point brown draft geotechnical report

Geotechnical Engineering Services Draft Report

Point Brown Sidewalks Project Ocean Shores, Washington

for David Evans and Associates

March 8, 2017

1101 South Fawcett Avenue, Suite 200 Tacoma, Washington 98402 253.383.4940

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Geotechnical Engineering Services Draft Report

Point Brown Sidewalks Project Ocean Shores, Washington

File No. 2634-012-00

March 8, 2017

Prepared for:

David Evans and Associates 1115 West Bay Drive NW, Suite 301 Olympia, Washington 98502

Attention: Debra Seeman, PE

Prepared by:

GeoEngineers, Inc. 1101 South Fawcett Avenue, Suite 200 Tacoma, Washington 98402 253.383.4940

Brett E. Larabee, PE Geotechnical Engineer

Garry H. Squires, PE, LG, LEG Principal

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Disclaimer: 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.

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March 8, 2017 | Page i File No. 2634-012-00

Table of Contents

INTRODUCTION AND PROJECT UNDERSTANDING ................................................................................................. 1

PURPOSE AND SCOPE OF SERVICES ..................................................................................................................... 1

SITE CONDITIONS ..................................................................................................................................................... 2

Geology Review .................................................................................................................................................... 2 Surface Conditions............................................................................................................................................... 2 Subsurface Explorations and Laboratory Testing .............................................................................................. 3 Subsurface Conditions ........................................................................................................................................ 3

Soil Conditions .............................................................................................................................................. 3 Groundwater Conditions ............................................................................................................................... 3

CONCLUSIONS AND RECOMMENDATIONS ............................................................................................................ 4

General ................................................................................................................................................................. 4 Site Development and Earthwork ....................................................................................................................... 4

General .......................................................................................................................................................... 4 Clearing and Stripping .................................................................................................................................. 4 Erosion and Sedimentation Control ............................................................................................................. 4 Subgrade Preparation ................................................................................................................................... 5 Wet Weather Construction and Subgrade Protection ................................................................................. 5 Temporary Excavation Support .................................................................................................................... 6 Permanent Cut and Fill Slopes ..................................................................................................................... 7 Groundwater Handling Considerations ........................................................................................................ 7 Fill Materials .................................................................................................................................................. 7 Fill Placement and Compaction ................................................................................................................... 8

Shallow Foundations ........................................................................................................................................... 9 General .......................................................................................................................................................... 9 Foundation Bearing Surface Preparation ................................................................................................. 10 Allowable Soil Bearing Pressure ................................................................................................................ 10 Foundation Settlement .............................................................................................................................. 10 Lateral Resistance ..................................................................................................................................... 10

Signal Pole and Luminary Pole Foundations ................................................................................................... 11 Design Parameters .................................................................................................................................... 11 Signal Pole Construction and Additional Design Considerations ............................................................ 11 Backfill Placement and Compaction Around Signal Pole and Luminary Pole Foundations .................. 12

Stormwater Infiltration ...................................................................................................................................... 12 General ....................................................................................................................................................... 12 Infiltration Suitability .................................................................................................................................. 12 Design Infiltration Rates ............................................................................................................................ 13 Infiltration Discussion ................................................................................................................................ 14

Asphalt Concrete Pavement Design Recommendations ................................................................................ 14 General ....................................................................................................................................................... 14 Pavement Subgrade Preparation .............................................................................................................. 15 Pavement Section Materials ..................................................................................................................... 15 Design AC Placement Sections ................................................................................................................. 15

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Pervious Concrete Pavement ........................................................................................................................... 15 General ....................................................................................................................................................... 15 Pavement .................................................................................................................................................... 16 Permeable Ballast ...................................................................................................................................... 16 Treatment Layer ......................................................................................................................................... 16 Subgrade Preparation and Geotextile Liner ............................................................................................. 17 Protection, Maintenance and Safety ........................................................................................................ 17

LIMITATIONS .......................................................................................................................................................... 17

LIST OF FIGURES

Figure 1. Vicinity Map Figures 2 and 3. Site Plan Figure 4. Depth to Groundwater Recorded in Monitoring Wells

APPENDICES

Appendix A. Subsurface Explorations and Laboratory Testing Figure A-1 – Key to Exploration Logs Figures A-2 through A-9 - Logs of Borings Figures A-10 and A-11 - Sieve Analysis Results

Appendix B. Report Limitations and Guidelines for Use

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INTRODUCTION AND PROJECT UNDERSTANDING

GeoEngineers is pleased to present this report presenting the results of our geotechnical engineering services for the Point Brown Sidewalks project in Ocean Shores, Washington. Our understanding of the project is based on information provided and discussions with you including attending a project kickoff meeting on November 8, 2016. We understand that pedestrian and roadway improvements will be added to Point Brown Avenue NE (Point Brown Avenue) between State Route 115 (SR 115) and East Chance A La Mer NE.

The proposed design will follow the “Complete Streets” concept, which focuses on providing safe and convenient access for all roadway users including pedestrians, bikes, and automobiles. The layout of the street improvements is still being developed; however, we understand at this time that planned improvements will likely include the following elements: constructing sidewalks on the west and east sides of Point Brown Avenue, adding pedestrian cross walks across Point Brown Avenue, constructing bike lanes, developing on street parking, adding roundabouts or other traffic control features to manage traffic flow and speed, and improving landscaping and hardscaping within the project area. As part of the development of Point Brown Avenue we understand that existing sections of the roadway will be removed and replaced. Additionally, the grass boulevard that currently runs down the center of Point Brown Avenue may be removed or narrowed to accommodate the improvements.

In addition to the improvements mentioned above we understand that stormwater infiltration facilities may be constructed along the alignment. At this time area facilities (e.g., permeable pavements, rain gardens, and bioretention facilities) which primarily infiltrate water that falls within the facility footprint or the immediately surrounding area are being considered for use at the project. We understand that stormwater design will be completed using the 2014 Washington State Department of Ecology (Ecology) Stormwater Management Manual for Western Washington (SWMMWW).

PURPOSE AND SCOPE OF SERVICES

The purpose of our services was to explore subsurface conditions by drilled borings and provide geotechnical and earthwork recommendations to support planning and design of the proposed improvements. We have provided our services in general accordance with our signed agreement dated July 10, 2016. Our specific scope of services included the following tasks:

1. Reviewing readily available published geologic data, and select relevant in-house files for existing information on subsurface conditions in the project vicinity.

2. Visiting the project site to mark out preliminary locations for explorations and contact the “One-Call” Utility Notification Center, as required by Washington State law.

3. Exploring subsurface conditions within the project area by advancing eight borings using subcontracted equipment. Two of the borings were completed as monitoring wells.

4. Conducting geotechnical laboratory testing on selected soil samples.

5. Providing a discussion of soil and groundwater conditions encountered in our explorations.

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6. Providing recommendations for site preparation and earthwork. We discuss temporary erosion and sedimentation controls, temporary and permanent slopes, estimated stripping and clearing depths, subgrade preparation, fill placement and compaction requirements, suitability of on-site material for use as structural fill, import fill requirements, wet weather considerations, groundwater handling and site drainage.

7. Providing design recommendations for shallow foundations. We provide bearing surface preparation recommendations, minimum recommended size, allowable bearing pressures, estimates of settlement, and allowable passive soil pressures and friction for resisting lateral loads.

8. Providing lateral soil bearing pressures for use in design of traffic signal pole foundations in accordance with Chapter 17 of the Washington State Department of Transportation (WSDOT) Geotechnical Design Manual (GDM), 2013 Edition.

9. Providing a discussion of suitability of site soils for stormwater infiltration, including estimated long-term design infiltration rates based on laboratory sieve analysis results and the criteria described in the 2014 SWMMWW.

10. Providing layer thickness recommendations for conventional asphalt concrete pavement (ACP) design sections, including subgrade preparation. We have included typical pavement sections for heavy and light traffic areas based on our experience and observed subsurface conditions. We also provide layer thickness recommendations for pervious cement concrete pavement.

11. Preparing this draft geotechnical report for design team review and comment. We will incorporate revisions in a final report.

In addition to our geotechnical engineering services, GeoEngineers is also providing Hazardous Material’s Investigation Services. These services will be provided in a separate document.

SITE CONDITIONS

Geology Review

According to the Geologic Map of the Copalis Beach Quadrangle (Logan 2003) the project site is underlain by Holocene Age beach deposits (Qb). Beach deposits are described in the literature as sand and (or) gravel with minor shell fragments deposited along shorelines.

