geotechnical engineering report...

GEOTECHNICAL ENGINEERING REPORT LOVELAND RIVER CROSSINGS REPLACEMENT PROJECT LOVELAND, COLORADO SEPTEMBER 12, 2014

September 12, 2014 File Number: 514110-000

CH2M Hill 9193 South Street Englewood, Colorado 80112

Attention: Kevin Heffernan, P.E. Vice President

Subject: Geotechnical Engineering Report Loveland River Crossings Replacement Project Big Thompson River, Loveland, Colorado

Mr. Heffernan:

Submitted herewith is the Geotechnical Engineering Report for the Loveland River Crossings Replacement Project. This study was conducted in general accordance with the contract between Brierley Associates and CH2M Hill. This report contains the results of Brierley’s findings, engineering interpretation with respect to the available project characteristics, and our design recommendations for the proposed construction.

We appreciate the opportunity to work with you on this project. If we can be of further assistance, or if you have any questions, please contact the undersigned.

Sincerely, BRIERLEY ASSOCIATES

Robin Dornfest, PG, CPG Steven C. Kuehr, PE Central Region Manager Principal

Lance Heyer, EI Geotechnical Engineer

2629 Redwing Road, Suite 150, Fort Collins, Colorado 80526 | 970.237.4988 | www.BrierleyAssociates.com

CH2M Hill Loveland River Crossings Replacement Project

September 12, 2014 Page i of i

TABLE OF CONTENTS 1 INTRODUCTION ................................................................................................................. 1 2 PROJECT CHARACTERISTICS ......................................................................................... 1 3 FIELD AND LABORATORY INVESTIGATIONS ................................................................. 2

Field Investigation ......................................................................................................... 2 3.13.1.1 Geotechnical Excavations ......................................................................................2 3.1.2 Soil Resistivity ........................................................................................................2 Laboratory Testing ........................................................................................................ 3 3.2

4 SUBSURFACE CONDITIONS ............................................................................................. 3 Fine Alluvium (CL-ML) .................................................................................................. 3 4.1 Coarse Alluvium (SM, SP, GW-GM, GM, GP) ............................................................... 4 4.2 Sandstone Bedrock (Lykins, South Platte, Lytle, and Niobrara Formations) .................. 4 4.3 Groundwater ................................................................................................................. 4 4.4

5 GEOTECHNICAL DESIGN RECOMMENDATIONS ............................................................ 4 Foundation Recommendations ..................................................................................... 4 5.1 Lateral Earth Pressures ................................................................................................ 6 5.2 Geotechnical Parameters for Counteracting Buoyancy ................................................. 6 5.3 Corrosion Potential ....................................................................................................... 6 5.4 Soluble Sulfates ............................................................................................................ 7 5.5 Particle Size Analysis for Scour .................................................................................... 7 5.6 Permanent Bank Slopes ............................................................................................... 7 5.7

6 CONSTRUCTION PROCEDURES AND RECOMMENDATIONS ........................................ 7 Temporary Excavations ................................................................................................ 8 6.1 Site Grading and Earthwork .......................................................................................... 9 6.2

6.2.1 Site Preparation .....................................................................................................9 6.2.2 Import Fill and Structural Backfill Material ..............................................................9 6.2.3 Backfill Material Placement ....................................................................................9 6.2.4 Backfill Compaction Specifications .......................................................................10 Crossing Excavations ................................................................................................. 10 6.3 Dewatering During Construction ................................................................................. 10 6.4

7 REVIEW AND CONSTRUCTION OBSERVATIONS ......................................................... 11 8 LIMITATIONS .................................................................................................................... 11 FIGURES Figure 1 – Project Location Map Figure 2 – Test Pit Locations Map TABLES Table 1 – Summary of Geotechnical Laboratory Test Results Table 2 – Resistivity Meter Field Measurements and Calculations Table 3 – Summary of Corrosion Test Results APPENDICES

Appendix A – Test Boring Key and Test Boring Reports Appendix B – Geotechnical Laboratory Test Results

Appendix C – Records of the Soil Resistivity Testing


September 12, 2014 Page 1 of 12

1 INTRODUCTION During the 2013 Colorado Floods, the Big Thompson River experienced exceedingly high flows, and during the flood event several of the water supply pipes used for transporting water from City of Loveland’s Water Treatment Facility were damaged, exposed, or otherwise compromised. The goal of this project is to better protect the river crossings against similar future events. CH2M Hill retained Brierley Associates (Brierley) to provide geotechnical engineering and geologic services to aid in the design of the river crossing improvements. The project is located approximately 4 ½ miles west of Loveland along US Highway 34 and the Big Thompson River. The purposes of this design report are to: 1) present the geologic and subsurface conditions encountered during our evaluation of the site and 2) provide geotechnical design criteria and construction recommendations for designing and constructing crossing locations. In preparing this report, Brierley has relied on: Geologic map of the Masonville quadrangle, Larimer County, Colorado: U.S. Geological

Survey, Geologic Quadrangle Map GQ-832, 1970;

Geologic map of the Boulder-Fort Collins-Greeley Area, Colorado: U.S. Geological Survey, Miscellaneous Geologic Investigations Map OF-2003-24, 2003;

Preliminary site and grading plans of the existing and proposed river crossing improvements, provided by CH2M Hill and City of Loveland on July 29, 2014 and August 1, 2014;

Polyethylene Encasement, Effective, Economical Protection for Ductile Iron Pipe in Corrosive Environments (DIRPA), 2012;

Site reconnaissance and geotechnical engineering investigation;

Other in-house geologic information and experience with similar projects.

2 PROJECT CHARACTERISTICS The proposed river crossing improvements are to be located in Larimer County, Colorado along US Hwy 34 and the Big Thompson River (Figure 1). More specifically, the river crossing include several locations where a 36 inch waterline crosses under the Big Thompson River as well as separate locations where a 20 inch waterline also crosses under the river. Maps provided by City of Loveland identify the specific location of each of the crossings and general location for the geological investigation. The following paragraph includes a brief site description and a summary of the proposed river crossing improvements. In order to better protect the two specified waterlines (a 20 inch cast iron pipe and a 36 inch steel pipe) against future flood events, the City plans to bury in the underlying bedrock at four (4) crossings for the 36 inch waterline (identified as 36.1, 36.2, 36.3, 36.4) and at two (2) crossings for the 20 inch waterline (identified as 20.1, 20.2). As an additional level of protection, both waterlines will also be encased in unreinforced concrete within the excavated bedrock trench.

http://ngmdb.usgs.gov/Prodesc/proddesc_9462.htm



3 FIELD AND LABORATORY INVESTIGATIONS Brierley conducted field and laboratory investigations to explore and evaluate the general subsurface conditions at the site locations. The investigations were specifically to provide geotechnical information related to the proposed river crossing improvements and the construction processes needed for the improvements. The following sections include details relating to our subsurface investigation and subsequent laboratory investigation.

