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HomeMy WebLinkAbout1.19 Geotechnical ReportGeotechnical Report Encana Oil and Gas (USA) Inc South Middle Fork Water Facility OLSSON ASSOCIATES OA Project No. 012-0400 June 2012 826 21 1/2 Road 1 Grand Junction, CO 81505 1 TEL 970.263.7800 1 FAX 970.263.7456 GEOTECHNICAL INVESTIGATION SOUTH MIDDLE FORK WATER FACILITY PARACHUTE, COLORADO March 23, 2012 Prepared For: Mr. Kevin McDowell Encana Oil & Gas (USA), Inc. 370 17th Street, Suite 1700 Denver, CO 80202 Prepared By: Yeh and Associates, Inc. 1525 Blake Avenue Glenwood Springs, CO 81601 Phone (970) 384-1500 Fax (970) 384-1501 Project No. 212-019 lA South Middle Fork Water Facility Project No. 212-019 TABLE OF CONTENTS 1.0 PROJECT INFORMATION 1 1.1 Purpose and Scope 1 1.2 Previous Investigations 1 1.3 Proposed Construction 1 1.4 Site Conditions 2 1.5 Site Geology 2 2.0 SITE INVESTIGATION 3 2.1 Subsurface Investigation 3 2.2 Subsurface Conditions 3 2.2.1 Groundwater 4 2.3 Site Grading 5 3.0 EXPANSIVE SOIL RISK 5 4.0 FOUNDATION RECOMMENDATIONS 6 4.1 Off-load Facility/Pad and Equipment Control Building Foundations 6 4.2 Pump Station, Off-load/Sludge Tanks and DAF Building Foundations 7 5.0 SLABS -ON -GRADE 8 6.0 SEISMIC CONSIDERATIONS 8 7.0 CONCRETE AND CORROSIVITY 9 8.0 SURFACE DRAINAGE 9 9.0 LIMITATIONS 9 South Middle Fork Water Facility Project No. 212-019 LIST OF FIGURES Figure 1 — Approximate Site Location Figure 2 — Approximate Test Hole Locations Figure 3 — Structure Drill Logs Figure 4 — Pond Area Drill Logs Figure 5 — Drill Log Legend Figures 6 through 12 — Sieve Analysis Test Results Figures 13 through 17 — Swell -Consolidation Test Results Laboratory Test Results and Summary Table ii South Middle Fork Water Facility Project No. 212-019 1.0 PROJECT INFORMATION 1.1 Purpose and Scope This report presents the results of our geotechnical investigation for the South Middle Fork Water Facility in Parachute, Colorado (Figure 1). The investigation was performed to provide foundation design recommendations for proposed structures, pond construction, site grading and surface drainage. The site investigation consisted of geologic reconnaissance and exploratory test hole drilling to investigate subsurface conditions. Test hole drilling was observed by a representative of Yeh and Associates. Samples obtained during the field exploration were examined by the project personnel and representative samples were subjected to laboratory testing to determine the engineering characteristics of materials encountered. This report summarizes our field investigation, the results of our analyses, and our conclusions and recommendations based on the proposed construction, site reconnaissance, subsurface investigation, and results of the laboratory testing. 1.2 Previous Investigations Yeh and Associates previously prepared a geotechnical investigation for the South Middle Fork Compressor Station under our Project Number 28-018A, dated April 11, 2008. The compressor site is located south of the proposed water facility. This report was reviewed prior to the preparation of this report. Current plans for the water facility refer to the compressor station site as the warehouse site. 1.3 Proposed Construction Plans provided by the client dated January 29, 2012, show that proposed construction will include new pads (upper, middle and lower) with structures related to the collection, treatment and storage of waste water associated with natural gas production. The upper pad will consist of the off-load pad, equipment control building and parking. The upper pad level will be accessed off of County Road 215 at elevation 5412 feet. Fills of 3 to 4 feet from existing test hole elevations will be necessary to achieve finish pad elevation. Structures on the middle pad will consist of the pump station, off-load tanks, DAF building and temporary frac tanks. This level will be accessed from the upper level and proposed grades will average near elevation 5399 feet. Fills of 2 to 3 feet and cuts of 1 to 8 feet from existing test hole elevations will be South Middle Fork Water Facility Project No. 212-019 necessary to achieve finish pad elevation. The lower pad will consist of four ponds. This level will be accessed from the middle level. Proposed grade will be at elevation 5394 feet at the top of ponds and 5374 feet at bottom of ponds. Fills of 2 to 13 feet will be necessary to achieve top of pond elevation and cuts 7 to 18 feet will be necessary to achieve bottom of pond elevation. Fills and cuts were estimated from existing test hole elevations. Plans indicated fill and cut slopes are planned at 2H:1 V. 1.4 Site Conditions The site was located about 4 miles north of Parachute, Garfield County, Colorado and Interstate 70 on the