Surface Conditions

The project site is located on Point Brown Avenue between SR 115 to the north and East Chance A La Mer NE to the south as shown on the Vicinity Map, Figure 1. Point Brown Avenue is a four-lane roadway (two lanes in each direction) with a central grass median. Turn lanes cross the central median to provide access to side streets and businesses. The roadway is paved with asphalt concrete and has gravel or asphalt paved shoulders. The grass median is planted with trees. Businesses, restaurants and other services are located on most of the parcels that face onto Point Brown Avenue. There are currently no controlled intersections or designated pedestrian crossings between SR 115 and East Chance A La Mer NE.

The project site is relatively flat. There appears to be little elevation difference between the north and south end of the project alignment. The grass median between the traveled lanes is typically flat, however, in

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some locations there is a slight depression in the median area creating a “ditch” between the two sides of the roadway. Utilities are located both overhead and below ground along Point Brown Avenue.

Subsurface Explorations and Laboratory Testing

Our understanding of subsurface conditions at the project site is based on our observations made during drilling of eight borings (designated B-1 to B-8) located at the approximate locations shown on the attached Site Plans, Figure 2 and Figure 3. All of our explorations were extended to approximately 16.5 feet below surrounding ground surface (bgs). Two of the explorations (B-2 and B-7) were completed as monitoring wells. Details of the exploration program are presented in Appendix A. A key to our summary exploration logs is presented as Figure A-1 and the summary exploration logs are provided as Figures A-2 through A-9.

Selected samples from our explorations were tested in our laboratory to determine pertinent engineering properties and to confirm field classifications. Our laboratory testing program consisted of eight grain-size analyses. Details of our testing program and laboratory testing results are provided in Appendix A.

Subsurface Conditions

Soil Conditions

Borings B-1, B-2 and B-7 were advanced within grass medians and borings B-3, B-4, B-5, B-6 and B-8 were advanced through the asphalt pavement within the roadway. We generally observed about 6 inches of sod in the explorations advanced within the medians. Measured pavement thickness in the explorations advanced within the roadway ranged from 6 to 11 inches but was typically around 10 inches.

Below the asphalt or sod in borings B-3, B-4, B-5, B-6, B-7 and B-8 we encountered what we interpret to be fill material. Fill material generally consisted of medium dense sand with silt and occasional gravel and silty sand with occasional gravel. The fill material extended to between 2 and 3 feet bgs. Starting below the sod in borings B-1 and B-2 and below the fill in borings B-3 through B-7 we encountered what we interpret to be natural beach deposits. Between the top of the beach deposits and about 4.5 to 8.5 feet bgs the beach deposits generally consisted of very loose to medium dense fine sand with trace silt. Starting between 4.5 and 8.5 feet bgs the relative density and silt content of the beach deposits tended to increase. All of our explorations were terminated within the beach deposits at a depth of 16.5 feet bgs.

Groundwater Conditions

Our understanding of groundwater conditions at the site is based on observations made at the time of drilling and groundwater data collected from the two monitoring wells. Groundwater was generally observed between 5 and 7.5 feet bgs during drilling. Groundwater was measured at around 4 feet bgs in the northern monitoring well (B-2) and around 5 feet bgs in the southern monitoring well (B-7) at the time of well installation. The City of Ocean Shores has installed two pressure transducers to record water levels in the wells. Data available during the preparation of this report is provided as Figure 4. Based on the available data we are unable to determine if the seasonal high groundwater level has been reached. However, the initial stabilized levels measured by the transducers appear to be lower than approximate levels observed during drilling. We understand that the transducers will continue to record water levels in the wells. Based on our observations during drilling and our experience in the area we anticipate that the seasonal high groundwater level will likely be within a few feet of what is shown on Figure 4.

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CONCLUSIONS AND RECOMMENDATIONS

General

Based on our understanding of the project, the explorations performed for this study and our experience, it is our opinion that the proposed improvements can be constructed generally as envisioned with regard to geotechnical considerations. A summary of the primary geotechnical considerations for the project is provided below and is followed by our detailed recommendations.

■ Near-surface soils were observed to be in a very loose to medium dense condition. Compaction of these soils will likely be necessary when preparing roadway subgrades or shallow foundation bearing surfaces.

■ Some of the site soils, especially the existing fill contain a significant amount of fines and are moisture sensitive. These soils may be difficult or impossible to work with when wet.

■ The soil types present at the project site are generally suitable for infiltration. The depth to the seasonal high groundwater level should be determined prior to completing design of the infiltration facilities.

Site Development and Earthwork

General

We anticipate that site development and earthwork will include demolishing existing pavements and flatwork, clearing and stripping of surface vegetation, establishing subgrades, adjusting site grades, excavating for utility lines, and placing and compacting fill and backfill materials. We expect that the majority of site grading can be accomplished with conventional earthmoving equipment. The following sections provide recommendations for stripping, excavation, erosion control, subgrade development, temporary and permanent slope inclinations, groundwater handling, fill materials, fill placement and compaction.

Clearing and Stripping

We anticipate that the majority of stripping activities will take place within the medians, shoulders and other landscaped areas along the alignment. In general, clearing and stripping depths at the project site should be on the order of 2 to 3 inches. However, greater stripping depths could be required within structural areas to remove organic-rich soil or otherwise unsuitable soils.

During demolition of existing hardscaping or other features excessive disturbance of surficial soils may occur, especially if left exposed to wet conditions. Disturbed subgrade soils may require moisture conditioning and recompaction during construction and grading.

Erosion and Sedimentation Control

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

■ Scheduling grading and construction to reduce soil exposure.

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■ Re-vegetating or mulching denuded areas.

■ Directing runoff away from denuded areas.

■ Reducing the length and steepness of slopes with exposed soils.

■ Decreasing runoff velocities.

■ Preparing drainage ways and outlets to handle concentrated or increased runoff.

■ Confining sediment to the project site.

■ Inspecting and maintaining control measures frequently.

Some sloughing and raveling of exposed or disturbed soil on slopes should be expected. We recommend that disturbed soil be restored promptly so that surface runoff does not become channeled.

Temporary erosion protection should be used and maintained in areas with exposed or disturbed soils to help reduce erosion and reduce transport of sediment to adjacent areas and receiving waters. Permanent erosion protection should be provided by paving, structure construction or landscape planting.

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

Subgrade Preparation

Subgrades below structures and roadways should be thoroughly compacted to a uniformly firm and unyielding condition on completion of stripping and before placing structural fill. We recommend that subgrades for foundations and roadways be proof-rolled or probed, as appropriate, to identify areas of yielding or soft soil. Proof-rolling should be accomplished with a heavy piece of wheeled construction equipment such as a loaded dump truck or grader.

If soft or otherwise unsuitable areas are revealed during proof-rolling or probing that cannot be compacted to a stable and uniformly firm condition, we recommend that: (1) the unsuitable soils be scarified (e.g., with a ripper or farmer’s disc), aerated and recompacted; or (2) the unsuitable soils be removed and replaced with compacted structural fill, as needed.

We recommend that project plans include a contingency for partial overexcavation of existing site soils and replacement with compacted structural fill. Typically, structural fill overexcavation at the location of structures and roadways should extend to the depth necessary for the proposed use as determined by our firm representative. For estimating purposes, we anticipate that typical overexcavation depths could be on the order of 12 to 18 inches. Other options for remediation of soft subgrades include stabilization methods such as use of geotextile products and/or placement of quarry spalls.

Wet Weather Construction and Subgrade Protection

Portions of the on-site soil, especially the existing fill soils, contain a high percentage of fines (material passing the U.S. Standard No. 200 sieve) and are moisture sensitive. When the moisture content of the soil is more than a few percent above the optimum moisture content, this soil may become muddy and unstable

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and it will be difficult or impossible to meet the required compaction criteria. Disturbance of near-surface soil should be expected if earthwork is completed during periods of wet weather.

The wet weather season generally begins in October and continues through May in this area; however, periods of wet weather may occur during any month of the year. The optimum earthwork period for this type of soil is typically June through September. If wet weather earthwork is unavoidable, we recommend that:

■ Structural fill placed during the wet season or during periods of wet weather consist of select granular fill as defined in this report.

■ The ground surface should be sloped to direct surface water away from the work area. The ground surface should be graded such that areas of ponded water do not develop. Measures should be taken by the contractor to prevent surface water from collecting in excavations and trenches. Measures should also be implemented to remove surface water from the work area.

■ Earthwork activities should not take place during periods of heavy precipitation.

■ Slopes with exposed soil should be covered with plastic sheeting or otherwise protected from erosion.

■ Measures should be taken to prevent on-site soil and soil stockpiles from becoming wet or unstable. The site soil should not be left uncompacted and exposed to moisture. Sealing the surficial soil by rolling with a smooth-drum roller prior to periods of precipitation should reduce the extent that the soil becomes wet or unstable.

