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Geotechnical Engineering Services Snoqualmie Switch Station Snoqualmie, Washington for Puget Sound Energy March 25, 2013

Geotechnical Engineering Services

Snoqualmie Switch Station Snoqualmie, Washington

for Puget Sound Energy

March 25, 2013

Plaza 600 Building 600 Stewart Street, Suite 1700 Seattle, Washington 98101 206.728.2674

March 25, 2013 | Page i File No. 0186-679-10

Table of Contents

INTRODUCTION AND SCOPE ..................................................................................................................... 1

FIELD EXPLORATION AND LABORATORY TESTING .................................................................................. 1

Field Explorations ................................................................................................................................... 1

SITE CONDITIONS ....................................................................................................................................... 1

Sensitive Areas ....................................................................................................................................... 1 Geology ................................................................................................................................................... 2 Surface Conditions ................................................................................................................................. 2 Subsurface Conditions .......................................................................................................................... 2

CONCLUSIONS AND RECOMMENDATIONS .............................................................................................. 2

Seismic Design ....................................................................................................................................... 2 IBC Design Parameters ................................................................................................................... 2

Shallow Foundations and Mat Foundations ......................................................................................... 3 Allowable Soil Bearing Pressure ..................................................................................................... 3 Embedment ..................................................................................................................................... 3 Settlement ....................................................................................................................................... 3 Lateral Resistance .......................................................................................................................... 4 Construction Considerations .......................................................................................................... 4

Retaining Walls ...................................................................................................................................... 4 General ............................................................................................................................................ 4 Design Parameters.......................................................................................................................... 5 Wall Drainage .................................................................................................................................. 5 Global Stability Analyses ................................................................................................................. 5

Storm Drain Pipe .................................................................................................................................... 5 Slope Stability .................................................................................................................................. 5 Steep Slope Construction Recommendations .............................................................................. 6

Earthwork ............................................................................................................................................... 7 Excavation Considerations ............................................................................................................. 7 Clearing and Grubbing .................................................................................................................... 7 Subgrade Preparation ..................................................................................................................... 7 Erosion and Sedimentation Control ............................................................................................... 7 Structural Fill ................................................................................................................................... 8 Weather Considerations ................................................................................................................. 9 Temporary Slopes ......................................................................................................................... 10 Permanent Slopes ......................................................................................................................... 10

LIMITATIONS ........................................................................................................................................... 11

REFERENCES .......................................................................................................................................... 11

Page ii | March 25, 2013 | GeoEngineers, Inc. File No. 0186-679-10

Table of Contents (continued)

LIST OF FIGURES

Figure 1. Vicinity Map Figure 2. Site Plan Figure 3. Global Stability Analysis – Static and Seismic Conditions

APPENDICES

Appendix A. Field Explorations Figure A-1. Key to Exploration Logs Figures A-2 through A-8. Logs of Borings

Appendix B. Report Limitations and Guidelines for Use

SNOQUALMIE SWITCH STATION Snoqualmie, Washington

March 25, 2013 | Page 1 File No. 0186-679-10

INTRODUCTION AND SCOPE

This report summarizes the results of our geotechnical engineering services for the proposed improvements to the existing Puget Sound Energy (PSE) Snoqualmie Switch Station. The site is located east of Salish Lodge off Railroad Avenue in Snoqualmie, Washington. The site is shown in relation to the surrounding area on the Vicinity Map, Figure 1, and the Site Plan, Figure 2. We previously issued a draft of this report dated March 15, 2015; this report supersedes our previous report.

We understand that the proposed improvements include bringing in underground feeder lines from Snohomish County Public Utility District run-of-the-river hydroelectric projects at Hancock Creek and Calligan Creek. These underground feeders will enter from the north and tie into the existing PSE switch station using a new regulator, transformer, and breaker switch, which will be located at the east end of the existing station. The improvements will require expansion onto the steep slope to the east, including a new retaining wall that will be approximately 2 to 9 feet high. Due to space limitations, the retaining wall will likely be a reinforced concrete wall. The proposed improvements will include modifications to the existing storm drainage system, including a new catch basin behind the retaining wall and a new drain pipe extending south down the steep slope and connecting to an existing catch basin that discharges into the Snoqualmie River. The approximate locations of the proposed improvements are shown on the attached Site Plan, Figure 2.

Our geotechnical engineering services were completed in general accordance with our proposal dated February 12, 2013. Our scope of service includes:

■ Completing four borings and three hand-augered borings at the site;

■ Providing geotechnical conclusions and recommendations for the proposed improvements, and

■ Preparing this report.

FIELD EXPLORATION AND LABORATORY TESTING

Field Explorations

The subsurface conditions at the site were evaluated by completing four borings (B-1 through B-4) to depths ranging from 11½ to 14 feet below existing site grades, and three hand-augered borings (HA-1 through HA-3). The approximate locations of the explorations are shown on the Site Plan, Figure 2. A detailed description of the field exploration program is presented in Appendix A.

SITE CONDITIONS

Sensitive Areas

We reviewed the available sensitive areas maps published online by King County. The maps include identification of areas with significant landslide, seismic, erosion, and coal mine hazards. No geologic sensitive areas are mapped in the vicinity of the proposed switch station improvements; however, based on the slope inclination, the steep slope would be characterized as an erosion and steep slope hazard area.


Page 2 | March 25, 2013 | GeoEngineers, Inc. File No. 0186-679-10

Geology

Geologic information for the project area (Dragovich, Joe D., Littke, Heather A., Anderson, Megan L., et al., 2009) indicates that surficial soils mapped at the site consist of glaciolacustrine deposits and alluvium underlain by bedrock. Glaciolacustrine deposits generally consist of silt, clayey or sandy silt, and silty sand, typically with scattered dropstones and occasional layers and lenses of sand and/or gravel. Alluvium generally consists of well sorted/stratified sand and silt with lesser gravelly sand, sandy pebble gravel, peat, and organic sediments. The glaciolacustrine deposits or alluvium is underlain by bedrock (Volcanic rocks of Snoqualmie Falls - Miocene).