west side of County Road 215, and situated between the road and Parachute Creek near Wheeler Gulch Road (Figure 1). The site slopes down to the west and southwest at grades of less than 2 percent. An existing, dry pond is located along the southern property line between proposed ponds 3 and 4. Existing stockpiles were located near the proposed off-load pad area and between pond numbers 2 and 3. Research indicated that the stockpiles are remnant berms that were constructed for water storage containment (from Google Maps, U.S. Geological Survey, 1993). We believe that the ponds were abandoned between the fall of 1993 and fall of 2005. We estimated that the stockpiles vary in height between 2.5 and 8 feet from existing test hole elevations. Parachute Creek, trending approximately north -south, was located approximately 250 feet to the west. Existing overhead power transmission lines that trend north -south intersect the site at the southeast corner. An existing multi -pipeline corridor easement is situated between the site and CR 215 and is parallel to CR 215. Existing compressors and well pads were observed on the parcel south of the site. The other adjacent parcels were vacant. There was evidence that the site is used for cattle grazing and was covered with native grasses, weeds, scrub and brush. 1.5 Site Geology The project area is located at the confluence of Parachute Creek Road (County Road 215), Wheeler Gulch and Riley Gulch approximately 4 miles northwest of Parachute, Colorado. Parachute Creek is located west of the site. This area is located in the Piceance Basin of western Colorado, a complex of numerous anticlines and synclines and a major gas production area. The asymmetrical, arc -shaped basin is 100 miles long by 50 miles wide and is oriented northwest -southeast and is deepest on the east edge. It is bounded structurally on the northeast by the Axial Uplift, on the east by the White River Uplift/Grand Hogback and the Elk South Middle Fork Water Facility Project No. 212-019 Mountains, on the south by the Uncompahgre Uplift and on the west by the Douglas Creek Arch. Exposed in the project area is Tertiary age sedimentary rocks including the ledge forming red, gray, and brown sandstone and siltstone and the slope forming variegated (purple, gray and brown) claystone of the Wasatch Formation. The surficial deposits include alluvium and flood plain deposits of mud, silt, sand and gravel and coalescing alluvial fans and sheetwash deposits of locally derived materials. Other deposits observed at the site included artificial fill in the stockpiles. 2.0 SITE INVESTIGATION 2.1 Subsurface Investigation Fifteen test holes were drilled on February 15 and 16, 2012. Test holes TH-1 through TH-7 were drilled in the proposed off-load pad area and test holes TH-8 through TH-15 were drilled in the general area of the proposed water storage ponds. Yeh and Associates chose test hole locations and used a hand held GPS unit to field locate test holes. Location accuracy is only within the limits of the methods/instrument used. Test hole depths for structures were drilled between 21 and 41 feet below existing grades. Test hole depths for the ponds were drilled at least 5 feet below proposed pond bottom elevations. The locations of the test holes are presented in Figure 2. All test holes were advanced using a CME 55 rubber track rig and 4 -inch continuous flight auger to pre -determined depths where a modified California sampler was used to record blow counts and obtain samples. To perform the modified California penetration resistance tests, a 2.0 -inch inside diameter sampler was seated at the bottom of the test hole, then driven up to 12 inches with blows of a standard hammer weighing 140 pounds and falling a distance of 30 inches utilizing a "cat head" hammer (ASTM D1586). The number of blows (Blow Count) required to drive the sampler 12 inches or a fraction thereof, constitutes the N -value. The N -value, when properly evaluated, is an index of the consistency or relative density of the material tested. Test hole logs and legend are presented on Figures 3, 4 and 5. 