geologist Reviewed by: A. David A. Young, P.E. 32-,216 JADlljf 'i� ••M••'' C7���� cc: Eagle County Environmental Health Dept. (environment@eaglecountv.us Job No, 113 141A Gg� teci^I