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HomeMy WebLinkAbout20140308.tiff EXHIBIT K SOILS REPORT KL EINFEL DER Bright People.Right Solutions. September 25, 2012 Project Number: 124271-6 Stuart Asselin, PE EVP Engineering and Operations Sterling Energy Investments LLC 1225 171h Street, Suite 2520 Denver, CO 80202 sasselin a,sterlingeneray,us CC: Dennis Miller, P.E. ZAP Engineering & Construction Services, Inc. rnillerd ct zapecs.corn Subject: Geotechnical Engineering Report Proposed Centennial Gas Plant Vicinity of County Road 89 and County Road 100 Weld County, Colorado Mr. Asselin: The attached final report presents the results of our Geotechnical Investigation for the proposed Centennial Gas Plant to be located in rural northeast Weld County, Colorado. Our services consisted of a subsurface exploration program, laboratory testing, engineering analyses, and preparation of this report. We appreciate this opportunity to be of service to you, and look forward to future endeavors. If you have any questions regarding this report or need additional information or services, please contact our office at (719) 632-3593. Respectfully submitted, KLEINFELDER WEST, INC. Kami D. Deputy Geological Engineer Brysen T. Mustain, PG William J. Bacreire, PE Engineering Geologist Senior Geotechnical Engineer KDD/BTM/WJB/jkw Enclosures 124271-6/CSP12R0416 Page 1 of 1 September 25, 2012 Copyright 2012 Kleinfelder 4815 List Drive, Unit 115, Colorado Springs, CO 80919-3340 pl 719.632.3593 fl 719.632.2648 KLE/NFELOER Ds 1 Pronto Mont Mo-ht Solutions. GEOTECHNICAL ENGINEERING REPORT PROPOSED CENTENNIAL GAS PLANT VICINITY OF COUNTY ROAD 89 AND COUNTY ROAD 100 WELD COUNTY, COLORADO Prepared by: Kami D. Deputy Reviewed By: a'i , Geological Engineer ��A�.,«an�ar� / rte, r 12045 c Brysen T. Mustain, PG William J. Barreire, PE ' 9/z"5/Z' Engineering Geologist Senior Geotechnical Engineer September 25, 2012 Kleinfelder Project Number: 124271-6 Kleinfelder 4815 List Drive, Unit 115 Colorado Springs, CO 80919 Phone: (719) 632-3593 Fax: (719) 632-2648 Copyright 2012 Kleinfelder All Rights Reserved ONLY THE CLIENT OR ITS DESIGNATED REPRESENTATIVES MAY USE THIS DOCUMENT AND ONLY FOR THE SPECIFIC PROJECT FOR WHICH THIS REPORT WAS PREPARED. 124271-6/CSP12R0416 Page i of iv September 25, 2012 Copyright 2012 Kleinfelder KLE/NFEL DER Bright ReapIR Right Sahrtiant. A Report Prepared for: Stuart Asselin, PE EVP Engineering and Operations Sterling Energy Investments LLC 1225 17th Street, Suite 2520 Denver, CO 80202 sasselin(a sterlingenergy.us CC: Dennis Miller, P.E. ZAP Engineering & Construction Services, Inc. millerd c(�zapecs.com Geotechnical Engineering Report Proposed Centennial Gas Plant Vicinity of County Road 89 and County Road 100 Weld County, Colorado Kleinfelder Job No. 124271-6 Prepared by: Kami D. Deputy Brysen T. Mustain, PG Geological Engineer Engineering Geologist Reviewed by: William J. BarreirePE Senior Geotechnical Engineer KLEINFELDER WEST, INC. 4815 List Drive Unit 115 Colorado Springs, Colorado 80919 (719) 632-3593 FAX: (719) 623-2648 September 25, 2012 124271-6/CSP12R0416 Page ii of iv September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER Bughr People.Hight Sduhom. TABLE OF CONTENTS PAGE 1 INTRODUCTION 1 1.1 GENERAL ..1 1.2 PROJECT DESCRIPTION 1 1.3 PURPOSE AND SCOPE 2 2 FIELD EXPLORATION AND LABORATORY TESTING 3 2.1 FIELD EXPLORATION 3 2.2 LABORATORY TESTING 5 2.2.1 Geotechnical Laboratory Testing 5 2.2.2 Analytical Laboratory Testing 5 3 SITE CONDITIONS 6 3.1 SURFACE 6 3.2 GEOLOGY 6 3.3 SEISMICITY 6 3.4 SUBSURFACE 7 3.5 GROUNDWATER 7 4 CONCLUSIONS AND RECOMMENDATIONS 8 4.1 GEOTECHNICAL FEASIBILITY OF PROPOSED CONSTRUCTION 8 4.2 CONSTRUCTION CONSIDERATIONS 9 4.2.1 Site Preparation and Grading 9 4.2.2 Excavation Characteristics 9 4.2.3 Imported Structural Fill Criteria 10 4.2.4 Utility Trench Backfill 10 4.2.5 Compaction Requirements 11 4.2.6 Construction in Wet or Cold Weather 11 4.2.7 Construction Testing and Observation 12 4.2.8 Surface Drainage and Landscaping 12 4.2.9 Permanent Cut and Fill Slopes 13 4.3 FOUNDATIONS 13 4.3.1 Foundation Option#1: Drilled Pier Recommendations 13 4.3,2 Foundation Option#2: Shallow Footing/Reinforced Mat Foundation Recommendations 15 4.4 CONCRETE FLOOR SLAB CONSTRUCTION 16 4.5 CORROSIVITY 18 4.5.1 Concrete 18 4.5.2 Buried Metal 18 4.6 PERCOLATION TESTING 19 4.7 GRAVEL"PAVEMENT"SECTION DESIGN RECOMMENDATIONS 19 4.7.1 Existing Roadway Subgrade Material 19 4.7.2 Design Traffic Loadings 20 4.7.3 Design Sections 20 4.8 GRAVEL SECTION CONSTRUCTION RECOMMENDATIONS 21 4.8.1 New Gravel Section Subgrade Preparation 21 4.8.2 New Gravel Section Materials 21 4.8.3 Drainage 21 5 ADDITIONAL SERVICES 22 5.1 REQUIREMENTS FOR ADDITIONAL SERVICES 22 5.2 REVIEW OF PLANS AND SPECIFICATIONS 22 5.3 PRE-CONSTRUCTION MEETINGS 22 124271-6/CSP12R0416 Page iii of iv September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER bright People.Right Solution 5.4 CONSTRUCTION OBSERVATION AND TESTING 22 6 LIMITATIONS 24 APPENDICES A Vicinity Map and Boring Location Plan B Boring Logs C Geotechnical Laboratory Test Results D Analytical Laboratory Test Results E Site Photos F Important Information About Your Geotechnical Engineering Report 124271-6/CSP12R0416 Page iv of iv September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER Bright People Flight So!urion,. 1 INTRODUCTION 1.1 GENERAL This report presents the results of Kleinfelder's Geotechnical Investigation performed for the proposed Centennial Gas Plant to be constructed in rural Weld County, Colorado. An attached Vicinity Map and Boring Location Plan (Plate A-1 in Appendix A) shows the general location of the project. Our investigation was performed for Sterling Energy Investments LLC (Sterling) and was authorized by Mr. Stuart Asselin. The report includes our recommendations relating to the geotechnical aspects of project design and construction. The conclusions and recommendations stated in this report are based upon the subsurface conditions found at the locations of our exploratory borings at the time our exploration was performed. They also are subject to the provisions stated in the report sections titled Additional Services and Limitations. Our findings, conclusions, and recommendations should not be extrapolated to other areas or used for other projects without our prior review. Furthermore, they should not be used if the site has been altered, or if a prolonged period has elapsed since the date of the report, without Kleinfelder's prior review to determine if they remain valid. 1.2 PROJECT DESCRIPTION We understand the proposed Gas Plant will consist of an office structure, warehouse structure, skids, flare, and other smaller equipment such as tanks, pipe supports, transformers, and small storage areas. A gravel access road and septic system are planned for the facility. We understand that the proposed location of the office structure has been moved to the west approximately 250-feet since the time of our field investigation. Based on the preliminary site plan provided, we anticipate that site grading required to reach finished site grades will generally consist of minimal cuts and fills, other than cuts required for foundation and floor slab subgrade preparation. Anticipated structural loads and dimensions were provided by ZAP Engineering and were utilized in our foundation design analysis and preparation of this report. If the type of construction, or proposed grading plans vary significantly from those described above, Kleinfelder should be notified immediately in order to review and revise our recommendations, as required. 124271-6/CSP12R0416 Page 1 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINFELDER Bright P opie Right Solutions 1.3 PURPOSE AND SCOPE The purpose of our investigation was to explore and evaluate subsurface conditions at various locations on the site and, based upon the conditions found, develop recommendations relating to the geotechnical aspects of project design and construction. Our conclusions and recommendations in this report are based upon analysis of the data from our field exploration, laboratory tests, and our experience with similar soil and geologic conditions in the area. Kleinfelder's scope of services included: • A visual reconnaissance to observe surface and geologic conditions at the project site and locating the exploratory borings. • Notification of Utility Notification Center of Colorado (UNCC) and working with Sterling personnel to locate underground utilities and identify potential conflicts with our subsurface exploration. • The drilling of a total of eighteen (18) exploratory borings within the proposed site development. • Drilling of a total of six (6) percolation test holes and performing percolation tests in the area of the proposed septic system. • Laboratory testing of selected samples obtained during the field exploration to evaluate relevant physical, analytical, and engineering properties of the soil. • Evaluation and engineering analyses of the field and laboratory data collected to develop our geotechnical conclusions and recommendations. • Preparation of this report. 124271-6/CSP12R0416 Page 2 of 24 September 25,2012 Copyright 2012 Kleinfelder KLEINFELDER Bright People.Right Sntuhbn. 2 FIELD EXPLORATION AND LABORATORY TESTING 2.1 FIELD EXPLORATION Our geotechnical exploration program was performed July 30 and 31, 2012 and included advancing the following borings at the approximate locations indicated on the attached Plate A-1: Table I — Summary of Field Exploration Program Approximate Depths of Boring Designation Exploration [feet] STRUCTURE BORINGS B-1 25 B-2 25 B-3 25 B-4 24% B-5 25 B-6 25 B-7 24% B-8 25 B-9 241/2 B-10 25 B-11 40% B-12 24% B-13 24% B-14 25% B-15 24% B-16 24% 124271-6/CSP12R0416 Page 3 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINPELDER --- — - Height People.Right Solutions. Approximate Depths of Boring Designation Exploration [feet] PAVEMENT BORING P-1 10 PERCOLATION TEST PROFILE BORING Percolation Profile 10% The approximate boring locations are indicated in the attached Vicinity Map and Boring Location Plan on Plate A-1; no surveyed latitude, longitude, or elevation data were provided for the boring locations. The exploratory borings were advanced using a truck- mounted CME-55 drill rig equipped with 4-inch outside-diameter, continuous-flight, solid- stem auger. Subsurface soil samples were obtained during exploration using a California-type sampler (2.5-inch I.D.) and standard split-spoon (SPT) sampler (1.375- inch I.D.) driven into the strata, with blows from a 140-pound hammer falling through a 30-inch drop. The blows required to drive the sampler in 6-inch increments into the strata are recorded on the logs. These blow counts are an indication of the relative density or consistency of the strata. Borings were backfilled with auger cuttings upon completion of drilling. However, the percolation test borings were left open per Weld County specifications. During drilling, a Kleinfelder geotechnical engineer/geologist examined and classified the materials encountered, obtained representative soil and rock samples, and recorded pertinent information. Representative soil samples were obtained and classified in accordance with American Society for Testing and Materials (ASTM) Standard D 2488. SPT samples were placed in plastic bags and California-type samples were sealed in plastic containers to limit moisture loss, labeled, and returned to our laboratory for further examination and testing. Appendix B includes individual boring logs describing the subsurface conditions encountered and a boring log legend. The lines defining boundaries between soil and rock types on the logs are based on drill rig behavior and interpolation between samples, and are therefore approximate. Transition between soil and rock types may be abrupt or may be gradual. 