2.2 Subsurface Conditions Subsurface conditions generally consisted of sandy clay, sandy silt, fairly clean to clayey sand and clayey gravel. Existing fill was encountered in test holes TH-1, TH-3, TH-4 and TH-13. The South Middle Fork Water Facility Project No. 212-019 depth of the fill varied between 2.5 and 8 feet and consisted of sand and clay material. We believe that the fill was remnant berms that were constructed previously for water storage containment. We believe existing fill may not have been placed in a controlled manner. Bedrock was not encountered to maximum depths explored. One sand fill sample tested had 47 percent fines (material passing the No. 200 sieve). Additionally, a water soluble sulfate was also performed on this sand fill sample. Results are reported under the concrete and corrosion section of this report. Seven clay samples tested had 55 to 86 percent fines. Atterberg limit testing on these samples indicated liquid limits of 28 to 43 percent and plastic indices of 15 to 27 percent. Two sand samples tested had 27 to 49 percent fines, liquid limits of 29 and 30 percent and plastic indices of 14 and 16 percent. Two gravel samples tested had 15 and 16 percent fines, liquid limits of 28 and 36 percent and plastic indices of 12 and 20 percent. An additional eight clay and one silt samples tested indicated low collapse to low swell (-1.1 to 1.6 percent) when wetted under an applied pressure of 1,000 psf. One sand sample tested indicated a low collapse of -2.4 percent when wetted under an applied pressure of 1,000 psf. The sand fill was very dense and classified as a SM according to the Unified Soil Classification System (USCS). The sand was medium dense and classified as a SC. The clayey gravel was dense to very dense and classified as a GC. The clay and silt was stiff to very stiff and classified as CL. Results of the laboratory testing are presented in Figures 6 through 17 and are summarized in the Summary of Laboratory Test Results. 2.2.1 Groundwater Groundwater was encountered during drilling. Piezometers were installed in selected pond test hole locations. For the off-load pad area, groundwater depths were approximately 28 to 34 feet below existing grade at an approximate elevation of 5373 feet. Groundwater depths for the ponds varied between 10 to 24 feet below existing grade at approximate elevations of 5368 to 5374 feet. We believe that groundwater will not impact the off-load pad area, however, based on proposed pond bottom elevations, groundwater could impact the ponds. Due to capillary action and current groundwater levels, pond liners may be susceptible to floating/uplift. Additional groundwater measurements are recommended, especially in the springtime, during high seasonal groundwater and possibly before construction. Dewatering and/or subgrade stabilization may be necessary for the construction of the ponds in order to provide a stable South Middle Fork Water Facility Project No. 212-019 platform. Variations in groundwater conditions may occur seasonally. The magnitude of the variation will be largely dependent upon the amount of spring snowmelt, duration and intensity of precipitation, site grading changes, and the surface and subsurface drainage characteristics of the surrounding area. 2.3 Site Grading For the off-load area, fills of up to 4 feet and cuts of up to 8 feet from existing test hole elevations are planned. For the pond area, cuts of up 18 feet from existing test hole elevations are planned to achieve pond bottom elevations. We believe the existing fill in the vicinity of the off-load facility and the off-load tanks may have been placed in an uncontrolled manner and may not be suitable to support foundations. The off-load tanks may not be affected by the existing fill due to cuts, but for the off-load bay facility and pump station, we recommend all existing fill below improvements be removed, moisture conditioned and recompacted to the specifications below. Based on drilling and our observations, we believe that material can be excavated by conventional construction equipment. We believe that proposed slopes of 2H:1V are appropriate for the soil conditions at the site. The on-site soils can be used in site grading fills provided the material is substantially free of organic material, debris and particles are no larger than 6 inches. Areas to receive fill should be stripped of vegetation, organic soils and debris. Topsoil is not recommended for fill material. Fill should be placed in thin, loose lifts of 8 inches thick or less. We recommend fill materials be moisture conditioned to 0 to 3 percent above optimum moisture content and compacted to at least 95 percent of maximum standard Proctor dry density (ASTM D 698). Placement and compaction of fill should be observed and tested by a representative of the geotechnical engineer. 