Surface Conditions

The site is bounded by Railroad Avenue to the north, Salish Lodge to the west, a paved surface parking lot to the east, and a construction access road to the south. The ground surface slopes down from the north where it is about Elevation 446 feet, to about Elevation 416 feet at the south margin of the site. The area of the proposed improvements is currently undeveloped and forested with deciduous and coniferous trees and brush.

Subsurface Conditions

Based on the explorations performed at the site, the subsurface conditions generally consist of topsoil and fill overlying glaciolacustrine deposits. We observed approximately 4 to 6 inches of topsoil in most of the explorations. The topsoil generally consists of forest duff and organic soil. Below the topsoil, we observed fill consisting of loose to medium dense silty sand/sandy silt with organics (fine roots, charcoal) and varying gravel content to a depth of approximately 3 to 7 feet. Below the fill, we observed glaciolacustrine deposits consisting of very stiff to hard silt with variable amounts of gravel. The glaciolacustrine deposits extended to the depths explored. Bedrock was not encountered in the explorations.

No groundwater was observed during drilling. These observations may or may not be representative of the long-term groundwater conditions at the site.

CONCLUSIONS AND RECOMMENDATIONS

Seismic Design

IBC Design Parameters

We recommend the 2012 International Building Code (IBC) parameters for Site Class, short period spectral response acceleration (SS), one-second period spectral response acceleration (S1) and Seismic Coefficients FA and FV presented in the following table.



2012 IBC SEISMIC PARAMETERS

2012 IBC Parameter Recommended Value

Site Class C

Short Period Spectral Response Acceleration, SS (percent g) 1.14

1-Second Period Spectral Response Acceleration, S1 (percent g) 0.43

Seismic Coefficient, FA 1.0

Seismic Coefficient, FV 1.37

We evaluated the site for seismic hazards including liquefaction, lateral spreading, fault rupture and earthquake-induced slope instability. Our evaluation indicates that the site does not have liquefiable soils present and therefore also has no risk of liquefaction-induced lateral spreading. In addition, the site has a low risk of fault rupture.

Shallow Foundations and Mat Foundations

Allowable Soil Bearing Pressure

The proposed switch station equipment may be supported on conventional shallow spread footings or mat foundations bearing either on the native soils or on properly compacted structural fill placed over the native soils. The mat foundations and spread footings, where required, may be designed using an allowable soil bearing pressure of 4,000 pounds per square foot (psf). The allowable soil bearing value applies to the total of dead and long-term live loads and may be increased by up to one-third when considering total loads including transient loads such as wind or seismic forces. A subgrade modulus of 200 pounds per cubic inch (pci) may be used for the design of mat foundations.

The retaining wall footing can be designed using the same parameters presented above, except we recommend the footing bear on undisturbed native soils or controlled density fill (CDF) placed over the native soils.

Embedment

In general, we recommend that the bottom of foundations be embedded at least 18 inches below the lowest adjacent grade for frost protection. The foundation embedment depth may be reduced to 12 inches for small, lightly loaded footings where frost action will not affect equipment performance, or an additional 6-inch-thick layer of gravel that is not susceptible to frost may be placed below the foundations to achieve an embedment of 18 inches. The retaining wall embedment is discussed separately in the “Retaining Walls” section.

Settlement

Provided all loose soil is removed and the subgrade is prepared and evaluated as recommended below in the “Construction Considerations” section, we estimate that the total settlement of shallow and mat foundations will be on the order of ½ to 1 inch. Differential settlements are expected to be less than ½ inch.



Lateral Resistance

Lateral foundation loads can be resisted by passive resistance on the sides of foundations and by friction on the base of the foundations. For foundations supported on native soils or on structural fill placed and compacted in accordance with our recommendations, the allowable frictional resistance can be computed using a coefficient of friction of 0.35 applied to vertical dead-load forces.

The allowable passive resistance can be computed using an equivalent fluid density of 300 pounds per cubic foot (pcf) (triangular distribution) if these elements are poured directly against compacted native soils or surrounded by structural fill. The structural fill should extend out from the face of the foundation element for a distance at least equal to three times the height of the element and be compacted to at least 95 percent of the maximum dry density (MDD) estimated in general accordance with American Society for Testing and Materials (ASTM) D 1557. For the retaining wall footing, due to the descending slope in front of the wall, passive resistance should be neglected.

The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of about 1.5.

Construction Considerations

If soft soil areas are present at the foundation bearing surface elevation, the soft soils in these areas must be removed and replaced with structural fill. In such instances, the zone of structural fill must extend laterally beyond the footing edges for a horizontal distance that is at least equal to the depth of overexcavation.

For the retaining wall footing, soft soil areas below the foundation subgrade elevation must be removed and replaced with CDF. The overexcavated areas must be neat-cut to limit the extent of the excavation and limit disturbance of the soils at the face of the retaining wall.

We recommend that a representative from our firm observe the condition of all footing excavations to evaluate whether the work is completed in accordance with our recommendations and whether the subsurface conditions are as anticipated.

Retaining Walls

General

The proposed improvements will require expansion onto the steep slope to the east, and the grade transition will be accomplished by using a reinforced concrete retaining wall up to 9 feet in height. Based on our explorations, we anticipate overexcavation will be required in some areas below the retaining wall footing. Loose soils must be overexcavated and backfilled with CDF, as discussed in the previous section. Retaining walls must be backfilled with a 12-inch wide zone of drainage aggregate, with weep pipes extending to the face of the wall.

The retaining wall must have a minimum of 24 inches of embedment at the face of the wall for wall heights up to 4 feet and a minimum of 36 inches of embedment at the face of the wall for wall heights greater than 4 feet.