■ Construction traffic should be restricted to specific areas of the site, preferably areas that are surfaced with materials not susceptible to wet weather disturbance.

■ Construction activities should be scheduled so that the length of time that soil is left exposed to moisture is minimized.

■ Contingencies should be included in the project schedule and budget.

Temporary Excavation Support

Excavations deeper than 4 feet should be shored or laid back at a stable slope if workers are required to enter. Shoring and temporary slope inclinations must conform to the provisions of Title 296 Washington Administrative Code (WAC), Part N, “Excavation, Trenching and Shoring.” Regardless of the soil type encountered in the excavation, shoring, trench boxes or sloped sidewalls will be required under Washington Industrial Safety and Health Act (WISHA). The contract documents should specify that the contractor is responsible for selecting excavation and dewatering methods, monitoring the excavations for safety and providing shoring, as required, to protect personnel and structures.

In general, based on our observations and explorations, temporary cut slopes in on-site soils should be inclined no steeper than about 1-1/2H:1V (horizontal:vertical). This guideline assumes that all surface loads are kept at a minimum distance of at least one-half the slope height away from the top of the slope and that significant seepage is not present on the slope face. Flatter slopes will be necessary where significant seepage occurs, where soils are disturbed or if voids are created during excavation. Sloughing and raveling of temporary cut slopes should be expected. Temporary covering with heavy plastic sheeting should be used to protect slopes during periods of wet weather.

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Permanent Cut and Fill Slopes

While not anticipated as part of site earthwork for this project, if permanent cut and fill slopes are planned we recommend that they be constructed at a maximum inclination of 2H:1V. Permanent slopes inclined at about 1.5H:1V are also feasible; however, the erosion hazards and potential for sloughing are greater for 1.5H:1V slopes than 2H:1V slopes. Retaining structures should be considered for permanent slopes steeper than about 1.5H:1V. Slopes should be re-vegetated or armored as soon as practical to reduce surface erosion and sloughing. Temporary protection should be used until permanent protection is established. Erosion and sedimentation control measures are discussed further in the section below.

Fill placement on slopes steeper than 5H:1V should be benched into the slope face. The configuration of the bench will depend on the equipment being used and the slope geometry. Typically, bench widths should be equal to at least twice the height (e.g., 2-foot high bench cut should extend at least 4 feet into the face of the existing slope). In order to achieve uniform compaction, we recommend that fill slopes be overbuilt and subsequently cut back to expose well-compacted fill.

Groundwater Handling Considerations

Based on the groundwater information collected at the site to date we anticipate that groundwater could be encountered in excavations that extend deeper than about 5 feet bgs at the site. Areas of perched water could also be encountered at shallower depths, however, we anticipate that zones of perched water will likely be isolated and discontinuous.

Temporary dewatering could be necessary for excavations below about 5 feet bgs along Point Brown Avenue. We anticipate that shallow perched groundwater can typically be handled adequately with sumps, pumps, and/or diversion ditches, as necessary.

Groundwater handling needs will typically be lower during the late summer and early fall months. Ultimately, we recommend that the contractor performing the work be made responsible for controlling and collecting groundwater encountered. We do not recommend placing or compacting structural fill in submerged areas. If excavation dewatering is not practical, it may be necessary to place quarry spalls to bring the base of the excavation above groundwater level before placing structural fill. The quarry spalls should be placed to an elevation at least 6 inches above the groundwater elevation at the time of placement, and compacted to a firm condition using appropriate compaction equipment, such as a smooth drum roller or hoepack.

Fill Materials

Structural Fill

Material used for structural fill must be free of debris, organic contaminants and rock fragments larger than 6 inches. We recommend that structural fill material consist of material similar to “Select Borrow” or “Gravel Borrow” as described in Section 9-03.14 of the WSDOT Standard Specifications.

The workability of material for use as structural fill will depend on the gradation and moisture content of the soil. As the amount of fines increases, soil becomes increasingly sensitive to small changes in moisture content. We recommend that crushed rock or select granular fill, as described below, be used for structural fill during the rainy season. If prolonged dry weather prevails during the earthwork phase of construction, materials with a somewhat higher fines content may be acceptable.

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Select Granular Fill

Select granular fill must consist of well-graded sand and gravel or crushed rock with a maximum particle size of 6 inches and less than 5 percent fines by weight based on the minus ¾-inch fraction. Organic matter, debris or other deleterious material must not be present. In our opinion, material with gradation characteristics similar to WSDOT Specification 9-03.9 (Aggregates for Ballast and Crushed Surfacing), or 9-03.14 (Borrow) is suitable for use as select granular fill, provided that the fines content is less than 5 percent (based on the minus ¾-inch fraction) and the maximum particle size is 6 inches.

Crushed Rock

We recommend that crushed rock used as structural fill consist of material of approximately the same quality as “crushed surfacing (base course)” described in Section 9-03.9(3) of the WSDOT Standard Specifications.

Quarry Spalls

We recommend that quarry spalls consist of 2- to 4-inch washed, crushed stone similar to that described in Section 9-13 of the WSDOT Standard Specifications. Alternative stone size ranges may be considered, depending on the application.

Crushed Surfacing Base Course

We recommend that material used as base course consist of material of approximately the same quality as “crushed surfacing (base course)” described in Section 9-03.9(3) of the WSDOT Standard Specifications.

Crushed Surfacing Top Course/Leveling Course

We recommend that material used as top course or leveling course consist of material of approximately the same quality as “crushed surfacing (top course)” described in Section 9-03.9(3) of the WSDOT Standard Specifications.

On-Site Soil

On-site soil may be considered for reuse provided the soil meets the gradation specification required for its intended use and can be placed and compacted as recommended. The granular fill material encountered in our explorations generally contained a significant amount of fines and will likely be difficult or impossible to work with when wet. The majority of natural beach deposit soils encountered in our borings consisted of poorly graded fine sands with little or no gravel and a relatively low percentage of fines. This soil is moderately well draining and so it should be possible to work and compact it in moderately wet weather. It will, however, be difficult or impossible to work if it becomes saturated. This soil will also become easily disturbed and difficult to work if it is dry.

The existing fill material and natural beach deposits encountered in our explorations do not appear to meet the gradation recommendations for use as roadway base course and top course/leveling course. Accordingly, we do not recommend that the existing site soils be used as part of the new roadway section. These materials could be considered for use as structural fill in other areas of the site.

Fill Placement and Compaction

General

To obtain proper compaction, fill soil should be compacted near optimum moisture content and in uniform horizontal lifts. Lift thickness and compaction procedures will depend on the moisture content and gradation characteristics of the soil and the type of equipment used. The maximum allowable moisture

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content varies with the soil gradation and should be evaluated during construction. Silty soil or other fine-grained soil may be difficult or impossible to compact during persistent wet conditions. Generally, 12-inch loose lifts are appropriate for steel-drum vibratory roller compaction equipment. Compaction should be achieved by mechanical means. During fill and backfill placement, sufficient testing of in-place density should be conducted to check that adequate compaction is being achieved.

Area Fills and Pavement Bases

Fill used to raise site grades and materials beneath pavements and structural areas should be placed on subgrades prepared as previously recommended. Fill material placed below structures and foundations should be compacted to at least 95 percent of the theoretical maximum dry density (MDD) per ASTM International (ASTM) D 1557. Fill material placed less than 2 feet below pavement sections should be compacted to at least 95 percent of the MDD. Fill placed deeper than 2 feet below pavement sections should be compacted to at least 90 percent of the MDD. Fill material placed in landscaping areas should be compacted to a firm condition that will support construction equipment, as necessary, typically around 85 to 90 percent of the MDD.

Trench Backfill

For utility excavations, we recommend that the initial lift of fill over the pipe be thick enough to reduce the potential for damage during compaction but generally should not be greater than about 18 inches. In addition, rock fragments greater than about 1 inch in maximum dimension should be excluded from this lift.

Trench backfill material placed below structures and foundations should be compacted to at least 95 percent of the MDD. In paved areas, trench backfill should be uniformly compacted in horizontal lifts to at least 95 percent of the MDD in the upper 2 feet below subgrade. Fill placed below a depth of 2 feet from subgrade in paved areas must be compacted to at least 90 percent of the MDD. In non-structural areas, trench backfill should be compacted to a firm condition that will support construction equipment as necessary.

Shallow Foundations

General

While larger structures are not anticipated as part of this project, some improvements, such as utility structures, may be supported on shallow foundations.

