North Lake Samish Road Bridge No. 107 Replacement – Type, Size, & Location (TS&L) Study Report

Prepared for:

Whatcom County Public Works - Engineering

August 2017

By: TranTech Engineering, LLC

EXECUTIVE SUMMARY

The existing North Lake Samish Road Bridge No. 107 is a five-span, 250’ long timber structure built in 1963. The bridge consists of wood glulam girders with timber piles and caps. This bridge provides access across the north end of Lake Samish and has an ADT of approximately 885.

During the previous bridge inspection, there were areas of wood rot found in the tops of the girders. A new load rating required that the bridge be severely weight restricted, to the point that school buses and fire district vehicles could not use the bridge. To address the bridge’s deteriorated conditions, a temporary traffic modification is set in place that restricts the bridge center span to one lane.

The County recently selected TranTech to prepare a final Type, Size, & Location (TS&L) report to investigate different viable bridge replacement alternatives and to recommend an alternative with the most desired attributes for advancement to full design.

Based on input from the County, public outreach, and engineering activities associated with work elements described in this report, three viable bridge replacement alternatives were investigated.

The studied alternatives are:

Alternative 1 – Straight alignment with pre-stressed concrete girders

Alternative 2A – Curved alignment with pre-stressed concrete girders

Alternative 2B – Curved alignment with steel girders

During three public outreach meetings, different aesthetic bridge components such as: look-out platforms, aesthetic fascia, and illumination were presented to the community and key stakeholders for consideration.

The results presented in this report leads to the conclusion that Alternative 2A best meets the criteria set forth by Whatcom County. This alternative was chosen over Alternative 1 because it was the overwhelming public favorite option and possesses the ability to satisfy the minimum design speed at the south approach without extensive fill/encroachment into the lake. The latter reduces costs and permitting challenges.

The design team’s recommendation is to advance Alternative 2A through final PS&E phase.

i TABLE OF CONTENTS

1. Introduction ...... 1

2. Type, Size, & Location (TS&L) Study ...... 2

2.1 Surveying & Mapping ...... 2 2.2 Geotechnical Investigations ...... 3 2.3 Permitting & Cultural Resources ...... 4 2.4 Hydrology ...... 4 2.5 Utility Coordination ...... 5 2.6 Public Involvement ...... 5 2.7 Roadway Design ...... 7 2.8 Structural Design ...... 8 2.9 Constructability and Cost Estimation ...... 9 2.10 TS&L Alternatives Comparison ...... 10

3. Concluding Remarks and Recommendations ...... 11

Appendices

A Survey Map B Geotechnical Investigations Memo C Environmental Permitting Memo D Cultural Resources Memo E Hydrology & Geomorphology Memo F Utility Coordination Memo G Public Involvement Memo H Roadway Alignment & Profile Preliminary Plans I Bridge Alternatives Plans J Bridge Alternatives Opinion of Cost

ii 1. INTRODUCTION

The County has recently selected TranTech to prepare a final Type, Size, & Location (TS&L) report to investigate different viable bridge replacement alternatives and to recommend an alternative with the most desired attributes for advancement to full design.

The TS&L Report includes the following components and meets the general format of Section 2.1.5 of the WSDOT Bridge Design Manual (BDM):

A. Right-of-way/easement investigation, record of survey, site topographic survey and base map preparation B. Geotechnical investigation C. Hydrologic and hydraulic analysis and design D. Environmental permitting E. Traffic and transportation impact analysis F. Identification of approximately three preliminary replacement design options and preparation of supporting documentation and life cycle costs; G. Facilitation of community meetings, including: a. Preparation of artistic rendering exhibits for design options b. Presentation of design options c. Gathering and compiling public comment

All the work abides to the current versions of the following codes; Whatcom County Development Standards, AASHTO LRFD, and the WSDOT Bridge Design Manual (BDM).

1 2. TYPE, SIZE & LOCATION (TS&L) STUDY In preparing this TS&L study report, many design team members in various engineering disciplines provided contributions to support this effort. In the following, a summary of these engineering activities is provided while detailed reports are provided as the appendices to this report.

2.1 SURVEYING & MAPPING

This activity is performed by Wilson Engineering, Inc (Wilson) with results provided to TranTech’s team.

A plan displaying the topo survey of the bridge site is presented in Appendix A. In preparing this topo map Wilson’s survey team performed the following activities:

 Setting/recovering durable survey control, proximate to the project site, fixed to the NAD83/11 WA State Plane (North Zone) Coordinate System, and the NAVD88 vertical datum, using local WSDOT control documentation and including descriptions on base map.  The area limits of topographic survey is 650 linear feet centered on the existing bridge, along N. Lake Samish Drive, with a width of about 100 feet, again centered on the existing bridge.  In general, the topo is developed in cross sections on 25 feet stationing and includes center line roadway, edges of pavement, edge of shoulders, top of banks, toe of banks, grade brakes ordinary high water, 100-year flood level, and lake bottom. The areas behind the existing abutments where new abutments are located are most critical locations and are the areas where the topography varies the most. The survey of this area is therefore denser.  The Surveying includes all soil boring locations.  Captured the existing bridge features including; bridge deck corners, guard rails, and abutments.  Bathymetric survey is on a nominal 25’ o.c. stationing, extending the full width of the water surface. Data is gathered along a line at each side adjacent to the existing bridge  Stationing layout will be from south to north as per existing plans.  The survey includes locating utilities to the best practical manner and locating wetlands within project limits. All wetland flagging was provided by the County staff and then captured by the survey team.  The character and extents of the existing rights-of-way have been captured, based upon available information of record as well as unrecorded documents and title reports provided to Wilson by Whatcom County Public Works, within the project limits.  Survey team contacted the 1-800-LOCATE, no-cost utility-marking service, and captured the resulting utility marking indicators set by same.

2 2.2 GEOTECHNICAL INVESTIGATIONS

This work element is performed by TranTech’s geotechnical engineering team member Aspect, Inc. A detailed technical memo on this topic is provided in Appendix B.

Aspect coordinated and executed a geotechnical engineering investigation consisting of four geotechnical exploration borings along the bridge. The borings were drilled using a truck-mounted drill rig, employing the rotary wash method. Two of the borings were drilled on land at the north and south abutments, and two borings were advanced through 10- or 12-inch diameter core-holes in the bridge deck. To the maximum extent possible, the borings were located between or outside of the active wheel path.

The rotary wash drilling method involves pumping a slurry of potable water and soil down a hollow drilling rod to a rotating drill bit, which together break up and loosen soil/weak bedrock. These “cuttings” are returned via the slurry to the surface, where the solids are screened out in a “mud-tub” and transferred into steel drums for offsite disposal (by Aspect’s drilling subcontractor). In the over-water borings, an outer 8-inch diameter steel casing is utilized as a seal to prevent turbidity generation in Lake Samish. At these locations, the steel casing was extended from the mud tub down through the bridge deck, air, and lake water, and extended approximately 15 feet into the lake sediments. Aspect subcontracted a licensed geotechnical driller, experienced with this type of work.

In all the borings, disturbed soil and weathered bedrock samples were obtained at 5-foot intervals in general accordance with the Standard Penetration Test (SPT) method. Each of the borings were drilled to fully penetrate all loose sediment and extended a sufficient distance into competent glacial drift or bedrock. When bedrock was encountered that could not effectively be drilled/sampled, the driller switched over to rock coring. Up to 30 feet of rock core was drilled.

On completion, each of the borings were backfilled with bentonite chips in accordance with Department of Ecology requirements. At the abutment borings, the pavement was patched with fast-curing ready-mix. At the two over-water borings, the bridge deck is re-covered with a temporary steel plate which was later patched by Whatcom County bridge maintenance staff.

Based on the field borings, Aspect prepared a preliminary geotechnical report providing a summary of geotechnical and geologic conditions, a geologic cross section, boring logs, and laboratory test results. This report includes preliminary conclusions and recommendations regarding feasible foundation types. This report also includes preliminary conclusions regarding the potential need for rock-socketed piling.

3 2.3 PERMITTING & CULTURAL RESOURCES

Whatcom County is leading all related services for this work element. Following the 30% major milestone submittal from the design team, the County will start on this important critical path task.

The County has made preliminary contacts with the permitting agencies in an on-going coordination effort to secure the project’s required environmental permitting approvals.

TranTech’s team member Anchor QEA (Anchor) has been providing as-needed assistance to the County with respect to this work element. Appendix C and D presents their contributions to the envisioned required Permitting process and Cultural Resources desk review memo respectively.

2.4 HYDROLOGY

This work element is also performed by Anchor. The following is a summary of the hydrological engineering considerations. A detailed technical memo on this topic is provided in Appendix E.

Task 1 – Preliminary Hydrologic Assessment

The Lake Samish Basin Comprehensive Stormwater Plan (LSBCSP) hydrologic modeling findings including lake inflows, outflows, storage, and stage predictions and their annual seasonal variability, including largest evaluated events will be reviewed. If other relevant flow or lake stage data are available from Whatcom County, that information will also be reviewed. Preliminary estimates are made for design event peak flows requiring conveyance through the bridge replacement cross-section as provided by TranTech. No added hydrologic modeling is conducted for this initial assessment, but other representative hydrologic methods (i.e., similar gaged basin transfers, regression equations) will be used in comparison with modeled/recorded flows and their variability. For lake stage variability and extremes, maximum historic lake levels will be reviewed based on available data and prior LSBCSP modeling. Preliminary estimates of expected lake stage extreme (low/high) elevations will be documented on bridge replacement cross-sections, and associated flow areas will be determined.

A preliminary lake stage-discharge hydraulic rating has been established for the replacement bridge opening based on estimated lake outlet hydraulic control (adjusted seasonally) and considers the small hydraulic gradient and losses across the lake to the bridge location. Comparisons to the existing bridge opening estimated hydraulic rating is made to determine the potential for small changes (increases or decrease) in upstream lake

4 stage associated with the bridge replacement section. Scour potential over the range of estimated bridge flows is assessed on a comparative basis for the conceptual design alternatives provided by TranTech.

Anchor QEA will coordinate with TranTech to assist in identifying replacement bridge conceptual best management practice (BMP) alternatives for stormwater runoff control and low-impact development (LID) practices application. Input is provided as to the minimum stormwater and LID requirements for the bridge per Whatcom County’s stormwater requirements. No stormwater analyses or modeling was conducted as part of this TS&L Study.

2.5 UTILITY COORDINATION

Utility coordination is provided by TranTech’s subconsultant Wilson. Several utilities are associated with the bridge crossing. Coordination and planning for these utilities during construction and for permanent reinstallation is essential.

The utility engineering and coordination services included the following subtasks:

1. Contacting utilities by telephone and in writing to obtain all available information and to ensure that each utility understands how the project impacts them. 2. Providing a written summary of all utilities present including the type, owner information, size, carrier pipe material requirements, and potential upgrade needs.

Appendix F presents the utility coordination performed for this phase of the project.

2.6 PUBLIC INVOLVEMENT

Public Involvement is provided by TranTech’s team member Makers Architecture, Inc. (Makers). Appendix G presents the public involvement Memo prepared by Makers for this phase of the project.

The following presents a summary of the activities performed by Makers for preparation of the Memo:

 Makers prepared a public engagement and outreach action plan, reviewed it with the County and incorporated comments.  Prepared for and conducted public work session #1 to identify the community’s objectives for the project and to provide an opportunity for participants to discuss concerns and ideas. At the work session, the project team introduced the project and described the need and engineering parameters and then led a discussion to gather the community participants’ feedback. The project team also conducted an exercise to explore the participants’ general preferences for

5 bridge elements and design. MAKERS documented the results of preliminary design objectives and preferences to be utilized for the development of alternatives.  The County created a project website to provide the public project information and updates and disseminate the web-based survey.  Makers prepared three-dimensional renderings of the studied bridge alternatives based on preliminary designs for the bridge structures and input from the first public work session.  The Team prepared a questionnaire regarding project objectives for posting on the website. The questionnaire posed questions related to the objectives and initial design alternatives. Later the responses were processed by the County staff and a summary document was prepared.  The Team conducted a second public work session to review the alternative designs and presented additional engineering design information as appropriate. MAKERS presented the alternatives and then conducted an exercise in which participants, working in small groups, identified the preferred features of the alternatives.  The results from public involvement #2 were summarized and utilized for developing a preferred alternative.  The preferred alternative was presented in public involvement #3 on July 27, 2017 and was embraced by the community and stakeholders. The preferred alternative has the following features: a. A horizontal curve b. Single piers at two points in the lake. c. A minimal abutment structure. d. A steel railing with the barrier incorporated into the design. e. Low level pedestrian lighting mounted on the railing. f. Plain walkway pavement. g. No art.

Renderings of the preferred alternative are provided in Appendix G.