Design Parameters

We recommend the retaining wall be designed using the parameters presented in the table below. The retaining wall foundations may be designed using the recommendations previously presented in the “Shallow Foundations and Mat Foundations” section. The parameters listed below assume drainage is provided as described in the “Wall Drainage” section below.

Soil Parameters Retained Soils

Unit Weight (pcf) 125

Friction Angle (degrees) 35

Seismic Coefficient, Kh 0.15

Active Earth Pressure (pcf) – triangular distribution 31H

Seismic Pressure (psf) – uniform distribution 6H

Wall Drainage

We recommend drainage for the retaining wall be provided by placing a 12-inch-wide zone of free-draining soil behind the wall (base course or yard course meet this requirement) and installing weepholes. Permanent drainage systems must intercept surface water runoff at the top and/or bottom of cut and fill slopes to prevent the surface water from flowing in an uncontrolled manner across the wall.

Global Stability Analyses

We performed slope stability analyses to evaluate the global static and seismic (pseudostatic) stability of the proposed retaining wall. For our analyses, we used the slope stability program Slope/W 2012. Soil strength parameters for the slope stability analysis were selected by reviewing the exploration logs and from our professional judgment based on the geologic origin of the soil units. A ground acceleration of 0.15g (where g is the gravitational constant) was used for seismic (pseudostatic) analysis. This ground acceleration corresponds to 50 percent of the effective IBC design ground acceleration, which is assumed equal to the design spectral response acceleration (SDS) divided by 2.5, per Section 1803.5.12 of the IBC, where SDS is determined in accordance with Section 1613.5.4 of the IBC.

Figure 3 presents the modeled soil strength parameters and slope geometry, along with the static and seismic factors of safety and resulting critical failure surface. The global factor of safety for the slopes is at least 1.5 for static conditions and at least 1.1 for seismic conditions. Based on our slope stability analyses and geotechnical evaluation, it is our opinion that the proposed retaining wall has adequate factors of safety for global stability.

Storm Drain Pipe

Slope Stability

Based on our field observations, subsurface explorations, and experience, it is our opinion that the steep slope is susceptible to surficial soil movement. It is our opinion that the upper weathered soil layer on the slope may move slowly downslope via raveling and soil creep. Instability of this nature is confined to the upper weathered or disturbed zone of soil, which typically has lower



strength than the underlying unweathered soil. This process is more significant on steeper slopes than on flatter slopes. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration, wet/dry and freeze/thaw cycles, and gravity. Erosion of the soils on the steep slope can be managed and effectively reduced through proper erosion control practices and surface restoration methods that are described in the “Earthwork” section of this report.

We recommend that the storm drain pipe be installed aboveground to limit potential impacts from slope movement. Recommendations for construction of the storm drain pipe in the steep slope area are presented below.

Steep Slope Construction Recommendations

The aboveground portion of the pipe should extend from an anchor point behind the retaining wall onto the face of the slope. The pipe should be butt-fuse welded into a continuous section of pipe, without joints.

Because the soils surrounding the pipe can experience movement, we recommend that the pipe be straight and oriented perpendicular to the contours on the face of the slope. This will reduce the loads that the soil movement could impose on the pipe, as compared with a pipe running cross-slope.

In addition, the pipe will likely experience some loss of support from surficial soil movement. Therefore, we recommend that the pipe be anchored securely at the top of the slope. We recommend against mid-slope anchorage of the pipe because any soil movement near the mid-slope anchors could cause distress to the pipe at the anchorage points. In our opinion, high density polyethylene (HDPE) pipe is appropriate for this project because the flexibility of the pipe will enable the pipe to withstand bending stresses if there is some loss of support.

The HDPE pipe should be anchored at the top of the slope with a structure designed to restrain the full weight of the pipe, plus the full weight and hydrodynamic loads of the designed stormwater contained within the pipe. We recommend that the anchorage be achieved by means of a structure of sufficient size or a structure plus a dead-man block of concrete. A manhole can be used for this structural anchorage, provided that the manhole has sufficient face area and the structural capacity to transmit the loads from the pipe into the ground. The pipe anchorage should be positioned behind the retaining wall. The anchor should be fully embedded in undisturbed dense native soil or structural fill. It may be possible to design the retaining wall as the anchorage, provided the retaining wall is properly designed for the increased lateral loads.

The capacity of the pipe anchorage can be evaluated using the parameters presented in the “Shallow Foundations and Mat Foundations” section. Lateral loads can be resisted by a combination of friction between the base of the anchor and the supporting soil, and by the passive lateral resistance of the soil at the face of the anchor.



Earthwork

Excavation Considerations

Topsoil, fill, and glaciolacustrine deposits were observed in the explorations. We anticipate that these soils can be excavated with conventional excavation equipment, such as trackhoes or dozers. Cobbles and boulders were encountered in the soils at the site, and the contractor should be prepared to remove them where necessary. Bedrock is anticipated to be present below the glaciolacustrine deposits, although explorations at the site did not extend to the bedrock.

Clearing and Grubbing

Trees, brush, and other vegetation, including topsoil with roots, should be stripped and removed from areas where structural fill will be placed. The stripped material should be placed in landscaping areas or transported off-site for disposal.

Subgrade Preparation

In areas where structural fill is to be placed, the upper 12 inches of existing subgrade soils must be evaluated prior to fill placement. This can be done by probing. Likewise, the bearing surface in the proposed foundation areas for structures and retaining walls must be evaluated after site grading is complete. Soft zones noted during probing must be overexcavated and replaced with compacted structural fill or CDF.