3.0 EXPANSIVE SOIL RISK The site appeared suitable for the proposed construction. Potentially expansive soils will require particular attention in the design and construction. We believe there is a low risk of poor slab -on -grade and foundation performance due to swelling or collapsible soils. We estimate movements of up to 2 inches could occur for foundations or slabs placed directly on the expansive soils. Expansive soils are stable at current moisture conditions. Upon wetting these South Middle Fork Water Facility Project No. 212-019 soils increase in volume and could cause movement of slabs -on -grade. The amount of movement is dependent on the availability of water due to surface drainage and the structural tolerances to movement. Slab -on -grade construction is considered acceptable provided the owner accepts the risk of potential slab movement. The expansive soils can be mitigated by subexcavation. Subexcavation consists of removal of the expansive soils and replacing the material with a non - expansive granular fill or moisture conditioning of the on-site soils and placement as a moisture conditioned, controlled fill. If selected, we recommend subexcavation to a depth of 3 feet below foundation or slab level. We estimate potential movements of about 1 -inch or less, if subexcavation is performed. 4.0 FOUNDATION RECOMMENDATIONS We believe the off-load facility/pad and equipment control structure can be supported on a footing, mat or pad foundation placed on properly placed fill or natural silt soils. Existing fill soils encountered in test hole TH-1 should be removed and placed as a controlled fill to the specifications above. For all other structures, we anticipate foundation soils would consist of low swelling clay or low collapsing soils. We believe there is a low risk of heave related damage due to expansive soils and therefore a low risk of foundation movement. We anticipate foundation movements of up to 2 inches for typical footing foundations and slabs placed on expansive clay soils. To reduce potential movements to about 1 inch or less, we recommend structures be support on a footing or pad foundation designed to maintain a minimum deadload. If foundations cannot be designed with recommended minimum deadload due to structural loadings, we recommend subexcavation be performed as described above. Foundation recommendations for structures are presented below. 4.1 Off-load Facility/Pad and Equipment Control Building Foundations Foundations should be constructed on properly placed fill or natural silt soils. Loose, disturbed soils encountered at foundation level should be removed and the foundation should be extended to undisturbed properly placed fill and/or natural silt soils. South Middle Fork Water Facility Project No. 212-019 1. Foundations can be designed for a maximum allowable soil pressure of 3,000 psf. 2. Resistance to sliding at the bottom of the mat foundation can be calculated based on a coefficient of friction of 0.30. Passive pressure against the side of the footing can also be considered for the sliding resistance if it is properly compacted. Passive pressure can be estimated based on an equivalent fluid density of 300 pcf for a level backfill. 3. The soils below foundations should be protected from freezing. We recommend the bottom of foundations be constructed at least 3.5 feet below finished exterior grade or as required by local municipal code. 4. All foundation excavations should be observed by a representative of the geotechnical engineer prior to placement of concrete. 4.2 Pump Station, Off-load/Sludge Tanks and DAF Building Foundations We believe there is a low risk of heave related damage due to expansive soils and therefore a low risk of foundation movement. We anticipate foundation movements of up to 2 inches for typical footing foundations and slabs placed on expansive clay soils. To reduce potential movements to about 1 inch or less, we recommend structures be support on a footing or pad foundation designed to maintain a minimum deadload. If foundations cannot be designed with recommended minimum deadload due to structural loadings, we recommend subexcavation be performed as described above. Recommendations for foundations designed to maintain a minimum deadload are as follows. 1. Foundations should be constructed on undisturbed, natural soils. Loose, disturbed soils encountered at foundation level should be removed and replaced with compacted fill or the foundation should be extended to undisturbed soils. 2. Footing foundations can be designed for a maximum allowable soil pressure of 3,000 psf. The footing foundation should be designed with a minimum deadload pressure of 1,000 psf. 3. Continuous wall footings should have a minimum width of at least 12 inches. Foundation pads for isolated columns should have a minimum dimension of 16 inches by 16 inches. Larger sizes may be required depending upon the loads and structural system used. 4. In order to maintain the minimum dead load pressure, it may be necessary to design and construct a system of grade beams and isolated footing pads. To maintain the minimum South Middle Fork Water Facility Project No. 212-019 dead load pressure on footings, a minimum 4 inch void space could be provided beneath the grade beams between footing pads (if utilized). 