124271-6/CSP12R0416 Page 4 of 24 September 25, 2012 Copyright 2012 Kleinfelder ti KLE/NPELDER Bright People.Right Solutions 2.2 LABORATORY TESTING 2.2.1 Geotechnical Laboratory Testing Laboratory tests were performed on selected soil samples to estimate their relative engineering properties. Tests were performed in general accordance with the local practice, ASTM or other recognized standards-setting bodies and included: • Sieve Analysis of Fine and Coarse Aggregates Test; • Natural Density and Moisture Content Test; • Atterberg Limits Test; • One-Dimensional Swell/Consolidation Potential; and • Determination of Resistance R-Value of Compacted Soils. Results of the laboratory tests are included in Appendix C. Selected test results are also shown on the boring logs contained in Appendix B. 2.2.2 Analytical Laboratory Testing A summary of test methods and results of the analytical laboratory testing are presented in Appendix D of this report. Analytical testing included: • pH; • Resistivity; • Water Soluble Sulfates; and • Water Soluble Chlorides. Results of the analytical testing are summarized below: Table 2—pH value, Resistivity, and Water Soluble Sulfate & Chloride Test Results Water Soluble Water Sample Location pH Value Resistivity Sulfates Soluble Lithology and Depth (Feet) (Ohm-cm) (percent} Chlorides (percent) B-4 @ 2' 7.9 808 0.011 0.0073 Lean CLAY (CL) B-10 @ 7' 8.3 877 0.009 0.0011 Lean CLAY (CL) 124271-6/CSP12R0416 Page 5 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINFELDER DER Bright Peoplc.Right Sabtmn,. 3 SITE CONDITIONS 3.1 SURFACE At the time of our exploration, the subject site comprised open grassland with native weeds and grasses. The site topography slopes gently downward to the north and has a slight rise in the southwest corner. The maximum elevation changes across the site were on the order of approximately 15-feet. 3.2 GEOLOGY Prior to drilling, site geology was evaluated by reviewing geologic maps including the USGS Geologic Map of Colorado (USGS, 2005). The mapping indicates that the project site comprises residual sand and clay overburden layers underlain by the White River Formation, which consists of interlayered ashy sandstone and claystone. This is generally consistent with our subsurface explorations. 3.3 SEISMICITY Based upon the geologic setting, subsurface soil conditions, and low seismic activity in this region, liquefaction is not expected to be a hazard at the site. Based on geologic mapping, we believe the subsurface profile at this site corresponds with Site Class C of the 2009 International Building Code (IBC). We recommend the following site coefficients be used at this site. Table 3—Design Acceleration for Short Periods SMS SDS SS Fa (SMs= FaSa) PDS=2/3 Skis) 0.147 1.2 0.177 0.118 Ss = The mapped spectral accelerations for short periods(U.S.Geological Survey Web Page,2012) Fa = Site coefficient from Table 1613.5.3(1),2009 IBC SMs = The maximum considered earthquake spectral response accelerations for short periods Stu = 5-percent damped design spectral response acceleration at short periods Table 4—Design Acceleration for 1-Second Period S1 F„ SM7 SD1 (SMl = FA) (SD.' =2/3 Sm.') 0.047 1.7 0.079 0.053 S, = The mapped spectral accelerations for 1-second period(U.S.Geological Survey Web Page, 2012) F', = Site coefficient from Table 1613.5.3(2),2009 IBC SM1 = The maximum considered earthquake spectral response accelerations for 1-second period Sp1 = 5-percent damped design spectral response acceleration at 1-second period 124271-6/CSP12R0416 Page 6 of 24 September 25,2012 Copyright 2012 Kleinfelder KL E/NFEL DER BrigAt People.Rhghr Toturicnr. 3.4 SUBSURFACE The subsurface conditions encountered in our borings generally consisted of lean to fat clay and silt in the upper 10- to 15-feet overlying claystone bedrock to boring termination. Field penetration testing (blow counts) indicated the consistency of the fine- grained soils were generally firm to hard. The consistency of the overburden material encountered indicates that it comprises residual weathered and formational bedrock from the White River Formation. One-dimensional swell/settlement testing on the clay soils indicated the material has a moderate to very high swell potential ranging between 2 and 8 percent when saturated under a 1 kip per square foot (ksf) load. More detailed descriptions of subsurface conditions encountered at individual exploration locations are presented on the boring logs included in Appendix B. 3.5 GROUNDWATER Free groundwater was not encountered during our field exploration. Based on our subsurface data along with our understanding of the proposed project, we do not anticipate that groundwater will significantly impact the proposed development. However, soil moisture levels and groundwater levels commonly vary over time and space depending on seasonal precipitation, irrigation practices, land use, and runoff conditions. These conditions and the variations that they create often are not apparent at the time of field investigation. Accordingly, the soil moisture and groundwater data in this report pertain only to the locations and times at which exploration was performed. They can be extrapolated to other locations and times only with caution. It should be noted that Kleinfelder has not performed a hydrologic survey to establish the seasonal variation in groundwater levels. 124271-6/CSP12R0416 Page 7 of 24 September 25, 2012 Copyright 2012 Kleinfelder r"--;"\ LE/NFELDER Bright Peopfc.Right So,utrons 4 CONCLUSIONS AND RECOMMENDATIONS :. 4.1 GEOTECHNICAL FEASIBILITY OF PROPOSED CONSTRUCTION Based on the information presented herein, it is Kleinfelder's opinion that development of the site as planned is feasible, provided that the recommendations in this report are incorporated in the design and construction of the project. Based upon the data obtained from our subsurface investigation, the major geotechnical issue involved in developing this site is the expansion potential of the clay soil materials at the anticipated foundation and floor slab elevations coupled with the anticipated relatively light loads of the proposed structures. Potential heave on the order of 3- to 6- inches is possible by the expansive soils in their current state. In order to mitigate the potential risk of future structure damage due to swell and associated heave, we recommend that the proposed structures be supported on a deep foundation system comprising straight-shaft drilled piers or a shallow footing foundation system bearing on a thick layer of structural fill. Foundation Option#1 A deep foundation system consisting of straight-shaft drilled piers bearing within the underlying CLAYSTONE BEDROCK would provide the lowest risk of movement for the proposed structures. This system would require voids beneath mat foundations/pier caps and floor systems. Foundation Option #2 Another potential foundation system option would be a shallow spread footing foundation system in conjunction with over-excavation of the expansive subgrade soils to a depth of 7-feet below the bottom of the anticipated foundation elevation and replacement of the on-site soils with approximately 7-feet of moisture conditioned and compacted structural fill. We should be allowed to review the proposed imported structural fill criteria submittals and the final grading plans. If proposed site development plans change, we should be notified immediately to review our recommendations. 124271-6/CSP12R0416 Page 8 of 24 September 25, 2012 Copyright 2012 Kleinfelder KL E/NFEL DER snot People Bight SoftMans. 4.2 CONSTRUCTION CONSIDERATIONS 4.2.1 Site Preparation and Grading All site preparation and earthwork operations should be performed in accordance with applicable codes, safety regulations and other Local, State or Federal guidelines. Begin site work by stripping the topsoil, vegetation and other deleterious materials now present at the ground surface within the subject site. This applies both to areas to be filled and areas to be cut. Remove the stripped materials for offsite disposal in accordance with local laws and regulations or, if appropriate, stockpile them for later use in landscaped areas. Areas to receive fill should be stripped of soft earth materials until a firm unyielding subgrade is exposed as evaluated by the geotechnical engineer. Prior to placement of structural fill, processing of the subgrade should be performed. This should include scarifying the subgrade to a depth of at least 8- inches, moisture conditioning, and compacting to the values indicated in Section 4.2.5. 4.2.2 Excavation Characteristics If drilled pier foundations are utilized, a drilling rig for excavation of the drilled piers of sufficient size to penetrate the very hard formational White River Formation bedrock (portion of log in Appendix B labeled CLAYSTONE BEDROCK) the required amount should be mobilized. We anticipate that excavation of the onsite clay and silt soils as described herein can be performed with standard heavy-duty earthmoving equipment. All excavations must comply with the applicable Local, State, and Federal safety regulations, and particularly with the excavation standards of the Occupational Safety and Health Administration (OSHA). Construction site safety, including excavation safety, is the sole responsibility of the Contractor as part of its overall responsibility for the means, methods and sequencing of construction operations. Kleinfelder's recommendations for excavation support are intended for the Client's use in planning the project, and in no way relieve the Contractor of its responsibility to construct, support and maintain safe slopes. Under no circumstances should the following recommendations be interpreted to mean that Kleinfelder is assuming responsibility for either construction site safety or the Contractor's activities. 124271-6/CSP12R0416 Page 9 of 24 September 25, 2012 Copyright 2012 Kleinfelder KL E/NFEL DER Bright People Righr So!utiont We believe that the overburden soils on this site will classify as Type C materials and the bedrock will classify as Type B materials using OSHA criteria. OSHA requires that unsupported cuts be laid back to ratios no steeper than 1Y2H:1V (horizontal:vertical) for Type C materials, and 1H:1V for Type B materials in cuts up to 20-feet in height. In general, we believe that these slope ratios will be temporarily stable under unsaturated conditions. If infiltration occurs, flatter slopes may be appropriate. Please note that the actual determination of soil type and allowable sloping must be made in the field by an OSHA-qualified "competent person." 4.2.3 Imported Structural Fill Criteria On-site silty and clayey soils should not be used for structural fill. However, the on-site soils or imported structural fill may be used as site grading fill to reach final grades. Imported structural fill should consist of a non-expansive, mainly granular material as specified below: Table 5— Structural Fill Criteria Gradation Requirements Standard Sieve Size Percent Passing 2-inch 100 No.200 10-35 Plasticity Requirements(Atterberg Limits) Liquid Limit 30 or less Plasticity Index 6 or less Prior to placement of the fill, it should be moisture conditioned as described in this report. A sample of any imported fill material should be submitted to our office for approval and testing at least one week prior to stockpiling at the site. Structural fill should be compacted according to the recommendations in Section 4.2.5 of this report. 4.2.4 Utility Trench Backfill Backfill material should be essentially free of plant matter, organic soil, debris, trash, other deleterious matter and rock particles larger than 2-inches. Backfill material in the "pipe zone" (from the trench floor to 1-foot above the top of pipe) should not contain rock particles larger than 1-inch. Strictly observe any requirements specified by the utility 124271-6/CSP12R0416 Page 10 of 24 September 25, 2012 Copyright 2012 Kleinfelder 4 KLE/NFELDER 8nght People.P,ght Solutions. agency for bedding and pipe-zone fill. In general, backfill above the pipe zone iltiiity trenches should be placed in lifts of 6- to 8-inches and compacted using power equipment designed for trench work. Compact trench backfill as recommended in Section 4.2.5 of this report. 4.2.5 Compaction Requirements Fill materials should be compacted to the following: Table 6— Compaction Specifications Percent Fill Location Material Compaction* Moisture Type (ASTM D-1557) Content Subgrade Preparation (after clearing, grubbing, On-site Soils 92 minimum -2%to+2% of excavation, and prior to fill (See Section 4.2.1) optimum placement) Interior Foundation Walls Imported Structural Fill 95 minimum -2%to+2% of Backfill (See Section 4.2.3) optimum Shallow Footing Foundations, Imported Structural Fill -2%to+2% of Mats,and 95 minimum (See Section 4.2.3) optimum Floor Slab Structural Fill Site Grading Fill and -2%to+2% of Foundation Excavation On-site Soils 95 minimum optimum Clay Cap Material CDOT Class 6 -2%to+2% of New Gravel Pavement Section 95 minimum Aggregate Base Course optimum Utility Trench Backfill On-site Soils or 92 minimum -2%to +2%of Imported Structural Fill optimum * In non-structural, non-pavement, or landscaped areas, the compaction specification may be reduced to 90 percent of Modified Proctor (ASTM D-1557). The higher compaction criteria should be utilized where two or more"fill locations"coincide. 