Field Investigation 3.1Brierley directed geotechnical test pit excavations at four site locations to investigate the general subsurface conditions near the proposed river crossings. Brierley also performed resistivity tests near each of the four locations. Figure 2 shows the locations of the test pits. 3.1.1 Geotechnical Excavations Brierley directed the excavation of four test pits at the site locations on August 5 and 6, 2014. The following table summarizes the locations in reference to numbers assigned by the City of Loveland for each of the crossings.

Test Pit Locations Test Pit ID Crossing ID

TP-1 36.2 TP-2 36.3 TP-3 36.3

TP-4A & TP-4B 20.2 Test pit locations were generally identified based upon the proposed river crossing replacements and were more specifically agreed upon during the investigation by Brierley, CH2M Hill, and the City. Excavations were conducted by the City of Loveland utilizing a Caterpillar 316EL hydraulic excavator. Test pit locations were surveyed by King Surveyors of Windsor, Colorado. Samples of subsurface materials were visually logged in the field by Brierley. Bulk samples excavated from the test pits were collected for further evaluation and testing. Descriptions and visual classifications of soil strata and samples were recorded on test pit reports during excavations. Test pit reports identify soil descriptions, preceded by soil classifications, in accordance with the ASTM D2487 or ASTM D2488. Completed test pit reports are provided in Appendix A. Appendix A also includes an explanatory sheet defining the terms and symbols used on the reports. Sampling information and other pertinent field data and observations are also included on the reports. The subsurface conditions revealed during the field investigation are discussed in Section 4. 3.1.2 Soil Resistivity During the preliminary investigations into the flood damage, the City discovered some of the existing waterlines had been compromised by corrosion. The City requested an additional investigation for corrosion potential. In-situ soil resistivity was measured to evaluate the corrosion potential for proposed improvements to the waterlines.



In accordance with ASTM G 57-95a (Wenner Four-Electrode Method), utilizing a Nilsson Model 400 4-Pin Soil Resistance Meter, soil resistivity tests were performed and recorded at each of the test pit locations. At each location several pin alignments and depths were recorded. Pin alignments were perpendicular as well as parallel to the waterline alignments. Depths included the approximate anticipated depth of the pipe (top of bedrock). Field resistivity measurements are presented in Table II. Records for the soil resistivity are reported in Appendix C.

Laboratory Testing 3.2To aid in classifying the soils and to determine general soil characteristics, selected laboratory tests were performed on representative samples; test method references are presented in the following table. Included in the table are tests performed for geotechnical parameters and soil corrosivity parameters of interest.

Laboratory Tests Parameter Method Reference

Atterberg Limits ASTM D4318 Gradation ASTM D6913 Chloride – Water Soluble AASHTO T291-91/ ASTM D4327 pH AASHTO T289-91 Redox Potential ASTM D1498 Resistivity AASHTO T288-91 Sulfate – Water Soluble AASHTO T290-91/ ASTM D4327 Sulfide AWWA C105

Gradation testing, performed by Martinez Associates, LLC, was conducted to provide particle size parameters for use in evaluating scour at each crossing location. Additional information related to scour parameters is provided in Section 5.6. Atterberg limits testing was performed to describe and classify subsurface materials. The field test pit reports and material classifications were amended as necessary to reflect the results of the laboratory test data. The results of the laboratory testing are summarized in Table I with graphical data included in Appendix B. Soil corrosion testing, performed by Colorado Analytical Laboratories, Inc., was used to evaluate the corrosion potential of the proposed buried ductile-iron pipes. Additional information related to excavated soils corrosive potential is presented in Section 5.4. 4 SUBSURFACE CONDITIONS The four test pits were excavated to a depth between 5 and 13 feet below ground surface (bgs). In general, materials encountered during the subsurface investigation included fine alluvium, coarse alluvium, and bedrock. A more detailed description of the materials encountered is provided in the following sections. Test pit logs included in Appendix A provide a more detailed description of the subsurface conditions encountered during Brierley’s field investigation.

Fine Alluvium (CL-ML) 4.1Fine alluvium was encountered in Test Pit 3, and extended from 0 to 5 feet below the existing ground surface (bgs). The material was classified as silty clay (CL-ML), and contained trace amounts of gravel and boulders with a maximum particle size of 2 feet. Fine alluvium ranged from moist to wet, and organics were noted near the ground surface.



Coarse Alluvium (SM, SP, GW-GM, GM, GP) 4.2

Coarse alluvium was encountered in all test pits, at depths ranging from 0 to 5 feet below the existing ground surface (bgs) and extending to the top of bedrock, approximately 5 to 12 feet bgs. The coarse alluvium contained cobbles and boulders. Coarse alluvium consisted of silty sand (SM), poorly-graded sand (SP), silty well-graded gravel (GW-GM), silty gravel (GM), and poorly graded gravel (GP). Individual grains were primarily rounded, however the angularity of particles generally increased with depth. The maximum particle size in TP-1, TP-2, and TP-3 ranged from approximately 24 to 48 inches. TP-4A and TP-4B generally contained finer coarse alluvium with a maximum particle size of 12 inches. Coarse alluvium was dry above the groundwater table and wet below the groundwater table.

Sandstone Bedrock (Lykins, South Platte, Lytle, and Niobrara Formations) 4.3Four distinct bedrock formations were encountered in each test pit: the Lykins Formation was encountered at approximately 5 feet bgs in TP-1; the South Platte Formation was encountered at approximately 10 feet bgs in TP-2; the South Platte Formation was encountered at approximately 7 feet bgs in TP-3; and the Niobrara Formation was encountered at approximately 12 feet bgs in TP-4B. Bedrock was not encountered in TP-4A, which was excavated to 10 feet bgs. In general bedrock consisted of sandstone bedrock. The field hardness of bedrock ranged from very soft to hard, and bedrock was slightly to highly weathered. Weathering tended to increase as test pits were located in closer proximity to the Big Thompson River.