5. Resistance to sliding at the bottom of the footing can be calculated based on a coefficient of friction of 0.30. Passive pressure against the side of the footing can also be considered for the sliding resistance if it is properly compacted. Passive pressure can be estimated based on an equivalent fluid density of 250 pcf for a level backfill. 6. Grade beams and foundation walls should be reinforced, top and bottom, to span undisclosed loose or soft soil areas. We recommend reinforcement sufficient to span an unsupported distance of at least 10 feet. Reinforcement should be designed by the structural engineer considering the effects of large openings on wall performance. 7. The soils below exterior footings or exterior edges of slabs should be protected from freezing. We recommend the bottom of footings be constructed at least 3.5 feet below finished exterior grade or as required by local municipal code. 8. All foundation excavations should be observed by an experienced engineering geologist or geotechnical engineer prior to placement of forms and concrete. 5.0 SLABS -ON -GRADE Based on our investigation, slabs will likely be underlain by low swelling clay soils. We believe there is a low risk of poor slab -on -grade performance due to swelling soils. Slab -on -grade movements of up to 2 inches could occur if subgrade soils are saturated. Given the engineering characteristics of clays, consideration should be given to the use of ground modification, such as subexcavation and moisture conditioning to the depths recommended above. The on-site soils, free of organics and debris, are suitable to support lightly loaded slabs -on -grade. Slabs should be separated from all load bearing walls and columns with slip joints. Control joints should be used to reduce damage from swelling soils. All fill below slabs should be compacted to at least 95 percent of maximum standard Proctor dry density at 0 to 3 percent above optimum moisture content. 6.0 SEISMIC CONSIDERATIONS Based upon the nature of the subsurface materials, a Site Class D, should be used for the design of the structure for the proposed project (2006 International Building Code, Table No. 1613.5.3 (1) and (2)). The project site is located in seismic area with a mapped maximum short period (Ss) and 1 -second period (S1) ground motion, respectively, of 0.28g and 0.068g as South Middle Fork Water Facility Project No. 212-019 indicated on Figures 1613.5 (1) and (2), in the 2006 International Building Code. The site coefficients, Fa and F,,, for the same periods are 1.5 and 2.4, respectively. 7.0 CONCRETE AND CORROSIVITY The concentration of water-soluble sulfates measured in the laboratory on two shallow samples taken from test holes TH-1 at 5 feet and TH-5 at 5 feet was 0.014 and 0.057 percent, respectively. This concentration of water-soluble sulfate represents a negligible/low (Class 0 exposure) degree of sulfate attack on concrete exposed to this material. The degree of attack is based on a range of 0.00 to less than 0.10 percent as presented in the American Concrete Institute Guide to Durable Concrete. Due to the negligible/low degree indicated by the test results, no special requirements for concrete are necessary for Class 0 exposure. 8.0 SURFACE DRAINAGE Surface drainage is crucial to the performance of foundations and flatwork. We recommend the ground surface surrounding structures be sloped to drain away. We recommend a slope of at least 6 inches in the first 10 feet for soil or gravel areas and a minimum slope of 1 percent for paved areas. Backfill around foundations should be moisture conditioned and compacted as recommended in the SITE GRADING section 2.3. 9.0 LIMITATIONS This study was conducted in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design purposes. The conclusions and recommendations submitted in this report are based upon the data obtained from exploratory test holes, field reconnaissance and anticipated construction. The nature and extent of subsurface variations across the site may not become evident until excavation is performed. If during construction, conditions appear to be different from those described herein; this office should be advised at once so reevaluation of the recommendations may be made. We recommend on-site observation of excavations by a representative of the geotechnical engineer. The scope of services for this project did not include, specifically or by implication, any environmental or biological (e.g., mold, fungi, and bacteria) assessment of the site or South Middle Fork Water Facility Project No. 212-019 identification or prevention of pollutants, hazardous materials or conditions or biological conditions. If the owner is concerned about the potential for such contamination, conditions or pollution, other studies should be undertaken. The report was prepared in substantial accordance with the generally accepted standards of practice for geotechnical engineering as exist in the site area at the time of our investigation. No warranties, express or implied, are intended or made. Respectfully Submitted: YEH AND ASSOCIATES, INC. Keith E. Asay Staff Engineer Reviewed by: Richard D. Johnson, P.E. Project Manager ), ht ti I '1 ti rj V {'b. 