4.2.6 Construction in Wet or Cold Weather During construction, grade the site such that surface water can drain readily away from the structural areas. Promptly pump out or otherwise remove any water that may accumulate in excavations or on subgrade surfaces, and allow these areas to dry before resuming construction. The use of berms, ditches, and similar means may be used to prevent stormwater from entering the work area and to convey any water off site efficiently. 124271-6/CSP12R0416 Page 11 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER 8,gh:People,R,gh:So!ut.ons. If earthwork is performed during the winter months when freezing is a factor, no grading fill, structural fill or other fill should be placed on frosted or frozen ground, nor should frozen material be placed as fill. Frozen ground should be allowed to thaw or be completely removed prior to placement of fill. A good practice is to cover the compacted fill with a "blanket" of loose fill to help prevent the compacted fill from freezing. If the structures are erected during cold weather, foundations, concrete slabs-on-grade, or other concrete elements should not be constructed on frozen soil. Frozen soil should be completely removed from beneath the concrete elements, or thawed, scarified and re-compacted. The amount of time passing between excavation or subgrade preparation and placing concrete should be minimized during freezing conditions to prevent the prepared soils from freezing. Blankets, soil cover or heating as required may be utilized to prevent the subgrade from freezing. 4.2.7 Construction Testing and Observation Testing and construction observation should take place under the direction of Kleinfelder to support our professional opinion as to whether the earthwork does or does not substantially conform to the recommendations in this report. Furthermore, the opinions and conclusions of a geotechnical report are based upon the interpretation of a limited amount of information obtained from the field exploration. It is therefore not uncommon to find that actual site conditions differ somewhat from those indicated in the report. Kleinfelder should remain involved throughout the project to evaluate such differing conditions as they appear, and to modify or add to the geotechnical recommendations as necessary. 4.2.8 Surface Drainage and Landscaping Positive drainage away from the structures is essential to the performance of foundations, flatwork and gravel drives, and should be provided during the life of the structures. Surface drainage should be created such that water is diverted off the site and away from backfill areas of adjacent buildings or equipment foundations. Landscape areas within 10-feet of the structures should slope away at a minimum of 8 percent. Areas where pavements or slabs are constructed adjacent to the structures should slope away at a minimum grade of 2 percent. All downspouts from roof drains should be tight lined to the storm water drainage system. Landscaping improvements that require supplemental watering are not recommended adjacent to improved areas 124271-6/CSP12R0416 Page 12 of 24 September 25, 2012 Copyright 2012 Kleinfelder i KLEINFELDER flOghl People.Right Sp?ution5 including foundations, pavements or slabs. In addition, to help reduce the risk of surface water entering the subgrade structural fill material and pooling on top of the underlying clay, a thick (minimum 18-inch) clay cap consisting of properly moisture conditioned and compacted on-site clay soils should be placed around the structure perimeter to hinder infiltration of surface water. 4.2.9 Permanent Cut and Fill Slopes Permanent cut and fill slopes exposing the materials encountered in our borings are anticipated to be stable at slope ratios as steep as 3H:1V under dry conditions. If infiltration occurs, flatter slopes may be appropriate. New slopes should be re-vegetated as soon as possible after completion to reduce erosion problems. 4.3 FOUNDATIONS The proposed structures may be founded on either a drilled pier foundation or a shallow mat/footing foundation constructed on 7-feet of imported structural fill, as described in Section 4.1 of this report. The guidelines below should be followed when constructing drilled piers or shallow foundations placed on properly prepared subgrade: 4.3.1 Foundation Option#1: Drilled Pier Recommendations Due to presence of highly expansive clay soils on this site at the proposed foundation elevations, it is recommended that the proposed structures be supported on a deep foundation system consisting of straight-shaft drilled piers bottomed within the underlying CLAYSTONE BEDROCK. For the purposes of this report, CLAYSTONE BEDROCK is defined as the zone of relatively unweathered claystone bedrock material that is considered appropriate for "socketing11 the piers to achieve the end bearing and skin friction criteria presented below, as well as providing proper "anchorage" of the lower portion of the pier against uplift forces due to expansive clay soils and claystone. This zone of CLAYSTONE BEDROCK is depicted by the lower portions of the boring logs labeled as "White River Formation" presented in Appendix B, attached to this report. Note that the material labeled WEATHERED CLAYSTONE on the boring logs is NOT sufficient for socketing/anchoring drilled piers. The following provides our design and construction recommendations for deep foundation systems. The drilled pier recommendations assume pier diameters of approximately 18- to 30-inches will be utilized. 124271-6/CSP12R0416 Page 13 of 24 September 25,2012 Copyright 2012 Kleinfelder KLE/NFELDER Bnght Mopto.Poght SOW6ons. • For compressive loading, piers should be designed for a maximum allowabfeend bearing pressure of 35,000 pounds per square foot (psf) and a skin friction value of 3,500 psf, for the portion of pier in contact with the underlying CLAYSTONE BEDROCK and at least 5-feet below the bottom of foundation walls or grade beams. Skin friction in soil or fill materials should be ignored. • We recommend piers have a minimum drilled length of 28-feet and penetrate the underlying CLAYSTONE BEDROCK a minimum of 8-feet, whichever results in the longer "drilled" length. Final pier depths should be determined by the geotechnical engineer in the field at the time of construction. • If piers are expected to resist lateral loads, we recommend designing the piers considering a lateral subgrade modulus of 600 kips per cubic foot (kcf) for the CLAYSTONE BEDROCK penetration, a value of 300 kcf for the Weathered Claystone, and a value of 150 kcf for the upper alluvium soils. Lateral soil resistance within the upper 5-feet of the pier should be ignored. • Piers should be designed by a qualified structural engineer. Piers should be reinforced their full length. As a minimum, we recommend the cross-sectional area of reinforcement be equal to at least 0.6 percent of the gross cross-sectional area of the pier. This percentage may vary for pier diameters other than that assumed above, of 18- to 30-inches. Grade 60 steel should be used. Reinforcement should extend into grade beams or foundation walls. • Provide at least an 8-inch continuous void beneath pier caps, mats, grade beams or foundation walls (between piers) to concentrate structure deadloads and isolate the superstructure from underlying expansive soils. • Concrete used in the drilled piers should be a fluid mix with a maximum slump of 4- inches for uncased pier holes and approximately 5- to 7-inches for cased holes to facilitate removal of temporary casing. • It is very important to avoid "mushrooming" or widening of the top of the pier hole as this provides additional surface onto which the expansive soils can exert uplift forces. Therefore we recommend the use of "sonotube" or other equivalent product to preserve the diameter of this section of the pier. The sonotube should be placed prior to pouring the upper portion of the pier. • Groundwater was not encountered in our borings during drilling operations. However, if groundwater is encountered during construction and cannot be controlled (no more than 3-inches of groundwater in the hole at time of pour), then the concrete should be pumped from the bottom of the hole to the top in order to displace the water. Piers should be filled with concrete immediately after they are drilled, cleaned and inspected. Open pier holes should not be left overnight. 124271-6/CSP12R0416 Page 14 of 24 September 25, 2012 Copyright 2012 Kleinfelder f%"-\ KLE/NFELDER Boght People.Rrgh:S&or on, • The pier drilling contractor should mobilize equipment of sufficient size to hieve required penetration into very hard bedrock strata and have available equipment necessary for groundwater control, if encountered. • It is important that the installation of drilled piers be observed by a Kleinfelder representative to identify the proper bearing strata, observe construction techniques, and confirm subsurface conditions are as anticipated from our exploratory borings. 4.3.2 Foundation Option#2: Shallow Footing/Reinforced Mat Foundation Recommendations In order to minimize the potential risk for structural damage caused by differential movement due to heave of the expansive soils near the foundation elevations, we recommend that shallow spread footing/mat foundations bear on at least 7-feet of properly compacted, imported granular structural fill that meets the requirements of properly compacted structural fill as described in Sections 4.2.3 and 4.2.5. The structural fill should extend a minimum 5-feet beyond the edges of footings/mats. In order to reduce surface water infiltration into the structural fill zone, a low permeability cap, minimum 18-inches thick, consisting of the on-site clay soils should be used around the structure perimeter. Exposed subgrades in foundation areas should be prepared before placement of structural fill by scarification and re-compaction as described in Section 4.2.1, Site Preparation and Grading. This includes scarifying, moisture conditioning, and re-compacting at least 8-inches of the existing subgrade prior to placement of any fill. The guidelines below should be followed when constructing the spread footing foundation: • Footings/mats placed on the imported structural fill as described above may be designed for a maximum allowable soil bearing capacity of 2,500 pounds per square foot (psf). This bearing pressure may be increased by one-third for transient loading. The maximum allowable bearing pressure shown above was developed based on static soil loading. • For vibratory loading, a reduction in the allowable static bearing pressure should be considered. • If continuous footings are utilized they should have a minimum width of 18-inches and isolated column footings should have a minimum width of 24-inches. Final foundation dimensions should be determined by a qualified structural engineer based on the soil bearing capacity and actual structural loads. 