Groundwater 4.4Groundwater was encountered at a depth of between 5 and 11 feet bgs. Groundwater was not encountered in TP-4A. In general, bedrock was encountered immediately above the bedrock surface. Based on the proposed waterline depths, groundwater is expected to exist above the final elevation of the waterlines at all crossing locations. Fluctuations in the groundwater levels may occur due to variations in climate, precipitation, temperature, site development, and other factors not evident at the time measurements were taken. 5 GEOTECHNICAL DESIGN RECOMMENDATIONS Brierley is providing geotechnical design parameters to aid in the development of the waterline crossing designs and cast in place vaults. The following sections present recommendations for foundations, lateral earth pressures and corrosion potential. Also included are particle size parameters for use in scour analyses, and maximum recommended permanent bank slopes. The parameters for design presented in the following sections are based on our understanding of the project and the proposed construction, an engineering assessment of the anticipated subsurface conditions, and our experience with similar projects.

Foundation Recommendations 5.1Brierley understands permanent structures requiring foundations include vault(s) used to access and maintain the proposed piping. If additional structures, especially those bearing closer to existing grades, those with alternative geometries, or those with uncharacteristically large loads are required, Brierley should be contacted to review the recommendations presented in this section to assure compliance with the proposed construction and geotechnical design recommendations.



Brierley recommends properly conditioning existing soils directly below foundation elements to a minimum of 12 inches below the base of the proposed vault, as described in Section 6.2.1. If proposed vaults rest on bedrock, subgrade preparation is not necessary. Brierley should be retained to assure excavation into suitable material prior to foundation construction in order to validate the following geotechnical design criteria. Due to the anticipated bearing material and the geometry of the proposed vault(s), mat foundations bearing on coarse alluvium or bedrock are recommended.

1. Mat foundations constructed on coarse alluvium or bedrock, can be designed for a net allowable soil bearing pressure of 3,000 pounds per square foot (psf). The allowable bearing pressure is expressed in terms of the net pressure transferred to the soil or bedrock. The net allowable bearing pressure is defined as the total structural design load, including the weight of the foundation elements, less the weight of the soil excavated for the foundation elements. The allowable bearing pressure may be increased by 33 percent for short term or infrequent loading such as wind and seismic loads.

2. To reduce potential for differential movement, Brierley recommends the foundations be constructed on one material type, either coarse alluvium or bedrock.

3. For structural slab support (mat foundations) on coarse alluvium or bedrock, Brierley recommends using of a modulus of subgrade reaction (k) of 150 pounds per cubic-inch (pci) or 300 pci, respectively.

4. Foundation excavations and bearing surfaces should be free of loose soil or debris. Loose or disturbed soil must be removed and properly compacted prior to foundation construction per the criteria presented in Sections 6.2.3 and 6.2.4.

5. Concrete should be placed as soon as practical after foundation excavations, with as little disturbance to bearing soils as practically possible. Water that collects in the excavations should be promptly removed prior to concrete placement.

6. Soils underneath foundations must be protected from freezing and the bottoms of foundations should be constructed at least 30-inches below the surrounding exterior grade, designed for shallow frost protection, or as local building codes allow.

7. Lateral loads can be resisted by friction between the bottom foundations and subgrade soils or bedrock can be used to resist lateral loads as well as passive earth pressure from engineered fill or natural ground against the side of the foundations, assuming that fill will remain in place for the lifetime of the structure. A horizontal coefficient of friction of 0.45 or 0.30 can be used for the design of the mat foundation resting on coarse alluvium or sandstone bedrock, respectively.

8. The total resulting foundation movements for structures constructed to the above criteria is estimated not exceed 1-inch, with differential movements on the order of 0.5-inch for the proposed structure. The structural designer must allow for limited vertical movement, specifically at pipe penetration locations. Careful field control and compaction techniques will substantially minimize ultimate and differential settlements.

9. All foundation elements should be designed by a Professional Engineer and properly reinforced.

Field observations of foundation excavations should be performed by a representative of Brierley prior to concrete placement to verify that the subgrade is suitable for foundation construction or to provide mitigative recommendations as appropriate.



Lateral Earth Pressures 5.2

Lateral pressures will be exerted on below grade, buried structures by backfill soil pressures, surcharge loads, and hydrostatic pressures caused by groundwater. Lateral earth pressures on walls depend upon the properties of adjacent backfilled material and the presence of groundwater. Allowable lateral earth pressures depend on the type of wall and allowable wall movements. Recommended lateral earth pressures are presented in the following table. Additional information regarding acceptable backfill material and allowances will be discussed in Section 6.2.2. For walls designed to resist movement by restraining upper wall elevations, lateral earth pressures should be estimated using the “at-rest” condition. For walls free to deflect at upper elevations, the “active” condition should be used to estimate the lateral earth pressures. As proposed, lateral earth pressures exerted on the structures will result from adjacent compacted backfill soils from onsite excavations. For the lateral earth pressures provided in the following table to apply, backfill material should be placed within a maximum 1H:1V (horizontal:vertical) slope up and away from the base of structure foundations.

Equivalent Earth Pressure Recommendations

Equivalent Fluid Pressure (pcf) Coefficient of Lateral Earth Pressure Unit

Wt (pcf)

Friction Angle (deg)

Active At-Rest Passive Active (Ka)

At-Rest (Ko)

Passive (Kp) Above

GW Below

GW Above

GW Below

GW Above

GW Below

GW Excavated Coarse Alluvium 40 83 61 94 423 282 0.31 0.47 3.25 130 32

The recommended equivalent fluid pressures for conditions below the water table include hydrostatic pressures. The recommended fluid pressures assume a horizontal backfill surface and do not include any surcharge due to nearby loading from structures, floor slabs, live loads or traffic.

Geotechnical Parameters for Counteracting Buoyancy 5.3The design water level for proposed structures should equal the elevation of the 100-yr design flood. For proposed structures, if the 100-yr flood elevation is above the foundation base, additional resistance to uplift can be achieved by extending foundations outside vertical walls and engaging the weight of an additional wedge of soil. For design purposes, the wedge of soil providing resistance on the extended mat foundation can be defined by including the soil within a 12-degree slope (measured from vertical) up and away from the bottom exterior edge of the extended footing to the ground surface. A saturated unit weight of 130 pcf may be used for the soil wedge if the buoyant force on the structure includes the weight of water displaced by the soil wedge. If the buoyant force on the structure does not include the weight of water displaced by the soil wedge, i.e. only the volume of water that is displaced by the structure itself, then a soil unit weight of 70 pcf should be used.