6 2.7 ROADWAY DESIGN

This work element is performed by TranTech’s Civil Engineering Group. Plans for two viable roadway alignment alternatives with associated plan and profiles are presented in Appendix H. In coming up with the presented alternative plans and profiles the following topics were investigated and optimized roadway alignments and profiles were derived:

Roadway Alignment TranTech prepared two alignments for the North Lake Samish Road Bridge Replacement project. The first alignment designated as Alternative 1 would closely follow the existing alignment but the horizontal curve on the south end of the bridge would not meet the desired design speed of 25 mph due to its constricted radius curve of 100-feet. It shall be noted that the design team attempted to increase the south alignment’s horizontal curve radius to accommodate the roadway’s 25 MPH design speed goal but the alignment required a large amount fill to be placed in the Lake. This option was abandoned from further investigations. This alternative assumes the south side road alignment will be signed for a maximum speed of 20 mph. For cost estimation activities, Alternative 1 has a tight approach curve such that roadway improvements do not encroach into the lake.

The second alignment designated as Alternative 2, has 3 horizontal curves, with the interior curve lying entirely on the bridge. The interior horizontal curve for this alignment has a gentle, aesthetically pleasing radius of 400-feet. This alignment deviates from the existing alignment and provides a design speed of 25 mph to match that of all surrounding public roads.

Both alignments neatly tie into Roy Road on the south end and the County park entrance on the north end. These alignment alternatives are expected to require minimal additional real estate.

Roadway Profile The profile for Alignment Alternatives 1 and 2 are similar as they both have gentle grades coming into the bridge with a relatively flat vertical curve on the bridge (approximately 2%). Both profiles will exceed the existing vertical clearance between the lake level and bottom soffit of the bridge so as not to impact boat traffic.

Roadway Section The roadway section used for the project is two 12-foot lanes, two 5-foot shoulders, and a 6-foot sidewalk on the west side of the bridge. With bridge rails added on both sides it will bring the total width of the bridge to 42-feet. The preliminary design assumes the bridge will have a full 2-percent super-elevation to enhance drainage to the inside of the curve. Per section 3.3.6 of AASHTO’s Policy on Geometric Design, this proposed curvature and super-elevation comply with the requirements for Low-Speed Urban Streets.

The design criteria utilized for the civil/ roadway design are outlined below:

7  Whatcom County Standards and Specifications.  AASHTO 2011, “A Policy of Geometric Design of Highways and Streets; 6th Edition”;  AASHTO 2004, “A Guide for Achieving Flexibility in Highway Design of Highways; 1st Edition”;  Washington State Department of Transportation, “Standard Specifications for Road and Bridge Construction”;  Washington State Department of Transportation, “Design Manual”;  Washington State Department of Transportation, “Standard Plans”  Washington State Department of Transportation, “Materials Laboratory Outline”;  Washington State Department of Transportation, “Construction Manual”;  Washington State Department of Transportation, “Local Agency Guidelines”;  Highway Research Board’s Manual entitled “Highway Capacity”;  FHWA and Washington State Department of Transportation, “Manual on Uniform Traffic Control Devices for Streets and Highways”;  WSDOT Highway Runoff Manual;  WSDOT Hydraulics Manual;  Washington Department of Ecology, “2012 Stormwater Management Manual”

2.8 STRUCTURAL DESIGN

Based on input from the County and engineering activities associated with work elements described previously in this report, TranTech’s structural team performed preliminary structural design associated with three viable bridge replacement alternatives. The design follows most current WSDOT Bridge Design Manual (BDM), AASHTO, and Whatcom County requirements. The studied Alternatives are described below:

Alternative 1 – Straight alignment with pre-stressed concrete slabs Alternative 2A – Curved alignment with pre-stressed concrete girders Alternative 2B – Curved alignment with steel girders

Throughout the structural design activities, the team was in continuous communication with the County for consultations on parameters like structure location, length and vertical clearance of the bridge. In addition, special care was given to incorporate low impact design like noise reduction, minimization of traffic impacts, long life cycle, and reducing environmental impacts. Regarding the important traffic impact minimization goal, the design team explored ideas such as:

 Full closure construction scenario to shorten construction duration  Investigation of barging material/ equipment to the site  Utilization of precast solutions for efficient/ faster construction duration

During our bridge design concept development, the team incorporated information provided by team members regarding topography survey, geotechnical, hydrology, utility, traffic, and civil engineering aspects of the bridge site. The concept plans for these alternatives is presented in Appendix I.

2.9 CONSTRUCTABILITY AND COST ESTIMATION

Constructability and Construction Cost Estimation is provided by TranTech’s subconsultant Ott-Sakai (OS).

OS has reviewed the alternatives developed during the Type, Size, & Location (TS&L) investigations, including work access and staging area considerations from a constructability viewpoint.

OS has also prepared cost estimates for the studied alternatives assuming the utilization of a work trestle by the contractor. Appendix J presents the construction cost data associated with the studied alternatives prepared by OS.

In parallel activities to OS, TranTech’s team also prepared engineer’s opinion of cost for the studied alternatives that is also presented in Appendix J. The results are within 5% of each other and the following chart summarizes both cost outcomes from both activities:

Alignment A Alignment B Straight Bridge Curved Bridge Alignment to the West of Alignment Existing Alignment

Alt. 1A Alt. 2A Alt. 2B concrete girders concrete girders steel plate girders 3 spans 3 spans 3 spans

Ott‐Sakai $4,859,593 $4,862,122 $5,336,501

TranTech $5,018,625 $5,085,250 $5,533,250

Average $4,939,109 $4,973,686 $5,434,876

Mobilization $493,911 $497,369 $543,488

30% Contingency $1,481,733 $1,492,106 $1,630,463

Anticipated Total Cost for 2019 Const. with Inflation $7,623,514 $7,676,884 $8,388,730 @ 5%/ yr.

9 2.10 TS&L ALTERNATIVES COMPARISON

The design team developed a list of critical project criteria and improvements/impacts for the project. Importance factors were developed for each issue in the three different categories: environmental issues, stakeholder issues, and project costs. The categories and issues used for comparison purposes included:

Environmental Issues:  Environmental Impacts

Stakeholder Issues:  Bridge Aesthetics

Project Costs:  Construction Costs (Bridge and Approaches)  Future Maintenance and Inspection Frequency

Each of the three studied alternatives were assigned scores of 1 through 3 in an ordinal scoring approach. The following table presents the results of this comparative investigations. The smallest score indicates the alternative with the most benefits.

Alignment A Alignment B Straight Bridge Curved Bridge Alignment to the Alignment West of Existing Alignment

Alt. 1A Alt. 2A Alt. 2B concrete concrete steel plate girders girders girders 3 spans 3 spans 3 spans

Environmental: Environmental Impacts 3 1 2

Stakeholders: Aesthetics 3 1 2

Cost: Construction Costs (Bridge and 1 1 3 Approaches)

Future Maintenance 1 1 3

Total Score 8 4 10 (Ordinal)

10 Regarding future maintenance cost considerations, we have used our past experience to estimate the costs associated with it. Our envisioned cost includes routine inspection and normal maintenance activities and have found out that for a 75-yr window, the present value cost is approximately $500K, $500K, and $1000K for Alts. 1, 2A and 2B.

3. CONCLUDING REMARKS AND RECOMMENDATIONS

Based on input from the County and engineering activities associated with work elements described previously in this report, three viable bridge replacement alternatives are investigated.

The studied Alternatives are:

Alternative 1 – Straight alignment with pre-stressed concrete slabs

Alternative 2A – Curved alignment with pre-stressed concrete girders

Alternative 2B – Curved alignment with steel girders

The results presented in this report lead to the conclusion that Alternative 2A best meets the criteria set forth by Whatcom County. This alternative was chosen over Alternative 1 because it was the overwhelming public favorite option and also possessed the ability to satisfy the minimum design speed at the south approach without extensive fill/encroachment into the lake. The latter reduces costs and permitting challenges.

The design team’s recommendation is to advance Alternative 2A through final PS&E phase.

Appendix A – Survey Map

SHEET DATE DESIGNED BY

10-10-2015 XXXX XXX X SCALE BELLINGHAM WASHINGTONDRAWN BY PAGE AS SHOWN XXXX XXX JOB NUMBER CHECKED BY X OF X XXXX SURVEY/ENGINEERING XXX-XXX Appendix B - Geotechnical Investigations Memo

PRELIMINARY GEOTECHNICAL REPORT North Lake Samish Bridge Replacement Whatcom County, Washington Prepared for: TranTech Engineering, LLC

Project No. 160142  December 1, 2016 + e a r t h w a t e r

pect CONSULTING

PRELIMINARY GEOTECHNICAL REPORT North Lake Samish Bridge Replacement Whatcom County, Washington Prepared for: TranTech Engineering, LLC

Project No. 160142  December 1, 2016

Aspect Consulting, LLC

PRELIMINARY

Jesse Favia, LG Erik O. Andersen, PE Senior Staff Geologist Senior Associate Geotechnical Engineer [email protected] [email protected]

V:\_GEOTECH\160142 North Lake Samish Bridge Replacement\Deliverables\Preliminary North Lake Samish Bridge Replacement Geotechnical Report.docx

e a r t h + w ate r Aspect Consulting, LLC 907 Harris Avenue Suite 301 Bellingham, WA 98225 360.746.8964 www.aspectconsulting.com ASPECT CONSULTING

Contents

1 Introduction and Project Description ...... 1

2 Site Conditions ...... 2 2.1 Surface Conditions ...... 2 2.2 Tectonics and Regional Geology ...... 2 2.3 Seismic Hazards ...... 3

3 Subsurface Conditions ...... 5 3.1 Field Exploration Program ...... 5 3.2 Stratigraphy ...... 5 3.2.1 Artificial Fill ...... 6 3.2.2 Alluvium ...... 6 3.2.3 Lake Sediments ...... 6 3.2.4 Glaciomarine Drift ...... 6 3.2.5 Darrington Phyllite ...... 7 3.3 Groundwater ...... 7

4 Conclusions and Preliminary Recommendations ...... 8 4.1 General Foundation Considerations ...... 8 4.2 Rock-Socketed Pile Construction ...... 8 4.3 Next Steps ...... 10

References ...... 11

Limitations ...... 12

PROJECT NO. 160142  DECEMBER 1, 2016 i ASPECT CONSULTING

List of Figures 1 Site Location Map 2 Site and Exploration Plan 3 Geologic Cross Section A-A’

List of Appendices

A Subsurface Explorations B Laboratory Test Results

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1 Introduction and Project Description

This report presents the results of a geotechnical engineering investigation by Aspect Consulting, LLC (Aspect) to support a Type, Size, and Location (TS&L) study of the North Lake Samish Bridge Replacement Project (Project). Our services were provided in support of engineering studies led by TranTech Engineering, LLC (TranTech) for Whatcom County Public Works (Client). The North Lake Samish Bridge crosses the west end of Lake Samish, located about 6 miles southeast of Bellingham in Whatcom County, Washington (SiteThe Project location is shown on Figure 1, Site Location Map. The Project involves the replacement of the existing 250-foot-long, 30-foot-wide, five- span, timber bridge with a new bridge along the existing lines and grades. The existing bridge is constructed on creosote timber piles over the suspended portion and on precast concrete bulkheads at each abutment. The bridge length and type have not been determined; however, our preliminary discussions with the Project team suggest the replacement structure may be three spans. The new bridge and abutments will be designed in accordance with the current American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications (BDS), and selected Washington State Department of Transportation (WSDOT) guidance and methodologies. This report summarizes the results of the completed field explorations and presents Aspect’s preliminary geotechnical engineering conclusions and recommendations to guide the TS&L study. This report is not a geotechnical design report for use with design of the replacement structure. Aspect will be available to provide geotechnical engineering support during the detailed PS&E phase of this Project.

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2 Site Conditions

2.1 Surface Conditions Surface conditions at the proposed Project consist of a 250-foot-long bridge spanning Lake Samish. The bridge is supported by fill prisms that extend from the native soils and bedrock on the north and south sides of Lake Samish into the lake. The fill prisms are 11-feet-high at the north end and 13-feet-high at the south end and are retained by formed concrete walls. The sides of the northern prism slope down at approximately 3H:1V (horizontal:vertical) towards Lake Samish (east) and Lake Samish County Park (west). The sides of the southern prism slope down at approximately 2H:1V towards Lake Samish (east and west). Lake Samish is at most 15-feet-deep beneath the bridge. The deepest point of the lake beneath the bridge (13 feet) is offset about 25 feet south of the center of the bridge.