We recommend all shallow foundations be established at least 18 inches below the lowest adjacent grade. Isolated foundations and continuous wall foundations should have minimum widths of 24 and 18 inches, respectively. Provided shallow foundations are established within a few feet of the ground surface it is our opinion that foundation drains are not necessary to maintain bearing support. If structures with deeper foundation depths are planned for the site (such as stormwater or utility vaults) it may be necessary to incorporate drainage measures below and around the foundations. We should evaluate the need for foundation drains below deeper embedded structures on a case-by-case basis.

The sections below provide our recommendations for foundation bearing surface preparation and foundation design parameters.

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Foundation Bearing Surface Preparation

Shallow foundation excavations should be performed using a smooth-edged bucket to limit bearing disturbance. Foundations should bear on firm existing granular fill, compacted natural soils, or on structural fill extending to these soils. The bearing surface should be compacted as necessary to a firm, unyielding condition. Loose or disturbed materials present at the base of footing excavations should be removed or compacted.

If structural fill is placed below foundations we recommend structural fill extend laterally beyond the foundation perimeter a distance equal to the depth of overexcavation (measured from the base of the footing where necessary), or 3 feet, whichever is less.

Foundation bearing surfaces should not be exposed to standing water. If water is present in the excavation, it must be removed before placing formwork and reinforcing steel. Protection of exposed soil, such as placing a 12- to 18-inch thick layer of crushed rock or quarry spalls, or a 4- to 6-inch layer of lean-mix concrete, may be needed to limit disturbance to bearing surfaces. We recommend that a member of our firm observe foundation excavations before placement of reinforcing steel in order to confirm that bearing surfaces have been prepared in accordance with our recommendations, or to provide recommendations for compaction or removal of unsuitable soil.

Allowable Soil Bearing Pressure

For foundations bearing on surfaces prepared as described above we recommend that shallow foundations be designed using an allowable downward soil bearing pressure of 2,500 pounds per square foot (psf).

This bearing pressure applies to the total of dead and long-term live loads and may be increased by one-third when considering total loads, including earthquake or wind loads. These are net bearing pressures. The weight of the footing and overlying backfill can be ignored in calculating footing sizes.

Foundation Settlement

As discussed above, loose or disturbed soil must be removed from the base of footing excavations and the bearing surface should be prepared as recommended. Provided these measures are taken, we estimate the total settlement of shallow foundations designed using an allowable downward soil bearing pressure of 2,500 psf will be on the order of ½ to 1 inch. Differential settlements across the base of the foundations could be on the order of ¼ to ½ inch. The settlements should occur rapidly, essentially as loads are applied. Settlements could be greater than estimated if loose, disturbed, or saturated soil is present below foundations.

Lateral Resistance

The ability of the soil to resist lateral loads is a function of the base friction, which develops on the base of foundations and slabs, and the passive resistance, which develops on the face of below-grade elements of the structure as these elements move into the soil. For foundations founded in accordance with the recommendations presented above, the allowable frictional resistance on the base of the footing may be computed using a coefficient of friction of 0.40 applied to the vertical dead-load forces.

The allowable passive resistance on the face of the footing or other embedded foundation elements may be computed using an equivalent fluid density of 300 pounds per cubic foot (pcf). This value assumes that

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footings and below-grade elements are located within about 4 feet of existing ground surface and that they are backfilled with structural fill placed and compacted as recommended. We should be consulted if excavations are expected to be deeper than 4 feet so that we can consider location and potential influence of groundwater on passive resistance.

These values include a factor of safety of about 1.5. The passive earth pressure and friction components may be combined provided that the passive component does not exceed two-thirds of the total. The top foot of soil should be neglected when calculating passive lateral earth pressure unless the area adjacent to the foundation is covered with pavement.

Signal Pole and Luminary Pole Foundations

Design Parameters

Table 1 below summarizes the recommendations for allowable lateral bearing pressure for the soils encountered in our borings. Bearing pressures are based on correlations between blow count and lateral bearing pressure values presented in Table 17-2 of the WSDOT GDM and our judgement.

TABLE 1. ALLOWABLE LATERAL BEARING PRESSURES FOR SIGNAL AND LUMINARY POLES

Location Nearest

Boring (s) Allowable Lateral Bearing

Pressure (psf)

Chance A La Mer Intersection STA 18+00 to STA 21+50 B-1 1,000

STA 21+50 to STA 25+00 B-2 2,000

STA 25+00 to STA 29+00 B-3 1,000

STA 29+00 to STA 34+75 B-4 2,000

STA 34+75 to STA 40+00 B-5 1,000

40+00 to SR 115 Intersection (STA 53+00) B-6, B-7, B-8 2,000

Signal Pole Construction and Additional Design Considerations

We present two conditions to consider when designing and constructing luminary and signal pole foundations (pole foundations):

■ Condition #1, an excavation the same dimension as the designed pole foundation is created and the foundation is cast directly against undisturbed earth. Or,

■ Condition #2, an excavation the same size or larger than the designed dimension of the pole foundation is created, a corrugated metal pipe (CMP) is placed into the excavation and the foundation concrete is cast inside the metal pipe. The CMP is left in place after pouring the foundation concrete. Any overexcavated area outside of the CMP is backfilled with controlled density fill (CDF) or soil.

Foundation Condition #1 requires the sidewalls of the excavation to remain stable and not cave into the excavation during construction. Foundation Condition #2 does not require the sidewalls of the excavation to remain stable during construction provided loose or disturbed soil around the CMP is replaced with properly compacted structural fill. Based on the soil types observed it is our opinion that there is a risk that the sidewalls of the excavations will cave, especially if excavation depths extend below the water table.

DRAFT


If excavations are deeper than 4 feet and workers will be required to enter the excavation, the sidewalls of the excavation must be supported or properly graded to a stable slope. Additional details about temporary excavations can be found in the “Temporary Excavation Support” section.

Backfill Placement and Compaction Around Signal Pole and Luminary Pole Foundations

Backfill in overexcavated areas around pole foundations must be compacted. If the overexcavated area is large enough for compaction equipment to access, import fill material or on-site material conforming to the specifications and discussion outlined above can be used to backfill the excavations; however, particle size may have to be considered depending on the area requiring backfill. Soils generated during excavation for the pole foundations may contain large size particles that will require removal. Backfill material around pole foundations must be compacted to at least 95 percent of the theoretical MDD per ASTM D 1557.

Alternatively, CDF could be used to backfill the excavation. CDF is a self-compacting, cementitious, flowable material requiring no subsequent vibration or tamping to achieve consolidation. CDF is included as an option for backfilling around pole foundations in the WSDOT standard signal foundation plans. If the area to backfill is too small for compaction equipment to access, CDF should also be used. Additionally, we recommend that CDF be used to backfill any large voids created during excavation if compaction equipment cannot access the void area, such as the conditions where undermining occurs.

Stormwater Infiltration

General

We understand that stormwater infiltration facilities will be designed following the 2014 Ecology SWMMWW. At this time, the type and location of stormwater infiltration facilities planned for the site are unknown, however. we understand that permeable pavements, or smaller footprint concentrated facilities such as rain gardens or bioretention facilities are being considered. Larger footprint infiltration ponds or underground vaults are also feasible, but in our understanding are not being considered at this time. The sections below provide our interpretation of the suitability of the site soil for infiltration and design long-term infiltration rates that may be used for design.

Infiltration Suitability

Generally speaking, the soil types present at the project site are suitable for infiltration. However, the fine sand material is susceptible to clogging over the long term and so maintenance of exposed subgrades or periodic sweeping of permeable pavements will be required. In our opinion the main factor limiting the feasibility of infiltration facilities is the location of the regional groundwater table. According to the 2014 SWMMWW, a minimum separation of 3 to 5 feet between the bottom of concentrated infiltration facilities, such as infiltration galleries or infiltration ponds, and the seasonal high groundwater level must be maintained. For bioretention facilities the minimum separation distance is 1 to 3 feet. For permeable pavements and rain gardens the minimum separation distance is 1 foot.

Based on available groundwater data recorded in the monitoring wells since installation the high-water level at the site appears to be about 8 feet bgs. We recommend that groundwater data continue to be collected through April to establish a peak seasonal high groundwater level.

DRAFT


Design Infiltration Rates

We have established long-term design infiltration rates for different soil types at the site based on the Soil Grain Size Analysis Method presented in the 2014 SWMMWW.

The SWMMWW recommends that correction factors, presented in Table 2 be applied to the grain-size analysis results to estimate long-term design infiltration rates. The correction factors account for uncertainties in testing caused by site variability and numbers of locations tested, test methodology, and long-term reductions in permeability due to biological activity and accumulation of fines (siltation and biofouling).