Corrosion Potential 5.4The standard “10-point” soil evaluation procedure (DIRPA, 2012) was followed to determine the corrosion potential of soils excavated from three of the test pits. The evaluation is based on selected soil’s resistivity, pH, oxidation-reduction (redox), sulfide content, and moisture. Samples from TP-1, TP-2, and TP-4B were evaluated, and the “point” totals for each were 6.5, 5.5, and 3, respectively. An environment evaluated at “10-points” or higher indicates a high



corrosive potential. Specific testing results used in evaluating selected test pits for corrosivity are included in Table III.

Soluble Sulfates 5.5As presented in Appendix B, three soluble sulfate tests were conducted on samples of excavated material from three of the test pits. Testing indicated the soluble sulfate content of excavated soil ranged from 120 parts per million (ppm) to 360 ppm. According to the Portland Cement Association (PCA), soluble sulfate content below 1000 ppm indicates a negligible risk of attack on concrete from surrounding soils.

Particle Size Analysis for Scour 5.6As presented in Appendix B, Brierley recommends the following D50 values for use in designing for scour potential at each crossing location:

Particle Size Test Pit ID Crossing ID D50 Design Value (mm)

TP-1 36.2 25 TP-2 & TP-3 36.3 2.2 TP-4a & TP-4b 20.2 17

D50 values presented in the previous table include estimates of larger particles (boulders and cobbles) scalped in the field by Brierley. Particles larger than 3 inches in diameter were hand removed from bulk-sampled, excavated material. Field estimates of specific particle sizes 3 inches and coarser were recorded during excavations. Due to the relatively coarse nature of the subsurface, and the large variation in particle size distribution, Brierley judged scalping a reasonable way to estimate the coarser material fraction at each test pit location. Material finer than 3 inches was sampled in bulk and tested for particle size by Martinez Associates. Therefore, laboratory gradation results are based solely on material smaller than 3 inches in diameter. Field estimated particle sizes for material coarser than 3 inches were combined with standard particle size curves provided by Martinez Associates. The estimated particle sizes provided a realistic estimate for D50 values for estimating scour.

Permanent Bank Slopes 5.7

Based on the attached lab testing and soils encountered during our subsurface investigation, Brierley recommends maximum permanent bank slopes in all locations of 3H:1V (Horizontal: Vertical). Based on our field investigation and laboratory testing program, 3H:1V slopes will be stable in empty, partially filled, or full river scenarios. Geotechnical stability does not account for dynamic river forces such as erosion, and only considers a static, steady-state, two-dimensional scenario. 6 CONSTRUCTION PROCEDURES AND RECOMMENDATIONS Variations in subsurface conditions may be encountered during construction, specifically in locations where only one side of a crossing was investigated (Crossings 36.2 and 20.2). In order to correlate design concepts with actual subsurface conditions encountered during construction, Brierley should be retained to provide monitoring and geotechnical engineering services during construction and to assist in developing design changes in the event that



subsurface conditions differ from those outlined in this report. Monitoring should include a comparison of the subsurface conditions revealed during excavation to the anticipated conditions presented herein. Brierley shall be made aware of any significant material and subsurface layer changes during excavations and construction, as the recommendations and design parameters presented herein may alter based on materials encountered. The following sub-sections of this report include comments on items related to excavation, foundation construction, earthwork, and related geotechnical engineering aspects of the proposed construction. This section is intended for use primarily by the Engineer responsible for preparation of plans and specifications. This section also addresses construction issues related to foundations and earthwork and will aid personnel who monitor construction activity. Brierley recommends the Contractor evaluate the proposed construction on the basis of their own knowledge and experience and on the basis of similar projects in other localities, taking into account their own proposed construction methods and procedures. Brierley should be notified if the Contractor has any objections or concerns to our recommendations presented in this report.

Temporary Excavations 6.1It is the Contractor’s responsibility to be fully aware of and become familiar with applicable local, state, and federal safety regulations, including the current Occupational Safety and Health Administration (OSHA) Excavation and Trench Safety Standards. Construction site safety is the sole responsibility of the Contractor who shall also be solely responsible for the means, methods, and sequencing of construction operations. Brierley is providing this information solely as a service to the Equity Ventures. Under no circumstances should the information provided below be interpreted to mean that Brierley is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred. The Contractor should be aware that slope height, slope inclination, or excavation depths should in no case exceed those specified in local, state, or federal safety regulations (e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or successor regulations). Such regulations are strictly enforced, and if they are not followed, the Contractor and its subcontractors could be liable for substantial penalties. For this site, subsurface conditions encountered within the proposed excavation zones include predominantly sandy and clayey soils, and sandstone bedrock. Generally, bedrock is considered to be Type A material, clayey soils are considered to be Type B soils, sandy soils are considered Type C soils when applying the OSHA regulations. OSHA recommends a maximum slope incline of ¾:1 (horizontal:vertical) for Type A material, 1:1 for Type B soils and 1.5:1 for Type C soils. The soils and bedrock to be penetrated by the proposed excavations may vary across the site. Brierley’s preliminary soil classifications are based solely on the materials encountered in the exploratory borings. The Contractor’s qualified person or Brierley’s onsite geotechnical representative should continually classify the soils and bedrock that are encountered as excavations progress with respect to OSHA requirements.



Based on the subsurface investigation, excavations extending up to 12 ft deep are anticipated during the construction. As specified by OSHA, for excavations exceeding 20 ft, temporary slopes must be designed by a professional engineer. The Contractor or the Contractor's specialty subcontractor should be made responsible in the specifications for the design of the temporary slopes in accordance with applicable regulatory requirements. Temporary excavations should not be confused with and are not applicable for permanent bank slopes, discussed in Section 5.7.