2.2 Tectonics and Regional Geology The geologic units in the Site area are predominantly metamorphic and sedimentary rocks in areas of raised relief, and sediments from the most recent glacial advance about 15,000 years ago in areas of low relief. These units are consistent with the surrounding geology seen on Chuckanut Mountain, Anderson Mountain, and Lookout Mountain. Metamorphic basement rocks underlying the Quaternary sediments in the Project area are the result of ocean crust being thrust under and onto the North American Continent between the Mid-Cretaceous and Mid-Palegoene period (approximately 100 to 45 million years ago). The interaction of oceanic and continental crust was accompanied by regional metamorphism, granitic intrusions, and folding and faulting associated with thrust faults. Sediments and rocks were subjected to increased heat and pressure during metamorphism, permanently altering their physical and chemical characteristics. Sedimentary basement rocks underlying the Quaternary sediments in the Project area are the result of erosion of uplifted continental tectonics were deposited into existing basins during the mid-Paleogene (about 65 to 40 million years ago). The sedimentary rocks unconformably overlie the metamorphosed rocks. Sedimentary rocks include conglomerates, sandstones, siltstones, coal. Sediments which overly bedrock were deposited by multiple continental glaciations and during interglacial periods beginning about two million years ago. During interglaciation periods, erosion was more predominant than deposition in the high-relief Chuckanut area, stripping many of the glacial sediments from the bedrock. In the surrounding river valleys, depositional processes were like those of the present Skagit River and Nooksack River valleys, where high-energy rivers traverse across the valley and deposit river channel and floodplain sediments. Geologic mapping in the area (Lapen, 2000) indicates the Site sits at an unconformable contact between the Darrington Phyllite of the Easton Metamorphic Suite (Jphd) and the Bellingham Bay Member of the Chuckanut Formation (Eccb). As discussed below, our

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explorations did not encounter the Chuckanut Formation, but we did encounter Darrington Phyllitye. Glaciomarine Drift of the Everson Interstade occurs in the lowlands at the south end of Lake Samish. The geologic map also indicates alluvial Fan (Qaf) deposits on the northern shore of the lake near the bridge. Artificial Fill is not mapped at the Site, but is present from roadway embankment and bridge construction. Soil units encountered in soil boring explorations completed at the Site are described in more detail below in Section 3.2.

2.3 Seismic Hazards The Project will be constructed within an area of active tectonic forces associated with the interaction of the offshore Juan de Fuca plate, the Pacific plate, and the onshore North American plate. These plate interactions result in seismic hazards to the Project. Significant hazards include regional ground shaking from shallow crustal earthquakes, deep earthquakes, and subduction zone earthquakes, all potentially causing liquefaction of soft ground or landslides of unstable slopes. The closest known shallow Quaternary active faults are the Macaulay Creek Fault and Boulder Creek Fault, which are located between 12 and 25 miles northeast of the Site (Petersen et al., 2008). Fault trenches across the Boulder Creek Fault indicate 8.25 feet of displacement have occurred in the last 7,600 years. This fault is Holocene active and the US Geological Survey (USGS) seismic hazard maps indicate mean magnitudes of 6.3 with a 33 percent contribution to Site seismic hazards (USGS, 2014). Deep intraplate earthquakes occur along the ocean crustal slab where it subducts beneath the North American Continent. These earthquakes typically occur greater than 18 miles beneath the ground surface and do not necessarily leave diagnostic markers such as fault scarps. The USGS seismic hazard maps indicate deep intra-slab earthquakes can have mean magnitudes of 6.6 and contribute to 40 percent of the Site seismic hazards. The Site is located within the Cascadia subduction zone (CSZ), an active seismic zone, and is subject to earthquakes on shallow crustal faults. Additional hazards associated with the CSZ include deep earthquakes and subduction zone earthquakes. Deep earthquakes, which occur from tensional rupture of the sinking oceanic plate, typically have magnitude 7.5 or less and occur approximately every 10 to 30 years. The Site area is generally protected from strong shaking caused by these earthquakes by the great depth to the hypocenter. Subduction zone earthquakes occur due to rupture between the subducting oceanic plate and the overlying continental plate. These earthquakes can have magnitudes over 9 and an average recurrence interval on the order of 500 years. The last great subduction zone earthquake in Washington occurred about 300 years ago. Due to the lengthy recurrence intervals between large seismic events, the potential for strong ground shaking is considered low during the life of the proposed Project.

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The Site shallow subsurface is underlain by loose gravel and sand and soft silts that are susceptible to liquefaction during a large earthquake. Liquefaction could result in vertical settlement and lateral displacements of the roadway fill embankment and unconsolidated lake and alluvial sediments.

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3 Subsurface Conditions

3.1 Field Exploration Program We completed four machine-drilled borings between October 17 and October 19, 2016. The borings, designated B-1 through B-4 (from north to south), were completed along the existing approach embankment and through the bridge deck into the lake bottom, as shown on Figure 2. Each of the borings were drilled and sampled every 5 feet until bedrock was reached. Once drilling encountered bedrock, the onsite geologist and Project engineer determined whether to either continue collecting disturbed samples every 5 feet, or to begin continuous diamond core drilling. Disturbed soil and bedrock samples were taken using Standard Penetration Testing (SPT) methods for soil density and consistency correlation. Diamond core was taken using HQ3 size triple-tube continuous-coring to improve chances of recovery and in situ fracture preservation. Sampling details for each boring are as follows:  Boring B-1 was sampled using SPT methods from the surface to 31.5 feet below ground surface (bgs) and continuous core from 31.5 feet bgs to the end of the borehole at 49.8 feet bgs.  Boring B-2 was sampled using SPT methods from 24 feet beneath the bridge deck (lake bottom) to 21 feet below the lake bottom.  Boring B-3 was sampled using SPT methods from 28 feet below the bridge deck (lake bottom) to 17.5 feet below the lake bottom, and with continuous core from 17.5 to 19.5 feet below the lake bottom, and with SPT methods from 19.5 feet to the end of the borehole at 27.7 feet below the lake bottom.  Boring B-4 was sampled using SPT methods from the surface to the end of the borehole at 55.4 feet bgs. Descriptions of the soils and rock units encountered in the borings, as well as the depths where characteristics of the geology and engineering units changed are indicated on the exploration logs presented in Appendix A. Definitions of the terminology and symbols used on the logs are included as Figures A-1 and A-2. We submitted selected soil samples to a soil testing laboratory to determine moisture content (ASTM D2216) and grain size distribution (ASTM C136). We submitted one intact run of rock core to the lab for unconfined compressive strength (ASTM D2116). The results of the geotechnical laboratory testing are provided in Appendix B.

3.2 Stratigraphy We observed a 3-inch layer of hot mix asphalt on the roadway and embankment fill under the roadway and behind the bridge abutments. Beneath the roadway fill and lake, we observed non-consolidated native alluvium, lake sediments, and glacial sediments.

PROJECT NO. 160142  DECEMBER 1, 2016 5 ASPECT CONSULTING

Beneath the non-consolidated sediments, we encountered Darrington Phyllite bedrock in all borings. Figure 3 presents our interpretation of geologic conditions across the bridge alignment.

3.2.1 Artificial Fill Artificial fill (fill) was observed in at least two phases of emplacement at the Site. The upper (most recent) phase of emplacement was encountered beneath the asphalt to 6 feet bgs at the southern bridge embankment, and to 12 feet bgs at the northern embankment. This upper phase of fill was moist to wet, brown, slightly gravelly, very silty SAND (SM)1 or sandy GRAVEL (GP). A lower (older) phase of fill was encountered beneath the upper phase of fill at the southern bridge embankment from 6 to 23 feet bgs. This fill was wet, gravelly, slightly silty SAND (SP-SM) and consisted almost entirely of phyllite fragments, with trace organics. This fill likely originated from a nearby quarry. The sand and gravel fraction gradation varied from fine to coarse. SPT2 sampling indicates the fill has very loose to loose relative density. The fill is expected to exhibit low shear strength and moderate compressibility. Under seismic shaking conditions, saturated areas of the fill may liquefy.

3.2.2 Alluvium Alluvium was encountered below the fill to 16 feet bgs at the north end of the bridge in boring B-1. The Alluvium consisted of wet, gray, silty SAND (SM). Alluvium was distinguished from overlying fill based on color. We interpret this unit to have originated as colluvium from the steep slopes along the north side of the lake, which was then transported and deposited by the slow-moving lake water. The Alluvium sand fraction was fine to medium and the gravel fraction was fine. SPT sampling indicated that the alluvium was very loose. The Alluvium is expected to exhibit low shear strength and moderate to high compressibility. Under seismic shaking conditions, saturated areas of the Alluvium may liquefy.

3.2.3 Lake Sediments Lake sediments were encountered beneath the Alluvium to 18.5 feet bgs at the north bridge embankment in boring B-1, and from the lake bottom to 5 feet below lake bottom in boring B-2. Lake sediments beneath the north bridge embankment were wet, brown, fibrous PEAT (PT). Lake sediments in boring B-2 were wet, brown, organic SILT (OL). SPT sampling indicates the lake sediments are loose or soft. The Alluvium is expected to exhibit low shear strength and high compressibility.

3.2.4 Glaciomarine Drift Glaciomarine drift was encountered beneath lake sediments at the north end of the Site in borings B-1 and B-2, beneath the lake bottom in boring B-3, and beneath the phyllite fill

1 Soil Classification per the Unified Soil Classification System (USCS). Refer to ASTM D2488. 2 SPT blow count refers to standard penetration test (SPT) N-values, in accordance with ASTM D1586.

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in boring B-4. Glaciomarine drift typically consisted of wet, gray, gravelly, silty SAND (SM), silty GRAVEL (GP-GM), or non-plastic, very sandy SILT (ML). The glaciomarine drift sand fraction was fine to coarse and the gravel fraction was typically fine. SPT sampling indicated the glaciomarine drift was loose to dense and typically medium dense. The glaciomarine drift is expected to exhibit moderate shear strength and low to moderate compressibility.

3.2.5 Darrington Phyllite Darrington Phyllite of the Easton Metamorphic Suite (Jphd) was encountered in all borings. Beneath the bridge embankments, phyllite was encountered beneath glaciomarine drift at 32 feet bgs in boring B-1 and at 25.8 feet bgs in boring B-4. Beneath the lake bottom, phyllite was encountered beneath glacial outwash at 16.8 feet bgs in boring B-2 and beneath glaciomarine drift at 8.2 feet bgs in boring B-3. The Darrington Phyllite was extremely weak rock to very weak rock, dark gray, unweathered to slightly weathered, unaltered to moderately altered, fine-grained Phyllite with clay alteration. Mineralogy was predominantly mica with feldspar, graphite, and quartz. Fabric was very thinly, intensely laminated with occasional quartz boudin layers and commonly inclines greater than 45 degrees from vertical. Fractures along the foliation fabric were common and occasionally observed across the foliation fabric. Surface structural measurements and geological mapping (Lappen, 2000) indicate that foliations typically dip to the north or northwest. Core recovery was poor, with 65 percent recovery from a 3.3 foot-long run in boring B-1. Total core recovery for all runs in boring B-1 was 18 percent. Rock-quality Designation (RQD) was 15 percent for the 3.3 foot-long run in boring B-1, but the lack of recovery for most of the cored rock indicates that RQD should be 0 for the phyllite encountered at Site. The Darrington Phyllite is expected to exhibit high shear strength and low compressibility. Shear strength is expected to be weaker along the foliation direction, about 45-degrees dip to the north-northwest.

3.3 Groundwater Groundwater was measured at 15 feet bgs in boring B-1 and wet samples were encountered within 5 feet of the ground surface in boring B-4. The lake level was above the beginning of borings B-2 and B-3. Groundwater levels are expected to vary due to seasonal variations in weather, snowmelt, and the water level of Lake Samish.

PROJECT NO. 160142  DECEMBER 1, 2016 7 ASPECT CONSULTING

4 Conclusions and Preliminary Recommendations

4.1 General Foundation Considerations Our field and laboratory investigation indicates the bridge is underlain by a sequence of unconsolidated sediments of variable thickness, extent, and engineering properties. These sediments are in turn underlain by Darrington Phyllite bedrock, which is competent and will provide good support for the new bridge structure. The thickness of the unconsolidated sediments (and depth to bedrock) varies from as little as 8 feet (below mudline) to 26 feet and 32 feet at the south and north abutments, respectively. These unconsolidated sediments are typically loose/soft and are weak and compressible. The saturated granular outwash, alluvium, and fill are susceptible to liquefaction during the AASHTO design-level earthquake event. The organic-rich lake bottom sediments are prone to long-term secondary compression and bio-degradation settlement. These unconsolidated deposits will not be suitable to support the new bridge. The Darrington Phyllite is competent and will provide good support for the new bridge structure. We recommend the new bridge be founded on piles or shafts that are socketed into the Darrington Phyllite. Based on our geotechnical engineering experience and judgement, in order to provide lateral fixity, the rock-socket depth should be a minimum of 10 feet or three times the pile or shaft diameter, whichever is greater (e.g., 36-inch diameter steel pipe piles should be socketed a minimum of 10 feet into the phyllite bedrock; or 48-inch diameter drilled shafts should be socketed at least 12 feet into the phyllite bedrock). We consider both open-ended steel pipe piles and drilled shafts as two feasible deep foundation types for this structure. However, steel pipe piles may be easier to construct at this site considering that construction equipment will be operating from the existing load- restricted bridge. For the interior piers, open-ended pipe piles and/or drilled shafts with permanent steel casing, will be a good choice from an environmental protection and constructability standpoint. Designing the substructure with the steel pipe or casing extending up to the underside of the bridge superstructure can minimize impacts on North Lake Samish. Additionally, this would avoid the expense of a cofferdam and associated dewatering that would be required with a conventional shaft-to-column connection. We request that TranTech review and comment on this structural detail. The geotechnical axial compressive capacities of properly-constructed rock-socketed shafts or piles will approach that of the structural section. Axial compressive capacity considerations will not control the foundation design.