Erosion and Sedimentation Control

Potential sources or causes of erosion and sedimentation depend upon construction methods, slope length and gradient, amount of soil exposed and/or disturbed, soil type, construction sequencing and weather. The project impact on erosion-prone areas can be reduced by implementing an erosion and sedimentation control plan. The plan should be designed in accordance with applicable city and/or county standards. The plan should incorporate basic planning principles, including:

■ Scheduling grading and construction to reduce soil exposure;

■ Retaining existing vegetation whenever feasible;

■ Revegetating or mulching denuded areas;

■ Directing runoff away from denuded areas;

■ Minimizing the length and steepness of slopes with exposed soils;

■ Decreasing runoff velocities;

■ Confining sediment to the project site, and;

■ Inspecting and maintaining control measures frequently.

We recommend that graded and disturbed slopes be tracked in place with the equipment running perpendicular to the slope contours so that the track marks provide a texture to help resist erosion and channeling. Some sloughing and raveling of slopes with exposed or disturbed soil should be expected.



Temporary erosion protection must be used and maintained in areas with exposed or disturbed soils to help reduce the potential for erosion and reduce transport of sediment to adjacent areas. Temporary erosion protection must include the construction of a silt fence around the perimeter of the work area prior to the commencement of grading activities. Permanent erosion protection must be provided by reestablishing vegetation using hydroseeding and/or landscape planting.

Until the permanent erosion protection is established and the site is stabilized, site monitoring must be performed by qualified personnel to evaluate the effectiveness of the erosion control measures and repair and/or modify them as appropriate. Provisions for modifications to the erosion control system based on monitoring observations must be included in the erosion and sedimentation control plan.

Structural Fill

MATERIALS

Materials used to raise site grades, placed to support structures or pavements, or used for utility trench backfill are classified as structural fill for the purpose of this report. Structural fill material quality varies depending upon its use as described below:

■ On-site soils must not be used as structural fill to support switch station equipment. On-site soils may be considered for use as structural fill for other purposes during dry weather. On-site soils may also be used during wet weather provided that they can be moisture-conditioned to meet compaction specifications. If on-site soils cannot be moisture-conditioned, imported gravel borrow must conform to Puget Sound Energy Base Course Aggregate Specification 1275.1310 as described in the following table:

US Standard Sieve Size Percent Passing (by weight)

3 inches 100

¾ inch 70 - 90

⅜ inch 60 - 80

¼ inch 50 - 70

U.S. No. 40 < 30

U.S. No. 200 5 maximum

■ Structural fill placed as “yard course crushed aggregate” surfacing material must be angular

crushed rock conforming to Puget Sound Energy Specification 1275.1330 as described in the following table:

US Standard Sieve Size Percent Passing (by weight)

1½ inches 100

1 inch 60 to 100

¾ or ⅝ inch 0 to 35

⅜ inch 0 to 5



FILL PLACEMENT AND COMPACTION CRITERIA

Structural fill must be mechanically compacted to a firm, non-yielding condition. In general, structural fill must be placed in loose lifts not exceeding 8 to 10 inches in thickness. Each lift must be conditioned to the proper moisture content and compacted to the specified density before placing subsequent lifts. Structural fill must be compacted to the following criteria:

■ Structural fill placed below foundations and roadways or to establish yard grades must be compacted to at least 95 percent of the MDD estimated in general accordance with ASTM D 1557. Structural fill placed to form finished slopes must also be compacted to at least 95 percent of the MDD.

■ Structural fill (including utility trench backfill) placed outside of areas where foundations, roadways, parking and yard areas are to be located must be compacted to at least 90 percent of the MDD estimated in general accordance with ASTM D 1557.

We recommend that a representative from our firm be present during proof-rolling and/or probing of the exposed subgrade soils in structure areas prior to the placement of structural fill and also during the placement of structural fill. Our representative will evaluate the adequacy of the subgrade soils and identify areas needing further work, perform in-place moisture-density tests in the fill to evaluate whether the work is being done in accordance with the compaction specifications, and advise on any modifications to procedures that may be appropriate for the prevailing conditions.

Weather Considerations

The native soils contain a sufficient percentage of fines (silt) and are moisture-sensitive. When the moisture content of these soils is appreciably above the optimum moisture content, these soils become muddy and unstable, operation of equipment on these soils will be difficult and it will be difficult to meet the required compaction criteria. Additionally, disturbance of these near-surface soils should be expected if earthwork is completed during periods of wet weather.

The wet weather season in the Puget Sound region generally begins in October and continues through May; however, periods of wet weather can occur during any month of the year. The optimum earthwork period for these types of soils is typically June through September. If wet weather earthwork is unavoidable, we recommend that:

■ Stockpiles of on-site soils that will be used as structural fill during wet weather be covered with plastic sheeting to protect them from rain.

■ If on-site soils cannot be moisture-conditioned to meet compaction requirements during wet weather, imported gravel borrow must be used as discussed previously in the “Structural Fill” section of this report.

■ The ground surface in and around the work area be sloped so that surface water is directed away from the work area. The ground surface must be graded such that areas of ponded water do not develop. The contractor must take measures to prevent surface water from collecting in excavations and trenches. Measures must be implemented to remove surface water from the work area.



Temporary Slopes

The soils encountered at the site are classified as Type C soil in accordance with the provisions of Title 296-155 of the Washington Administrative Code (WAC), Part N, “Excavation, Trenching, and Shoring”. We recommend that temporary slopes in excess of 4 feet in height be inclined no steeper than 1H:1V. Flatter slopes may be necessary if localized sloughing occurs. For open cuts at the site, we recommend that:

■ No traffic, construction equipment, stockpiles or building supplies be allowed at the top of cut slopes within a distance of at least 5 feet from the top of the cut.

■ Exposed soil along the slope be protected from surface erosion using waterproof tarps or plastic sheeting.

■ Construction activities be scheduled so that the length of time that the temporary cut is left open is kept as short as possible.

■ Erosion control measures be implemented as appropriate such that runoff from the site is reduced to the extent practicable.

■ Surface water be diverted away from the excavation.