Site Grading and Earthwork 6.2Appropriate site preparation, backfill selection, and material placement and compaction will reduce potential issues related to lateral earth pressures, differential movements, and surface drainage. 6.2.1 Site Preparation All areas that will support vault foundation elements and fills should be properly prepared as described in this section. After rough grade has been established and prior to placement of fill in fill areas, the exposed subgrade should be observed by a representative of our firm and tested as judged necessary during construction. The exposed foundation subgrade should be evaluated to check for soft or yielding material where space permits. Any unsuitable materials encountered should be removed. It is expected that bedrock will be exposed at each crossing location, due to the proposed pipeline protection method of encasing the waterlines within bedrock. If bedrock is not exposed, subgrade materials should be scarified, and moistened or dried if necessary, to a minimum depth of 12 inches. Scarified material should then be compacted as outlined below. 6.2.2 Import Fill and Structural Backfill Material The proposed excavations can be backfilled with inorganic, non-plastic onsite material. Although appropriate fill can include onsite material excavated during the construction process, imported engineered fill, or a combination of the onsite and imported material can be selected at the Contractor’s discretion. Onsite material utilized as fill should contain less than 25 percent fines with a liquid limit less than 15 percent. The fill composition should be submitted to Brierley and confirmed prior use. Fill material should contain a maximum particle size of 6-inches, although the lift immediately above the proposed encased pipe should not include particles larger than 3-inches. Given the coarse nature of the onsite materials, some screening and processing may be required. If onsite fill does not meet the criteria stated, an additional source of borrow material will be necessary to complete construction. 6.2.3 Backfill Material Placement Onsite soils are acceptable for use as bearing materials. Excavated fill is also suitable for engineered backfill, as discussed in Section 6.2.2. Artificial debris and other deleterious material in the fill should not be used. Any particles or debris larger than 6-inches exposed during excavations should be removed and not placed in fill or backfill areas. Any areas of fill under foundations, adjacent to subsurface walls, and backfill for excavations should be placed in maximum 8-inch loose lifts and compacted according to the specifications outlined below. In areas where bedrock is not exposed during excavation, a minimum 12 inches



of material should scarified and appropriately compacted below the proposed bearing surfaces. Only lightweight compaction equipment (hand held or walk-behind) should be operated immediately adjacent to subsurface walls and immediately on top of the encased waterlines. 6.2.4 Backfill Compaction Specifications Minimum recommended compaction specifications are presented in the table, below. In addition to adequate density, appropriate water contents should be maintained throughout the earthwork compaction process to help facilitate an appropriate level of compaction and efficiency. Backfill materials should be tested in the laboratory for their specific moisture-density relationships prior to backfilling. The onsite Geotechnical Engineer is responsible for determining similarity of materials to laboratory tested materials and facilitate the need for additional onsite and laboratory testing during construction.

Material Exhibiting a Well-Defined Moisture-Density Relationship

Material Not Exhibiting a Well-Defined Moisture-

Density Relationship

Fill Type

Minimum % of Standard Proctor

(ASTM D 698) Maximum Dry Density

Moisture Content Relative to Optimum Moisture

Content Minimum Relative Density (ASTM D 4253 and D 4254) Cohesive

Soils Granular

Soils Recompacted in situ soils or engineered fill behind walls and under foundations 95% -1 to +3% -2 to +2% 65%

Recompacted in situ soils or engineered fill in excavated trenches 95% -2 to +3% -3 to +3% 65%

Field density tests should be performed on each lift as necessary to verify adequate compaction. The amount of field density tests required for each lift should be agreed upon by the Contractor and Brierley in order to assure adequate compaction. Mechanical compaction is required for all types of backfill under foundation elements, adjacent to foundation walls, or within excavated trenches. Compaction of any material by flooding or any method involving large quantities of water is not considered acceptable. This method will generally not achieve the desired compaction and the large quantities of water will tend to soften and/or cause swelling of the subgrade soils.

Crossing Excavations 6.3River crossings excavations should be observed by a representative of Brierley to verify that the proposed waterlines are embedded in competent bedrock and highly weathered, loose, unsuitable materials do not exist. The necessary depth of penetration will be established during site observations. If soft or loose soils or undesirable materials are encountered during excavations, the proposed excavation base may be re-established by backfilling after the material has been removed. Backfilling may be done with a well-compacted, suitable, structural fill as approved in writing by our firm. Backfill should be placed and compacted according to specifications outlined in this report.

Dewatering During Construction 6.4Groundwater was encountered during subsurface investigation test pit excavations. Groundwater depths ranged from 5 to 11 ft bgs. Groundwater will be encountered during construction in the river and at the depths found in our test pits or possibly shallower depth



depending on the time of construction. Temporary construction dewatering and rerouting the river around construction areas will be required to construct the proposed waterline crossings. Construction dewatering must adhere the Colorado Department of Public Health and Environment (CDHE) regulations. Brierley is available to assist with design of coffer dams and temporary dewatering systems. 7 REVIEW AND CONSTRUCTION OBSERVATIONS Variations in subsurface conditions may be encountered during construction at the site. To permit correlation between the investigation data and the conditions encountered during construction, and to provide conformance with the plans and specifications as originally contemplated, Brierley should provide observations of construction operations and excavations and to direct quality control testing of fill and backfill placement and compaction. 8 LIMITATIONS Boundaries between soil and bedrock types presented in our Test Pit Reports are approximate and transitions between material types may be gradual or more abrupt. Our Test Pit Reports and related information depict subsurface conditions only at the test pit locations and at the time of our subsurface investigation. Lateral variations in subsurface conditions not identified during our subsurface investigation may occur. Subsurface conditions, especially degree of weathering, soil and bedrock consistencies, and groundwater levels may change with time. This report has been prepared for CH2M Hill for specific application of the replacing waterline crossings under the Big Thompson River for the City of Loveland as understood by Brierley at this time, in accordance with generally accepted geotechnical engineering and engineering geologic practices common to the local area. No other warranty, express or implied, is made. In the event that changes in the nature, design or location of the planned project are made, the conclusions and recommendations presented in this report should not be considered valid, unless the changes are reviewed by Brierley, and the recommendations presented in this report are revised or verified in writing. Our analyses and recommendations are based, in part, upon the data obtained from our subsurface investigation and our experience with similar projects and subsurface conditions. The nature and extent of variations between test pits may not be evident until excavation and/or construction. If differing conditions from those anticipated based on our subsurface investigation(s) are encountered, Brierley should be notified immediately to determine if changes to our recommendations presented herein are warranted. Brierley’s recommendations presented in this report are for the proposed construction as understood by us at the time of issuing this report. Test pits performed at the locations of the planned construction are intended for informational use only. The scope of Brierley Associates services does not include an environmental assessment and does not provide an evaluation of the presence or absence of hazardous or toxic materials in the soil, bedrock, groundwater, or surface water within or beyond the project boundaries. Any statements in this report or on the test pit reports regarding odors or other unusual conditions observed are strictly for the information of our client. If not already conducted, Brierley



recommends an environmental assessment of the site be conducted by a qualified professional prior to initiation of any excavation and/or construction at the site.