4.2 Rock-Socketed Pile Construction Based on our experience, we consider rock-socketed open-ended pipe suitable for this Project. The equipment necessary to install pipe piles is lighter than that required to install larger diameter drilled shafts. Crane-mounted pile-driving equipment and down- hole rock-socket tooling can be set-back a further distance from the interior piers

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compared to drill-shaft equipment (which typically needs to operate directly over the shaft). We understand the replacement bridge will be located along the existing bridge alignment in order to minimize disturbance to adjacent properties and avoid new property acquisition. The existing roadway will be closed and traffic will be detoured around the work zone—this will greatly simplify construction. Construction of the new interior pier foundations will be most economical if they can be installed with equipment operating on the existing bridge structure. Depending on the type of foundation substructure that is selected, it may be necessary to install a temporary pile-supported working trestle to support the foundation installation equipment. This should be minimized to the extent that is practical. We request that our constructability reviewer (Ott-Sakai) evaluate and comment on foundation construction. Our geotechnical explorations reveal that rock-sockets can be advanced into the weak phyllite bedrock unit. Drilling tools to advance the rock sockets could include down-hole chisels, or similar percussion bits or tri-cone (rotary) drilling bits. These tools would operate within the steel pipe or casing. The broken-up rock could be removed from the hole using grabs or augers. To facilitate rock socket construction, the open-ended pipe piles must be large enough to allow down-hole drilling equipment and augers or grabs to work inside the pipe. Based on our experience with similar Projects, we suggest 3-foot diameter pipe piles will be appropriate. The pipe piles should be heavy-walled (we recommend 5/8- or 3/4-inch thick) and they should be equipped with externally flush (internally projecting) hardened driving shoes, to handle hard driving conditions. The construction sequence would be as follows: 1) The open-ended piles would be advanced with a vibratory or impact hammer down through the overburden material and some distance into the Darrington Phyllite. 2) The hammer would be removed and an auger or grab or airlift would be lowered into the pipe to remove soil and expose the surface of the intact bedrock. 3) A down-hole drill or percussion bit would be used to break up the rock some distance beyond the tip of the pipe pile. 4) The auger or grab would be used to remove some of this broken-up material 5) The impact hammer would be used to advance the pile further downward. The impact energy would dislodge any intact rock around the circumference of the pile and it would be displaced into the center of the pile/socket. Care must be taken to avoid over-stressing and damaging the pipe during driving. 6) The process would be repeated until the required socket depth has been reached. 7) A reinforcing cage could be placed and the pipes tremie-filled with structural concrete, as necessary.

PROJECT NO. 160142  DECEMBER 1, 2016 9 ASPECT CONSULTING

4.3 Next Steps We prepared this draft preliminary geotechnical evaluation prior to a collaboration and discussion meeting with the TranTech team. We request an internal collaboration meeting to review these preliminary conclusions and recommendations so that we may further understand other (non-geotechnical) considerations. We will be pleased to revise this report as appropriate, such that our foundation recommendations are aligned with the team’s overall recommendations.

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References

American Association of State Highway and Transportation Officials (AASHTO), 2014, LRFD Bridge Design Specifications, Seventh Edition, Customary U.S. Units. American Society for Testing and Materials (ASTM), 2012, American Society of Testing Materials Annual Book of Standards, Vol. 4.08, West Conshohocken, Pennsylvania. Lapen, T.J., 2000, Geologic Map of the Bellingham 1:100,000 Quadrangle, Washington, Washington Division of Geology and Earth Resources, OFR 2000-5, December 2000 Petersen, M.D., A.D. Frankel, S.C. Harmsen, C.S. Mueller, K.M. Haller, R.L. Wheeler, R.L. Wesson, Y. Zeng, O.S. Boyd, D.M. Perkins, N. Luco, E.H. Field, C.J. Wills, and K.S. Rukstales, 2008, Documentation for the 2008 Update of the United States National Seismic Hazard Maps: U.S. Geological Survey Open-File Report 2008–1128, 61 p. U.S. Geological Survey (USGS), 2014, U.S. Seismic Design Maps Website accessed on November 1, 2016, http://earthquake.usgs.gov/designmaps/us/application.php. Washington State Department of Transportation (WSDOT), 2016, Standard Specifications for Road, Bridge and Municipal Construction, Document M 41-10.

PROJECT NO. 160142  DECEMBER 1, 2016 11 ASPECT CONSULTING

Limitations

Work for this Project was performed for TranTech Engineering, LLC (Client), and this report prepared in accordance with generally accepted professional practices for the nature and conditions of work completed in the same or similar localities, at the time the work was performed. All reports prepared by Aspect Consulting are intended solely for the Client and apply only to the services described in the Agreement with Client. Any use or reuse by Client for purposes outside of the scope of Client’s Agreement is at the sole risk of Client and without liability to Aspect Consulting. Aspect Consulting shall not be liable for any third parties’ use of the deliverables provided by Aspect Consulting. Aspect Consulting’s original files/reports shall govern in the event of any dispute regarding the content of electronic documents furnished to others. This report and our conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Experience has shown that subsurface soil and groundwater conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by a geotechnical study. Further geotechnical evaluations, analyses and recommendations may be necessary for the final design of this Project. If there is a substantial lapse of time between the submission of this report and the start of construction, or if conditions have changed due to construction operations at or near the Site, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse.

12 PROJECT NO. 160142  DECEMBER 1, 2016 FIGURES

i ! Bellingham

Port ! SITE Angeles LOCATION ! # Seattle Spokane ! Wenatchee ! Olympia Tacoma ! W A S H I N G T O N ! Yakima

SITE LOCATION (!

Site Location Map North Lake Samish Bridge Replacement Bellingham, Washington 0 2,000 4,000

BY: Feet NOV-2016 JGF/ASC FIGURE NO. PROJECT NO. REVISED BY: C O N SU LTI N G 160142 - - - 1 Basemap Layer Credits || Sources: Esri, HERE, DeLorme, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, MapmyIndia, © OpenStreetMap contributors, and the GIS User Community Copyright:© 2014 Esri

APPENDIX A

Subsurface Explorations

ASPECT CONSULTING

A.1 Field Exploration Program

A.1.1 Geotechnical Borings Between November 17 and November 19, 2016, we performed a site reconnaissance and completed four geotechnical soil borings:  B-1 to a total depth of 49.8 feet bgs;  B-2 to a total depth of 21 feet below the lake bottom (45 feet below the bridge deck);  B-3 to a total depth of 27.7 feet below the lake bottom (55.7 feet below the bridge deck); and  B-4 to a total depth of 44 feet bgs. The borings were advanced using a track-mounted CME 55 rotary drill rig using 6.5-inch outer diameter hollow-stem auger methods, 4-inch outer diameter mud-rotary methods, or HQ3-core-diameter diamond continuous core methods. The borings were sampled at selected depth intervals using the Standard Penetration Test (SPT) in general accordance with ASTM method D1586 or by continuous core triple tube methods. The locations of the borings are shown on Figure 2 of the report. SPT sampling involves driving a 2-inch outside diameter split-barrel sampler 18-inches into the soil with a 140-pound hammer free-falling from 30-inches (the drill rig employed on this project used an automatic-trip hammer). The number of blows for each 6-inch interval is recorded and the number of blows required to drive the sampler the final 12 inches is known as the Standard Penetration Resistance (“N”) or blow count. The resistance, or N-value, provides a measure of the relative density of granular soils or the relative consistency of cohesive soils. Diamond continuous core drilling involves advancing a diamond and matrix drill bit at high rotations-per-minute with a hollow drill string. An outer one-piece core barrel fitted with an inner split-barrel is lowered into the drill string prior to drilling. The core in removed by lifting the core barrel to the surface and pumping the inner split-barrel out of the outer barrel with pressurized water. Core is measured and recovery is recorded as a percent of the entire length drilled and depths marked each foot on the core. Rock-quality Designation is determined is general accordance with ASTM D6032, Standard Test Method for Determining Rock Quality Designation (RQD) of Rock Core. Core is photographed in the field. An Aspect Consulting Geologist was present throughout the field exploration program to observe the drilling procedure, assist in sampling, and to prepare descriptive logs of the exploration. Soils were classified in general accordance with ASTM D2488, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Rocks

PROJECT NO. 160142  DECEMBER 1, 2016 A-1 ASPECT CONSULTING

were classified in general accordance with the Washington State Department of Transportation (WSDOT) Geotechnical Design Manual (GDM), Chapter 4, Soil and Rock Classification and Logging. The summary exploration log represents our interpretation of the contents of the field logs. The stratigraphic contacts shown on the individual summary logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The subsurface conditions depicted are only for the specific date and locations reported, and therefore, are not necessarily representative of other locations and times.

A-2 PROJECT NO. 160142  DECEMBER 1, 2016 Well-graded gravel and Terms Describing Relative Density and Consistency (2) (5) GW gravel with sand, little to Density SPT blows/foot no fines Very Loose 0 to 4 Test Symbols Coarse- Loose 4 to 10 FC = Fines Content Grained Soils 5% Fines Poorly-graded gravel Medium Dense 10 to 30 G = Grain Size GP and gravel with sand, Dense 30 to 50 M = Moisture Content little to no fines Very Dense >50 A = Atterberg Limits (1) (2) C = Consolidation Silty gravel and silty Consistency SPT blows/foot DD = Dry Density Very Soft 0 to 2

(5) K = Permeability gravel with sand Fine- GM Soft 2 to 4 Grained Soils Str = Shear Strength Medium Stiff 4 to 8 Env = Environmental

Retained on No. 4 Sieve Stiff 8 to 15 Clayey gravel and PiD = Photoionization 15% Fines Very Stiff 15 to 30 Detector clayey gravel with sand (1) GC Hard >30

Gravels - More than 50% of Coarse Fraction Component Definitions Well-graded sand and Descriptive Term Size Range and Sieve Number

(5) SW sand with gravel, little Boulders Larger than 12" to no fines Cobbles 3" to 12" Gravel 3" to No. 4 (4.75 mm)

5% Fines Poorly-graded sand Coarse Gravel 3" to 3/4" SP and sand with gravel, Fine Gravel 3/4" to No. 4 (4.75 mm) little to no fines Sand No. 4 (4.75 mm) to No. 200 (0.075 mm) Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Silty sand and Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) (5) SM silty sand with Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) (1)

Passes No. 4 Sieve gravel

Coarse-Grained Soils - More than 50% Retained on No. 200 Sieve Silt and Clay Smaller than No. 200 (0.075 mm) Clayey sand and 15% Fines clayey sand with gravel Estimated Percentage Moisture Content SC Percentage Dry - Absence of moisture, Sands - 50% or More of Coarse Fraction by Weight Modifier dusty, dry to the touch Silt, sandy silt, gravelly silt, <5 Trace Slightly Moist - Perceptible moisture ML silt with sand or gravel 5 to 15 Slightly (sandy, silty, Moist - Damp but no visible clayey, gravelly) water Clay of low to medium 15 to 30 Sandy, silty, clayey, Very Moist - Water visible but gravelly) not free draining CL plasticity; silty, sandy, or gravelly clay, lean clay 30 to 49 Very (sandy, silty, Wet - Visible free water, usually clayey, gravelly) from below water table Silts and Clays Organic clay or silt of low Symbols plasticity Cement grout Liquid Limit Less than 50 OL Blows/6" or surface seal Sampler portion of 6" Type Bentonite chips

(1) Elastic silt, clayey silt, silt 2.0" OD Sampler Type Description MH with micaceous or diato- Split-Spoon Grout maceous fine sand or silt Sampler seal (SPT) Continuous Push Filter pack with Non-Standard Sampler Clay of high plasticity, blank casing Bulk sample section sandy or gravelly clay, fat CH 3.0" OD Thin-Wall Tube Sampler Screened casing clay with sand or gravel (including Shelby tube) or Hydrotip with Grouted filter pack Grab Sample Transducer Silts and Clays Organic clay or silt of Portion not recovered End cap Liquid Limit 50 or More Fine-Grained Soils - 50% or More Passes No. 200 Sieve medium to high OH (5) plasticity (1) Percentage by dry weight Combined USCS symbols used for (2) (SPT) Standard Penetration Test fines between 5% and 15% as Peat, muck and other (ASTM D-1586) estimated in General Accordance (3) In General Accordance with highly organic soils with Standard Practice for PT Standard Practice for Description Description and Identification of Soils Highly

Organic and Identification of Soils (ASTM D-2488) Soils (ASTM D-2488) (4) Depth of groundwater ATD = At time of drilling BGS = below ground Static water level (date) surface

Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual-manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System.