TABLE 2. MEASURED HYDRAULIC SATURATED CONDUCTIVITY RATE REDUCTION FACTORS

Issue Partial Correction Factor

Site Variability and Number of Locations Tested CFv = 0.33 to 1.0

Test Method

Large-Scale PIT CFt = 0.75

Small-Scale PIT CFt = 0.50

Grain Size Method CFt = 0.40

Siltation and Biofouling CFm = 0.9

Note:

Table adapted from 2014 SWMMWW Volume 3.

The correction factors selected for the sieve analysis results are as follows:

■ Site variability and number of locations tested, CFv = 0.75 (selected because of general uniformity of soil conditions between explorations);

■ Test method (grain size method), CFt = 0.4;

■ Degree of long-term maintenance to prevent siltation and bio-build-up, CFm = 0.9.

The total correction factor (CF) is based on these partial correction factors and equal to CFv x CFt x CFm.

The table below summarizes the results of the grain-size infiltration rate analysis.

TABLE 3. SOIL INFILTRATION RATE ANALYSIS1

Exploration Soil Sample

Depth (feet)

Soil Unit Approximate

Percent Fines2

USCS Soil Classification3

Long-term Design Infiltration Rate4 (Inches per Hour)

B-2 5 Native (Beach Deposits) 3 SP 13.4

B-2 10 Native (Beach Deposits) 6 SP-SM 11.0

B-3 2.5 Native (Beach Deposits) 3 SP 12.8

B-4 1 Fill 15 SM 4.3

B-5 2.5 Native (Beach Deposits) 2 SP 11.8

B-6 5 Native (Beach Deposits) 2 SP 13.1

DRAFT


Exploration Soil Sample

Depth (feet)

Soil Unit Approximate

Percent Fines2

USCS Soil Classification3

Long-term Design Infiltration Rate4 (Inches per Hour)

B-7 2.5 Fill 10 SP-SM 6.3

B-8 5 Native (Beach Deposits) 6 SP-SM 11.1

Notes: 1 For selected soil samples. 2 Fines = Silt and clay-sized particles passing U.S. No. 200 sieve. 3 Unified Soil Classification System (USCS). See Figure A-1 for additional descriptions. 4 Based on the procedures outlined in the 2014 SWMMWW and includes appropriate reduction factors.

Infiltration Discussion

The values presented above are for the samples obtained in a particular area at a particular depth and represent an estimate of the design infiltration rates as indicated by gradation characteristics. The grain-size distribution tests do not account for in-situ conditions that can affect infiltration, such as soil relative density, saturation, and proximity to the groundwater table. Accordingly, in our experience the values calculated using sieve analysis method can be an over-estimate of the actual infiltration rate. We recommend that the calculated long-term values be reduced by one-half to account for these factors. In our opinion a long-term design infiltration rate on the order of 5.5 inches per hour is suitable for the native beach deposit soils.

Infiltration appears to be feasible through the fill soils at the site, but due to the relatively higher fines content of the fill compared to the native soils and the fact that the fill unit does not appear to be very thick across the site we recommend that fill soils be removed from below the base of infiltration facilities during construction. We recommend GeoEngineers be given the opportunity during construction of the infiltration facilities to observe the soils at the base of the facilities to confirm whether the design infiltration is suitable for the in-situ soils or provide revised recommendations as necessary and appropriate.

Equipment should not be permitted in the infiltration areas after they are excavated to grade because of the potential for compaction of the subgrade that could reduce the infiltration rate. Stormwater should be treated in accordance with current regulations prior to infiltration. To help reduce clogging of infiltration facilities, we recommend they be protected during construction with siltation control facilities such as temporary settling basins, silt fences, and hay bales. Suspended solids can clog the soil and reduce the infiltration rate. Periodic sweeping of paved areas, during and following construction, will help extend the life of the infiltration facilities.

Asphalt Concrete Pavement Design Recommendations

General

The sections below provided recommendations for pavement subgrade preparation, material specifications for the pavement section and two design asphalt concrete (AC) sections. The “light-duty” section is suitable for areas subject to loading by automobiles only, such as parking areas and automobile driveways. The “heavy-duty” section is suitable for use in areas that will experience heavy automobile traffic and traffic from large trucks, buses, and RVs. The recommended sections are based on our experience and have not been designed for a specific design life or for specific traffic volumes. These pavement sections may not be adequate for heavy construction traffic loads such as those imposed by concrete transit mixers, dump

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trucks or cranes. Additional pavement thickness may be necessary to prevent pavement damage during construction. The recommended sections assume that final improvements surrounding the conventional ACP will be designed and constructed such that stormwater or excess irrigation water from landscape areas does not accumulate below the pavement section or pond on pavement surfaces.

Pavement Subgrade Preparation

Pavement subgrades should be prepared following the recommendations in the “Subgrade Preparation” section of this report.

Pavement Section Materials

Crushed surfacing base course and top course should conform to recommendations presented in the “Fill Materials” section of this report. Hot mix asphalt should conform to applicable sections of 5-04, 9-02 and 9-03 of the WSDOT Standard Specifications.

Design AC Placement Sections

Standard-Duty ACP – Automobile Driveways and Parking Areas

■ 3 inches of hot mix asphalt, class ½ inch, PG 58-22

■ 4 inches of crushed surfacing base course

■ 6 inches of subbase consisting of select granular fill to provide uniform grading and pavement support, to maintain drainage, and to provide separation from fine-grained subgrade soil

■ Native subgrade or structural fill prepared in accordance with the “Subgrade Preparation” section of this report

Heavy-Duty ACP – Areas Subject to Heavy-Duty Traffic

■ 6 inches of hot mix asphalt, class ½ inch, PG 58-22

■ 6 inches of crushed surfacing base course

■ 6 inches of subbase consisting of select granular fill to provide a uniform grading surface and pavement support, to maintain drainage, and to provide separation from fine-grained subgrade soil

■ Native soil or structural fill on subgrades prepared in accordance with the “Subgrade Preparation” section of this report.

Pervious Concrete Pavement

General

Our recommendations for pervious pavement design sections are based on information provided in the technical guidance manual for LID (Puget Sound LID manual), completed by the Puget Sound Partnership (December 2012) and our experience designing permeable pavement sections. The pavement sections presented below are suitable for use in driveway and parking areas and may not be suitable for use on surface streets or in areas with heavy traffic loads. The design of pervious pavements for stormwater management should consider storage capacity of the pervious pavement system and infiltration rate of the subgrade soils. Our general recommendations are provided in the following sections; however, pervious pavement design should be in accordance with the complete recommendations provided in the Puget Sound LID manual.

DRAFT


Our recommended pervious concrete pavement section is presented below followed by specific recommendations for each layer.

Pervious Cement Concrete Section

■ 6 inches of pervious cement concrete

■ 6 inches (minimum) of permeable ballast, more permeable ballast may be required to provide adequate storage capacity for the section

■ 6 inches treatment layer (if necessary)

■ Geotextile separation liner (if necessary)

■ Subgrade prepared as recommended below

Pavement

Permeable pavements should be open graded and should have a minimum infiltration rate of at least 8 inches per hour when newly installed. Field infiltration tests should be performed on newly placed permeable pavements to verify the infiltration rate.

Permeable Ballast

We recommend a minimum 6-inch thick permeable ballast layer that meets the specification for American Public Works Association (APWA) General Special Provision (GSP) 9-03.9(2) Option 1 (shown in Table 4 below). A thicker permeable ballast layer may be necessary to provided sufficient storage capacity for the design infiltration rate. In general, the permeable ballast can be considered to have a porosity of 30 percent.

TABLE 4. GRADATION SPECIFICATION FOR PERMEABLE BALLAST

Sieve Size Percent Passing

2½ inches 99-100

2 inches 65-100

¾ inch 40-80

No. 4 0-5

No. 100 0-2

% Fracture 95

Permeable ballast layers between 6 and 12 inches thick should be placed as a single lift. The ballast should be lightly compacted to a firm unyielding condition. Overcompaction of the ballast can result in reduced permeability. The prepared ballast layer should be observed by a qualified engineer to ensure that the ballast has been adequately compacted prior to placement of the permeable pavement. If the permeable ballast layer is thicker than 12 inches, it should be placed and compacted in multiple lifts not exceeding 12 inches in thickness.

Treatment Layer

If treatment of the collected stormwater is necessary before infiltration, a minimum 6-inch thick layer of sand or permeable treatment media should be included in the pavement section and located below the

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permeable ballast. A geotextile liner is required between the ballast layer and the treatment layer to prevent the treatment media from migrating into the ballast layer. The permeability of the treatment layer should match or exceed that of the permeability ballast layer. The treatment layer should be placed and compacted following the recommendations in the “Permeable Ballast” section above.