124271-6/CSP12R0416 Page 15 of 24 September 25, 2012 Copyright 2012 Kleinfelder KL EINFEL DER @right People.Right 5o'ulior. • We estimate that the potential movement of the spread footing/mat foundation, designed and constructed in accordance with recommendations provided in this report, will be approximately 1-inch or less. Due to the expansive nature of the site soils, limiting foundation movement requires proper surface drainage and measures to hinder water intrusion into the fill beneath the foundations, as described above with the use of a clay cap, will be implemented. • Lateral loads may be resisted using a coefficient of friction for sliding of 0.40 (assuming concrete footings cast directly on structural fill) and an unfactored passive earth pressure of 360 pounds per cubic foot (pcf) for the foundation wall backfill consisting of compacted imported granular structural fill. As large movements are generally required to mobilize the full passive earth pressure, we recommend a factor of safety of 2 be applied to the above passive earth pressure value. • Exterior shallow footings or mats in unheated areas should have at least 36-inches of soil cover above the bearing elevation for frost protection, or that required by local building codes, whichever is greater. If foundations are placed near the surface, a reduction in the maximum allowable soil bearing capacity may be required, and the foundations must be underlain by at least 36-inches of non-frost susceptible material (i.e. material containing less than 6 percent passing the No. 200 sieve). • If the foundations are placed near the surface and non-frost susceptible material is utilized, we recommend a minimum 18-inch thick cap of on-site clay materials be placed at the surface around the footings or mats, sloped away from the structures, and extend to the edge of foundation excavations in order to prevent moisture infiltration into the structural fill material. The clayey cap should be compacted to the recommendations in Section 4.2.5. • The foundation subgrade should be protected from wetting and drying prior to and after concrete placement. Footings should be backfilled as soon as practical after concrete placement. • A representative of Kleinfelder should observe all foundation excavations prior to placement of concrete and/or fill. Additionally, the placement and compaction of structural fill should be observed and tested by a representative of our firm. 4.4 CONCRETE FLOOR SLAB CONSTRUCTION If the slab-on-grade option is selected by the owner and the project design team with an understanding of the associated risk described in Section 4.1, the existing site soils should be excavated to a depth of at least 7-feet below the bottom of the proposed concrete slab. The floor slab subgrade backfill should consist of imported structural fill as defined in Section 4.2.3. Depending on the fines content of the import select fill, 124271-6/CSP12R0416 Page 16 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINFELDER ,rrght Peopto.Right So!urionc. placement of a gravel working course at the floor slab subgrade elevation rrIay�be desirable, at the contractor's discretion. The floor slab structural fill should be placed on a horizontal plane and placed in loose lifts not to exceed 8-inches in thickness, and compacted according to the criteria presented in the Section 4.2.5 of this report. The design and construction criteria presented below should be observed for floor slabs constructed on grade. 1. For design of floor slabs, a modulus of subgrade reaction of 200 pounds per cubic inch (pci) may be used in design of slabs bearing on 7-feet of imported structural fill. 2. Floor slabs should be separated from all bearing walls, columns, utilities or other elements that penetrate the floor slab with expansion joints that allow unrestrained vertical movement. Floor slabs should not extend into wall panel cutouts unless saw cut or jointed to allow unrestrained movement. Utilities or other elements that penetrate the floor slab should be separated from the slab with expansion joints to allow free vertical movement of the slab to avoid damage. 3. Interior, non-bearing partitions resting on floor slabs, wallboards and doorframes should be provided with slip joints at the bottoms so that, if the slabs move, the movement cannot be transmitted to the upper structure. Slip joints, which will provide a minimum void space of at least 2-inches, are recommended. If slab bearing masonry block or steel stud partitions are constructed, the slip joints are placed at the top of the wall. If the floors move, it is likely the wall will show signs of distress where they meet the exterior walls. Connecting the partition walls to the exterior walls using slip channels may reduce distress. 4. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Control joint spacing is a function of slab thickness, aggregate size, slump and curing conditions. The requirements for concrete slab thickness, joint spacing, and reinforcement should be established by the designer, based on experience, recognized design guidelines and the intended slab use. Placement and curing conditions will have a strong impact on the final concrete slab integrity. If vibrating machinery will be installed at this site, the machine foundations should be physically isolated from other foundations and slabs to reduce vibration damage. The 124271-6/CSP12R0416 Page 17 of 24 September 25, 2012 Copyright 2012 Kleintelder KLEINFELDER Smyth!Moptc Rlght Sa,uticns design of such foundations requires special analysis that is beyond the scope .tttis investigation. Please contact Kleinfelder for additional analysis and recommendations if machine vibrations will be an issue at this building. 4.5 CORROSIVITY 4.5.1 Concrete The concentration of water-soluble sulfates measured on subsurface soil submitted for testing was averaged at approximately 0.01 percent. In accordance with ACI Building Code 318, the requirements for concrete exposed to sulfate-containing soils are presented in following table: Table 7—Requirements for Concrete Exposed to Sulfate-Containing Soils Sulfate Exposure Water soluble sulfate(SO4)in Cement Type soil, percent by weight Negligible 0.00 to 0.10 -- II, IP(MS), IS(MS), Moderate 0.10 to 0.20 P(MS),I(PM)(MS), l(SM)(MS) Severe 0.20 to 2.00 V Very Severe Over 2.00 V plus pozzolan The concentration of water-soluble sulfates measured on subsurface soils submitted for testing represents a negligible degree of sulfate attack on concrete exposed to the soils. These results indicate that a locally available Type I/II cement should be used for concrete in contact with the soils. 4.5.2 Buried Metal The pH and electrical resistivity were determined for a selected sample. Test results averaged a pH value of 8.1 for the onsite soils. Resistivity measurements had an average value of 840 ohm-centimeters for the existing onsite soils. The primary physical property for evaluating corrosivity in soil is electrical resistivity. Electrical resistivity is a measure of resistance to the flow of electrical current. Corrosion of buried metal is an electrochemical process in which the amount of metal loss due to corrosion is directly proportional to the flow of electrical current (DC) from metal in to the soil. As resistivity decreases, the corrosivity of the soil increases. The following table provides a correlation between soil resistivity and corrosivity towards ferrous metal. 124271-6/CSP12R0416 Page 18 of 24 September 25, 2012 Copyright 2012 Kleinfelder KL EINFEL DER Bright People.Right So,utions. Table 8— Corrosivity Classification Resistivity in Ohm-centimeters Corrosivity Category 0 to 1,000 Severely corrosive 1,000 to 2,000 Corrosive 2,000 to 10,000 Moderately Corrosive Greater than 10,000 Mildly Corrosive Based on the resistivity measurements discussed above, the native soils are expected to be severely corrosive. A qualified corrosion engineer should review this data to determine the appropriate corrosion protection measures at the site. 4.6 PERCOLATION TESTING Kleinfelder performed percolation testing at six (6) locations within the proposed septic field at the site. The average percolation rate obtained at the site was 30 minutes per inch, or 2 inches per hour. The boring log for boring "Perc. Profile" (presented in Appendix B) should be reviewed for more detailed descriptions of the subsurface conditions at the boring location explored. 4.7 GRAVEL"PAVEMENT" SECTION DESIGN RECOMMENDATIONS A pavement section is a layered system designed to distribute concentrated traffic loads to the subgrade. Performance of the pavement structure is directly related to the physical properties of the subgrade soils and traffic loadings. Soils are represented for pavement design purposes by means of a soil support value for flexible pavement systems. This value is empirically related to strength. Pavement design procedures are based on strength properties of the subgrade and pavement materials, along with the design traffic conditions. Proper surface drainage is essential for adequate performance of the gravel section on these soils. Our pavement analysis was generally performed in accordance with the 1993 AASHTO Guide for Design of Pavement Structures Low- Volume Road Design for Aggregate-Surfaced Roads, as well as local guidelines. 4.7.1 Existing Roadway Subgrade Material The subgrade soils encountered consisted predominantly of silty and clayey soils. A Hveem stabilometer test (R-Value) was performed on a representative bulk soil sample of the soils obtained and resulted in an R-value less than 5. Seasonal resilient modulus values were estimated using the 1993 American Association of State Highway and Transportation Officials (AASHTO) Low-Volume Road Design procedures for Aggregate- 124271-6/CSP12R0416 Page 19 of 24 September 25,2012 Copyright 2012 Kleinfelder KL E/NFEL DER doghr People.e,ght So!urlon, Surfaced Roads. The R-value presented above and its associated MR value of 3,025-psi are typical of the clayey soils encountered and were used as the basis for our gravel section thickness calculations. 4.7.2 Design Traffic Loadings For this project, we have assumed typical traffic at the site will be limited and consist of occasional light vehicle and heavy truck traffic. We have assumed a minimum 18-kip equivalent single axle load (ESAL) of 10,000 for a 20-year design life. It should be noted that this value does not include impacts of the typically much heavier construction traffic during construction of the project. Therefore, if this gravel section is placed early in the construction process, repairs due to heavy construction vehicle loads should be expected. A properly constructed access road as described below will have the ability to support the anticipated traffic loadings in accordance with AASHTO specifications at the assumed frequency described above. It is not expected that the proposed roadway will bear continuous heavy traffic. Therefore, we should be contacted to review our recommendations if conditions vary from those assumed herein. 4.7.3 Design Sections The design sections for the roadway alignment were calculated using the 1993 AASHTO Guide, as well as criteria from the 2011 Colorado Department of Transportation (CDOT) Pavement Standard Specifications for Road and Bridge Construction. Based on laboratory test results, the estimated design traffic parameters, and the referenced design procedures, we recommend the following gravel road section: Table 9— Gravel Road Section Thickness Gravel Road Section 9-inches CDOT Class 6 Aggregate Base Course overlying 8-inches Properly Prepared Subgrade (see Sections 4.2.1 and 4.9.1) 124271-6/CSP12R0416 Page 20 of 24 September 25, 2012 Copyright 2012 Kleinfelder i KLEINFELDER 8nght People.R,ghr Solurianc. 4.8 GRAVEL SECTION CONSTRUCTION RECOMMENDATIONS 4.8.1 New Gravel Section Subgrade Preparation As previously discussed, to create a more uniform and stable subgrade, the subgrade should be scarified to a depth of at least 8-inches, moisture conditioned and re- compacted in accordance with Section 4.2.5 of this report, prior to placement of any new roadway embankment or the new gravel section. Prior to placing the new gravel section, the subgrade should also be proof-rolled with a heavily loaded pneumatic-tired vehicle (such fully loaded water truck) after preparation. Areas that deform under heavy wheel loads are not stable and should be removed and replaced to achieve a stable subgrade. 4.8.2 New Gravel Section Materials The new gravel section materials should conform to CDOT Standard Specifications for Class 6 Aggregate Base Course (ABC) per Section 703.03 of the CDOT Standard Specifications for Road and Bridge Construction (2011). The ABC material should be placed in a uniform layer without segregation of size to a compacted depth not to exceed 6-inches and should be compacted to a minimum 95 percent density, ASTM D1557. 4.8.3 Drainage The collection and diversion of surface drainage away from gravel road areas is extremely important to the satisfactory performance of a gravel section constructed on clay soils such as those encountered on this site. Drainage design should provide for the efficient drainage of water and snow off of gravel areas and preventing ponding and excessive wetting of the subgrade soils. Water sources include but are not limited to snowmelt, storm water runoff, and localized groundwater seepage. 