DATE: PROJECT NO.

DESIGNED BY: earth + water Exploration Log Key DRAWN BY: FIGURE NO. www.aspectconsulting.com REVISED BY: A-1 Q:\_ACAD Standards\Standard Details\Exploration Log Key A1.dwg FIGURE A-2 EXPLANATION OF BEDROCK TERMS

Weathering or Alteration Abundant fractures coated with oxides, carbonates, sulfates, mud, etc., Very Weathered / Altered through discoloration, rock disintegration, mineral decomposition Medium Weathered / Some fracture coating, moderate or localized discoloration, little to no effect Altered on cementation, slight mineral decomposition Slightly Weathered / A few stained fractures, slight discoloration, little to no effect on cementation, Altered no mineral decomposition Unweathered / Altered Unaffected by weathering agents, no appreciable change with depth

Scale of Rock Strength Discontinuity Aperture Description UCS, psi Field Identification Extremely 40 – 150 Indented by thumbnail. Description for Separation of Weak Rock Fractures, walls (mm) Very Weak 150 – 3,600 Specimen crumbles under sharp Joints, etc. Rock blow with point of geological hammer, and can be cut with a Closed 0.0 pocket knife. Moderately 3,600 – Shallow cuts or scrapes can be Very Narrow 0.0 - 0.1 Weak Rock 7,300 made in a specimen with a pocket Narrow 0.1 - 1.0 knife. Geological hammer point indents deeply with firm blow Wide 1.0 - 5.0 Moderately 7,300 – Specimen cannot be scraped or cut Strong Rock 15,000 with a pocket knife, shallow Very Wide 5.0 - 25+ indentation can be made under firm blows from a hammer point. Strong Rock 15,000 – Specimen breaks with one firm blow 29,000 from the hammer end of a geological hammer. Very Strong > 29,000 Specimen requires many blows of a Rock geological hammer to break intact sample. *UCS = Unconfined Compressive Strength in pounds per square inch

Discontinuity Spacing

Description for Bedding, Description for Joints, Spacing Foliation, or Flow Banding Faults, or other Fractures Very Thickly more than 2 meters more than 6 feet Very Widely Thickly 60 cm to 2 meters 2 to 6 feet Widely Medium 200 mm to 60 cm 6 to 24 inches Medium Thinly 60 to 200 mm 2-1/2 to 6 inches Closely Very Thinly 20 to 60 mm 3/4 to 2-1/2 inches Very Closely

Description for Lamination, Description for Joints, Spacing Foliation, or Cleavage Faults, or other Fractures Intensely / Laminated 6 to 20 mm 1/4 to 3/4 inch Extremely Close Very Intensely / Thinly Laminated less than 6 mm less than 1/4 North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, North abutment. 613490, 1258990 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-1 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 283.9' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) 6.25" Hollow-stem auger Josh - Mud rotary - HQ3 Core 10/17/2016 NA 15' (ATD) Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 FILL 3-inches Hot Mix Asphalt. Loose, moist, brown, slightly gravelly, very silty SAND (SM); fine to coarse sand, fine subrounded to subangular gravel.

Boring filled with bentonite grout and capped with cold-patch asphalt.

280

5 5 5 2 MC 3 S1

Becomes very loose and wet at 8' bgs.

275

10 10 2 2 MC 1 S2

ALLUVIUM Very loose, wet, gray, very gravelly, silty SAND (SM); fine to medium sand, fine subrounded gravel.

270

15 10/17/2016 15 1 2 GS 1 S3 LAKE SEDIMENTS Very loose, moist, brown, fibrous PEAT (PT); trace DRAFTsand. GLACIOMARINE DRIFT 265 Medium dense, wet, gray, sandy, silty GRAVEL (GM); fine to coarse sand, fine subrounded gravel, scattered organic fragmemts.

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery Water Level ATD explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Rock Core Level Logged by: JGF Water B-1 Method Sample Approved by: Sheet 1 of 3 Review Stage:DRAFT Rev.1 ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ LAKE SAMISH BRIDGE P:\GINTW\PROJECTS\NORTH STANDARDASPECTTEMPLATE EXPLORATION LOG December 2016 1, North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, North abutment. 613490, 1258990 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-1 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 283.9' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) 6.25" Hollow-stem auger Josh - Mud rotary - HQ3 Core 10/17/2016 NA 15' (ATD) Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 1 GLACIOMARINE DRIFT 5 Medium dense, wet, gray, sandy, silty GRAVEL (GM); 6 S4 fine to coarse sand, fine subrounded gravel, scattered organic fragmemts. (continued) Medium dense, wet, gray, sandy, silty GRAVEL (GM); fine to coarse sand, fine to coarse subrounded gravel, scattered organic fragmemts.

260

25 25 4 4 GS 6 S5

255

30 30 7 10 10 S6

DARRINGTON PHYLLITE (Jphd) Extremely weak, dark gray, fresh to slightly weathered, PHYLLITE; predominantly mica with accessory graphite and quartz, foliated with greater than 10 foliations/ mm.

250

35 35 S7Run 1 S7Run 50/1" CR= 0 RQD=0

CR= 0 RQD=0 DRAFTRun 2 245 CR= 60% QU RQD=15% Run 3

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery Water Level ATD explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Rock Core Level Logged by: JGF Water B-1 Method Sample Approved by: Sheet 2 of 3 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, North abutment. 613490, 1258990 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-1 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 283.9' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) 6.25" Hollow-stem auger Josh - Mud rotary - HQ3 Core 10/17/2016 NA 15' (ATD) Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 CR= 60% QU RQD=15%

Very weak, dark gray, unweathered, PHYLLITE; predominantly mica, about 20% quartz, and accessory graphite, foliated with greater than 10 foliations/ mm, foliations typically at 45 degrees to

Run 3 core axis.

240

CR= 0 Very weak, dark gray, unweathered, ; RQD=0 PHYLLITE 45 predominatly mica with accessory graphite and 45 quartz, foliated with greater than 10 foliations/ mm, foliations typically at 45 degrees to core axis. Run 4

235

50 Bottom of exploration at 49.8 ft. bgs. 50

230

55 55 DRAFT 225

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery Water Level ATD explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Rock Core Level Logged by: JGF Water B-1 Method Sample Approved by: Sheet 3 of 3 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, North interior. 613400, 1258980 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-2 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 261.57' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 LAKE SEDIMENTS Soft, wet, brown, organic SILT (OL); non-plastic, trace fine sand.

260

Boring backfilled with bentonite grout.

8 2 2 S1

5 5 GLACIOMARINE DRIFT Loose, wet, gray, gravelly, silty SAND (SM); fine to coarse sand, fine subrounded to subangular gravel, 1 4 GS 255 4 S2

Medium dense, wet, gray, sandy silty GRAVEL (GM); fine to coarse subrounded to subangular gravel, sand content washed from sample.

10 10

10 10 250 7 S3

1 5 16 S4 15 15

15 44 245

S5 50/4" DARRINGTON PHYLLITE Extremely weak, dark gray, slightly weathered, PHYLLITE; predominantly mica, 10 % quartz, and accessory graphite, quartz pockets, foliated and fractured with greater than 10 foliations/ mm, strong DRAFTfracture controlled clay alteration, clay infill on fractures 1 to 2 mm thick, foliations at greater than 50 degrees to core axis. S6 Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-2 Method Sample Approved by: Sheet 1 of 2 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, North interior. 613400, 1258980 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-2 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 261.57' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 15 32 S6 44 Bottom of exploration at 21 ft. bgs. 240 Note: Log begins from mudline 24 feet below the existing bridge deck.

25 25

235

30 30

230

35 35 225 DRAFT

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-2 Method Sample Approved by: Sheet 2 of 2 Review Stage:DRAFT Rev.1 ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ LAKE SAMISH BRIDGE P:\GINTW\PROJECTS\NORTH STANDARDASPECTTEMPLATE EXPLORATION LOG December 2016 1, North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, South interior. 613310, 1259000 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-3 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 257.61' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary - HQ3 core 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 GLACIOMARINE DRIFT Loose, wet, gray, gravelly, silty SAND (SM); fine to coarse sand, fine subangular gravel.

Boring backfilled with bentonite grout. 255

5 8 5 3 3 S1

Becomes very silty at 6' bgs

3 6 GS 250 50 S2

DARRINGTON PHYLLITE Extremely weak, dark gray, slightly weathered, PHYLLITE; predominantly mica, 10 % quartz, and accessory graphite, quartz pockets, foliated and fractured with greater than 10 foliations/ mm, strong 10 fracture controlled clay alteration, clay infill on fractures 10 1 to 2 mm thick, foliations at 45 degrees to core axis.

39 58 245 S3 50/3"

15 15

101 S4 240 CR= 0% No recovery RQD=0

DRAFTRun 1

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-3 Method Sample Approved by: Sheet 1 of 2 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, South interior. 613310, 1259000 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-3 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 257.61' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary - HQ3 core 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 Extremely weak, dark gray, slightly weathered, PHYLLITE; predominantly mica, 20 % quartz, and accessory graphite, quartz pockets, extremely foliated and fractured with greater than 10 foliations/ mm, strong fracture controlled clay alteration, clay infill on fractures 1 to 2 mm thick, foliations subparallel to core axis. (continued) 50 50/5" 235 S5

25 25 Extremely weak, dark gray, slightly weathered, PHYLLITE; predominantly mica, 10 % quartz, and accessory graphite, quartz pockets, foliated and fractured with greater than 10 foliations/ mm, weak fracture controlled clay alteration, clay infill on fractures 1 to 2 mm thick, foliations subparallel to core axis.

S6 50/1" 230 Bottom of exploration at 27.7 ft. bgs.

Note: Log begins from mudline 28 feet below the existing bridge deck.

30 30

225

35 35

220 DRAFT

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-3 Method Sample Approved by: Sheet 2 of 2 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, South abutment. 613220, 1259000 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-4 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 284.35' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 FILL 3-inches Hot Mix Asphalt. Loose, wet, gray and brown, sandy GRAVEL (GP); trace coarse sand, fine and coarse subrounded to angular gravel, sand fraction may have washed out of sample.

280

5 5 4 5 4 S1 Loose, wet, gravelly, slightly silty SAND (SP-SM); fine to coarse sand, angular fine and coarse gravel, sample entirely composed of phyllite fragments, trace organic fragments.

275

10 10 4 4 3 S2

270

15 15 2 4 GS 2 S3 DRAFT

265

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-4 Method Sample Approved by: Sheet 1 of 3 Review Stage:DRAFT Rev.1 ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ LAKE SAMISH BRIDGE P:\GINTW\PROJECTS\NORTH STANDARDASPECTTEMPLATE EXPLORATION LOG December 2016 1, North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, South abutment. 613220, 1259000 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-4 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 284.35' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 5 Loose, wet, gravelly, slightly silty SAND (SP-SM); fine 5 to coarse sand, angular fine and coarse gravel, sample 3 S4 entirely composed of phyllite fragments, trace organic fragments. (continued)

GLACIOMARINE DRIFT Medium dense, moist, brown, very sandy SILT (ML); non-plastic, fine to coarse sand, trace fine subrounded to angular gravel. 260

25 25 14 12 22 S5 DARRINGTON PHYLLITE Extremely weak, dark gray, unweathered, PHYLLITE; predominatly mica with accessory graphite and quartz, foliated with greater than 10 foliations/ mm.

255

30 30 62

S6 50/3"

Extremely weak, dark gray, unweathered, PHYLLITE; predominantly mica, 30 % quartz, and accessory graphite, foliated with greater than 10 foliations/ mm, foliations at about 45 degrees to core axis.