Subgrade Preparation and Geotextile Liner

Subgrades below permeable pavement sections should be lightly compacted to a firm and unyielding condition before constructing the permeable pavement section; however, overcompaction of the subgrade should be avoided. Prepared subgrades should be protected from construction traffic, standing water or other disturbance. If portions of the subgrade become disturbed or are overcompacted, the subgrade should be scarified to a minimum depth of 8 inches and recompacted. The subgrade should be recompacted to between 90 and 92 percent of the MDD.

A layer of non-woven geotextile filter fabric should be placed between the prepared subgrade soils and permeable pavement section if the subgrade soils contain more than about 7 percent fines by weight based on the minus ¾-inch fraction. In our opinion filter fabrics are not necessary provided subgrade soils consist of natural beach deposits. If included, filter fabric should meet the requirements of WSDOT Standard Specifications Section 9-33.1 for separation.

Protection, Maintenance and Safety

It is imperative that soils are not tracked onto pervious pavement surfaced areas during construction. Periodic visual inspections should be performed throughout the pavement life to determine if pervious pavement surfaces are clogged with fine soil or vegetation. Surfaces should be swept with a high-efficiency or vacuum sweeper regularly (at least 2 to 4 times per year) and washed with a high-pressure hose at least once per year.

Because the relatively porous base and subbase layers allow some air movement below the pavement, pervious pavement surfaces may become icy more easily than surrounding conventional pavement surfaces. This problem is similar to differential icing of bridges and elevated road structures. Users should be made aware of the possibility of differential icing if pervious pavements are used.

LIMITATIONS

We have prepared this report for David Evans and Associates for the Point Brown Sidewalks project in Ocean Shores, Washington. David Evans and Associates may distribute copies of this report to owner and owner’s authorized agents and regulatory agencies as may be required for the Project.

Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices for geotechnical engineering services in this area at the time this report was prepared. The conclusions, recommendations, and opinions presented in this report are based on our professional knowledge, judgment and experience. No warranty, express or implied, applies to the services or this report.

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

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E Chance a La Mer NE

State Route 115

µ

SITE

Vicinity Map

Figure 1

Point Brown Sidewalks ProjectOcean Shores, Washington

3,000 3,0000

Feet

Data Source: Mapbox Open Street Map, 2016

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.

Projection: NAD 1983 StatePlane Washington South FIPS 4602 Feet

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Figure 2


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Boring by GeoEngineers, 2017

Pt Brown Ave NW

Minard Ave NW

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B-2 Monitoring Well by GeoEngineers, 2017

WE

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0120 120

LegendNotes: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 contentof electronic files. The master file is stored by GeoEngineers,Inc. and will serve as the official record of this communication.

Data Source: Base CAD files provided by David Evans & AssociatesInc. dated 12/8/16.

Background imagery by Google Earth Images dated 8/17/16.

Projection: NAD83 WA State Planes, South Zone, US Foot

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Boring by GeoEngineers, 2017B-5

B-7 Monitoring Well by GeoEngineers, 2017

WE

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0120 120

LegendNotes: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 contentof electronic files. The master file is stored by GeoEngineers,Inc. and will serve as the official record of this communication.

Data Source: Base CAD files provided by David Evans & AssociatesInc. dated 12/8/16.

Background imagery by Google Earth Images dated 8/17/16.

Projection: NAD83 WA State Planes, South Zone, US Foot

DRAFT

Figure 4

Depth to Groundwater Recorded in Monitoring

Wells

Point Brown Sidewalks Project

Ocean Shores, Washington

2634-012-00 Date Exported: 022317

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* Elevations referenced to City of Ocean Shores Vertical Datum “Ruskin Fisher 1963”

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APPENDIX A Subsurface Explorations and Laboratory Testing

DRAFT

March 8, 2017 | Page A-1 File No. 2634-012-00

APPENDIX A SUBSURFACE EXPLORATIONS AND LABORATORY TESTING

Subsurface Explorations

General

Subsurface conditions were explored by completing eight soil borings. Approximate locations of the explorations are provided on Figures 2 and 3. The exploration locations shown on Figures 2 and 3 were established using hand-held GPS equipment and should be considered approximate. We did not survey the exact locations and elevations of the borings and monitoring well casings.

A representative of GeoEngineers, Inc. selected the locations for subsurface explorations, observed and classified the soils encountered and prepared a detailed log of each subsurface exploration. The soils were classified according to the system described in Figure A-1. The boring logs are presented in Figures A-2 through A-9.

Drilling and Soil Sampling

The borings were drilled using a truck-mounted drill rig equipped with hollow-stem auger. Soil samples were obtained from the borings at approximate 2.5- to 5-foot-depth intervals using a 2-inch, outside-diameter, standard split-spoon sampler (Standard Penetration Test [SPT]) in general accordance with ASTM D 1586. The sampler was driven into the soil using a 140-pound automatic hammer, free-falling 30 inches. The number of blows required to drive the samplers each of three, 6-inch increments of penetration were recorded in the field. The sum of the blow counts for the final 12 inches of penetration, unless otherwise noted, is reported on the boring logs.

All soil cuttings were collected in drums and removed from the site. Borings were drilled and backfilled by Holocene Drilling, Inc. subcontracted to GeoEngineers.

Groundwater Monitoring Well Installation

Drilling and construction of the monitoring wells was conducted by a Washington State licensed driller in accordance with the Minimum Standards for Construction and Maintenance of Wells (Chapter 173-160 Washington Administrative Code [WAC]; Ecology 2006). Installation of the monitoring wells was observed by a GeoEngineers’ representative who maintained a detailed log of the materials and depths of the wells.

The wells were constructed using 2-inch-diameter, flush-threaded Schedule 40 polyvinyl chloride (PVC) casing with machine-slotted PVC screen (0.010 inch). Following placement of the well screen and casing in the borehole, a sand pack was installed around the well screen. Sand pack material consisted of commercially prepared 10-20 silica sand. A minimum of a 1-foot-thick bentonite seal was placed above the sand pack. The surface of each well was completed with a concrete seal and steel flush-mount monument.

DRAFT

AC

Cement ConcreteCC

Asphalt Concrete

No Visible SheenSlight SheenModerate SheenHeavy SheenNot Tested

NSSSMSHSNT

ADDITIONAL MATERIAL SYMBOLS

Measured groundwater level inexploration, well, or piezometer

Measured free product in well orpiezometer

Graphic Log Contact

Groundwater Contact

Material Description Contact

Laboratory / Field Tests

Sheen Classification

Sampler Symbol Descriptions

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.

GRAPH

Topsoil/Forest Duff/Sod

Crushed Rock/Quarry Spalls

FIGURE A-1

2.4-inch I.D. split barrel

SYMBOLS TYPICAL

KEY TO EXPLORATION LOGS

CR

DESCRIPTIONSLETTER

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

Standard Penetration Test (SPT)

Shelby tube

Piston

Direct-Push

Bulk or grab

Continuous Coring

Distinct contact between soil strata

Approximate contact between soilstrata

Contact between geologic units

Contact between soil of the samegeologic unit

%F%GALCACPCSDSHAMCMDOCPMPIPPPPMSATXUCVS

Percent finesPercent gravelAtterberg limitsChemical analysisLaboratory compaction testConsolidation testDirect shearHydrometer analysisMoisture contentMoisture content and dry densityOrganic contentPermeability or hydraulic conductivityPlasticity indexPocket penetrometerParts per millionSieve analysisTriaxial compressionUnconfined compressionVane shear

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.

A "WOH" indicates sampler pushed using the weight ofthe hammer.

Rev. 02/16

DRAFT

4

2

26

15

1

2

3

4

SOD

SP

SP-SM

Brown silty fine to medium sand with organicmatter (grass, roots) (loose, moist) (sod)

Brown fine to medium sand, trace silt (loose, moist)

Grades to gray with occasional wood debris, andvery loose

Grades to wet

Dark gray fine sand with silt (medium dense, wet)

10

8

18

18

Groundwater observed at 7½ feet bgs at thetime of drilling

Note: See Figure A-1 for explanation of symbols.Coordinates Data Source: Horizontal approximated based on Aerial Imagery, Vertical approximated based on Aerial Imagery

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MATERIALDESCRIPTION

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Sheet 1 of 1Project Number:

Project Location:

Project:


2634-012-00

Log of Boring B-1Point Brown Sidewalks Project

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Drilled

HammerData

SystemDatum

Notes:

Surface Elevation (ft)Vertical Datum

LatitudeLongitude

Mobile B59140 (lbs) / 30 (in) Drop

DrillingEquipment

19NAVD88

47.0083-124.1615

WA State Plane SouthWGS84 (feet)

TotalDepth (ft)

Start EndChecked By BEL

ALWDriller Holocene Drilling, Inc. Drilling

Method Hollow Stem Auger16.51/5/20171/5/2017

GroundwaterDate Measured

Logged By

Depth toWater (ft) Elevation (ft)

See Remarks

DRAFT

11

14

18

18

9

9

35

41

1

2SA

3SA

4

SOD

SP

SP-SM


Brown fine sand, trace silt (loose, moist)

Groundwater measured at 7 feet bgs at time of wellinstallation

Gray fine sand with silt (dense, moist)

Grades to wet

27

22

3

6

2.0

3.0

5.0

14.0

16.5

Concrete surfaceseal2-inch Schedule 40PVC well casing

Bentonite backfill

2-inch Schedule 40PVC screen,0.01-inch slot width

Silica sand

StartDrilled 1/5/2017

HammerData

Date MeasuredHorizontalDatum

Vertical Datum

DOE Well I.D.: BJU 386A 2 (in) well was installed on 1/5/2017 to a depth of 14(ft).