September 12, 2014

FIGURES


September 12, 2014

TABLES

PROJECT NAME: Loveland River Crossings Replacement ProjectPROJECT NUMBER: 514110-000

Test Pit No.Depth (feet)

Gravel (%) Sand (%)Fines

Content (%)

LL (%) PI (%)

TP-1 0-7 61.7 27.8 10.5 NP1 NV2 GP-GMPoorly-graded Gravel with Silt and Sand

TP-2 0-10 38.9 51.3 9.8 NP1 NV2 SP-SMPoorly-graded Sand with Silt and Gravel

TP-4B 0-13 67.7 26.4 5.9 NP1 NV2 GW-GMWell-graded Gravel with Silt and Sand

1NP: Nonplastic2NV: No Value

Table ISummary of Geotechnical Laboratory Testing Results

SAMPLE LOCATION ATTERBERG LIMITS

USCS SOIL OR ROCK DESCRIPTION

GRAIN SIZE DISTRIBUTION

Table II, Page 1 of 2

PROJECT NAME: Loveland River Crossings Replacement ProjectPROJECT NUMBER: 514110-000 DATE(S): August 5 - 6, 2014

Test Pit No.

Test No. Location Ground Cover

Pin Spacing, a (ft)

Dial Value Multiplier

Resistance, R (Ω)

Resistivity,1,2

ρ (Ω/cm) Notes

136.2, Northeast side of Big Thompson River, near TP-1, parallel and on top of pipe alignment

Silty sand with gravel and cobbles. Very sparse vegetation at testing location

12 2.7 1 2.7 6,205Water pipe only known underground utility

236.2, Northeast side of Big Thompson River, near TP-1, parallel and 5 ft north of pipe alignment

As above 12 3.8 1 3.8 8,732 As above

336.2, Northeast side of Big Thompson River, near TP-1, perpendicular and crossing pipe alignment, 20 feet from endpoint measured along alignment to river

As above 12 3.3 1 3.3 7,583 As above


As above 6 1.0 10 10 11,490 As above


As above 6 9.7 1 9.7 11,145Water pipe only known underground utility (same location as previous)

636.2, Northeast side of Big Thompson River, near TP-1, parallel and on top of pipe alignment, 15 feet from endpoint measured along alignment to river

As above 6 6.1 1 6.1 7,009 As above

736.2, Northeast side of Big Thompson River, near TP-1, parallel and 3 feet west of pipe alignment, 15 feet from endpoint measured along alignment to river


836.2, Northeast side of Big Thompson River, near TP-1, perpendicular and crossing pipe alignment, 20 ft feet from endpoint measured along alignment to river

As above 3 1.1 10 11 6,320 As above

936.3, Southeast side of Big Thompson River, near TP-2, parallel to alignment; offset 5 ft north

Silty sand with cobbles. Little to some vegetation cover at testing location.


1036.3, Southeast side of Big Thompson River, near TP-2, perpendicular to alignment; offset 5 ft north

As above 11 4.5 1 4.5 9,479 As above

1136.3, Southeast side of Big Thompson River, near TP-2, parallel to alignment; no offset

As above 10 3.9 1 3.9 7,469 As above

TP-1

TP-2

Table IIResistivity Meter Field Observations and Calculations

Table II, Page 2 of 2

Test Pit No.

Test No. Location Ground Cover

Pin Spacing, a (ft)

Dial Value Multiplier

Resistance, R (Ω)

Resistivity,1,2

ρ (Ω/cm) Notes

1236.3, Northwest side of Big Thompson River, near TP-3, parallel to alignment; offset 10 ft north

Silty clay with cobbles. Varying (50 - 100%) vegetation cover at testing location.


1336.3, Northwest side of Big Thompson River, near TP-3, perpendicular to alignment


1436.3, Northwest side of Big Thompson River, near TP-3, 45⁰ to alignment; offset 10 ft north (SW corner to NE corner)


1536.3, Northwest side of Big Thompson River, near TP-3, on top of alignment and backfill

As above 8 1.1 10 11 16,852 As above

1620.2, West side of Big Thompson River, parallel to alignment, near TP-4A and 4B, offset 8 ft north of alignment

Sand with gravel, little (>25% vegetation) within testing location. Heavier vegetation outside of testing area.





As above 10 4.8 1 4.8 9,192 As above



2020.2, West side of Big Thompson River, perpendicular to alignment, near TP-4A and 4B, east side of probes crossed tangent to alignment

As above 12 2.4 1 2.4 5,515 As above





1ASTM G 57 - 95a (2001)2 ρ = 191.5aR

TP-3

TP-4A & 4B

PROJECT NAME: Loveland River Crossings Replacement ProjectPROJECT NUMBER: 514110-000

Test Pit No.Depth (feet)

pH (units)

Point Value Assigned2

Redox Potential

(mv)

Point Value Assigned2 Sulfides

Point Value Assigned2

Resistivity (Saturated) (ohm.cm)

Point Value Assigned2 Moisture43 Point Value

Assigned2

TP-1 0-10 0.0008 0.036 7.4 0 106 0 Positive 3.5 2,967 1 Wet 2 6.5

TP-2 0-10 0.0026 0.014 7.6 0 85 3.5 Negative 0 4,016 0 Wet 2 5.5

TP-4B 0-13 0.0006 0.012 7.6 0 127 0 Negative 0 3,906 0 Wet 2 2

2Value assigned as per ANSI/AWWA C105/A21.5 Standard3Moisture: Poor drainage, continuously wet due to waterlines being below water table.4Totals of Values Assigned1 for each of the five (5) 10-point corrosive potential categories, DIPRA 2012

Resistivity Moisture

1Soluble sulfate content less than 0.10 percent by mass in soil indicates a negligible risk of aatach on contacted concrete, PCA IS536.01

5"If the sum is 10 or more, the soil is considered corrosive to Ductile Iron pipe, and protective measures should be taken."

Table IIISummary of Corrosion Test Results and DIPRA 10-Point Corrosion Rating

DIPRA Totals4,5

Sulfates - Water

Soluble1 (%)

SAMPLE LOCATIONChloride

(%)

pH Redox Potential Sulfides


September 12, 2014

APPENDIX A Test Pit Key

& Test Pit Reports

0

2.5

5

7.5

10

12.5

15

Loose, red to red-brown to red-yellow, well-graded silty GRAVEL withsand (GM), little medium to coarse sand, little cobble, mps: 24 in.,subrounded to rounded, organic decay odor

As above, medium dense to dense (1 - 2 ft)

-COARSE ALLUVIUM-

2 ft.Medium dense to dense, red, red-brown, red-yellow, well-graded GRAVELwith silt and sand (GW-GM), fine to coarse gravel, little cobbles, fewboulders, subangular, mps: 24 in., organic odor, wet, nested gravel andcobbles

-COARSE ALLUVIUM-

As above, gravel increasing with depth

Artesian groundwater condition on top of bedrock

5 ft.Soft to very soft, red-yellow, fine-grained, SANDSTONE BEDROCK (BR),upper 6 - 12" highly weathered, below 12" unweathered, blocky

-LYKINS FORMATION-

7 ft.End of Exploration

61.7 27.8 10.5 NV NP

TEST PIT REPORT Test Pit No. TP-1

Project: File No. 514110-00

Start: 8/05/2014Client:

Finish:Excavating Contractor: Excavator:

Contractor Equipment and Procedures BA Rep.:

Elevation: None

Excavator Make & Model: CAT 316ELDatum:

Location:36.2, North side of Big Thompson River near 36 in alignment

Water Level Data Notes

WaterLevel

Datemm/dd/yy

TimeElapsed

TimeBottomof Hole

Depth toWater

08/05/14 5 ft

Maximum particle size is determined by direct observation within the limitations of the sampler.Boring No: TP-1

NOTE: Soil and rock identification based on visual-manual methods of the USCS as practiced by Brierley Associates.