250

35 35 100/4" S7

Extremely weak, dark gray, unweathered, PHYLLITE; DRAFTpredominantly mica with accessory graphite and quartz, foliated with greater than 10 foliations/ mm, foliations between 60 and 75 degrees to core axis. 245

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-4 Method Sample Approved by: Sheet 2 of 3 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ North Lake Samish Bridge Replacement - 160142 Geotechnical Exploration Log Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Exploration Number North Lake Samish Bridge, Whatcom County, Washington, South abutment. 613220, 1259000 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) B-4 Gregory Drilling Track mounted CME-55 Autohammer - Rotary Core 284.35' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Josh Mud rotary 10/17/2016 NA No Water Encountered Blows/foot Depth Elev. Exploration Completion Sample Water Content (%) Blows/6" Tests Material Description Depth (feet) (feet) and Notes Type/ID Type (ft) 0 10 20 30 40 50 100/3" S8 Extremely weak, dark gray, unweathered, PHYLLITE; predominantly mica with accessory graphite and quartz, foliated with greater than 10 foliations/ mm, foliations between 60 and 75 degrees to core axis. (continued)

240

45 45 150/4" S9

235

50 50 140/4" S10

230

55 55 150/4" S11 Bottom of exploration at 55.4 ft. bgs. DRAFT

225

Legend Plastic Limit Liquid Limit See Exploration Log Key for No Soil Sample Recovery No Water Encountered explanation of symbols Exploration Split Barrel 2" X 1.375" (SPT) log

Level Logged by: JGF Water B-4 Method Sample Approved by: Sheet 3 of 3 Review Stage:DRAFT Rev.1 Stage:DRAFT Review ASPECT STANDARD EXPLORATION LOG TEMPLATE P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ December 1, 2016 December LOG EXPLORATION TEMPLATE ASPECT STANDARD P:\GINTW\PROJECTS\NORTH LAKE SAMISH BRIDGE REPLACEMENT-160142.GPJ APPENDIX B

Geotechnical Laboratory Test Results

B.1 Geotechnical Laboratory Testing

Geotechnical laboratory tests were conducted on selected soil and rock samples collected during the field exploration program. Eight samples were dispatched to Materials Testing and Consulting, Inc. for determination of moisture content, grain size distribution, or unconfined compressive strength:  Moisture content was determined by ASTM D2216, Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass.  Grain size analysis was conducted in accordance with ASTM C136, Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates.  Unconfined compressive strength of an 11-inch long piece of rock core was determined in accordance with ASTM D7012, Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures Method C. The results of the tests are presented below.

PROJECT NO. 160142  DECEMBER 1, 2016 B-1

Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Client: Aspect Consulting Date: May 15, 2015 Address: Seattle, WA Project: North Lake Samaish Bridge Project #: 16T023-05 Attn: Jesse Favia Sample #: Several

As requested MTC, Inc. has performed the following test(s) on the sample referenced above. The testing was performed in accordance with current applicable AASHTO or ASTM standards as indicated below. The results obtained in our laboratory were as follows below or on the attached pages:

Test(s) Performed: Test Results Test(s) Performed: Test Results

x Sieve Analysis see attached Sulfate Soundness Proctor Bulk Density & Voids Sand Equivalent WSDOT Degradation Fracture Count x Moisture Content see attached x UCS of rock core see attached Minimum Resistivity Organic Content Atterberg Limits Asphalt Extraction/Gradation Rice Density

If you have any questions concerning the test results, the procedures used, or if we can be of any further assistance please call on us at the number below.

Respectfully Submitted,

Harold Benny WABO Supervising Laboratory Technician

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Project: North Lake Samaish Bridge Client: Aspect Consulting Project #: 16T023-05 Date Received: November 23, 2016 Sampled by: Others Date Tested: November 30, 2016 Tested by: HB, KO

Moisture Content - ASTM C-566, ASTM D-2216 & AASHTO T-265

Sample # Location Tare Wet + Tare Dry + Tare Wgt. Of Moisture Wgt. Of Soil % Moisture T16-2246 B-1, S-1 at 5 ft 16.88 265.06 243.47 21.59 226.59 9.5% T16-2247 B-1, S-2 at 10 ft 16.90 320.16 285.69 34.47 268.79 12.8% T16-2248 B-1, S-3 at 15 ft 10.07 344.47 271.17 73.30 261.10 28.1% T16-2249 B-1, S-5 at 25 ft 10.47 122.21 103.47 18.74 93.00 20.2% T16-2251 B-2, S-2 at 30 ft 10.51 556.65 489.28 67.37 478.77 14.1% T16-2252 B-3, S-2 at 35 ft 10.16 500.24 451.58 48.66 441.42 11.0% T16-2253 B-4, S-3 at 15 ft 10.65 365.54 318.75 46.79 308.10 15.2%

All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Sieve Report

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 ASTM D-2487 Unified Soils Classification System Project #: 16T023-05 Sampled By: Client SM, Silty Sand with Gravel Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color: Source: B-1, S-3 at 15 ft Tested By: HB, KO Grayish Brown Sample#: T16-2248 ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821

D(5) = 0.021 mm % Gravel = 30.6% Coeff. of Curvature, CC = 1.01 Specifications D(10) = 0.041 mm % Sand = 51.3% Coeff. of Uniformity, CU = 9.56 No Specs D(15) = 0.062 mm % Silt & Clay = 18.2% Fineness Modulus = 2.80 Sample Meets Specs ? N/A D(30) = 0.128 mm Liquid Limit = n/a Plastic Limit = n/a D(50) = 0.244 mm Plasticity Index = n/a Moisture %, as sampled = n/a D(60) = 0.395 mm Sand Equivalent = n/a Req'd Sand Equivalent = D(90) = 17.741 mm Fracture %, 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 22/75 Fracture %, 2+ Faces = n/a Req'd Fracture %, 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Grain Size Distribution Cumulative Cumulative

1¼"

¾"

½"

Sieve Size Percent Percent Specs Specs

2" 8" 6" 3" 10" 4" #8 ¼" #10 #16 #30 #50 #60 #80 5/8" #4 1" #40 #100 #140 #170 3/8" #200 1½" #20 US Metric Passing Passing Max Min 100% 100.0% 12.00" 300.00 100% 100.0% 0.0% 10.00" 250.00 100% 100.0% 0.0% 8.00" 200.00 100% 100.0% 0.0% 90% 90.0% 6.00" 150.00 100% 100.0% 0.0% 4.00" 100.00 100% 100.0% 0.0% 80% 80.0% 3.00" 75.00 100% 100.0% 0.0% 2.50" 63.00 100% 100.0% 0.0%

2.00" 50.00 100% 100.0% 0.0% 70% 70.0% 1.75" 45.00 100% 100.0% 0.0% 1.50" 37.50 100% 100.0% 0.0% 1.25" 31.50 100% 100.0% 0.0% 60% 60.0% 1.00" 25.00 100% 100% 100.0% 0.0% 3/4" 19.00 92% 92% 100.0% 0.0% 50% 50.0% 5/8" 16.00 87% 100.0% 0.0% % Passing % Passing 1/2" 12.50 80% 80% 100.0% 0.0% 3/8" 9.50 73% 73% 100.0% 0.0% 40% 40.0% 1/4" 6.30 70% 100.0% 0.0% #4 4.75 69% 69% 100.0% 0.0% #8 2.36 67% 100.0% 0.0% 30% 30.0% #10 2.00 67% 67% 100.0% 0.0%

#16 1.18 66% 100.0% 0.0% 20% 20.0% #20 0.850 65% 65% 100.0% 0.0% #30 0.600 63% 100.0% 0.0% #40 0.425 62% 62% 100.0% 0.0% 10% 10.0% #50 0.300 54% 100.0% 0.0% #60 0.250 51% 51% 100.0% 0.0% 0% 0.0% #80 0.180 40% 100.0% 0.0% 100.000 10.000 1.000 0.100 0.010 0.001 #100 0.150 35% 35% 100.0% 0.0% #140 0.106 25% 100.0% 0.0% Particle Size (mm) #170 0.090 21% 100.0% 0.0% #200 0.075 18.2% 18.2% 100.0% 0.0% Sieve Sizes Max Specs Min Specs Sieve Results Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Comments:

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Sieve Report

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 ASTM D-2487 Unified Soils Classification System Project #: 16T023-05 Sampled By: Client GM, Silty Gravel with Sand Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color: Source: B-1, S-5 at 25 ft Tested By: HB, KO Gray Sample#: T16-2249 ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821

D(5) = 0.020 mm % Gravel = 59.5% Coeff. of Curvature, CC = 0.64 Specifications D(10) = 0.041 mm % Sand = 22.1% Coeff. of Uniformity, CU = 267.34 No Specs D(15) = 0.061 mm % Silt & Clay = 18.4% Fineness Modulus = 4.57 Sample Meets Specs ? N/A D(30) = 0.534 mm Liquid Limit = n/a Plastic Limit = n/a D(50) = 8.647 mm Plasticity Index = n/a Moisture %, as sampled = n/a D(60) = 10.898 mm Sand Equivalent = n/a Req'd Sand Equivalent = D(90) = 16.898 mm Fracture %, 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 50/79 Fracture %, 2+ Faces = n/a Req'd Fracture %, 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Grain Size Distribution Cumulative Cumulative

1¼"

¾"

½"

Sieve Size Percent Percent Specs Specs

2.00" 50.00 100% 100.0% 0.0% 70% 70.0% 1.75" 45.00 100% 100.0% 0.0% 1.50" 37.50 100% 100.0% 0.0% 1.25" 31.50 100% 100.0% 0.0% 60% 60.0% 1.00" 25.00 100% 100.0% 0.0% 3/4" 19.00 100% 100% 100.0% 0.0% 50% 50.0% 5/8" 16.00 86% 100.0% 0.0% % Passing % Passing 1/2" 12.50 69% 69% 100.0% 0.0% 3/8" 9.50 52% 52% 100.0% 0.0% 40% 40.0% 1/4" 6.30 44% 100.0% 0.0% #4 4.75 41% 41% 100.0% 0.0% #8 2.36 37% 100.0% 0.0% 30% 30.0% #10 2.00 36% 36% 100.0% 0.0%

#16 1.18 34% 100.0% 0.0% 20% 20.0% #20 0.850 33% 33% 100.0% 0.0% #30 0.600 31% 100.0% 0.0% #40 0.425 29% 29% 100.0% 0.0% 10% 10.0% #50 0.300 26% 100.0% 0.0% #60 0.250 25% 25% 100.0% 0.0% 0% 0.0% #80 0.180 23% 100.0% 0.0% 100.000 10.000 1.000 0.100 0.010 0.001 #100 0.150 22% 22% 100.0% 0.0% #140 0.106 20% 100.0% 0.0% Particle Size (mm) #170 0.090 19% 100.0% 0.0% #200 0.075 18.4% 18.4% 100.0% 0.0% Sieve Sizes Max Specs Min Specs Sieve Results Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Comments:

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Sieve Report

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 ASTM D-2487 Unified Soils Classification System Project #: 16T023-05 Sampled By: Client SM, Silty Sand with Gravel Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color: Source: B-2, S-2 at 30 ft Tested By: HB, KO Gray Sample#: T16-2251 ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821

D(5) = 0.016 mm % Gravel = 15.6% Coeff. of Curvature, CC = 0.92 Specifications D(10) = 0.031 mm % Sand = 60.4% Coeff. of Uniformity, CU = 16.69 No Specs D(15) = 0.047 mm % Silt & Clay = 23.9% Fineness Modulus = 2.40 Sample Meets Specs ? N/A D(30) = 0.123 mm Liquid Limit = n/a Plastic Limit = n/a D(50) = 0.325 mm Plasticity Index = n/a Moisture %, as sampled = n/a D(60) = 0.523 mm Sand Equivalent = n/a Req'd Sand Equivalent = D(90) = 11.225 mm Fracture %, 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 5/12 Fracture %, 2+ Faces = n/a Req'd Fracture %, 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Grain Size Distribution Cumulative Cumulative

1¼"

¾"

½"

Sieve Size Percent Percent Specs Specs

2.00" 50.00 100% 100.0% 0.0% 70% 70.0% 1.75" 45.00 100% 100.0% 0.0% 1.50" 37.50 100% 100.0% 0.0% 1.25" 31.50 100% 100.0% 0.0% 60% 60.0% 1.00" 25.00 100% 100% 100.0% 0.0% 3/4" 19.00 94% 94% 100.0% 0.0% 50% 50.0% 5/8" 16.00 93% 100.0% 0.0% % Passing % Passing 1/2" 12.50 91% 91% 100.0% 0.0% 3/8" 9.50 89% 89% 100.0% 0.0% 40% 40.0% 1/4" 6.30 86% 100.0% 0.0% #4 4.75 84% 84% 100.0% 0.0% #8 2.36 78% 100.0% 0.0% 30% 30.0% #10 2.00 77% 77% 100.0% 0.0%

#16 1.18 71% 100.0% 0.0% 20% 20.0% #20 0.850 69% 69% 100.0% 0.0% #30 0.600 62% 100.0% 0.0% #40 0.425 57% 57% 100.0% 0.0% 10% 10.0% #50 0.300 48% 100.0% 0.0% #60 0.250 44% 44% 100.0% 0.0% 0% 0.0% #80 0.180 37% 100.0% 0.0% 100.000 10.000 1.000 0.100 0.010 0.001 #100 0.150 33% 33% 100.0% 0.0% #140 0.106 28% 100.0% 0.0% Particle Size (mm) #170 0.090 26% 100.0% 0.0% #200 0.075 23.9% 23.9% 100.0% 0.0% Sieve Sizes Max Specs Min Specs Sieve Results Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Comments:

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Sieve Report

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 ASTM D-2487 Unified Soils Classification System Project #: 16T023-05 Sampled By: Client SM, Silty Sand with Gravel Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color: Source: B-3, S-2 at 35 ft Tested By: HB, KO Gray Sample#: T16-2252 ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821

D(5) = 0.012 mm % Gravel = 29.3% Coeff. of Curvature, CC = 0.27 Specifications D(10) = 0.024 mm % Sand = 39.3% Coeff. of Uniformity, CU = 32.90 No Specs D(15) = 0.036 mm % Silt & Clay = 31.4% Fineness Modulus = 2.98 Sample Meets Specs ? N/A D(30) = 0.072 mm Liquid Limit = n/a Plastic Limit = n/a D(50) = 0.306 mm Plasticity Index = n/a Moisture %, as sampled = n/a D(60) = 0.786 mm Sand Equivalent = n/a Req'd Sand Equivalent = D(90) = 30.378 mm Fracture %, 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 37/65 Fracture %, 2+ Faces = n/a Req'd Fracture %, 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Grain Size Distribution Cumulative Cumulative

1¼"

¾"

½"

Sieve Size Percent Percent Specs Specs

2.00" 50.00 100% 100.0% 0.0% 70% 70.0% 1.75" 45.00 100% 100.0% 0.0% 1.50" 37.50 100% 100% 100.0% 0.0% 1.25" 31.50 92% 100.0% 0.0% 60% 60.0% 1.00" 25.00 82% 82% 100.0% 0.0% 3/4" 19.00 80% 100.0% 0.0% 50% 50.0% 5/8" 16.00 78% 100.0% 0.0% % Passing % Passing 1/2" 12.50 77% 77% 100.0% 0.0% 3/8" 9.50 75% 75% 100.0% 0.0% 40% 40.0% 1/4" 6.30 72% 100.0% 0.0% #4 4.75 71% 71% 100.0% 0.0% #8 2.36 66% 100.0% 0.0% 30% 30.0% #10 2.00 66% 66% 100.0% 0.0%

#16 1.18 62% 100.0% 0.0% 20% 20.0% #20 0.850 61% 61% 100.0% 0.0% #30 0.600 58% 100.0% 0.0% #40 0.425 55% 55% 100.0% 0.0% 10% 10.0% #50 0.300 50% 100.0% 0.0% #60 0.250 48% 48% 100.0% 0.0% 0% 0.0% #80 0.180 42% 100.0% 0.0% 100.000 10.000 1.000 0.100 0.010 0.001 #100 0.150 40% 40% 100.0% 0.0% #140 0.106 35% 100.0% 0.0% Particle Size (mm) #170 0.090 33% 100.0% 0.0% #200 0.075 31.4% 31.4% 100.0% 0.0% Sieve Sizes Max Specs Min Specs Sieve Results Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Comments:

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting

Sieve Report

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 ASTM D-2487 Unified Soils Classification System Project #: 16T023-05 Sampled By: Client SM, Silty Sand with Gravel Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color: Source: B-4, S-3 at 15 ft Tested By: HB, KO Grayish Brown Sample#: T16-2253 ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821

D(5) = 0.027 mm % Gravel = 41.1% Coeff. of Curvature, CC = 2.24 Specifications D(10) = 0.054 mm % Sand = 45.2% Coeff. of Uniformity, CU = 93.88 No Specs D(15) = 0.105 mm % Silt & Clay = 13.8% Fineness Modulus = 4.38 Sample Meets Specs ? N/A D(30) = 0.790 mm Liquid Limit = n/a Plastic Limit = n/a D(50) = 3.316 mm Plasticity Index = n/a Moisture %, as sampled = n/a D(60) = 5.116 mm Sand Equivalent = n/a Req'd Sand Equivalent = D(90) = 20.606 mm Fracture %, 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 9/16 Fracture %, 2+ Faces = n/a Req'd Fracture %, 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Grain Size Distribution Cumulative Cumulative

1¼"

¾"

½"

Sieve Size Percent Percent Specs Specs

2.00" 50.00 100% 100.0% 0.0% 70% 70.0% 1.75" 45.00 100% 100.0% 0.0% 1.50" 37.50 100% 100.0% 0.0% 1.25" 31.50 100% 100.0% 0.0% 60% 60.0% 1.00" 25.00 100% 100% 100.0% 0.0% 3/4" 19.00 86% 86% 100.0% 0.0% 50% 50.0% 5/8" 16.00 82% 100.0% 0.0% % Passing % Passing 1/2" 12.50 78% 78% 100.0% 0.0% 3/8" 9.50 73% 73% 100.0% 0.0% 40% 40.0% 1/4" 6.30 63% 100.0% 0.0% #4 4.75 59% 59% 100.0% 0.0% #8 2.36 44% 100.0% 0.0% 30% 30.0% #10 2.00 42% 42% 100.0% 0.0%

#16 1.18 34% 100.0% 0.0% 20% 20.0% #20 0.850 31% 31% 100.0% 0.0% #30 0.600 27% 100.0% 0.0% #40 0.425 24% 24% 100.0% 0.0% 10% 10.0% #50 0.300 21% 100.0% 0.0% #60 0.250 20% 20% 100.0% 0.0% 0% 0.0% #80 0.180 18% 100.0% 0.0% 100.000 10.000 1.000 0.100 0.010 0.001 #100 0.150 17% 17% 100.0% 0.0% #140 0.106 15% 100.0% 0.0% Particle Size (mm) #170 0.090 14% 100.0% 0.0% #200 0.075 13.8% 13.8% 100.0% 0.0% Sieve Sizes Max Specs Min Specs Sieve Results Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Comments:

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting

Project: North Lake Samaish Bridge Date Received: 23-Nov-16 Unified Soils Classification System, ASTM D-2487 Project #: 16T023-05 Sampled By: Client NA Client: Aspect Consulting Date Tested: 30-Nov-16 Sample Color Source: B-1, 41.3 to 42 ft Tested By: HB Gray Sample #: T16-2250

Unconfined Compressive Strength of Rock Core

Description: Gray, highly fractured rock core, about 11 inches in length, with a piece of core flaked away near the middle of the core, reducing the crosssectional area of the core near the middle.

Core Diameter: 2.40 inches

Core Area: 4.52 square inches

Peak Load: 1630 pounds

Strength: 360 psi

Each end of the rock core was saw cut to a flat, perpendicular face. However, because of the many fractures in the rock, some pieces became loose and fell out of the specimen, requiring end capping. The ends of the core were capped using high strength gypsum. The gypsum was allowed to cure for 2 hours and the strength was determined.

Copyright Spears Engineering & Technical Services PS, 1996-98 All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.

Reviewed by:

Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974 Visit our website: www.mtc-inc.net Recommended Soil and Rock Properties for Use in LPILE Software Project No. 160142 - North Lake Samish Bridge Replacement, Whatcom County, Washington Static Conditions | Non-liquefied Unit Effective Unit Effective Friction Angle, φ' Strain Soil Layer Weight, γ Weight, γ' Undrained Cohesion, c (psf)LPILE Soil Model Modulus, k (pci) (degrees) Factor, E (pcf) (pcf) 50 Fill (unsaturated) 105 105 30 N/A Sand (Reese)25 N/A Fill (saturated) 105 42 30 N/A Sand (Reese)20 N/A Alluvium Deposits 105 42 29 N/A Sand (Reese)20 N/A Lake Sediments 90 27 N/A 250 Soft Clay (Matlock)N/A Default Glaciomarine Drift 120 57 32 N/A Sand (Reese)60 N/A

Unit Effective Unit Uniaxial Initial Modulus Strain Factor, LPILE Rock Rock Layer Weight, γ Weight, γ' Compressive of Rock Mass RQD (%) k rm Model (pcf) (pcf) Strength, qu (psi) (psi)

Darrington Phyllite 160 160 180 2,000 0 0.0005 Weak Rock (Reese)

Post-Seismic Conditions | Liquefied1 Unit Effective Unit Strain Factor, Soil Layer Weight, γ Weight, γ' Undrained Cohesion, c (psf) LPILE Soil Model E (pcf) (pcf) 50 Fill (saturated) 105 4290 Soft Clay (Matlock) Default Alluvium Deposits 105 4290 Soft Clay (Matlock) Default Lake Sediments 90 2790 Soft Clay (Matlock) Default Glaciomarine Drift 120 5790 Soft Clay (Matlock) Default

Notes: 1Liquefaction susceptibility based on the 1,000-year AASHTO design event Darrington Phyllite and unsaturated Fill are not susceptible to liquefaction. pcf = pounds per cubic foot psf = pounds per square foot pci = pounds per cubic inch p-multipliers in accordance with Table 10.7.2.4-1 of the AASHTO LRFD BDS should be applied to account for the closely spaced foundation elements

Aspect Consulting 12/30/2016 North Lake Samish Bridge M:\whatcom county\North Lake Samish Bridge Replacement\Analyses\LPILE\N. Lake Sammish Bridge LPILE Soil Properties Page 1 of 1 Appendix C – Environmental Permitting Memo

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May 2017 North Lake Samish Road Bridge Replacement

Environmental and Permitting Considerations Assessment

Prepared for Whatcom County Public Works Department

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May 2017 North Lake Samish Road Bridge Replacement

Environmental and Permitting Considerations Assessment

Prepared for Prepared by Whatcom County Public Works Department Anchor QEA, LLC 322 N. Commercial Street, Suite 210 1605 Cornwall Avenue Bellingham, Washington 98225 Bellingham, Washington 98225

Project Number: 161036-02.01 \\fuji\anchor\Projects\Whatcom County\North Lake Samish Bridge\Env and Permittting Memo\NorthLakeSamishBridge_Environmental Report_Draft_2017-05-26.docx

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TABLE OF CONTENTS

1 Introduction ...... 1 1.1 Project Description ...... 1 1.2 Regulatory Context ...... 1

2 Environmental Considerations ...... 4 2.1 Potential Direct Impacts to Lake Samish ...... 4 2.1.1 Overwater Coverage ...... 4 2.1.2 In-water Infrastructure ...... 5 2.1.3 In-water Fill ...... 5 2.2 Stormwater ...... 6 2.3 Wetlands ...... 7 2.4 Federal Endangered Species Act Considerations ...... 7 2.5 USDOT 4(F) Lands and Recreational Uses ...... 8 2.5.1 Section 4(f) Properties in the Project Vicinity ...... 8 2.5.2 Project Compliance with Section 4(f) ...... 9

3 Anticipated Permits and Approvals ...... 11

4 References ...... 13

TABLES Table 1 Changes in Overwater Cover...... 4 Table 2 Changes in In-water Infrastructure ...... 5 Table 3 New In-Water Fill ...... 5 Table 4 Anticipated Permits and Approvals for North Lake Samish Road Bridge No. 107 Replacement Project ...... 11

FIGURES Figure 1 Project Vicinity ...... 2 Figure 2 Bridge Replacement Alternatives ...... 3 Figure 3 Samish Park and North Lake Samish Drive ...... 9

Environmental and Permitting Considerations Assessment i May 2017

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ABBREVIATIONS BMP best management practice CFR Code of Federal Regulations DAHP Department of Archaeology and Historic Preservation DPS Distinct Population Segment Ecology Washington State Department of Ecology ESA Endangered Species Act FHWA Federal Highway Administration LID low impact development NMFS National Marine Fisheries Services NPDES National Pollutant Discharge Elimination System OHWM ordinary high water mark Project North Lake Samish Road Bridge No. 107 Replacement Project SEPA State Environmental Policy Act SWPPP Stormwater Pollution Prevention Plan TSL Type, Size, and Location (study) U.S.C. United States Code USACE U.S. Army Corps of Engineers USDOT U.S. Department of Transportation USFWS U.S. Fish and Wildlife Service WDFW Washington Department of Fish and Wildlife WDNR Washington Department of Natural Resources

Environmental and Permitting Considerations Assessment ii May 2017

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1 Introduction Anchor QEA, LLC is supporting TranTech Engineering, LLC in developing a Type, Size, and Location (TSL) study for the North Lake Samish Road Bridge No. 107 Replacement Project (Project) for Whatcom County Public Works. This support includes developing information on environmental and permitting considerations related to the Project for use in developing the TSL study. This report describes the potential environmental considerations that will need to be addressed as part of the environmental process for and additionally provides a summary of the anticipated permits and approvals that will be needed to construct the Project.

1.1 Project Description The Project is located in Whatcom County, Washington in Section 27, Township 37 North, Range 3 East (Figure 1). It will replace the existing 250-foot bridge that conveys North Lake Samish Road over Lake Samish in a north-south direction across the narrow strait that connects the two basins of the lake. Currently, two alternatives are under evaluation for the Project, each of which would replace the bridge at its current location, but which vary in specific alignment (Figure 2). These alternatives are further defined as Alternative 1 – Straight Alignment and Alterative 2 – Curved Alignment due to the orientation of the roadway for each alternative.