2/12/2017LatitudeLongitude

DrillingEquipment

Top of CasingElevation (ft) 17.60

Mobile B59

Elevation (ft)

Groundwater Depth toWater (ft)

Notes:

Surface Elevation (ft)

140 (lbs) / 30 (in) Drop

10.40

18NAVD88

47.0091-124.1616

WA State Plane SouthWGS84 (feet) 7.60

Logged ByBEL

DrillingMethod1/5/2017

EndChecked By Driller

ALWTotalDepth (ft) Hollow Stem AugerHolocene Drilling, Inc.16.5


Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATA

Rec

over

ed (

in)

Blo

ws/

foot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eT

estin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Moi

stur

eC

onte

nt (%

)

Fine

sC

onte

nt (%

)

WELL LOG


Project Location:

Project:


2634-012-00

Log of Monitoring Well B-2Point Brown Sidewalks Project

Figure A-3

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_W

ELL_

%F

DRAFT

2

4

25

32

1SA

2

3

4

AC

SM

SP

SP-SM

10 inches asphalt concrete

Brownish gray with orange mottle fine to coarsesand with occasional gravel (medium dense,moist) (fill) (base coarse)

Brown fine sand, trace silt and occasional wooddebris (very loose, moist)

Grades to loose

Grades to wet

Gray fine sand with silt (medium dense, wet)

Grades to dense

6

12

15

18

330

Groundwater observed at 7 feet bgs at the timeof drilling


Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATAB

low

s/fo

ot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eTe

stin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Rec

over

ed (

in)


Project Location:

Project:


2634-012-00


Figure A-4

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_S

TAN

DAR

D_%

F

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

Drilled

HammerData

SystemDatum

Notes:


LatitudeLongitude


DrillingEquipment

19NAVD88

47.0101-124.1616


TotalDepth (ft)





Logged By


See Remarks

DRAFT

14

11

50

36

1SA

2

3

4

AC

SM

SP

SP-SM


Brownish gray with orange mottle silty fine tocoarse sand with gavel (medium dense, moist)(fill) (base coarse)

Grayish brown fine sand, trace silt (medium dense,moist)

Grades to wet

Gray fine sand with silt (very dense, wet)

Grades to dense

15

8

18

18

1415



Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATAB

low

s/fo

ot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eTe

stin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Rec

over

ed (

in)


Project Location:

Project:


2634-012-00


Figure A-5

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_S

TAN

DAR

D_%

F

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

Drilled

HammerData

SystemDatum

Notes:


LatitudeLongitude


DrillingEquipment

18NAVD88

47.0115-124.162


TotalDepth (ft)





Logged By


See Remarks

DRAFT

1

8

25

13

1SA

2

3

4

AC

SM

SP

SP-SM


Brown silty fine to coarse sand with occasionalgravel (medium dense, moist) (fill) (basecoarse)

Gray to brown fine to coarse sand, trace silt andoccasional gravel (very loose, most)

Gray fine sand with silt (loose, wet)

Grades to medium dense

8

11

18

18

217

Groundwater observed at 5.5 feet bgs at timeof drilling.


Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATAB

low

s/fo

ot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eTe

stin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Rec

over

ed (

in)


Project Location:

Project:


2634-012-00


Figure A-6

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_S

TAN

DAR

D_%

F

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

Drilled

HammerData

SystemDatum

Notes:


LatitudeLongitude


DrillingEquipment

18NAVD88

47.013-124.162


TotalDepth (ft)





Logged By


See Remarks

DRAFT

12

6

42

25

1

2SA

3

4

AC

SM

SP

SP-SM


Brown with orange mottle silt, fine to coarse sandwith occasional gravel (medium dense, moist)(fill) (base coarse)

Grayish brown fine sand, trace silt (loose, moist)

Grades to wet

Gray fine sand with silt (dense, wet)

Grades to medium dense

13

11

18

18

229



Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATAB

low

s/fo

ot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eTe

stin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Rec

over

ed (

in)


Project Location:

Project:


2634-012-00


Figure A-7

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_S

TAN

DAR

D_%

F

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

Drilled

HammerData

SystemDatum

Notes:


LatitudeLongitude


DrillingEquipment

18NAVD88

47.0143-124.1623


TotalDepth (ft)





Logged By


See Remarks

DRAFT

14

12

18

18

4

22

42

8

1SA

2

3

4

SOD

SP-SM

SP

SP-SM


Grayish brown with orange mottle fine to coarsesand with silt and gravel (medium dense, moist)(fill)

Brown fine sand, trace silt (loose, moist)

Gray fine sand with silt (medium dense, wet)Groundwater measured at 5 feet bgs at time of well

installation

Grades to loose

25 10

2.0

3.0

5.0

14.0

16.5

Concrete surfaceseal

2-inch Schedule 40PVC well casing

Bentonite backfill

2-inch Schedule 40PVC screen,0.01-inch slot width

Colorado coarseSilica sand

StartDrilled 1/4/2017

HammerData

Date MeasuredHorizontalDatum

Vertical Datum

DOE Well I.D.: BJU 385A 2 (in) well was installed on 1/4/2017 to a depth of 14(ft).

2/10/2017LatitudeLongitude

DrillingEquipment

Top of CasingElevation (ft) 17.10

Mobile B59

Elevation (ft)

Groundwater Depth toWater (ft)

Notes:

Surface Elevation (ft)

140 (lbs) / 30 (in) Drop

9.30

18NAVD88

47.016-124.1625

WA State Plane SouthWGS84 (feet) 8.70

Logged ByBEL

DrillingMethod1/4/2017

EndChecked By Driller

ALWTotalDepth (ft) Hollow Stem AugerHolocene Drilling, Inc.16.5


Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATA

Rec

over

ed (

in)

Blo

ws/

foot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eT

estin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Moi

stur

eC

onte

nt (%

)

Fine

sC

onte

nt (%

)

WELL LOG


Project Location:

Project:


2634-012-00

Log of Monitoring Well B-7Point Brown Sidewalks Project

Figure A-8

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_W

ELL_

%F

DRAFT

15

15

29

20

1

2SA

3

4

AC

SP-SM

SP

SP-SM


Dark brown sand with silt and occasional gravel(medium dense, moist) (fill) (base coarse)

Brown fine sand with trace silt (loose, moist)

Gray fine sand with silt and occasional wood debris(medium dense, wet)

Grades to without wood debris

13

18

18

18

635 Groundwater observed at 5 feet bgs at the timeof drilling


Elev

atio

n (f

eet)

15

10

5

Dep

th (f

eet)

0

5

10

15

Inte

rval

Wat

er L

evel

Gra

phic

Log

FIELD DATAB

low

s/fo

ot

Col

lect

ed S

ampl

e

Sam

ple

Nam

eTe

stin

g

Gro

upC

lass

ifica

tion

MATERIALDESCRIPTION

Rec

over

ed (

in)


Project Location:

Project:


2634-012-00


Figure A-9

Taco

ma:

Dat

e:3

/8/1

7 P

ath:

P:\

2\2

63

40

12

\GIN

T\2

63

40

12

00

.GP

J D

BTe

mpl

ate/

LibT

empl

ate:

GEO

ENG

INEE

RS

_DF_

STD

_US

_20

17

.GD

T/G

EI8

_GEO

TEC

H_S

TAN

DAR

D_%

F

Fine

sC

onte

nt (%

)

Moi

stur

eC

onte

nt (%

) REMARKS

Drilled

HammerData

SystemDatum

Notes:


LatitudeLongitude


DrillingEquipment

19NAVD88

47.0166-124.1625


TotalDepth (ft)