Depth

(ft.)

Ele

vation (

ft.)

Wate

r Level

Str

atigra

phy

Soil: Density/consistency, color, GROUP NAME, max. particle size,structure, odor, moisture,optional descriptions, geologic interpretation

Rock: Hardness, weathering, color, LITHOLOGY, texture,joint spacing, drilling rate (min./ft.)

Visual-Manual Identification and Description

M

ois

ture

(%

)

G

ravel (%

)

S

and (

%)

F

ines (

%)

LL (

%)

P

I (%

)

U

CS

(ksf)

S

well/

Colla

pse (

%)

S

well

Pre

ssure

(ksf)

Sheet No. 1 of 1

8/05/2014

ShawnNathan

Loveland River Crossings Replacement Project CH2M Hill

City of Loveland

0

2.5

5

7.5

10

12.5

15

Loose to medium dense, red-brown, silty SAND (SM), mostly coarse sand,some medium to fine sand, little boulders, some cobbles, some gravel,mps: 3 - 4 ft. rounded, no odor, dry

-COARSE ALLUVIUM-

As above, increasing moisture

Medium dense, dark brown to brown to red-brown, silty SAND with gravel(SM), fine to medium sand, fine to coarse gravel, little boulders, littlecobbles, mps: 3 - 4 ft., boulders more angular, no aparent odor, moist towet near bottom of layer

As above, gravel content increasing with depth

10 ft.Medium to hard, red-orange to light brown, slight to moderatelyweathered, fine to medium grained, SANDSTONE BEDROCK (BR)

-DAKOTA GROUP, SOUTH PLATTE FORMATION-10.5 ft.

End of Exploration

38.9 51.3 9.8 NV NP






Elevation: None


Location:36.3, Southeast side of Big Thompson River near 36 in alignment


WaterLevel

Datemm/dd/yy

TimeElapsed

TimeBottomof Hole

Depth toWater

Test pit was performed in same locationas pothole.

8/05/14 9 ft



Depth

(ft.)

Ele

vation (

ft.)

Wate

r Level

Str

atigra

phy




M

ois

ture

(%

)

G

ravel (%

)

S

and (

%)

F

ines (

%)

LL (

%)

P

I (%

)

U

CS

(ksf)

S

well/

Colla

pse (

%)

S

well

Pre

ssure

(ksf)

Sheet No. 1 of 1

8/05/2014

ShawnNathan


City of Loveland

0

2.5

5

7.5

10

12.5

15

Medium stiff, brown to dark brown, SILTY CLAY (CL- ML), trace gravel,trace boulders, mps: 2 ft., no apparent odor, moist to wet, organics (roots)present.

-FINE ALLUVIUM-

5 ft.Dense to very dense, red-yellow to yellow-brown, poorly-graded GRAVEL(GP), fine to coarse, few boulders, mps: 2 - 3 ft., rounded to sub-angular,no odor, wet

-COARSE ALLUVIUM-

7 ft.Medium-hard, red-orange to light brown, fine to medium grained,moderate weathering, SANDSTONE BEDROCK (BR)

-DAKOTA GROUP, LYTLE OR SOUTH PLATTE FORMATION-







Elevation: None


Location:36.3, Northwest of Big Thompson River, North of 36 in alignment


WaterLevel

Datemm/dd/yy

TimeElapsed

TimeBottomof Hole

Depth toWater

8/05/14 10 ft



Depth

(ft.)

Ele

vation (

ft.)

Wate

r Level

Str

atigra

phy




M

ois

ture

(%

)

G

ravel (%

)

S

and (

%)

F

ines (

%)

LL (

%)

P

I (%

)

U

CS

(ksf)

S

well/

Colla

pse (

%)

S

well

Pre

ssure

(ksf)

Sheet No. 1 of 1

8/05/2014

ShawnNathan


City of Loveland

0

2.5

5

7.5

10

12.5

15

Loose to very loose, tan to yellow-brown, poorly-graded SAND with gravel(SP), little cobbles, few boulders, mps: 12", gravel rounded, cobbles andboulders semi-angular, no odor, dry

-COARSE ALLUVIUM-

As above, moist

Dense, brown to red-brown, poorly-graded SAND with gravel (SP), somefine to coarse gravel, little cobbles, few boulders, mps: 6 in., gravelrounded, cobbles and boulders sub-angular, no odor, moist

As above, increasing gravel, cobble, and boulder content

7 ft.Dense, brown to red-brown, poorly graded GRAVEL with sand (GP), fewcobbles, few boulders, mps: 14 in., rounded to semi-angular, moist towet

-COARSE ALLUVIUM-

10 ft.End of exploration: Bedrock not reached because of concern of damagingor disturbing cast-iron pipe.

TEST PIT REPORT Test Pit No. TP-4A





Elevation: None


Location:20.2, West side of Big Thompson River Northwest of 20 in alignment


WaterLevel

Datemm/dd/yy

TimeElapsed

TimeBottomof Hole

Depth toWater

None

Maximum particle size is determined by direct observation within the limitations of the sampler.Boring No: TP-4A


Depth

(ft.)

Ele

vation (

ft.)