■ The general condition and stability of the slopes be visually assessed periodically by a geotechnical engineer.

Because the contractor has control of the construction operations, the contractor must be made responsible for the stability of all temporary slopes, as well as the safety of the excavations. All shoring and temporary slopes must conform to applicable local, state and federal safety regulations.

Permanent Slopes

We recommend that permanent cut and fill slopes be constructed no steeper than 2H:1V. To achieve uniform compaction, we recommend that fill slopes be overbuilt slightly and subsequently cut back to expose properly compacted fill. Fill placed on existing slopes that are steeper than 5H:1V must be properly keyed into the native soil slope surface. This can be done by constructing the fill in a series of 6- to 8-foot-wide horizontal benches cut into the slope. Bench surfaces must be thoroughly compacted prior to placing the fill soils.

To reduce erosion, newly constructed slopes must be planted or hydroseeded shortly after completion of grading. Until the vegetation is established, some sloughing and raveling of the slopes should be expected. This may require localized repairs and reseeding. Temporary covering, such as clear heavy plastic sheeting, jute fabric, loose straw or excelsior matting must be used to protect the slopes during periods of rainfall.



LIMITATIONS

We have prepared this report for the exclusive use of Puget Sound Energy and their authorized agents for the proposed Snoqualmie Switch Station Improvements in Snoqualmie, Washington.

Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood.

Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.

Please refer to Appendix B, Report Limitations and Guidelines for Use, for additional information pertaining to use of this report.

REFERENCES

International Code Council, “International Building Code.” 2012.

Dragovich, Joe D., Littke, Heather A., Anderson, Megan L., et al., 2009, Geologic map of the Snoqualmie 7.5-minute quadrangle, King County, Washington, Washington Division of Geology and Earth Resources Geologic Map GM-75.

King Country GIS database. URL: http://www.metrokc.gov/gis/mapportal/iMAP_main.htm.

United States Geological Survey, U.S. Seismic Design Maps, 2008 data, accessed on 3/12/13 at: http://geohazards.usgs.gov/designmaps/us/application.php.


Type Name of Services HereName of Project Here

forType Client Name Here

Type Date of Report Here

Three Forks ParkThree Forks ParkRiver View ParkRiver View Park

Borst LakeBorst Lake

Snoqualmie RiverSnoqualmie River

Meadowbrook SloughMeadowbrook Slough

Tokul CreekTokul Creek

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MM uu dd CC rr ee ee kk

CC oo aa ll CC rr ee ee kk

KKiimmbbaallll CCrreeeekk

SE 80Th St

SE Tokul Rd

Mill Pond Rd

SE Park St

SE 47Th St

Preston Snoqualmie Trl

396Th Dr SE

Falls Ave SE

SE 60Th St

396T

h Ave

SE

378T

h Ave

SE Silva

St

SE David Powell Rd

SE 53Rd St

384T

h Ave

SE

SE 49Th St

SE 86Th St

Fish Hatchery Rd

364T

h Ave

SE

372N

d Pl S

E

Stearns Rd

SE Cedar St

2Nd Ave NW

SE 70Th Dr

Railroad Pl SE

SE 47Th Pl

Alpha St

402Nd Ave SE

King St

SE 77Th St

SE 85Th St

372Nd Ave SE371St Ct SE

SE 82Nd St

SE 56Th St

376Th Ave SE

382N

d Ave

SE

SE Gravenstein Ct

365Th

Ave SE

358T

h Ave

SE

4Th St

SE 88Th St

Railroad Pl SE

SE 60Th St

UV202

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Vicinity Map

Figure 1

Snoqualmie Switch StationSnoqualmie, Washington

King

Snohomish

Kittitas

Kitsap

Pierce

SeattleBellevue

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UV167

2,000 2,0000

Feet

Data Sources: ESRI Data & Maps, Street Maps 2005

Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission.

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Notes1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in

showing features discussed in an attached document.GeoEngineers, Inc. cannot guarantee the accuracy and contentof electronic files. The master file is stored by GeoEngineers, Inc.and will serve as the official record of this communication.

Reference: CAD file "SK-056401.dwg" provided by PSE on 3-4-13.

B-1

HA-1

Legend

Figure 2


Site Plan

Not to Scale

SharePoint Working\Figure 3 Slope Stability Analyses.ppt HPD:tb2 03/08/13

Global Stability AnalysisStatic and Seismic Conditions


Figure 3

APPENDIX A Field Explorations


March 25, 2013 | Page A-1 File No. 0186-679-10

APPENDIX A FIELD EXPLORATIONS

Field Explorations

Subsurface conditions were explored at the site by completing four borings (B-1 through B-4), and three hand-augered borings (HA-1 through HA-3). The borings were completed by Geologic Drill Exploration Inc of Bellevue, Washington, on February 22, 2013. The locations of the explorations were estimated in the field by measuring distances from site features through taping and pacing. The approximate locations of the explorations are shown on the Site Plan, Figure 2. Exploration elevations were estimated based on a site plan (SK-056401.dwg) provided by Puget Sound Energy on March 4, 2013.

Borings

The borings were drilled using a hand-portable hollow-stem auger drill rig. The borings were continuously observed by a geotechnical engineer from our firm who examined and classified the soils encountered, collected soil samples, observed groundwater conditions and prepared a detailed log of each boring. The soils encountered in the borings were sampled with a 2-inch outside diameter split-barrel standard penetration test (SPT) sampler or with a 3-inch diameter Shelby tube sampler. The SPT samples were obtained by driving the sampler 18 inches into the soil with a 140-pound hammer free-falling 30 inches. The number of blows required for each 6 inches of penetration was recorded. The blow count ("N-value") of the soil was calculated as the number of blows required for the final 12 inches of penetration. This resistance, or N-value, provides a measure of the relative density of granular soils and the relative consistency of cohesive soils. Where very dense soil conditions precluded driving the full 18 inches, the penetration resistance for the partial penetration was entered on the log. The blow counts are shown on the boring logs at the respective sample depths. The Shelby tube sampler was pushed into the soft peat to collect relatively undisturbed samples for laboratory consolidation testing.