Logged By


See Remarks

DRAFT

0

10

20

30

40

50

60

70

80

90

10

0

0.0

01

0.0

10

.11

10

10

01

00

0

PERCENT PASSING BY WEIGHT

GR

AIN

SIZ

E I

N M

ILLIM

ETE

RS

U.S

. S

TA

ND

AR

D S

IEV

E S

IZE

SA

ND

SIL

T O

R C

LA

YC

OB

BLE

SG

RA

VE

L

CO

AR

SE

ME

DIU

MF

INE

CO

AR

SE

FIN

E

Bo

rin

g N

um

be

r

De

pth

(fe

et)

La

bo

rato

ry S

oil D

escri

pti

on

B-2

B-2

B-3

B-4

10 5 2.5 1

Po

orl

y gra

de

d s

an

d w

ith

silt

(SP

-SM

)

Po

orl

y gra

de

d s

an

d (

SP

)

Po

orl

y gra

de

d s

an

d (

SP

)

Silty

sa

nd

wit

h g

rave

l (S

M)

Sym

bo

l

Mo

istu

re

(%)

22

27

30

15

3/8”

3”

1.5”

#4

#1

0#

20

#4

0#

60

#1

00

3/4”

Figure A-10

Sieve Analysis Results



26

34

-01

2-0

0 D

ate

Exp

ort

ed

: 0

1/1

3/1

7

No

te:

Th

isre

po

rtm

ay

no

tb

ere

pro

du

ce

d,

exc

ep

tin

full,

wit

ho

ut

wri

tte

na

pp

rova

lo

fG

eo

En

gin

ee

rs,

Inc.

Te

st

resu

lts

are

ap

plica

ble

on

lyto

the

sp

ecif

icsa

mp

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nw

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hth

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we

re

pe

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d,a

nd

sh

ou

ldn

ot

be

inte

rpre

ted

as

rep

rese

nta

tive

of

an

yo

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ob

tain

ed

at

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er

tim

es,d

ep

ths

or

loca

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rge

ne

rate

db

yse

pa

rate

op

era

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ns

or

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ce

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s.

Th

egra

insiz

ea

na

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lts

we

reo

bta

ine

din

ge

ne

rala

cco

rda

nce

wit

hA

STM

D6

91

3.

#2

00

DRAFT

0

10

20

30

40

50

60

70

80

90

10

0

0.0

01

0.0

10

.11

10

10

01

00

0

PERCENT PASSING BY WEIGHT

GR

AIN

SIZ

E I

N M

ILLIM

ETE

RS

U.S

. S

TA

ND

AR

D S

IEV

E S

IZE

SA

ND

SIL

T O

R C

LA

YC

OB

BLE

SG

RA

VE

L

CO

AR

SE

ME

DIU

MF

INE

CO

AR

SE

FIN

E

Bo

rin

g N

um

be

r

De

pth

(fe

et)

La

bo

rato

ry S

oil D

escri

pti

on

B-5

B-6

B-7

B-8

2.5 5 2.5 5

Po

orl

y gra

de

d s

an

d (

SP

)

Po

orl

y gra

de

d s

an

d (

SP

)

Po

orl

y gra

de

d s

an

d w

ith

silt

an

d g

rave

l (S

P-S

M)

Po

orl

y gra

de

d s

an

d w

ith

silt

(SP

-SM

)

Sym

bo

l

Mo

istu

re

(%)

17

29

25

35

3/8”

3”

1.5”

#4

#1

0#

20

#4

0#

60

#1

00

3/4”

Figure A-11

Sieve Analysis Results



26

34

-01

2-0

0 D

ate

Exp

ort

ed

: 0

1/1

3/1

7

No

te:

Th

isre

po

rtm

ay

no

tb

ere

pro

du

ce

d,

exc

ep

tin

full,

wit

ho

ut

wri

tte

na

pp

rova

lo

fG

eo

En

gin

ee

rs,

Inc.

Te

st

resu

lts

are

ap

plica

ble

on

lyto

the

sp

ecif

icsa

mp

leo

nw

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we

re

pe

rfo

rme

d,a

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sh

ou

ldn

ot

be

inte

rpre

ted

as

rep

rese

nta

tive

of

an

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mp

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ob

tain

ed

at

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er

tim

es,d

ep

ths

or

loca

tio

ns,o

rge

ne

rate

db

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pa

rate

op

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ns

or

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s.

Th

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ea

na

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hA

STM

D6

91

3.

#2

00

DRAFT

APPENDIX B Report Limitations and Guidelines for Use

DRAFT

March 8, 2017 | Page B-1 File No. 2634-012-00

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.

Read These Provisions Closely

It is important to recognize that the geoscience practices (geotechnical engineering, geology and environmental science) rely on professional judgment and opinion to a greater extent than other engineering and natural science disciplines, where more precise and/or readily observable data may exist. To help clients better understand how this difference pertains to our services, GeoEngineers includes the following explanatory “limitations” provisions in its reports. Please confer with GeoEngineers if you need to know more how these “Report Limitations and Guidelines for Use” apply to your project or site.

Geotechnical Services Are Performed for Specific Purposes, Persons and Projects

This report has been prepared for David Evans and Associates and for the Project(s) specifically identified in the report. The information contained herein is not applicable to other sites or projects.

GeoEngineers structures its services to meet the specific needs of its clients. No party other than the party to whom this report is addressed may rely on the product of our services unless we agree to such reliance in advance and in writing. Within the limitations of the agreed scope of services for the Project, and its schedule and budget, our services have been executed in accordance with our Agreement with David Evans and Associates dated November 3, 2016 and generally accepted geotechnical practices in this area at the time this report was prepared. We do not authorize, and will not be responsible for, the use of this report for any purposes or projects other than those identified in the report.

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

This report has been prepared for the Point Brown Sidewalks Project in Ocean Shores, 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, it is important not to 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.

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

■ the function of the proposed structure;

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

DRAFT


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

■ composition of the design team; or

■ project ownership.

If changes occur after the date of this report, GeoEngineers cannot be responsible for any consequences of such changes in relation to this report unless we have been given the opportunity to review our interpretations and recommendations. Based on that review, we can provide written modifications or confirmation, as appropriate.

Environmental Concerns Are Not Covered

Unless environmental services were specifically included in our scope of services, this report does not provide any environmental findings, conclusions, or recommendations, including but not limited to, the likelihood of encountering underground storage tanks or regulated contaminants.

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 man-made events such as construction on or adjacent to the site, new information or technology that becomes available subsequent to the report date, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. If more than a few months have passed since issuance of our report or work product, or if any of the described events may have occurred, please contact GeoEngineers before applying this report for its intended purpose so that we may evaluate whether changed conditions affect the continued reliability or applicability of our conclusions and recommendations.

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 the specific subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied its professional judgment to render an informed opinion about subsurface conditions at other locations. Actual subsurface conditions may differ, sometimes significantly, from the opinions presented in this report. Our report, conclusions and interpretations are not a warranty of the actual subsurface conditions.

Geotechnical Engineering Report Recommendations Are Not Final

We have developed the following recommendations based on data gathered from subsurface investigation(s). These investigations sample just a small percentage of a site to create a snapshot of the subsurface conditions elsewhere on the site. Such sampling on its own cannot provide a complete and accurate view of subsurface conditions for the entire site. Therefore, the recommendations included in this report are preliminary and should not be considered final. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for the recommendations in this report if we do not perform construction observation.

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We recommend that you allow sufficient monitoring, testing and consultation during construction by GeoEngineers to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes if the conditions revealed during the work differ from those anticipated, and to evaluate whether earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective means of managing the risks associated with unanticipated conditions. If another party performs field observation and confirms our expectations, the other party must take full responsibility for both the observations and recommendations. Please note, however, that another party would lack our project-specific knowledge and resources.

A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation

Misinterpretation of this report by members of the design team or by contractors can result in costly problems. GeoEngineers can help reduce the risks of misinterpretation by conferring with appropriate members of the design team after submitting the report, reviewing pertinent elements of the design team’s plans and specifications, participating in pre-bid and preconstruction conferences, and 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. The logs included in a geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other design drawings. Photographic or electronic reproduction is acceptable, but separating logs from the report can create a risk of misinterpretation.

Give Contractors a Complete Report and Guidance

To help reduce the risk of problems associated with unanticipated subsurface conditions, GeoEngineers recommends giving contractors the complete geotechnical engineering or geologic report, including these “Report Limitations and Guidelines for Use.” When providing the report, you should preface it with a clearly written letter of transmittal that:

■ advises contractors that the report was not prepared for purposes of bid development and that its accuracy is limited; and

■ encourages contractors to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer.

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 adjacent properties.

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

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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.

A Client that desires these specialized services is advised to obtain them from a consultant who offers services in this specialized field.

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point brown draft geotechnical report

Documents