124271-6/CSP12R0416 Page 21 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER &JO:People.Prgh!foluNens 5 ADDITIONAL SERVICES 5.1 REQUIREMENTS FOR ADDITIONAL SERVICES In most cases, other services beyond completion of a geotechnical report are necessary or desirable to complete a project satisfactorily. It also sometimes happens that, while performing our services, we discover conditions or circumstances that require the performance of additional work that was not anticipated when the geotechnical report was written. Kleinfelder offers a range of environmental, geological, geotechnical, and construction services to suit the varying needs of our clients. This section outlines some of those services that may pertain to this project. Kleinfelder will be happy to submit a proposal for performing any such services upon request. 5.2 REVIEW OF PLANS AND SPECIFICATIONS We strongly recommend that Kleinfelder be given an opportunity to review the plans and specifications for this project before they are finalized. Such a review allows us to verify that our recommendations and concerns have been adequately incorporated in the design. It also gives us an opportunity to discuss those recommendations and concerns with other members of the design team so that we can clear up misunderstandings or ambiguities before the project reaches the construction stage. 5.3 PRE-CONSTRUCTION MEETINGS We recommend that the Owner, the Contractor, and the other members of the design team hold a pre-construction meeting with Kleinfelder's project engineer. The purpose of this meeting is to go over geotechnical aspects of the project so that all parties have a clear understanding of the geotechnical issues that affect the Contractor's work and how they will be handled. The meeting also allows us to set up the communication and coordination needed for construction observation and testing, and to identify points of confusion or disagreement that need to be resolved. 5.4 CONSTRUCTION OBSERVATION AND TESTING The recommendations in this report depend on the assumption that an adequate program of testing and observation will be made during construction to verify compliance with our recommendations. These tests and observations may include, but not necessarily be limited to, the following: 124271-6/CSP12R0416 Page 22 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINFELDER Bright Peoptr.Hight Solutions. • Observations and density testing during site preparation and earthwork. • Observation of foundation excavations and foundation installation. • Observation and testing of construction materials. • Consultation as may be required during construction. Adequate testing and observation is essential to successful and economical completion of a construction project. Testing and observation allow us to verify that our recommendations are being followed. They also make it possible to identify new or changed conditions that require us to modify those recommendations. Construction testing and observation should be scheduled in advance so that our personnel can plan to be available for the work. It is also desirable that we receive a set of project plans and specifications at the time our work is first scheduled. 124271-6/CSP12R0416 Page 23 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLE/NFELDER Bight People.Right Soiutiens. 6 LIMITATIONS The recommendations in this report are based on our field observations, laboratory testing, and our present understanding of the proposed construction. It is possible that subsurface conditions can vary between or beyond the points explored. If the conditions found during construction differ from those described in this report, please notify us immediately so that we can review our report in light of those conditions and provide supplemental recommendations as necessary. We should also review the report if the scope of the proposed construction, including the proposed loads or structure locations, changes from that described in this report. Kleinfelder has prepared this report for the exclusive use of Sterling Energy Investments LLC for the proposed Centennial Gas Plant Site to be constructed in rural Weld County, Colorado. 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 warranty is expressed or implied. The recommendations in this report are based on the assumption that Kleinfelder will be provided review comments and additional information as required to revise/refine recommendations. They also are based on the assumption that Kleinfelder will be retained to conduct an adequate program of construction testing and observation to evaluate compliance with our recommendations. This report may be used only by the Client, and only for the purposes stated, within a reasonable time from its issuance, but in no event later than one year from the date of the report. Land use, site conditions (both on- and off-site), or other factors may change over time, so that additional investigation or revision of our recommendations may be required with the passage of time. It is the Client's responsibility to see that all parties to the project including the designer, contractor, and subcontractors, are made aware of this report in its entirety. The use of information contained in this report for bidding purposes shall be at the Contractor's option and risk. Any party other than the Client who wishes to use this report must notify Kleinfelder of such intended use. Based on that intended use of the report, Kleinfelder may require that additional work be performed and that an updated report be issued. Noncompliance with these requirements by the Client or anyone else will release Kleinfelder from any liability resulting from the use of this report by an unauthorized party. 124271-6/CSP12R0416 Page 24 of 24 September 25, 2012 Copyright 2012 Kleinfelder KLEINPELDER DER 8ngh!People Right Sdut,eni APPENDIX A Vicinity Map and Boring Location Plan 124271-6/C S P 12 R0416 Copyright 2012 Kleinfelder O to - - - ----- - *B-11 I \ } SITE o N �� �� . Z#1/CR 100/ �`�o N O • • O CC U O d cm = r--, liB-14 `--J CR 90/Highway 1 O ci SEPTIC/ � FIELD 'W► VICINITY MAP NOT TO SCALE o� K%� B-10 o a 6 PERC. ---8=13 PROFILE B_7 o o,rot LEGEND o /oV f/'o�. \4 0 O LJ L'._1 N CV �\ IS SOIL BORING o : o U 49�S C + PERC. TEST O B-S 0 100 200 r-d_L--- _..�-.. ._.-T._..T.._.._ _ T.._ B-15 o ill SCALE: 1"=100 SCALE IN FEET I i •j I 1 a j ! I i I B-4 j em Ij i• t { i m i o O O iIIIIIIllllllI IIII lIIIII llII _c I „ro m r�l ro ,r0 7 o m F`I F"I t— Frei -I !-I I I f't {�► fil �1 , F'• - LJ ,L°J L°J gLJ �L°J L®°-' O rLi- U U� UUHS 8 ljl ; } j i : : rawing O1 f ii ILLI II ' B provided by Sterling Energy on July 19th, 2012. g 1 I i i I I l i i I l l j l l E. } I l j I I j j I i 1 I j N � s uuuuuuu U OOOO __2 B-5 U 0 CIO _) C O The Information included on the graph=representation has been compiled horn variety of sources end is 0 (.J W subject,a change wdhout notice.Klemfelder miles no,opresenUlons or wnrranlms.Mate.or impend, O us tc eccurncy,completeness,loneliness.or rights to the use of such Informaton Ties downenl is not (D' B-1 cc a W Intended for nor as-lined survey prnrfuc nor is it desired or imendnd ns a conswUion design dncanonl O H Tho use or memo of the,emanation contoinnd on rho graphic represenlehon is et lho horn risk or the pod), } us,ng or misus.ng the infom al:tn. CNI ,S N - P_1 �r.-^."-. PROJECT NO"Th . 124271-6 VICINITY MAP AND PLATE ..`.C," *B^ / DRAWN BY DAD BORING LOCATION PLAN O �' KL E/NFEL DER /� I.11 I - f f CHECKED BY BTM Proposed Centennial Gas Plant !'1'1 o �y_-- Bright People.Right Solutions. DATE: 9/10/12 Vicinity of County Road 89 and County Road 100 o --_ z" \\............._._......__-- REVISED: Weld County, Colorado PAGE: 1 of 1 KLE/NFELDER •�9ngh;People Rghr So'uticni APPENDIX B Boring Logs 124271-6/CSP12R0416 Copyright 2012 Kleinfelder Date Begin-End: 7/31/12 Drill Company: Custom Auger Drilling BORING LOG B-1 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,70 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS II . c x a . � No Coordinates Available - y° a .?. o ro t2 r ,d No Elevation Available f- _ Z N Z^ E> a �, Surface Condition:Grass&Weeds ar ii a a�i rn� c°m Z Z .. v E 3$ 8 UE 2E- 2m yo 5> ma LE O C9 rn B, cc mto MU O a.ln d# n? o- 0c 57 FAT CLAY(CH):gray-brown,slightly moist,hard L LBC=11 CH 16.8 100 96 52 27 5 11 _ 10 SILT(ML):light brown,slightly moist,firm , BC=8 16.1 79 Compression=-27% - 10 13 r under 1 ksf when — wetted. Silty LEAN CLAY(CL):fight brown,slightly moist, LBC=12 12.9 15 hard 13 — _ 14 White River Formation BC=26 26.4 108 20 CLAYSTONE BEDROCK:red-brown,slightly moist to 50/47- — moist,very hard BC=19 CH 21.5 100 99 58 33 25 50/9" Fr = The exploration was terminated at approximately 25.3 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after backfilled with auger cuttings on July 31,2012. completion. GENERAL NOTES' 30— PROJECT NO. 124271-6 BORING LOG B-1 PLATE DRAWN BY: DAD r KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B1 - Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-2 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Cloudy,80 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS Lc x rnn o m 04.-- ..... —J No Coordinates Available a 'ea..; o Z. o m "m c i mce No Elevation Available H Z N Z; 'm E> a w Surface Condition:Grass&Weeds m g'a m o c m 7 0 o I— w - m g E 3$ 8 U E c H No o> m� r E l7 w o. m D >. 00 .. mN N rA .. CE 7m MU O am Q. Jv rl? occ %f FAT CLAY with sand(CH):gray.brown,slightly moist, G J�J,/ firm to hard IL,BC=10 14.6 91 Expansion=3.2%under 5 J 13 ,- 1 ksf when wetted. — - BC=7 CH 11.3 100 80 52 32 9 s White River Formation BC=17 19.7 103 10-� 25 ,, - \\ WEATHERED CLAYSTONE:red-brown,slightly moist,moderately hard to hard BC=12 16.1 15— \\\ 26 — 22 Ni ,- \\\\� ILBC--24 20—,\\ 46 '" — White River Formation BC=27 = 25 CLAYSTONE BEDROCK:red-brown,slightly moist, 50172 — \very hard I - GROUNDWATER LEVEL INFORMATION: The exploration was terminated at approximately 25.1 Groundwater was not encountered during drilling or after = ft.below ground surface. The exploration was GENERAL completion. NOTES' - backfilled with auger cuttings on July 30,2012. 30— i PROJECT NO. 124271-6 BORING LOG B-2 PLATE �•^ DRAWN BY: DAD KL E/NFEL,DER CHECKED BY: BTM Proposed Centennial Gas Plant B'2 I'JJw Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 1O0 LL `�1� Weld County,Colorado '` REVISED: PAGE: 1 of 1 Date Begin-End: 7/31/12 Drill Company: Custom Auger Drilling BORING LOG B-3 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,70 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS SZ No Coordinates Available o. m m z. o e is c a ca OP Ta No Elevation Available i - ° w Z^ > E> a in u Surface Condition:Grass&Weeds ar >a y e.. c rn� 0,_r -'o o ar m F _c o a cat > (c1.3,no . W CD N m 'no v : 0Z �m o O E 3v cg !n c yr ma �] �a E c1oo m� re nw 50 o tivo a. _-�i? a? 0 c % Silty LEAN CLAY(CL):gray-brown,slightly moist,firm VA t to very hard ID Z o .) .BC=11 17.6 85 14 _ J m 5 LBC=12 19.2 Jam% 17 / - 14 ll - 10 IBC=18 15.4 110 —Ff z CWhite River Formation N WEATHERED CLAYSTONE:gray-brown to - red-brown,sliigMiy moist to moist,moderately hard to BC--26 10.5 15 `y hard 16 r — ILBC=25 21.1 106 20 \ 43 /- — kl ‘ BC=32 25— White River Formation \ 50/5 j iT CLAYSTONE BEDROCK:red brown to gray,slightly 1 GROUNDWATER LEVEL INFORMATION: - moist to moist,very hard 1 Groundwater was not encountered during drilling or after - completion. The exploration was terminated at approximately 24.9 GENERAL NOTES' - ft.below ground surface. The exploration was backfilled with auger cuttings on July 31,2012. 30- i PROJECT NO. 124271-6 BORING LOG B-3 PLATE /7. \ DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-3 1; Bright People.Right Solutions, DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 ��. Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30112 Drill Company: Custom Auger Drilling BORING LOG B-4 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Cloudy,80 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS m _j No Coordinates Available o. m-- o A. o m m e�° m No Elevation Available l'.. I Z a Z^ > E> o- i v U oa C7 G of g m c." �m J O ,5z ~_ Surface Condition:Grass Available Weeds f a E Ut o UE v'c C vii > oDcop -= ii H i 2 O C7 co m: c4 =rn 2O O 0.co a..It J .cr n.? 0 o r LEAN CLAY with sand(CL):gray brown,slightly y' moist,firm to hard LBC--6 13.4 Chlorides=0.0073 o 8 pH=7.9 c.j .