Soils encountered in the borings were visually classified in general accordance with the classification system described in Figure A-1. A key to the exploration log symbols is also presented in Figure A-1. The logs of the borings are presented in Figures A-2 through A-4. The logs reflect our interpretation of the field conditions and the results of laboratory testing and evaluation of samples. They also indicate the depths at which the soil types or their characteristics change, although the change might actually be gradual.

The borings were backfilled in accordance with Department of Ecology standards. No groundwater was observed during drilling. These observations may or may not be representative of the long-term groundwater conditions at the site.

Hand-Augered Borings

Hand-augered borings were completed using hand tools. The hand-augered borings were completed by GeoEngineers, Inc on February 22, 2013 and were continuously monitored by a representative from our firm who examined and classified the soils encountered, obtained representative soil samples, observed groundwater conditions and prepared a detailed log of each exploration.


Page A-2 | March 25, 2013 | GeoEngineers, Inc. File No. 0186-679-10

Soils encountered in the hand-augered borings were visually classified in general accordance with the classification system described in Figure A-1. A key to the hand-augered boring log symbols is also presented in Figure A-1. The logs of the borings are presented in Figures A-5 through A-7. The hand-augered boring logs are based on our interpretation of the field data, and indicate the various types of soils encountered.

No groundwater was observed during excavation of the hand-augered borings. These observations may or may not be representative of the long-term groundwater conditions at the site.

Sheen Classification

NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurfaceconditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they arenot warranted to be representative of subsurface conditions at other locations or times.

CC

Asphalt Concrete

NSSSMSHSNT

Shelby tube

ADDITIONAL MATERIAL SYMBOLS

%FALCACPCSDSHAMCMDOCPMPIPPPPMSATXUCVS

Graphic Log Contact

Distinct contact between soil strata orgeologic units

Approximate location of soil stratachange within a geologic soil unit

Approximate location of soil stratachange within a geologic soil unit

Measured groundwater level inexploration, well, or piezometer

Measured free product in well orpiezometer

GRAPH

Topsoil/Forest Duff/Sod

Direct-Push

Crushed Rock/Quarry Spalls

Blowcount is recorded for driven samplers as the numberof blows required to advance sampler 12 inches (ordistance noted). See exploration log for hammer weightand drop.

A "P" indicates sampler pushed using the weight of thedrill rig.

FIGURE A-1

2.4-inch I.D. split barrel

SYMBOLS TYPICAL

KEY TO EXPLORATION LOGS

CR

Bulk or grab

Piston

Standard Penetration Test (SPT)

DESCRIPTIONSLETTER

Distinct contact between soil strata orgeologic units

TSGC

PT

OH

CH

MH

OL

GM

GP

GW

DESCRIPTIONSTYPICAL

LETTER

(APPRECIABLE AMOUNTOF FINES)

MAJOR DIVISIONS

POORLY-GRADED SANDS,GRAVELLY SAND

PEAT, HUMUS, SWAMP SOILSWITH HIGH ORGANICCONTENTS

CLEAN SANDS

GRAVELS WITHFINES

CLEANGRAVELS

HIGHLY ORGANIC SOILS

SILTSAND

CLAYS

SILTSAND

CLAYS

SANDAND

SANDYSOILS

GRAVELAND

GRAVELLYSOILS

(LITTLE OR NO FINES)

FINEGRAINED

SOILS

COARSEGRAINED

SOILS

SW

MORE THAN 50%OF COARSEFRACTION

RETAINED ON NO.4 SIEVE

CL

WELL-GRADED SANDS,GRAVELLY SANDS

SILTY GRAVELS, GRAVEL - SAND- SILT MIXTURES

LIQUID LIMITGREATER THAN 50

SILTY SANDS, SAND - SILTMIXTURES

(APPRECIABLE AMOUNTOF FINES)

SOIL CLASSIFICATION CHART

LIQUID LIMITLESS THAN 50

SANDS WITHFINES

SP(LITTLE OR NO FINES)

ML

SC

SM

NOTE: Multiple symbols are used to indicate borderline or dual soil classifications

MORE THAN 50%OF COARSEFRACTION

PASSING NO. 4SIEVE

CLAYEY GRAVELS, GRAVEL -SAND - CLAY MIXTURES

CLAYEY SANDS, SAND - CLAYMIXTURES

INORGANIC SILTS, ROCKFLOUR, CLAYEY SILTS WITHSLIGHT PLASTICITY

ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOWPLASTICITY

INORGANIC SILTS, MICACEOUSOR DIATOMACEOUS SILTYSOILS

ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY

INORGANIC CLAYS OF HIGHPLASTICITY

MORE THAN 50%PASSING NO. 200

SIEVE

MORE THAN 50%RETAINED ON NO.

200 SIEVE

WELL-GRADED GRAVELS,GRAVEL - SAND MIXTURES

POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES

INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTYCLAYS, LEAN CLAYS

GRAPH

SYMBOLS

AC

Cement Concrete

Sampler Symbol Descriptions

Groundwater Contact

Material Description Contact

No Visible SheenSlight SheenModerate SheenHeavy SheenNot Tested

Laboratory / Field TestsPercent finesAtterberg limitsChemical analysisLaboratory compaction testConsolidation testDirect shearHydrometer analysisMoisture contentMoisture content and dry densityOrganic contentPermeability or hydraulic conductivityPlasticity indexPocket penetrometerParts per millionSieve analysisTriaxial compressionUnconfined compressionVane shear

1

2

3

4

5

6

12

16

16

16

12

20

60

65

Quarry spalls

Brown silty fine to medium sand with graveland organics (fine roots) (loose to mediumdense, moist to wet) (fill)

Grades to medium dense

Brownish-gray silt with trace sand and orangemottling (very stiff, moist)

Grades to hard

CR

SM

ML

3½ feet excavated by hand

Rough drilling

Easier drilling

TotalDepth (ft)

HammerData

SystemDatum

Start EndChecked ByLogged By

HPDDrilled

Notes:

ZAS

Surface Elevation (ft)Vertical Datum

Driller

GroundwaterDepth toWater (ft)Date Measured Elevation (ft)

Easting (X)Northing (Y)

Hand PortableAckerSoil Mechanic Drill

Geologic DrillExploration, Inc.