'ti v..{ jfj�f� . l J{J 57 `l—y vim-'-` �" fes-"-� 4 _ vl )Y 6 1.1 rf !. - f " e -. 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Gas, DSA PROJECT NUF��I 212-019 Approximate Site Location SCALE HURLD NOT TO SCALE VERT' F11T TO SCALE Consulting ,&gam 4 -BAY OFF-LOAD FACILITY 1 �� 132226' EOUIPMENT CONTROLS 500 BS' &S CONDENSATE TANK DUPLEX PUMP STATION �I HIGH PRESSURE PUMP 51 AT!ON OIL✓WATER SEPARATOR ,N,% DAF BULDING SLUDGE TANKS FRESH WATER TANKS OFF-LOAD TANKS (60' DIA x 40 POND NO. 4 (290,156 BDLS) POND NO. 3 (290,156 BBt S) POND NO. 2 (303,746 BBLS) POND NO. i (210,500 BBLS 1 DUPLEX FEED PUMP ` TEMPORARY FRAC TANKS 588' 37'31"E +83.92' DOW/ENCANA WILDLIFE MITIGATION AREA (ENCANA LAND) ' TALL) POND - Y PUMP POND PUMP_ PO 1' PUMP POND PUMP Approximate Test Hale Location NOTE1 1. BORING LOCATIONS WERE NOT SURVEYED AND ARE APPROXIMATE 2. DRAWING BASED ON PLAN SET DATED JANUARY 29, 2012, PROVIDED BY ENCANA OIL GAS PROPOSED WAREHOUSE 4 SITE PLAN v' ESC EL&-61-1:G ICALSTRTUBE \) Yeh and Associates, Inc. Consulting Engineers & Scientists DR N BY, SW DATE, 311/2012 CHECKED 8Y' RDJ DATE, 3/1/X12 DESIGNED FOR' ENCANA OIL . GAS. USA PROJECT South Middle Fork Water Facility PROJECT NUMBERS 212-019 SCALE HORIZ' I' = 200' VERT, V = 200' 190' Approximate Test Hole Locations FIGURE 2 FENCES BY ELEVATION - A SIZE 212-019, SMFWF LOGS.GPJ RDJ.GDT 3/21/12 5,415 5,410 5,405 5,400 5,395 O t 5,390 0) W 5,385 5,380 5,375 5,370 5,365 THA Off -Load Facility/Pad Elevation: 5409.0 ft Equipment Controls Elevation: 5408.0 ft PROPOSED PAD ELEVATION 5412 ft TH-4 Off-LoadT.ank Elevation: 5407.0 ft F F 50/8 45/12 41/12 31/12 32/12 TH-3 High Pressure Pump Station Elevation: 5397.0 ft 50/11 46/12 38/12 TH-5 Off -Load Tank Elevation: 5400.0 ft 50/12 TH-6 TH-7 Sludge Tanks Elevation: 5399.0 ft DAF Building Elevation: 5396.0 ft PROPOSED PAD AVERAGE ELEVATION 50/10 50/11 50/11 % 1 50/10 50/9 48/12 46/12 43/12 42/12 l 50/11 37/12 ,/,/e50/10 50/12 / 50/12 �/� 40/12 j 42/12 j 26/12 4 ' —I 25/12 //tel 50/10 5399 ft 0011 0• 42/12 36/12 54/12 39/12 5,415 5,410 5,405 5,400 5,395 5,390 5,385 5,380 5,375 5,370 5 365 YEH AND ASSOCIATES, INC. GEOTECHNICAL ENGINEERING CONSULTANTS South Middle Fork Water Facility Proposed Structures Project Number: 212-019 Figure No. 3 FENCES BY ELEVATION - A SIZE 212-019, SMFWF LOGS.GPJ RDJ.GDT 3/21/12 5,395 5,390 5,385 5,380 5,375 0 ca 5,370 0) W 5,365 5,360 5,355 5,350 5,345 TH-8 Pond No. 4 Elevation: 5392.0 ft PRQPOSED.TQP.OF POND ELEVATION F1 TH-10 5394 ft Pond No. 3 Elevation: 5389.0 ft TH-12 TH-13 TH-9 Pond No. 4 Elevation: 5384.0 ft 38/12 31/12 50/10 TH-11 Pond No. 3 Elevation: 5385.0 ft Pond No..2 Pond No..2 Elevation: 5387.0 ft Elevation: 5387.0 ft 26/12 •-1 20/12 1%7/12 Pry 133/12 14/12 i TH-14 Pond No. 1 Elevation: 5383.0 ft TH-15 j 26/12 25/12 Pond No. 1 Elevation: 5381.0 ft 20/12 j�� 9/12 1/-120/12 PROPOSED BOTTOM OF POND ELEVATION 5374 ft 9/12 5,395 5,390 5,385 5,380 5,375 5,370 5,365 5,360 5,355 5,350 5 345 YEH AND ASSOCIATES, INC. GEOTECHNICAL ENGINEERING CONSULTANTS South Middle Fork Water Facility Proposed Ponds Project Number: 212-019 Figure No. 4 I¥EH AND ASSOCIATES, INC. GEOTECHNICAL ENGINEERING CONSULTANTS Project: South Middle Fork Water Facility Project Number: 212-019 Legend for Symbols Used on Test Hole Logs Sample Types Modified California Sampler. The symbol 50/8 indicates that 50 blows from a 140 pound hammer falling 30 inches was used to drive 2 -inch I.D. sampler 8 inches. Bulk sample was obtained from auger cuttings at the depths indicated.. Other Symbols V Indicates depth to groundwater at time of drilling. 1 Indicates delayed depth to groundwater (March 6, 2012). Soil Lithology iii j Fill: sand, silty, occasional cobbles, bedrock fragments, dense, slightly moist to moist, brown. Fill: clay, sandy, occasional cobbles, bedrock fragments, very stiff, slightly moist to moist, brown. Sand, fairly clean, bedrock fragments, medium dense, moist to wet, tan, brown (SP). Sand, silty, occasional cobbles, bedrock fragments, medium dense, slightly moist to moist, tan, brown (SM). Sand, clayey, occasional cobbles, bedrock fragments, dense to very dense, slightly moist to moist, tan, brown (SC). Gravel, clayey, occasional cobbles, bedrock fragments, dense, slightly moist to wet, brown (GC). Clay, sandy, occasional cobbles, bedrock fragments, medium stiff to very stiff, slightly moist to very moist, brown (CL). Silt, sandy, occasional cobbles, bedrock fragments, medium stiff to very stiff, slightly moist to very moist, brown (ML). NOTES: 1. Test holes were drilled on February 15 and 16, 2012 with 4 -inch continuous flight auger. 