- Sulfates=0.011 c 5 ILBC=12 15.7 88 Resistivity=808 15 Expansion=2.4%under _ - 1 ksf when wetted. - 10L BC=7 CL 14.8 98 74 47 27 t, White River Formation WEATHERED CLAYSTONE:red-brown,sightly `- 15 \ moist to moist,moderately hard to hard �6�42 15.5 108 — LBC=13 30.5 20 22 — 7. White River Formation26 r- ABC=5014 j 25 CLAYSTONE BEDROCK:red-brown,moist,very GROUNDWATER LEVEL INFORMATION: `hard Groundwater was not encountered during drilling or after completion. The exploration was terminated at approximately 24.3 GENERAL NOTES; ft.below ground surface. The exploration was backfilled with auger cuttings on July 30,2012. 30 • PROJECT NO. 124271-6 BORING LOG B-4 PLATE DRAWN BY: DAD 2. • r KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-4 Bright People.Right Solutions. DATE: 9/812012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/31/12 Drill Company: Custom Auger Drilling BORING LOG B-5 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,75 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION �+ LABORATORY RESULTS u • 2J o x'tU °.. No Coordinates Available o. Ow `° — o a, r m c? "a Ili No Elevation Available i Z '�- w Z^ y E> ,U. m u, ��- Surface Condition:Grass&Weeds a o a y-2 .c 4) o'- 2'- -z is z I-'� m c cv1 E a 8 LI U E •m e O m m CD m ai >> m a r E O as b= a> u) >s op O 2' m.- m CZ Z m ET. ro -0n W Dy 2t.) O am aU �.� a Z. 5re m FAT CLAY(CL):gray-brown,slightly moist,very w dense z / E o 0 - Y m BC=21 16.9 91 Expansion=6.0%under O. 5 27 1 ksf when wetted. — CC C m / BC=7 CH 17.6 100 92 54 30 6 dd5 /m �BC=11 21.2 81 10 13 ,- — o' - o z (7,, \ White River Formation \ WEATHERED CLAYSTONE:red-brown,slightly 15 moist,weathered �BGB 19.2 — a 9 _ r _ N White River Formation \BC=50/1r 20 CLAYSTONE BEDROCK:red-brown to gray,slightly — moist,very hard B20 25- 1 50/5", _ The exploration was terminated at approximately 24.9 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after - backfilled with auger cuttings on July31,2012. completion. GENERAL NOTES• 30— r•'i T. 71 C." PROJECT NO. 124271-6 BORING LOG B-5 PLATE T'' I' \ DRAWN BY: DAD N KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-5 iiij Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 t �- Weld County,Colorado z REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-6 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert: 0 degrees Exploration Method: Solid Stem Auger Weather: P.Cloudy,90 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS as ii. . m x U No Coordinates Available a B m ^ o w --m e m ZN No Elevation Available I- T-, H Z^ m E> a m rn Surface Condition:Grass&Weeds d GQ� o m -1 Z Z F- '? p, d U t o — rn+o. O 76 ? 'goo V II a 11 CO I� Cl w coT -Bo Z' mm ION Q> "- 2 coto Et 0: Dm 2O 0 o_in d� 11? In—?, Ott ;r % Silty LEAN CLAY(CL):gray-brown,slightly moist,firm J! to hard _ BC=14 13.3 92 Expansion-3.2%under c 5 18 r 1 ksf when=wetted. 4 BC=5 13.6 -5 _ 10 BC-14 16.1 102 - 18 � s'\; White River Formation WEATHERED CLAYSTONE:red-brown,slightly - i;_ \ moist to moist,firm \\ LBC=13 25.0 15 \ 11 14 - \\ BC=27 29.1 90 P0_ ' White River Formatiom 50/5- _ CLAYSTONE BEDROCK:red-brown,slightly moist to moist,very hard L BC=30 25 "! \ 50/37 The exploration was terminated at approximately 24.8 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after - back filled with auger cuttings on July 30,2012. completion. GENERAL NOTES* 30- i - _ �+ PROJECT NO. 124271.6 BORING LOG B-6 PLATE "% DRAWN BY: DAD KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant B-6 • :;, Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado 7. REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-7 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angie from Veit: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,80 F Auger Diameter: 4 In.O.D. FIELD EXPLORATION LABORATORY RESULTS )ic o X.5 tut v a, m � No Coordinates Available T m 1 .. z. o a) • Ta c m `2 No Elevation Available l- o � m ur Z^ m E 0- m y 2 Surface Condition:Grass&Weeds w 'o a a, o c c. c' c m -r z J.4"z r-- u a a o co Np 0 •N a •5p P u = n W 0 o m to a .p o Z m m m c0+i az �°Z L aa) to to n! Du) �U 0 au) a xt _,� a� ore ,, FAT CLAY with sand(CH):gray-brown,slightly moist, P-i firm to hard _ z BC--6 CH 14.3 100 72 52 30 L'.% 7 5 ,�BC=23 15.7 100 — n C. White River Fom)atlon �BC=99 21.3 10 \ WEATHERED CLAYSTONE:red-brown,slightly 16 — 3 moist to moist,moderately hard 21 ,- i k B15 30.9 91 Expansion=2.1%under 15 31 ,- 1 ksf when wetted, — L BC=18 20— White River Formation 50/9" _ CLAYSTONE BEDROCK:red-brown to gray-brown, slightly moist to moist,very hard - M ABC=50/5- 25— The exploration was terminated at approximately 24.4 GROUNDWATER LEVEL INFORMATION: - ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after back611ed with auger cuttings on July 30,2012. completion. GENERAL NOTES- ;:. 30— PROJECT NO, 124271 6 BORING LOG B-7 PLATE ." � DRAWN BY: DAD t KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-7 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-8 Logged By: D.DiCenso Drill Crew: Fred Hor:Vert Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 In. Angle from Veit: 0 degrees Exploration Method: Solid Stem Auger Weather: P.Cloudy,90 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS a, U m �t _ n v N —J No Coordinates Available 51- C ^o o m c L rm o' No Elevation Available i .0 '�� H Z^o > 0- 0 m L Surface Condition:Grass&Weeds m 'o a o .-c m "� c z z �'� [7 m oc d to 00 2.1 2- oZ 2Z m Silty LEAN CLAY(CL):gray-brown,slightly moist,firm y' / tohard LI- 5 [BC=9 14.1El 7 — J 5 r 10 ,��20 14 13.7 101 - I White River Formation - CLAYSTONE BEDROCK red-brown,slightly moist to - a; LL' moist,very hard cr B16 10.1 15 50/8" _ BC=36 27.9 95 20 50/3r - BC=40 20.0 '' 25 1 50/4j The exploration was terminated at approximately 24.8 GROUNDWATER LEVEL INFORMATION: ft.below ground surface, The exploration was Groundwater was not encountered during drilling or after backfilled with auger cuttings on July 30,2012. completion. GENERAL NOTES* 30- • PROJECT NO. 124271.6 BORING LOG B-8 PLATE • r'�� DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-8 .L Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 �___ Weld County,Colorado REVISED: = PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-9 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Veit: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,90 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS i \ m x U 715 No Coordinates Available a) m m o ,Z. I.. a m ms i m is No Elevation Available l— § m Z^ y E> tL t Surface Condition:Grass&Weeds m v�a > o .g m 2t.— 2F) o O Ill :n a Od Cgt p �d N Q a m )O D� a Z _ O (9 m g 8 m e7 z, o o Z` d m N .> 4. L sEi to con tY mtn 2v o n_to aac _? a? Ow C. e Sandy FAT CLAY(CH):gray-brown,slightly moist, Lu firm to hard LBC=4 CH 29.8 100 67 52 31 6 7 _� BG=22 20.4 109 J! _ LBG11 23.9 10, White River Formation 12 — WEATHERED CLAYSTONE red-brown,slightly 22 moist to moist,moderately hard - - ` IILBC--20 CH 23.8 99 100 99 59 36 - 15— White River Formation 50/5-/- — CLAYSTONE BEDROCK:red-brown,slightly moist to - moist,very hard - -1 - BC=21 20— 5018" — MI ABC=50/4/ - 25 The exploration was terminated at approximately 24.3 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after baddilled with auger cuttings on July 30,2012. completion. GENERAL NOTES; 30— PROJECT NO. 124271-6 BORING LOG B-9 PLATE DRAWN BY: DAD I KL E/NFEL OER CHECKED BY: BIM Proposed Centennial Gas Plant B-9 Bright People.Right Solutions. DATE: 916/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-10 Logged By: D,DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,75 F Auger Diameter: 4 in.0.0. FIELD EXPLORATION LABORATORY RESULTS _ v= 3 No Coordinates Available a m o o m o c 2 01 w No Elevation Available l `e.� y Z,7 m E> a. ro w Surface Condition:Grass&Weeds m ,315 > y Z ' m Ft Eno v Z '�II —Z I—-g 9 N g E 3u U N C ❑ N Wtl L_ E l- ❑ t.7 n oc N rn O O Z' N. NN O'Z Z N ce Silty LEAN CLAY with sand(CL):gray-brown,slightly N w moist,firm to hard - 8 n 19.9 m 5 1.13C=12F 16.4 107 22 — c W , BC=3 Chlorides=0.0011 pH=8.3 y\ 7 ,- Sulfates=0.009 White River Formation , BC=19 15.3 114 Resistivity=877 10 WEATHERED CLAYSTONE red broom,slightly \ 22 ,- — o. \ moist to moist,firm to hard a a \\ a - z LL k. L LBC=30 29.2 15 25 -:-:, 32 s . BC=28 20— White River Formation - 50/4` _ CLAYSTONE BEDROCK red-brown,slightly moist to moist,very hard - BC=27 25— \ 5015, The exploration was terminated at approximately 24.9 GROUNDWATER LEVEL INFORMATION: ft,below ground surface. The exploration was Groundwater was not encountered during drilling or after backfilled with auger cuttings on July 30,2012. completion. GENERAL NOTES- 30— a - PROJECT NO. 124271-6 BORING LOG B-10 PLATE N / DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-10 Bright People.Right Solutions. DATE: 817/2012 Vicinity of County Road 89 and County Road 100Ez Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-11 Logged By: D.DiCenso Drill Crew: Fred Hor.Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,70 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS H . o X.V co m � No Coordinates Available r B - o Z^ o m • m e y3 42 No Elevation Available 0 z 05�. w z- m E> a m y w r Surface Condition:Grass&Weeds ii a — c m c rn J Z '�Z ~ U a m m n a• A E 38 u U c ' y > mp >> Wa tE Om 0 CO o 07 :D 0 0 Z' N m N N 4'Z N Z m V1 mM tY OW 2U 0 drn d# �... ri-S ore % LEAN CLAY with sand(CL):fight brown to t-' gray brown,slightly moist,hard u. BC=15 18.2 98 5 21 r _ LI 10J%/� L BG10 CL 16.6 100 82 45 30 c White River Formation V 14 r _ o CLAYSTONE BEDROCK:red-brown,gray-brown and olive-gray,sfigthly moist to moist,hard to very hard, softer at 31 feet Ill BC=25 28.6 89 Expansion=3.7%under 15— 1 50/4f 1 ksf when wetted. — _ �BC=17 24.7 20 50/67- - M-\BC=50/57-: 31.3 91 7 25— — �BC=5016"/ 30 — II\BC 30 35— 31 r — L , , BC=15 28 - \ 36 / a. - The exploration was terminated at approximately 40.5 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after bacldilled with auger cuttings on July 30,2012. completion, GENERAL NOTES' PROJECT NO. 124271-6 BORING LOG B-11 PLATE DRAWN BY: DAD , _ r KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-11 People.Right Solutions. DATE: 81712012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-12 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: M.Cloudy,90 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS rn " � "a' o m m No Coordinates Available o. m 1 ^o i. o m "g c m CD d g No Elevation Available rno rn,'m_ j o O 07 y n Surface Condition:Grass&Weeds E 3 t ≥ rn�° y a. c a� c o - Z T2 Z H m R E ;2 § of c vim Mp Q> Ra it L E 0o Z m._ m e FAT CLAY(CH):gray-brown,slightly moist,firm to 6 hard ,J IBC=29 ` sf 18.0 89 6c oenn Wetted. 5 LBC=180 CH 19.7 100 91 52 28 - 5 r - H. - / .BC=13 15.5 101 10 14 , _ — White River Formation LBC=15 12.8 15 WEATHERED CLAYSTONE:red-brown,slightly 15 _ moist to moist,firm 15 k BC=40 30.5 91 20— White River Formation 50/37- _ CLAYSTONE BEDROCK:red-brown to gray brown, - slightly moist to moist,very hard - I• ,BC=50/8", 25— The exploration was terminated at approximately 24.5 GROUNDWATER LEVEL INFORMATION: - ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after backfilled with auger cuttings on July 30,2012. completion. GENERAL NOTES- 30— PROJECT NO. 124271-8 BORING LOG B-12 PLATE �� DRAWN BY: DAD .i ( KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-12 Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 �� Weld County,Colorado ��� REVISED: - PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-13 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,85 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS 13, i^_ ci x V 15 No Coordinates Available °- m f- .. d a a c�° No Elevation Available I- a Q. Q o o i•^o F L :Ft Surface Condition:Grass 8 Weeds n c�t c „�o N« ❑m a d o p z II a z ya .- N o c N tO T a o Z' N m to nt 6z Luz L OE7 �/�/�/ Silty LEAN CLAY(CL):gray-brown,slightly moist, hard L. _ 5 •BC=149 15.7 94 under when wetted - 'J - /� — - J BC- 19.1 10 L 8 — _.-..t C White River Formation iiBC=18 15 ,\` WEATHERED CLAYSTONE:red-brown,slightly - 36 ,- — \\\\ moist to moist,moderately hard to hard C BC=12 30.9 PO � 19 — White River Formation BC=5014: 25- CLAYSTONE BEDROCK:red Exam,slightly moist to GROUNDWATER LEVEL INFORMATION: moist,very hard I Groundwater was not encountered during drilling or after — completion. _ The exploration was terminated at approximately 24.3 GENERAL NOTES' ft.below ground surface. The exploration was - backtilied with auger cuttings on July 30,2012. 