DrillingMethod

Hollow-stem Auger14

Rope & Cathead140 (lbs) / 30 (in) Drop

DrillingEquipment

2/22/20132/22/2013

Not encountered

446

Notes: See Figure A-1 for explanation of symbols.

FIELD DATA

Dep

th (

feet

)

0

5

10

Inte

rval

Ele

vatio

n (f

eet)

445

440

435

Sam

ple

Nam

eT

estin

g

Rec

over

ed (

in)

Gra

phic

Log

Co

llect

ed S

amp

le

Blo

ws/

foot

MATERIALDESCRIPTION

Gro

upC

lass

ifica

tion

Wat

er L

evel

Log of Boring B-1Snoqualmie Switch Station

Snoqualmie, Washington

0186-679-10

Project:

Project Location:

Project Number:Figure A-2Sheet 1 of 1S

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Dry

Den

sity

,(p

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1

2

3

4

10

12

16

14

25

52

50/5.5"

50/5"

Dark brown silty fine to medium sand with tracegravel and organics (fine roots) (loose tomedium dense, moist) (fill)

Brownish-gray silt with trace sand, occasionalgravel, and orange mottling (very stiff,moist)

Brownish-gray silt with trace sand and orangemottling (hard, moist)

Grades to moist to wet

SM

ML

ML

TotalDepth (ft)

HammerData

SystemDatum


HPDDrilled

Notes:

ZAS


Driller





DrillingMethod

Hollow-stem Auger11.5


DrillingEquipment

2/22/20132/22/2013

Not encountered

448


FIELD DATA

Dep

th (

feet

)

0

5

10

Inte

rval

Ele

vatio

n (f

eet)

445

440

Sam

ple

Nam

eT

estin

g

Rec

over

ed (

in)

Gra

phic

Log

Co

llect

ed S

amp

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Blo

ws/

foot

MATERIALDESCRIPTION

Gro

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ifica

tion

Wat

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0186-679-10

Project:

Project Location:


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Moi

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%

Dry

Den

sity

,(p

cf)

1

2

3

4

4

18

18

18

5

3

21

50/6"

GravelDark brown silty fine to coarse sand with gravel

and organics (fine roots) (loose, moist) (fill)

Brown/yellow silty fine to coarse sand withgravel and organics (fine roots andcharcoal) (very loose, moist)

Greenish-gray silt with trace sand and orangemottling (very stiff, moist)

Grayish-brown silt with trace sand (hard, moist)

CR

SM

SM

ML

ML

Gravels/cobbles

TotalDepth (ft)

HammerData

SystemDatum


HPDDrilled

Notes:

HPD


Driller





DrillingMethod



DrillingEquipment

2/22/20132/22/2013

Not encountered

450


FIELD DATA

Dep

th (

feet

)

0

5

10

Inte

rval

Ele

vatio

n (f

eet)

445

440

Sam

ple

Nam

eT

estin

g

Rec

over

ed (

in)

Gra

phic

Log

Co

llect

ed S

amp

le

Blo

ws/

foot

MATERIALDESCRIPTION

Gro

upC

lass

ifica

tion

Wat

er L

evel



0186-679-10

Project:

Project Location:


eattl

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ate:

3/18

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plat

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plat

e:G

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EN

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EE

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8.G

DT

/GE

I8_G

EO

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CH

_ST

AN

DA

RD

REMARKS

Moi

stur

eC

onte

nt,

%

Dry

Den

sity

,(p

cf)

1

2

3

4

10

16

18

18

15

45

52

58

6 inches topsoil

Dark brown silty fine to coarse sand with gravel(medium dense, moist) (fill)

Grayish-brown silt with trace sand (hard, moist)

Becomes moist to wet

With orange mottling

TS

SM

ML

Rough drilling

TotalDepth (ft)

HammerData

SystemDatum


HPDDrilled

Notes:

ZAS


Driller





DrillingMethod



DrillingEquipment

2/22/20132/22/2013

Not encountered

448


FIELD DATA

Dep

th (

feet

)

0

5

10

Inte

rval

Ele

vatio

n (f

eet)

445

440

Sam

ple

Nam

eT

estin

g

Rec

over

ed (

in)

Gra

phic

Log

Co

llect

ed S

amp

le

Blo

ws/

foot

MATERIALDESCRIPTION

Gro

upC

lass

ifica

tion

Wat

er L

evel



0186-679-10

Project:

Project Location:


eattl

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ate:

3/18

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Tem

plat

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8.G

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_ST

AN

DA

RD

REMARKS

Moi

stur

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onte

nt,

%

Dry

Den

sity

,(p

cf)

1

2

Dark brown silty fine to coarse sand with gravel and organics (fine roots)(loose to medium dense, moist to wet) (fill)

Increasing gravel content, becomes medium denseHand auger refusal at 1 foot due to gravelNo groundwater seepage observedNo caving observed

SM

Notes: See Figure A-1 for explanation of symbols.The depths on the hand auger logs are based on an average of measurements across the hand auger and should be considered accurate to 0.5 foot.

Sea

ttle:

Dat

e:3/

18/1

3 P

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S8.