Wate

r Level

Str

atigra

phy




M

ois

ture

(%

)

G

ravel (%

)

S

and (

%)

F

ines (

%)

LL (

%)

P

I (%

)

U

CS

(ksf)

S

well/

Colla

pse (

%)

S

well

Pre

ssure

(ksf)

Sheet No. 1 of 1

8/05/2014

ShawnNathan


City of Loveland

0

2.5

5

7.5

10

12.5

15

Very loose to loose, tan to yellow-brown, poorly-graded SAND with gravel(SP), little gravel, few cobbles, mps: 5 in., rounded, organic odor, dry

-COARSE ALLUVIUM-

As above, moist

5 ft.Dense, brown, poorly-graded GRAVEL with sand (GP), some fine tomedium sand, little cobbles, mps: 7 in., rounded to semi-angular, moist

-COARSE ALLUVIUM-Heavy root layer from 5 - 6 ft depth

Other foreign material present (concrete barriers and trash) at 9 - 10 ft

Large 3 - 4 ft. boulder at 10.5 ft

As above, except mps: 3 - 4 ft

12 ft.Hard, light brown to medium gray, slightly weathered, fine-grained,SANDSTONE BEDROCK (BR), extremely thin planar foliation

-NIOBRARA FORMATION-

Estimated to be top of bedrock. Excavator was near its depth limit forexcavation.


67.7 26.4 5.9 NV NP

TEST PIT REPORT Test Pit No. TP-4B





Elevation: None


Location:20.2, West side of Big Thompson River (apprx. 50 ft. west of west bank)


WaterLevel

Datemm/dd/yy

TimeElapsed

TimeBottomof Hole

Depth toWater

TP-4B separate from TP-4A pothole

8/06/14 11 ft

Maximum particle size is determined by direct observation within the limitations of the sampler.Boring No: TP-4B


Depth

(ft.)

Ele

vation (

ft.)

Wate

r Level

Str

atigra

phy




M

ois

ture

(%

)

G

ravel (%

)

S

and (

%)

F

ines (

%)

LL (

%)

P

I (%

)

U

CS

(ksf)

S

well/

Colla

pse (

%)

S

well

Pre

ssure

(ksf)

Sheet No. 1 of 1

8/05/2014

ShawnNathan


City of Loveland


September 12, 2014

APPENDIX B Laboratory Test Results

Tested By: J. Medina Checked By: K. Runner

USCS-poorly graded gravel with silt andsand

USCS-poorly graded sand with silt andgravel

USCS-well graded gravel with silt and sand

inches numbersize size

0.0 61.7 27.8 10.5 GP-GM A-1-a NP NV

0.0 38.9 51.3 9.8 SP-SM A-1-b NP NV

0.0 67.7 26.4 5.9 GW-GM A-1-a NP NV

3"2"

1-1/2"1"

3/4"1/2"3/8"

100.086.884.468.663.056.248.9

100.091.187.478.473.768.963.9

100.086.064.859.548.447.2

#4#8#16#30#50

#100#200

38.334.631.026.621.415.810.5

61.155.148.739.527.216.7

9.8

32.330.827.422.915.5

9.45.9

15.4715 3.8865 19.5122

1.0030 0.3500 1.9507

0.0769 0.1630

0.41 1.20

50.56 119.67

Location: TP-1 Depth: 0-7'

Location: TP-2 Depth: 0-10'

Location: TP-4B Depth: 0-13'

Breirley Associates, LLC. BA Project No. 514110-000

Loveland River Crossings Replacement Project

14-0066

+3" % GRAVEL % SAND % SILT % CLAY USCS AASHTO PL LL

SIEVE PERCENT FINER SIEVE PERCENT FINER Material Description

GRAIN SIZE REMARKS:

D60

D30

D10

COEFFICIENTS

Cc

Cu

Client:

Project:

Project No.: Figure

PE

RC

EN

T F

INE

R

0

10

20

30

40

50

60

70

80

90

100

GRAIN SIZE - mm.

0.0010.010.1110100

6 in.

3 in.

2 in.

1½

in.

1 in.

¾ in.

½ in.

3/8

in.

#4

#10

#20

#30

#40

#60

#100

#140

#200

Particle Size Distribution Report

Project: Loveland Waterline Big Thompson River CrossingsProject No.: 514110-000

12 in

.

3 in

.

#4

3/4

in.

#200

0

10

20

30

40

50

60

70

80

90

100

0.010.1110100100010000

PERC

ENT

FIN

ER

GRAIN SIZE - mm

Particle Size Distribution with Cobbles and Boulders

TP-1

TP-2

TP-4B

D50 Values

TP-1 (36.2): 26 mm TP-2 (36.3): 2.2 mm TP-4B (20.2): 17 mm

Cobbles Gravel Boulders Sand Silts and Clays

Note: Shaded values are estimated from field observations


September 12, 2014

APPENDIX C Soil Resistivity Testing

Records of Soil Resistivity Testing for Loveland River Crossings Replacement Project

1. Supplier name, contact information, and project number

Brierley Associates 2629 Redwing Road Suite 150 Fort Collins, CO 80526 Ph: 970.237.4988

Project No. 514110-000

2. Site locationLoveland, CO: Waterline Crossings, Big Thompsons River

3. Date of measurement or sample retrievalAugust 5 & 6, 2014

4. Test type; (i.e., in-situ or soil box)In-situ

5. Manufacturer and model number of the meter(s) usedNilsson Model 400 4-Pin Soil Resistance Meter

6. Ambient air temperature (°F or °C) on date of test or sample retrieval.82°F

7. Describe the weather conditions; i.e., snow, rain, ice, slush, arid, fog, humid, etc.Warm, mostly sunny with little cloud cover, 50% humid (during readings), little wind

8. Describe recent precipitation; i.e., 2" of rain yesterday, 6" of snow on the ground duringtesting, etc.

Up to 2 inches of precipitation was recorded at nearby weather stations five (5) days prior to first readings. 0.02 – 0.05 inches was recorded over the evening hours of August 5th at nearby weather stations (with 0.5 - 3 miles of tests)

9. Describe the difficulty of inserting the electrodes; i.e., easy, required some force, hard,drilled and filled with highly conductive slurry such as bentonite mud, saltwater infusedmud, etc.

Hand pressure to some force (few hammer taps) required

10. Describe the soil composition for each traverse; i.e., grassy, rocky, sandy, clayey, silty,spoils, etc.

See data table

11. Describe traverse terrain near or through obstacles such as equipment, foundations,structures, swales, roads, significant elevation changes, etc.

N/A

12. Electrode "a" spacing or soil sample depth (feet or meters) See data table

13. Electrode penetration depth (inches or millimeters) Approx. 4 inches

14. Current and potential test lead cable size 16 gauge

15. Electrode length, diameter, and material

18 inches long, 3/8 inch diameter, steel

16. Hand marked drawing of any relocated traverse N/A

17. Frost line depth (feet or meters) if working in frozen soil N/A

geotechnical engineering report...

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