2. Test hole descriptions are subject to explanations contained in this report. 3. Elevations were estimated from topography by others. Figure No. 5 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" 2" - 1 1/2" - 1" 3/4 " 100 1/2,, 96 3/g" 94 #4 87 #10 76 #40 63 #200 47 Gravel (%) 13 LL NL Project Name: South Middle Fork Water Facility Sand (%) 40 PL NP Fines (%) 47 PI NP Sample ID: Sample Depth (ft.): TH-1 Yeh & Associates, Inc. Geotechnical Engineering Consultants 5 SIEVE ANALYSIS Sample Description: Silty SAND (SM) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 6 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 0 4 8 10 16 30 40 50 40 •• • 100 200 • • • • • 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches - U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 0 4 8 10 16 30 40 50 40 •• • 100 200 • • • • • 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" - 2" - 1 1/2" - 1" - 3/4 „ - 1/2„ - 3/8" 100 #4 100 #10 99 #40 95 #200 57 Gravel (%) 0 LL 43 Project Name: South Middle Fork Water Facility Sand (%) 43 PL 16 Fines (%) 57 PI 27 Sample ID: Sample Depth (ft.): TH-5 Yeh & Associates, Inc. Geotechnical Engineering Consultants 5 SIEVE ANALYSIS Sample Description: Sandy CLAY (CL) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 7 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 0 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches - U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 0 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" - 2" - 1 1/2" - 1" - 3/4 „ - 1/2„ - 3/8" 100 #4 100 #10 99 #40 87 #200 49 Gravel (%) 0 LL 30 Project Name: South Middle Fork Water Facility Sand (%) 51 PL 14 Sample ID: TH-7 )A Yeh & Associates, Inc. Geotechnical Engineering Consultants Fines (%) 49 PI 16 Sample Depth (ft.): 10 SIEVE ANALYSIS Sample Description: Clayey SAND (SC) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 8 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 Particle Size (mm) 01 0.01 Sieve Size Passing 3" - 2 1/2" 2" - 1 1/2" - 1" 3/4 " 100 1/2., 99 3/g" 94 #4 76 #10 59 #40 42 #200 27 Gravel (%) 24 LL 29 Project Name: South Middle Fork Water Facility Sand (%) 49 PL 15 Fines (%) 27 PI 14 Sample ID: Sample Depth (ft.): TH-8 Yeh & Associates, Inc. Geotechnical Engineering Consultants 10 SIEVE ANALYSIS Sample Description: Clayey SAND with gravel (SC) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 9 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" 2" - 1 1/2" - 1" 3/4 " 100 1/2., 65 3/8" 61 #4 53 #10 43 #40 29 #200 16 Gravel (%) 47 LL 36 Project Name: South Middle Fork Water Facility Sand (%) 37 PL 16 Sample ID: TH-9 )A Yeh & Associates, Inc. Geotechnical Engineering Consultants Fines (%) 16 PI 20 Sample Depth (ft.): 4 SIEVE ANALYSIS Sample Description: Clayey, sandy GRAVEL (GC) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 10 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 4 8 10 16 30 40 50 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" 2" - 1 1/2" - 1" 3/4 " 100 1/2., 75 3/8" 67 #4 52 #10 36 #40 23 #200 15 Gravel (%) 48 LL 28 Project Name: South Middle Fork Water Facility Sand (%) 37 PL 16 Sample ID: TH-11 )A Yeh & Associates, Inc. Geotechnical Engineering Consultants Fines (%) 15 PI 12 Sample Depth (ft.): 14 SIEVE ANALYSIS Sample Description: Clayey, sandy GRAVEL (GC) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 11 Revised 04/22/2004 Percent Passing 100 90 80 70 60 50 40 30 20 10 0 12" 6 1" 3/4" 1/2" 3/8" 4 0 8 10 16 30 40 50 00 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size Sieve Analysis 3" Hydrometer Analysis Sieve Opening in Inches - U.S. Standard Sieves Size of Particles in mm 12" 6 1" 3/4" 1/2" 3/8" 4 0 8 10 16 30 40 50 00 100 200 1000 100 10 1 Particle Size (mm) 01 0.01 Sieve Size % Passing 3" - 2 1/2" - 2" - 1 1/2" - 1" - 3/4 „ - 1/2„ - 3/$„ - #4 100 #10 100 #40 95 #200 55 Gravel (%) 0 LL 30 Project Name: South Middle Fork Water Facility Sand (%) 45 PL 13 Fines (%) 55 PI 17 Sample ID: Sample Depth (ft.): TH-12 Yeh & Associates, Inc. Geotechnical Engineering Consultants 4 SIEVE ANALYSIS Sample Description: Sandy CLAY (CL) Drawn By: SW Checked By: RDJ Project No.: 212-019 Figure No.: 12 Revised 04/22/2004 0.0 Graph 1 — -1.0 — WATER ADDED 0 -2.0 — -3.0 3 z -4.0 — o o •a -5.0 — O C e„) -6.0 — -7.0 — -8.0 0.1 1 Applied Normal Pressure, ksf 10 100 0.0 Graph 2 — WATER ADDED -1.0 -2.0 -I) — -3.0 cA -4.0 — © cl -5.0 o CA _ © -6.0 — -7.0 — -8.0 - 0.1 1 10 100 Applied Normal Pressure, ksf Graph