GD

T/G

EI8

_TE

ST

PIT

_1P

_GE

OT

EC

Date Excavated:

Equipment:

Logged By:2/22/2013

Hand Auger Total Depth (ft)

ZAS

1.0

Tes

ting

Sam

ple

Dep

th (

feet

)

1

SAMPLE

Gra

phic

Log

Ele

vatio

n (f

eet)

437

Sam

ple

Nam

eT

estin

gMATERIAL

DESCRIPTION

Gro

upC

lass

ifica

tion

Enc

ount

ered

Wat

er

Moi

stur

eC

onte

nt,

% REMARKS

Log of Hand-Augered Boring HA-1Snoqualmie Switch Station


0186-679-10

Project:

Project Location:

Project Number:Figure A-6Sheet 1 of 1

1 Gray fine to coarse gravel with silt and sand (medium dense, moist)

Hand auger refusal at ½ footNo groundwater seepage observedSignificant caving observed

GP-GM


Sea

ttle:

Dat

e:3/

18/1

3 P

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GD

T/G

EI8

_TE

ST

PIT

_1P

_GE

OT

EC

Date Excavated:

Equipment:

Logged By:2/22/2013


ZAS

0.5

Tes

ting

Sam

ple

Dep

th (

feet

)

SAMPLE

Gra

phic

Log

Ele

vatio

n (f

eet)

Sam

ple

Nam

eT

estin

gMATERIAL

DESCRIPTION

Gro

upC

lass

ifica

tion

Enc

ount

ered

Wat

er

Moi

stur

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onte

nt,

% REMARKS



0186-679-10

Project:

Project Location:


1

2

3

4

6 inches topsoil

Dark brown silty fine to medium sand with organics (fine roots) (loose,moist) (fill)

Brownish-gray silt with sand and orange mottling (soft, moist)

Hand auger completed at 3 feetNo groundwater seepage observedNo caving observed

TS

SM

ML

Becomes denser, cobble at 3 feet


Sea

ttle:

Dat

e:3/

18/1

3 P

ath:

W:\R

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T/G

EI8

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ST

PIT

_1P

_GE

OT

EC

Date Excavated:

Equipment:

Logged By:2/22/2013


ZAS

3.0

Tes

ting

Sam

ple

Dep

th (

feet

)

1

2

3

SAMPLE

Gra

phic

Log

Ele

vatio

n (f

eet)

443

442

441

Sam

ple

Nam

eT

estin

gMATERIAL

DESCRIPTION

Gro

upC

lass

ifica

tion

Enc

ount

ered

Wat

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Moi

stur

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onte

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% REMARKS



0186-679-10

Project:

Project Location:


APPENDIX B Report Limitations and Guidelines for Use


March 25, 2013 | Page B-1 File No. 0186-679-10

APPENDIX B REPORT LIMITATIONS AND GUIDELINES FOR USE1

This appendix provides information to help you manage your risks with respect to the use of this report.

Geotechnical Services Are Performed for Specific Purposes, Persons and Projects

This report has been prepared for the exclusive use of Puget Sound Energy and their authorized agents. This report may be made available to prospective contractors for their bidding or estimating purposes, but our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. This report is not intended for use by others, and the information contained herein is not applicable to other sites.

GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction contractor or even another civil engineer or architect that are involved in the same project. Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique, prepared solely for the specific client and project site. Our report is prepared for the exclusive use of our Client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third parties with which there would otherwise be no contractual limits to their actions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with our Agreement with the Client and generally accepted geotechnical practices in this area at the time this report was prepared. This report should not be applied for any purpose or project except the one originally contemplated.

A Geotechnical Engineering or Geologic Report Is Based on a Unique Set of Project-Specific Factors

This report has been prepared for the proposed improvements to the Snoqualmie Switch Station located on Railroad Avenue in Snoqualmie, Washington. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was:

■ not prepared for you,

■ not prepared for your project,

■ not prepared for the specific site explored, or

■ completed before important project changes were made.

1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org.


Page B-2 | March 25, 2013 | GeoEngineers, Inc. File No. 0186-679-10

For example, changes that can affect the applicability of this report include those that affect:

■ the function of the proposed structure;

■ elevation, configuration, location, orientation or weight of the proposed structure;

■ composition of the design team; or

■ project ownership.

If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate.

Subsurface Conditions Can Change

This geotechnical or geologic report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine if it remains applicable.

Most Geotechnical and Geologic Findings Are Professional Opinions

Our interpretations of subsurface conditions are based on field observations from widely spaced sampling locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions.

Geotechnical Engineering Report Recommendations Are Not Final

Do not over-rely on the preliminary construction recommendations included in this report. These recommendations are not final, because they were developed principally from GeoEngineers’ professional judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for this report's recommendations if we do not perform construction observation.

Sufficient monitoring, testing and consultation by GeoEngineers should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective method of managing the risks associated with unanticipated conditions.


March 25, 2013 | Page B-3 File No. 0186-679-10

A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation

Misinterpretation of this report by other design team members can result in costly problems. You could lower that risk by having GeoEngineers confer with appropriate members of the design team after submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing construction observation.

Do Not Redraw the Exploration Logs

Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs from the report can elevate risk.

Give Contractors a Complete Report and Guidance

Some owners and design professionals believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might an owner be in a position to give contractors the best information available, while requiring them to at least share the financial responsibilities stemming from unanticipated conditions. Further, a contingency for unanticipated conditions should be included in your project budget and schedule.

Contractors Are Responsible for Site Safety on Their Own Construction Projects

Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to on-site personnel and to adjacent properties.

Read These Provisions Closely

Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report Limitations and Guidelines for Use” apply to your project or site.

Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged


Page B-4 | March 25, 2013 | GeoEngineers, Inc. File No. 0186-679-10

The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project.

Biological Pollutants

GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations, recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts.

If Client desires these specialized services, they should be obtained from a consultant who offers services in this specialized field.

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