30— ,. , _ c U �' PROJECT NO. 124271-6 BORING LOG B-13 PLATE c /�/". ."" \ DRAWN BY: DAD Gi KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-13 .,, Bright People.Right Solutions. DATE: 8f7/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-14 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,75 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS 11 e 7 N N No Coordinates Available o. m-0 E. ,+ o w rE a —`.i '-c--T, '2-..) `5 No Elevation Available I— o m Z m y m Surface Condition:Grass&Weeds a) o a m o m o o �c J Ti E Ug v UE c O N NO J mn rE m o c9 rn mD CC co c) Cl n-u) a ' '? E? 0 C iFAT CLAY with sand(CH):gray-brown,slightly moist, � firm to hard J J LI3C=10 CH 17.9 100 75 51 30 :;--1,- 5� 11 - 14 L . - 8C--9 29.8 91 Expansion=2.0%under p 1 White River Formation ,-s. 14 ,_ 1 ksf when wetted. - WEATHERED CLAYSTONE:red-brown,slightly moist to moist,weathered to hard - - - BC=15 28.9 15\` 28 - -\ 35 - likBC=24 20 �\ 45 45 r — 25\ BC�23 28.3 35 — White River Formation -\ 50/6, - \CLAYSTONE BEDROCK:red-brown,slightly moist to I moist,very hard GROUNDWATER LEVEL INFORMATION: Groundwater was not encountered during drilling or after completion. - The exploration was terminated at approximately 25.5 GENERAL NOTES• ft.below ground surface. The exploration was - backfilled with auger cuttings on July 30,2012. 30— PROJECT NO. 124271-6 BORING LOG B-14 PLATE d y�� DRAWN BY: DAD / .: KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant B-14 _ Bright People.Right Solutions. DATE: 817/2012 Vicinity of County Road 89 and County Road 100 . Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-15 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Cloudy,85 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS rn ° 7 x a m - No Coordinates Available - m o : o 0 ra c IS �' c� No Elevation Available l— c 55 2' �, c rno m t o _ Alc Surface Condition:Grass&Weeds m y o c m c" F a a OE $ Un m O .y m NO •:OZ vZ N m E m s$ m rn >. ..to. c . m 0) co 033 N c> �0_ L y a O L9 co COD XX07 2O O am aac DZ.. d? O C ,T 7 Sandy LEAN CLAY(CL):gray-brown,slightly moist, -' E IBG=10 14.2 100 5 14 _ tu CL J 10 , gC ft CL 17.7 100 64 45 26 — r � White River Formation �\ WEATHERED CLAYSTONE:red-brown,slightly •BC--23 19.7 105 15 moist to moist,moderately hard 38 c BC=15 26.7 20- White River Formation 50/8W - CLAYSTONE BEDROCK red-brown,slightly moist to moist,very hard - \BC- 0/3'y 25- The exploration was terminated at approximately 24.3 GROUNDWATER LEVEL INFORMATION: _ ft.below ground surface. The exploration was Groundwater was not encountered during drifting or after backfilled with auger cuttings on July 30,2012. completion. - GENERAL NOTES; 30- PROJECT NO. 124271.6 BORING LOG B-15 PLATE -'�� DRAWN BY: DAD /<L E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant B-15 Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 �. Weld County,Colorado REVISED: PAGE: 1 of 1 • Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG B-16 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Cloudy,90 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS rn i . u m N CO .J No Coordinates Available a m e o a W e -11 — No Elevation Available F- m o g. m v, Z` 2 E o m m Surface Condition:Grass&Weeds a LIE > a , =° a rn _Z z .R E. E 3� c�i UE arc cn > TA' � n yu mE t] sr o. m rA T O o Z' co m mg!' cr>. Lup- o •(5") G U) m� W DO) 2O D a.co D.* D 5.-F..• jLEAN CLAY with sand(CL):gray brown,slightly moist,firm to hard .1-.'i 5 BC=99 CL 15.8 100 82 49 27 - ►. 9 - ILBC-22 15.2 110 BCC 16.9 10 L ; . — 77 White River Formation �BC=50/6;.. 15 CLAYSTONE BEDROCK:gray to red-brown,slightly — moist to moist,hard to very hard,ash lens at 14-14.5 E. feet and a sandy lens at 24 feet - LBC=18 20 25 — 25 —\650/4 j - 25— ' The exploration was terminated at approximately 24.3 GROUNDWATER LEVEL INFORMATION: - ft.below ground surface. The exploration was Groundwater was not encountered during drilling or after backfilled with auger cuttings on July 30,2012. completion. - GENERAL NOTES' E-' 30— PROJECT NO. 124271 BORING LOG B-16 PLATE ;':� DRAWN BY: DAD ri 't KL E/NFEL OER CHECKED BY: BTM B—I 6 Proposed Centennial Gas Plant 'd, Bright People.Right Solutions, DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 � : Weld County,Colorado REVISED: — PAGE: 1 of 1 Date Begin-End: 7/30/12 Drill Company: Custom Auger Drilling BORING LOG Perc.Profile Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Cloudy,80 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS No Coordinates Available . B— , . o e :•••= c m x3 w No Elevation Available H f.£ L. y m Z\ m E> a m 2 Surface Condition:Grass&Weeds m a o > o c m S'� S� J Z Z ~ Q m Ti'D 0l U E y c � > o 5 �� i m E u) ,, O 0 2 caw cog > a t 0 o CO 0) Ea- D �0 �O ❑ am a* J J . a? 0 C r Sandy FAT CLAY(CH):gray-brown.slightly moist, hard • BC=17 CH 100 61 53 28 I 26 5 = White River Formation BC=17 CLAYSTONE BEDROCK red-brown,slightly moist, 50/10" 10— very hard — The exploration was terminated at approximately 10.3 GROUNDWATER LEVEL INFORMATION: ft.below ground surface. The exploration was not Groundwater was not encountered during drilling or after backfilled because Weld County Specifications. completion. GENERAL NOTES- 15— ; PROJECT NO. 1242716 BORING LOG Perc. Profile PLATE • DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-17 ,; Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 Date Begin-End: 7/31/12 Drill Company: Custom Auger Drilling BORING LOG P-1 Logged By: D.DiCenso Drill Crew: Fred Hor.-Vert.Datum: Not Available Drill Equipment: CME-55 Hammer Type-Drop: 140 lb.Automatic-30 in. Angle from Vert.: 0 degrees Exploration Method: Solid Stem Auger Weather: Sunny,80 F Auger Diameter: 4 in.O.D. FIELD EXPLORATION LABORATORY RESULTS p� 1i t-1.. o m m v No Coordinates Available o m° ^ C m ro c 2 w TO No Elevation Available I— c w Z^ m E> a y CO V.. t Surface Condition:Grass&Weeds 0 a s y o .-a m c c fA ' '�Z I—-E J O. n O. o U coE yc 0 '. > 'f.o 5II yll mE in C9 r/) mD it Du) MO ❑ au) O. :J? ll? OC 'f FAT CLAY with sand(CH):light brown,slightly moist, CH 100 64 52 27 firm mr _ fn o Silty LEAN CLAY(CL):gray-brown,slightly moist, BC=18 17.1 92 Expansion=8.6%under -/ hard to very hard I 30 0.2 ksf when wafted. 5 — j1 ,r.: I BC=12 15.0 92 7. 10 A - The exploration was terminated at approximately 10 ft. GROUNDWATER LEVEL INFORMATION: _ below ground surface. The exploration was badcfiiled Groundwater was not encountered during drilling or after n. with auger cuttings on July 31,2012. GENEcomplRAL = GENERAL NOTES' 15- PROJECT NO, 124271.6 BORING LOG P-1 PLATE //' \ DRAWN BY: DAD CHECKED BY: BTM KL E/NFEL QER Proposed Centennial Gas Plant B-1 8 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: PAGE: 1 of 1 SAMPLER GRAPHICS UNIFIED SOIL CLASSIFICATION SYSTEM(ASTM D 2487) - HYDRO EXCAVATION WELL-GRADED GRAVELS, CLEAN Cu z4 and •'' GW GRAVEL-SAND MIXTURES WITH } m GRAVEL 1s �. LITTLE OR NO FINES 'I HAND AUGER y WITH ° POORLY GRADED GRAVELS, 11 l Cu'4 and/ ° / FINES GP GRAVEL-SAND MIXTURES WITH x BULK/BAG SAMPLE m or 1,Cc>3 ) // \\ O 0 LITTLE OR NO FINES m • WELL-GRADED GRAVELS, CALIFORNIA SAMPLER = • ° GW-GM GRAVEL-SAND MIXTURES WITH (3 inch outside diameter) Cu:A and �•a LITTLE FINES -' MODIFIED CALIFORNIA SAMPLER `-° 1s3 a WELL-GRADED GRAVELS, (2 OR 2-1/2 inch outside diameter) c GRAVELS ' GW-GC GRAVEL-SAND MIXTURES WITH STANDARD PENETRATION SPLIT SPOON SAMPLER TI 5%o f TO H '� LITTLE CLAY FINES i;, (2 inch outside and 13/8 inch inner diameter) .° 12% ° POORLY GRADED GRAVELS, m FINES ° GP-GM GRAVEL-SAND MIXTURES WITH SHELBY TUBE SAMPLER OR > m Csi Cu<4 and/ O 0 LITTLE FINES I▪ PUSH TUBE SAMPLER N 0 or 1,Cc>3 0 • POORLY GRADED GRAVELS, TEXAS CONE PENETRATION # GP-GC GRAVELSAND MIXTURES WITH m L LITTLE CLAY FINES ,`, DYNAMIC CONE PENETRATION R m ° ° GM SILTY GRAVELS,GRAVEL-SILT-SAND $ e )O D MIXTURES o ` 2 le VANE SHEAR ED GRAVELS le J ▪ r WITH> CLAYEY GRAVELS, I GEO PROBE/MACROCORE SAMPLER 12% GC GRAVEL-SAND-CLAY MIXTURES FINES `/ E GC-03 0 GM CLAYEY GRAVELS, ', SONIC SAMPLER o GRAVEL-SAND-CLAY-SILT MIXTURES _ 55 CONTINUOUS CORE SAMPLE c o CLEAN Cu?6 and WELL-GRADED SANDS,SAND-GRAVEL HO CORE SAMPLE E T SANDS '1`x`3 SW MIXTURES WITH LITTLE OR NO FINES `', 4 (2.500 inch(63.5 mm)core diameter) o H WITH POORLY GRADED SANDS, NQ CORE SAMPLE FINES SP SAND-GRAVEL MIXTURES WITH F (1.874 inch(47.6 mm)core diameter) 5 LITRE OR NO FINES NX CORE SAMPLE o m WELL-GRADED SANDS.SAND-GRAVEL (2.154 inch(54.7 mm)core diameter) z m Cum and ;;; O E ▪ SWSM MIXTURES WITH LITTLE FINES L , HOLLOW STEM AUGER 0 W 1sCcs3 / SANDS -� SyySC WELL-GRADED SANDS,SAND-GRAVEL re m WITH MIXTURES WITH LITTLE CLAY FINES • SOLID STEM AUGER Q 0 5%TO • / v 1 12% POORLY GRADED SANDS, 1. VWATER LEVEL(level where first observed) Z FINES SP-SM SAND-GRAVEL MIXTURES WITH LITTLE FINES Cud and/ 1 WATER LEVEL(level after exploration completion) g or 1,Cc>3 / POORLY GRADED SANDS, SP-SC SAND-GRAVEL MIXTURES WITH Z WATER LEVEL(additional levels after exploration) LITTLE CLAY FINES To r OBSERVED SEEPAGE 1.The report and log key are an integral part of these logs. All data g SM SILTY SANDS,SAND-GRAVEL-SILT • and interpretations in this log are subject to the stated explanations e and limitations stated In the report g SANDS 2.Lines separating strata on the logs represent approximate o /j/ ai WITH> A. SC MIXTURES YSANDS.SAND-GRAVEL-CLAY CLAY boundaries only. Actual transitions may be gradual or differ from those shown. FINES 3. No warranty is provided as to the continuity of soil or rock % SCSM 50 CLAYEY I CfURES DS,SAND-SILT-CLAY conditions between individual sample locations. 4. Logs represent general soil or rock conditions observed at the INORGANIC SILTS AND VERY FINE SANDS,SILTY OR point of exploration on the date indicated. To ML CLAYEY FINE SANDS,SILTS WITH SLIGHT PLASTICITY in % CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY.GRAVELLY 0 5. In general,Unified Soil Classification System designations J SILTS AND CLAYS j CLAYS,SANDY CLAYS,SILTY CLAYS.LEAN CLAYS presented on the logs were based on visual classification in the field se E m> ("Alum Limit INORGANIC CLAYS-SILTS OF LOW PLASTICITY,GRAVELLY and were modified where appropriate by visual classifications in the O .c.c m less than 50) j CL-ML CLAYS,SANDY CLAYS.SILTY CLAYS.LEAN CLAYS office and/or laboratory gradation and index property testing. m d°' OL ORGANIC SILTS&ORGANIC SILTY CLAYS Z m-0 - - = a r - OF LOW PLASTICITY I 6. Fine grained soils that plot within the hatched area on the Plasticity a m y E INORGANIC SILTS,MICACEOUS OR ▪ Chart,and coarse grained soils with between 5%and 12%passing C9 gH m MH DIATOMACEOUS FINE SAND OR SILT e the No.200 sieve require dual USCS symbols,ie.,GW-GM,GP-GM, w - SILTS AND CLAYS INORGANIC CLAYS OF HIGH PLASTICITY, GW GC,GP GC,GC-GM,SW-SM,SP-SM,SW-SC,SP-SC.SC-SM. LL an 5 CH FAT CLAYS greater than 50) ORGANIC CLAYS&ORGANIC SILTS OF 7. 50/X indicates number of blows required to drive the identified ,o.Ma OH MEDIUM-TO-HIGH PLASTICITY sampler X inches with a 140 pounds hammer falling 30 Inches. PROJECT NO. 124271-6 GRAPHICS KEY PLATE e DRAWN BY: DAD i1 KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant B-19 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: GRAIN SIZE DESCRIPTION SIEVE GRAIN APPROXIMATE SIZE SIZE SIZE Boulders >12" >12" Larger than basketball-sized Cobbles 3-12' 3-12" Fist-sized to basketball-sized coarse 3/4-3" 3/4-3" Thumb-sized to fist-sized Gravel #4-3/4" 0.19-0.75" Pea-sized to thumb-sized Y^ \\ coarse #10-#4 0.079-0.19" Rock salt-sized to pea-sized •O • Sand medium #40-#10 0.017-0.079" Sugar-sized to rock salt-sized Q a fine #200-#10 0.0029-0.017" Flour-sized to sugar-sized _ o U Fines Passing#200 <0.0029 Flour-sized and smaller ° in u.r a o ANGULARITY N ` DESCRIPTION CRITERIA a War Particles have sharp edges and relatively plane O sides with unpolished surfaces ---- .1'r w Particles are similar to angular description but have O O ^ Subangular rounded edgesen " • Subrounded Particles have nearly plane sides but have O O Q k? well-rounded corners and edges Rounded Particles have smoothly curved sides and no edges Rounded Subrounded Subangular Angular PLASTICITY MOISTURE CONTENT DESCRIPTION LL FIELD TEST DESCRIPTION FIELD TEST Non-plastic NP A 1/8-in.(3 mm)thread cannot be rolled at Dry Absence of moisture,dusty,dry to the touch El P any water content Moist Damp but no visible water S The thread can barely be rolled and the lump o' Low(L) <30 or thread cannot be formed when drier than the Wet Visible free water,usually soil is below water table cc plastic limit. z The thread is easy to roll and not much time is required to reach the plastic limit. REACTION WITH HYDROCHLORIC ACID rn• Medium(M) 30-50 The thread cannot be rerolled after reaching J the plastic limit. The lump or thread crumbles DESCRIPTION' FIELD TEST when drier than the plastic limit None No visible reaction `= It takes considerable time rolling and kneading •n to reach the plastic limit. The thread can be Weak Some reaction,with bubbles forming slowly High(H) >50 rerolled several times after reaching the plastic Strong I Violent reaction,with bubbles forming immediately .