Number Boring Number Depth (ft) Natural Dry Density (pcf) Moisture Content (%) Swell(+) / Consolidation(-) (%) Soil Description SWELL / CONSOLIDATION GRAPH 1 TH-1 20 116 11.8 -0.2 Clay Drawn By: SW 2 TH-2 5 110 6.1 -0.5 Silt Checked By: RDJ Job No: 212-019 Project Name: South Middle Fork Water Facility Figure No. 13 YEH & ASSOCIATES, INC. 1.0 Graph 1 0.0 WATER ADDED -1.0 - + -2.0 — 3 z ,, -3.0 — 0 c 7c -4.0 — 0 v, _ cj -5.0 -6.0 — -7.0 0.1 1 10 100 Applied Normal Pressure, ksf 0.0 • 1 1 1 1 WATER ADDED Graph 2 -1.0 • -2.0 0 -3.0 un • -4.0 0 m -5.0 O v, _ — U -6.0 -7.0 -8.0 0.1 1 10 100 Applied Normal Pressure, ksf Graph Number Boring Number Depth (ft) Natural Dry Density (pcf) Moisture Content (%) Swell(+) / Consolidation(-) (%) Soil Description SWELL / CONSOLIDATION GRAPH 1 TH-3 15 123 7.9 0.1 Clay Drawn By: SW 2 TH-4 10 122 4.5 -0.8 Clay Checked By: RDJ Job No: 212-019 Project Name: South Middle Fork Water Facility Figure No. 14 YEH & ASSOCIATES, INC. 1.0 Graph 1 0.0 -1.0 — + WATER ADDED -2.0 — 3 z ,, -3.0 — 0 c '! -4.0 — 0 v, _ cj -5.0 -6.0 — -7.0 0.1 1 10 100 Applied Normal Pressure, ksf 1 0-- Graph 2 0.0 -1.0 o WATER ADDED / -2.0 74 3 z F -3.0 — o — vi -4.0 O v, — U -5.0 -6.0 — -7.0 - 0.1 1 10 100 Applied Normal Pressure, ksf Graph Number Boring Number Depth (ft) Natural Dry Density (pcf) Moisture Content (%) Swell(+) / Consolidation(-) (%) Soil Description SWELL / CONSOLIDATION GRAPH 1 TH-4 20 124 7.6 1.1 Clay Drawn By: SW 2 TH-5 10 120 5.9 1.6 Clay Checked By: RDJ Job No: 212-019 Project Name: South Middle Fork Water Facility Figure No. 15 YEH & ASSOCIATES, INC. 1.0 Graph 1 0.0 -1.0 ° + WATER ADDED -2.0 — 3 z • ,, -3.0 0 c '! -4.0 — 0 v, _ cj -5.0 -6.0 — -7.0 0.1 1 10 100 Applied Normal Pressure, ksf 1 0-- Graph 2 0.0 -1.0 WATER ADDED -2.0 , z -3.0 — 0 ct — -4.0 0 v, _ — U -5.0 -6.0 — -7.0 0.1 1 10 100 Applied Normal Pressure, ksf Graph Number Boring Number Depth (ft) Natural Dry Density (pcf) Moisture Content (%) Swell(+) / Consolidation(-) (%) Soil Description SWELL / CONSOLIDATION GRAPH 1 TH-5 15 102 6.9 -1.2 Clay Drawn By: SW 2 TH-6 10 126 6.5 1.1 Clay Checked By: RDJ Job No: 212-019 Project Name: South Middle Fork Water Facility Figure No. 16 YEH & ASSOCIATES, INC. 0.0 Graph 1 -1.0 -2.0 WATER ADDED -3.0 + -4.0 3 z -5.0 o -6.0 c 7g -7.0 0 v, o -8.0 U -9.0 -10.0 -11.0 0.1 1 10 100 Applied Normal Pressure, ksf 0.0 • Graph 2 WATER ADDED -1.0 -2.0 — — o -3.0 -4.0 z -5.0 — _ © -6.0 'c -7.0 O o -8.0 U -9.0 — -10.0 -11.0 - 0.1 1 10 100 Applied Normal Pressure, ksf Graph Number Boring Number Depth (ft) Natural Dry Density (pcf) Moisture Content (%) Swell(+) / Consolidation(-) (%) Soil Description SWELL / CONSOLIDATION GRAPH 1 TH-6 20 116 9.5 -1.1 Clay Drawn By: SW 2 TH-7 5 115 6.1 -2.4 Sand, clayey Checked By: RDJ Job No: 212-019 Project Name: South Middle Fork Water Facility Figure No. 17 YEH & ASSOCIATES, INC. YEH & ASSOCIATES, INC Project No: 212-019 Summary of Laboratory Test Results Project Name: South Middle Fork Water Facility Sample Location Moisture Content (%)(%) Dry Density (pcf) Grain Size Analysis Atterberg Limits % Swell + Consoli- dation (-) Water Soluble Sulfate (%) Soil Description Test Hole th De ft p () Sample Type Gravel > Sand Fines() #200 (%) LL PL PI TH-1 5 CA 7.8 124 13 40 47 NL NP NP 0.014 FILL: Sand, silty (SM) 20 CA 11.8 116 -0.2 Clay TH-2 5 CA 6.1 110 -0.5 Silt, sandy (ML) TH-3 5 CA 6.8 116 57 29 13 16 Clay, sandy (CL) 15 CA 7.9 123 0.1 Clay TH-4 10 CA 4.5 122 -0.8 Clay 20 CA 7.6 124 1.1 Clay TH-5 5 CA 8.0 112 0 43 57 43 16 27 0.057 Clay, sandy (CL) 10 CA 5.9 120 1.6 Clay 15 CA 6.9 102 -1.2 Clay TH-6 10 CA 6.5 126 1.1 Clay 20 CA 9.5 116 -1.1 Clay TH-7 5 CA 6.1 115 -2.4 Sand, clayey 10 CA 6.9 113 0 51 49 30 14 16 Sand, clayey (SC) TH-8 10 CA 6.7 115 24 49 27 29 15 14 Sand, clayey with gravel (SC) TH-9 4 CA 5.0 109 47 37 16 36 16 20 Gravel, clayey, sandy (GC) TH-10 9 CA 12.6 112 69 32 14 18 Clay, sandy (CL) CA - Indicates Modified California sampler NL - Indicates non -liquid NP - Indicates non -plastic Page 1 of 2 )A YEH & ASSOCIATES, INC Project No: 212-019 Summary of Laboratory Test Results Project Name: South Middle Fork Water Facility Sample Location Moisture Content (%) Dry Density (pcf) Grain Size Analysis Atterberg Limits % Swell i ) Consoli- dation (-) Water Soluble Sulfate (%) Soil Description Test Hole Depth (ft) Sample Type Gravel > #4 (%) Sand (%) Fines(4.) < #200 ° (%) LL PL PI TH-11 14 CA 12.3 120 48 36 15 28 16 12 Gravel, clayey, sandy (GC) TH-12 4 CA 7.9 120 0 45 55 30 13 17 Clay, sandy (CL) TH-13 19 CA 20.0 109 76 28 13 15 Clay with sand (CL) TH-14 4 CA 11.6 116 86 32 14 18 Clay (CL) TH-15 14 CA 21.2 107 71 42 16 26 Clay with sand (CL) CA - Indicates Modified California sampler NL - Indicates non -liquid NP - Indicates non -plastic Page 2 of 2