-z limit. The lump or thread can be formed without crumbling when drier than the plastic limit APPARENT/RELATIVE DENSITY-COARSE-GRAINED SOIL1 CONSISTENCY-FINE-GRAINED SOIL APPARENT MODIFIED CA CALIFORNIA RELATIVE UNCONFINED DENSITY SPT-N50 SAMPLER SAMPLER DENSITY CONSISTENCY STRENGTH COMPRESSIVE psf) CRITERIA (#blows/ft) (#blows/ft) (#blows/ft) (%) <100D Thumb will Very Loose <4 <4 <5 0-15 Very Soft penetrate soil more than 1 in.(25 mm) Loose 4-10 5-12 5-15 15-35 Soft 1000-2000 Thumb wit penetrate soil about 1 in.(25 mm) Medium Dense 10-30 12-35 15-40 35-65 Firm 2000<4000 Thumb will indent soil about 1/4 in.(6 mm) Dense 30-50 35-60 40-70 65-85 Hard 4000<8000 Thumb wit not indent soil but readily indented with thumbnail Very Dense >50 >60 >70 85-100 Very Hard >8000 Thumbnail will not indent soil 'NOTE:AFTER TERZAGHI AND PECK,1948 STRUCTURE DESCRIPTION CRITERIA Stratified Alternating layers of varying material or color with layers at least 1/4 in.thick,note thickness CEMENTATION Laminated Alternating layers of varying material or color with the layer less than 1/4 in.thick,note thickness DESCRIPTION FIELD TEST Fissured Breaks fracture w e res along definite planes of ith littlistance Weakl Crumbles or breaks with handling or slight a, to fracturing y finger pressure 8 Slickensided Fracture planes appear polished or glossy,sometimes striated Moderately Crumbles or breaks with considerable "I _ finger pressure a Blocky Cohesive soil that can be broken down into small angular Strongly Will not crumble or break with finger pressure lumps which resist further breakdown 9 yg Inclusion of small pockets of different soils,such as small lenses ti• Lensed of sand scattered through a mass of clay:note thickness Homogeneous Same color and appearance throughout PROJECT NO. 124271-6 SOIL DESCRIPTION KEY PLATE • !p �J A`\ DRAWN BY: DAD KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant B-20 w Bright People.Right Solutions DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 • �� Weld County,Colorado t- REVISED: REVISED: KLE/NFELDER Blight Rcopl^.Right Soforicns APPENDIX C Geotechnical Laboratory Test Results 124271-6/CSP 12 R0416 Copyright 2012 Kleinfelder SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • 90 80 70 l: J V Z_ 60 G trJ U, "' F. 50 w c - a.40 30 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passin Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-1 4 N/A 100 100 96 52 25 27 FAT CLAY m B-1 24 N/A 100 100 99 58 25 33 CLAYSTONE BEDROCK PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE 44 DRAWN BY: DAD :i' KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-1 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 \. Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • 90 80 70 ca z m 60 J V) IJ din • Z 50 W lY • w 40 cl▪ 30 • 20 • 10 - 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing • Symbol Exploration ID 1 ' Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-2 7 N/A 100 100 80 52 20 32 FAT CLAY WITH SAND PROJECT NO. 124271.6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3' 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 90 80 70 C7 Z in 60 Q a Z 50 W tY a 40 30 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-4 9 N/A 100 98 74 47 20 27 LEAN CLAY WITH SAND PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE • : DRAWN BY: DAD 1 KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-3 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • •- • • -f 90 80 70 z • t5 60 u (p tl d • ▪ Z 50 - W U CL a 40 i, 30 • 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing • Symbol Exploration ID Approx. Sample 314 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-5 7 N/A 100 100 92 54 24 30 FAT CLAY PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD CHECKED BY: BTM KL E/NFEL DER Proposed Centennial Gas Plant C-4 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • - 90 80 70 Z T 60 Q = n. z50 - w tu • c40 30 LE 20 Y. 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-7 2 N/A 100 100 72 52 22 30 FAT CLAY WITH SAND PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-5 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • •� 90 80 TO C7 Z En 60 to O.. z 50 w 9 U d 40 30 20 .75 a 10 - r 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. SamPie 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-9 2 N/A 100 100 67 52 21 31 SANDY FAT CLAY m B-9 14 N/A 100 100 99 59 23 36 WEATHERED CLAYSTONE • • w -6 0 0 a U PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C-6 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 • • • •- -- -- • 90 80 70 • Z v5 60 • 0- • z 50 • w U a 40 30 ▪ 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID DepthApprox. Sample 3/4 inch #4 #200Liquid uit i Plastic i Index Sample Description • B-11 9 N/A 100 100 82 45 15 30 LEAN CLAY WITH SAND • PROJECT NO. 124271-s SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-7 Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 I I I I I I I I I I I 100 riD • • 90 80 70 z • u)60 J (() s., Z 50 w x � • a 40 30 20 • 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-12 4 N/A 100 100 91 52 24 28 FAT CLAY • PROJECT NO. 124271.6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-8 Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 \ Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 90 80 70 J) ♦n J • Z th 60 w V1 Q z50 ▪ U m � L 40 cc 30 • 20 — c • 10 U u 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-14 4 N/A 100 100 75 51 21 30 FAT CLAY WITH SAND • PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD r� KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C'9 Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 ��. Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 90 80 70 C7 Z V)60 a Z 50 c - a.a 40 30 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID p R} Sample i t 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth • B-15 9 N/A 100 100 64 45 19 26 SANDY LEAN CLAY PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed c-10 Centennial Gas Plant Bright People.Right Solutions. DATE: 8/7/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: i SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 �-- 90 80 70 • C9 • Z • rn 60 ▪ to • 0 ▪ z 50 • w 0 - w 40 30 - 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • B-16 4 N/A 100 100 82 49 22 27 LEAN CLAY WITH SAND PROJECT NO. 124271-s SIEVE ANALYSIS PLATE DRAWN BY: DAD I KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-1 1 Bright People.Right Solutions. DATE: 8!7/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 I I I I I 100 90 • 80 70 _ (ry Z _ d)60 a H z 7: 50 w U w d 40 30 20 10 0 10 1 0.1 PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID Approx.pr Sample 3/4 inch #4 #200 Liquid Limit Plastic Plastic Sample Description �p • P-1 0-5 N/A 100 100 84 52 25 27 FAT CLAY WITH SAND PROJECT NO. 124271.6 SIEVE ANALYSIS PLATE DRAWN BY: DAD KL E/NPEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C-12 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: SIEVE SIZE 3" 1-1/2" 3/4" 3/8" #4 #8 #10 #16 #30 #40 #50 #100 #200 100 90 80 70 y ▪ Z N 60 GO G7 d z 50 • w U X a 40 30 20 • 10 0 10 1 0.1 Ti PARTICLE SIZE IN MILLIMETERS Percent Passing Symbol Exploration ID APProx. Sample 3/4 inch #4 #200 Liquid Plastic Plastic Sample Description Depth(ft) No. Limit Limit Index • PERC.PROFILE 4 N/A 100 100 61 53 25 28 SANDY FAT CLAY PROJECT NO. 124271-6 SIEVE ANALYSIS PLATE DRAWN BY: DAD iKL E/NFEL D R CHECKED BY: BTM Proposed Centennial Gas Plant C-13 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: 20 16 Compression=-2.7% under 12 1 ksf when wetted. I— w _ 2 4 w L 04._ m . 1 __♦ -► J -4 j co -8 -12 -16 _ -20 0.1 1 10 STRESS(ksf) Exploration ID Approx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description ( ) No. (Pct) (°/o) (Pct) Pg B-1 9 N/A 92 16.1 79 SILT(ML) 17, 20 I 16 - Expansion=3.2%under 12 1 ksf when wetted. .is- 8 z w 4 2 w • ..---'---------N„ :::, r 0._________ co ......„„ J '4 J w co -8 - -12 -16 -20 0.1 1 10 • STRESS(ksf) Exploration ID Approx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description a (ft) No. (P (/a) (Pcf) N ca B-2 4 N/A 104 14.6 91 FAT CLAY WITH SAND 1-1 (CH) a v PROJECT NO. 124271-6 SWELUCOMPRESSION PLATE �� DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C—1 4 J Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 �;„_ Weld County,Colorado REVISED: 20 16 Expansion=2.4% under 12 1 ksf when wetted. 8 H t• w 4 2 w O J ,n (n 04,---__________ • J W u ., -12 9 -16 -20 0.1 1 10 STRESS(ksf) ▪ Exploration ID Approx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (pct) (%) (Pd) z. B-4 4 N/A 102 15.7 88 LEAN CLAY WITH SAND (CL) 20 16 Expansion=6.0%under 12 1 ksf when wetted. 'e 8 I- Z w 4 w —__________. w a to - J 4 -J w -8 co -12 -16 -20 0.1 1 10 STRESS(ksf) Exploration ID APprox.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (KO (%) (pelt B-5 4 N/A 107 16.9 91 FAT CLAY(CH) PROJECT NO. 124271-6 SWELL/COMPRESSION PLATE a.7....` DRAWN BY: DAD IKL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C-15 Bright People.Right Solutions. DATE: 916/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: 20 16 Expansion=3.2%under 12 1 ksf when wetted. O▪ 8 I- W 4 • o 0s • n � r.. J -4 r�. J t -8 o to -12 -16 -20 0.1 1 10 LEI STRESS(ksf) Exploration ID App(m)DePth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description No. (Pcf) (%) (Pcf) B-6 4 N/A 104 13.3 92 SILTY LEAN CLAY(CL) 20 16 - Expansion=2.1% under 12 1 ksf when wetted. ▪ '- 8 - • I- z w 4 2 co -8 -12 -16 -20 0.1 1 10 STRESS(ksf) ▪ Exploration ID APProx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (P (%) lPcf) 8-7 14 N/A 119 30.9 91 WEATHERED CLAYSTONE • • PROJECT NO. 124271-6 SWELUCOMPRESSION PLATE DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-16 ui Bright People.Right Solutions. DATE: 916/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: 20 16 _ Expansion=3.7%under _ 12 1 ksf when wetted. _ 8 z W 4 M _ III ♦ -♦ - 0C •w 7n cr) m _ J -4 J W - -8 ui -12 -16 -20 0.1 1 10 STRESS(ksf) Exploration ID APProx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (Pcf) N (Pcf) B-11 14 N/A 115 28.6 89 CLAYSTONE BEDROCK 20 16 - Expansion=8.5%under . _I 12 1 ksf when wetted. 8 r i— z W 4 w J W J -4 J W co -6 7. -12 cs -16 -20 0.1 1 10 • STRESS(ksf) ' Exploration ID APProx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight on (ft) No. (p(K0g (%a) (Put) g P Description Sample(Pc(Put) Pg B-12 2 N/A 105 18.0 89 FAT CLAY(CH) PROJECT NO. 124271-6 SWELUCOMPRESSION PLATE ;':� DRAWN BY: DAD s KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C-17 iii Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: 20 16 Expansion=2.4%under 12 1 ksf when wetted. i v 8 I— `' w 4 J -4 J W -12 . -16 -20 ", 0.1 1 10 STRESS(ksf) F�cploration ID APProx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (Pcf (Ma) (Pct) B-13 4 N/A 109 15.7 94 SILTY LEAN CLAY(CL) 20 j 16 Expansion=2.0%under 12 1 ksf when wetted. 8 = I- z w 4 • W J -4 -8 cn -12 -16 - -20 0.1 1 10 STRESS(ksf) - Exploration ID APprox.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (Pa) (%) (P B-14 9 N/A 118 29.8 91 WEATHERED CLAYSTONE PROJECT NO. 124271-6 SWELUCOMPRESSION PLATE e 7''''--- \''------- DRAWN BY: DAD KL E/NFEL DER CHECKED BY: BTM Proposed Centennial Gas Plant C-1 8 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: 20 16 Expansion=8.6%under 12 , 0.2 ksf when wetted. 8 • w ��• 2 4 7 fl O. • O Gh -4 J J � -8 :iJ `° -12 -16 -20 0.1 1 10 STRESS(ksf) Exploration ID APProx.Depth Sample Total Unit Weight Moisture Content Dry Unit Weight Sample Description (ft) No. (Pe) (%) (pot) P-1 4 N/A 107 17.1 92 FAT CLAY WITH SAND (CH) PROJECT NO. 124271-6 SWELUCOMPRESSION PLATE DRAWN BY: DAD KL E/NFEL OER CHECKED BY: BTM Proposed Centennial Gas Plant C-19 Bright People.Right Solutions. DATE: 9/6/2012 Vicinity of County Road 89 and County Road 100 Weld County,Colorado REVISED: E . U Cti L Cu O J Du L I- 50 9 s a � ,L .a O O C CD P O CCD C c .14 ° Y 1 m•s i v r . r '� d oD co E ` c c G H¢¢ 0V o o ^ 7 O 0 •a 0 N c a u } mU -Eric .... C N o o `o �H m ca O 8 I 6 LLI W o g� a E8 04 C9 o J __ d an in a N N C U r� Q J U co 1N '4 o N F n 8 . 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