1.2 Regulatory Context Work within waterbodies of the U.S. and Washington State requires applying for and receiving a variety of federal, state, and local permits and approvals prior to constructing a project. As part of this regulatory process, specific impacts of a project must be identified, including how a project will impact specific elements of the natural environment. This report summarizes the expected impacts to the natural environmental that will result from the Project and additionally provides a list of the anticipated permits and approvals that will need to be required to construct the Project.

Environmental and Permitting Considerations Assessment 1 May 2017 a m i s h k e S L a

Service Layer Credits: Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community Project Area Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community

Publish Date: 2017/05/25, 11:05 AM | User: bbundy Filepath: \\fuji\anchor\Projects\Whatcom County\North Lake Samish Bridge\Env and Permittting Memo\NLakeSamish_EnvMemo_Fig1.mxd

0 500 Figure 1 Project Vicinity [ Feet Environmental and Permitting Considerations Assessment North Lake Samish Road Bridge Replacement

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Alternative 1 – Straight Alignment Alternative 2- Curved Alignment

Filepath: \\fuji\anchor\Projects\Whatcom County\North Lake Samish Bridge\Env and Permittting Memo\NLakeSamish_EnvMemo_Fig2.docx

Figure 2 Bridge Replacement Alternatives Environmental and Permitting Considerations Assessment North Lake Samish Road Bridge Replacement

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2 Environmental Considerations The North Lake Samish Road Bridge and other overwater and in-water structures are located along the shorelines and within Lake Samish. These features, while important for recreation, transport, and commerce, also can have impacts on the shoreline ecology and other elements of the environment. The following section provides an overview of the potential effects of replacing the North Lake Samish Road Bridge, including direct impacts to Lake Samish from new overwater coverage, in-water infrastructure, and in-water fill, as well as impacts to wetlands within the Project footprint. It also provides information on Endangered Species Act (ESA)-listed species presence and considerations in the Project area and associated stormwater considerations.

2.1 Potential Direct Impacts to Lake Samish

2.1.1 Overwater Coverage The existing North Lake Samish Road Bridge covers an approximately 6,982-square-foot area below the ordinary high water mark (OHWM) of Lake Samish. For the purposes of this report, the OHWM was calculated using an estimated Lake Samish water surface elevation of 273.2 feet above sea level (Wilson 2012). Both of the proposed bridge alternatives will result in an increase of overwater coverage due to an increase in the overall width of the traffic lanes, shoulder, and sidewalk. Table 1 provides a summary of the increase in square footage of overwater cover that would result from each alternative.

Table 1 Changes in Overwater Cover

New Overwater Current Overwater Change in Overwater Alternative Cover1 Cover1 Cover1 Alternative 1 – Straight Alignment 9,586 6,982 2,604 Alternative 2 – Curved Alignment 9,708 6,982 2,726 Notes 1. All units are in square feet.

Regulatory agencies will typically require mitigation for increases in overwater cover to compensate for anticipated increases in fish predation, changes in fish behavior and impacts to habitat functions. Mitigation measures to address these potential overwater cover impacts may be required by various regulatory agencies.

Environmental and Permitting Considerations Assessment 4 May 2017

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2.1.2 In-water Infrastructure The existing North Lake Samish Road Bridge is supported by approximately 59 12-inch-diameter wooden pilings, which appear to be treated with a creosote finish. Both of the proposed bridge alternatives will result in an increase of in-water structure because both alternatives propose to use a single-column pier system (two 6-foot-diameter piers in total) to support the bridge deck. Table 2 provides a summary of the increase in square footage of in-water infrastructure that would result from each alternative.

Table 2 Changes in In-water Infrastructure

New In-Water Current In-Water Change in In-Water Alternative Infrastructure1 Infrastructure1 Infrastructure1 Alternative 1 – Straight Alignment 56.5 46.3 10.2 Alternative 2 – Curved Alignment 56.5 46.3 10.2 Notes: 1. All units are in square feet.

Regulatory agencies will typically require mitigation for increases in in-water infrastructure to compensate for anticipated impacts to the lake bed and associated habitat loss. Mitigation measures to address these potential overwater cover impacts may be required by various regulatory agencies. Because the existing bridge pilings appear to be treated with creosote, the regulatory agencies may consider removal of these pilings to be adequate mitigation for the increase in in-water infrastructure. However, this will need to be worked out with the regulatory agencies during the Project permitting process.

2.1.3 In-water Fill Both of the proposed bridge alternatives would require new fill to be placed below the OHWM of Lake Samish to support the bridge approaches. Table 3 provides a summary of the area of new in-water fill that would result from each alternative.

Table 3 New In-Water Fill

Alternative New In-Water Fill1 Alternative 1 – Straight Alignment 122 Alternative 2 – Curved Alignment 219 Notes: 1. All units are in square feet.

Environmental and Permitting Considerations Assessment 5 May 2017

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Regulatory agencies will typically require mitigation for new in-water fill to compensate for anticipated impacts to the lake bed and associated habitat loss. Mitigation measures to address these potential in-water fill impacts may be required by various regulatory agencies.

Additionally, because the fill is expected to occur within the 100-year floodplain for Lake Samish, mitigation for flood plain impacts and development of a zero-rise analysis that demonstrates that there will be no increase in flooding as a result of the Project may need to be performed for the Project.

2.2 Stormwater Under both alternatives, impervious surface area will be increased; therefore, certain stormwater management minimum requirements for site redevelopment are expected to apply. Those requirements will need to be evaluated and documented through a Stormwater Site Plan. Stormwater runoff from the existing impervious and pervious surfaces currently discharges directly into Lake Samish. The stormwater runoff is not treated for water quality or quantity prior to discharge aside from incidental filtering of roadway approach area runoff through vegetated surfaces.

If left untreated, stormwater can transport heavy metals, such as copper and zinc, and other toxic contaminants associated with motor vehicles and urban runoff from roadways to nearby surface waters (Camponelli et al. 2010). Contaminants discharged to surface waters from untreated roadway runoff have the potential to impact fish and other aquatic biota (e.g., benthic invertebrates) that may be present through ingestion and long-term bioaccumulation (Sandahl et al. 2007).

Stormwater best management practice (BMP) controls are expected to be required during construction and operation of the project. Stormwater controls during construction (e.g., construction BMPs) will be required to prevent disturbed or eroded soils or other materials from the construction area from entering adjacent surface waters. It is assumed that either 1) greater than 1 acre of ground disturbance will result from either alternative, or 2) the proximity of the Project improvements to the lake, including in-water work for bridge pier construction and bridge work over the lake, will likely result in the Washington State Department of Ecology (Ecology) requiring a National Pollutant Discharge Elimination System (NPDES) Construction Stormwater General Permit for the Project. A Stormwater Pollution Prevention Plan (SWPPP) will be needed to address construction stormwater BMP control specifics.

During operation, it is anticipated that permanent stormwater BMP controls, potentially including low impact development (LID) and treatment BMP measures, will be required to address the overall replacement and increases in impervious surface under either alternative. It is possible that these stormwater controls may require additional land disturbance and increase the Project footprint, so

Environmental and Permitting Considerations Assessment 6 May 2017

DRAFT any additional impacts resulting from new stormwater features should be addressed as part of further project design and permitting efforts.

2.3 Wetlands No wetland delineations have been completed for the Project to date. However, based on a preliminary field reconnaissance, a potential wetland area appears to be located in the southeast corner of the Project footprint of both alternatives. This wetland is expected to have to be filled to accommodate construction of the Project.

The wetland appears to be less than 1/10th of an acre in size and, therefore, impacts to this wetland are anticipated to be able to be permitted via a USACE Nationwide Permit 14 for linear transportation projects. However, this wetland will need to be officially delineated before a final determination can be made as to the appropriate permitting process for addressing impacts to this wetland. If this wetland area is determined to be a jurisdictional wetland and is required to be filled for the Project, mitigation in accordance with Ecology and USACE standards is expected to be required.

There are additional areas nearby, but outside of, the footprint of both alternatives to the northeast, southeast, and southwest that have vegetation typical to wetlands; however, these wetlands are not expected to be impacted by the Project based on the footprints of the two alternatives.

2.4 Federal Endangered Species Act Considerations Based on information from the Washington Department of Fish and Wildlife (WDFW 2017), Lake Samish is used by the following fish species that are listed under the ESA:

• Fall Chinook salmon (Oncorhynchus tshawytscha) – Puget Sound Evolutionarily Significant Unit ‒ Use cited in Lake Samish, Friday Creek, and Barnes Creek • Winter steelhead (Oncorhynchus mykiss) – Puget Sound Distinct Population Segment (DPS) ‒ Use cited in Lake Samish and Friday Creek • Bull trout (Salvelinus confluentus) – Coastal-Puget Sound DPS ‒ Use cited in Lake Samish and Friday Creek

No ESA critical habitat is located in Lake Samish.

Due to the potential presence of these ESA-listed species, an ESA Biological Assessment will need to be developed to address the potential effects from construction (e.g., pile installation, construction stormwater) and ongoing operation of the new bridge including addressing potential total and dissolved copper and zinc concentrations from Project-related stormwater discharges.

Environmental and Permitting Considerations Assessment 7 May 2017

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2.5 USDOT 4(F) Lands and Recreational Uses The U.S. Department of Transportation (USDOT) requires consideration of park and recreational lands, wildlife and waterfowl refuges, and historic sites in transportation project development. The process for this consideration is commonly known as Section 4(f), because it was originally published in that section of the USDOT Act of 1966. The law is now codified in 49 United States Code (U.S.C.) §303 and 23 U.S.C. §138, and its implementing regulations are found at 23 Code of Federal Regulations (CFR) 774.

Section 4(f) states that no publicly owned park, recreation area, wildlife or waterfowl refuge, or land of historic site that is of national, state, or local significance shall be used, acquired, or affected, unless there is no feasible and prudent alternative.

Use of a Section 4(f) property includes the following:

• Permanently incorporating land into a transportation facility • Temporarily using land in a way that is adverse in terms of the statute's preservation purpose • Having proximity impacts so severe that the protected activities, features, or attributes of a property are substantially impaired

If a project will use a 4(f) property, the Federal Highway Administration (FHWA) must determine that either the use will be de minimis (will not adversely affect the activities, features, or attributes of the property), or that there is no feasible and prudent alternative. Both scenarios require coordination with the official with jurisdiction over the resource, and the latter requires a Section 4(f) Evaluation.

2.5.1 Section 4(f) Properties in the Project Vicinity The northern portion of the Project area, on the north shore of Lake Samish, is within Samish Park, a Whatcom County park. (Figure 3). Maps and aerial photos do not show any other parks, trails, or other recreational facilities in the Project vicinity.

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Figure 3 Samish Park and North Lake Samish Drive

The Lake Samish bridge is older than 50 years, and may be historically significant. It has not been evaluated to determine whether it is eligible for national, state, or local preservation registers. There are no other recorded historic properties in the Project area, though no survey has been conducted. It is possible that there are unrecorded archaeological sites in the area of ground disturbance. However, archaeological sites only considered 4(f) properties if they are exceptionally historically important and therefore worthy of preservation in place.

There are no wildlife or waterfowl refuges in the Project vicinity; the nearest refuges appear to be in Mt. Vernon, Washington, and Surrey, British Columbia.

2.5.2 Project Compliance with Section 4(f) Further review and coordination under Section 4(f) will be required to determine:

1- If the project will use any part of Samish Park, and if so, whether the project use is de minimis 2- Whether the North Lake Samish Bridge is historically significant

Coordination will occur with Whatcom County Parks and Recreation for Samish Park, and the Department of Archaeology and Historic Preservation (DAHP) for North Lake Samish Bridge.

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Coordination with DAHP will occur through the process of complying with Section 106 of the National Historic Preservation Act.

If there is no use of the park, and the bridge is determined to be not historically significant, the Project can proceed without further review. The finding that no 4(f) properties are present will be supported in the National and State Environmental Policy Act documentation.

If there is de minimis use of the park, the finding must be documented in communication with Whatcom County Parks and Recreation. The communication should describe measures to avoid, minimize, or mitigate impacts, and to enhance benefits.

If the bridge is historically significant, an analysis should occur to determine whether the project is eligible to make use of the Programmatic Section 4(f) Evaluation and Approval for FHWA Projects that Necessitate the Use of Historic Bridges. If it is eligible to use the programmatic evaluation, the process of completing the Section 4(f) Evaluation would be streamlined. If not, a more detailed evaluation would be required.

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3 Anticipated Permits and Approvals Replacing and expanding the footprint of an existing overwater or in-water facility requires applying for and obtaining an array of federal, state, and local permits and approvals. The scope, nature, and public perception of a project drives the level of agency review required, which in turn determines the extent and complexity of documentation to be prepared, the time and effort it takes to obtain a permit or approval, and whether a public comment period and consultation with Native American tribes is required—all of which may add cost, time, and uncertainty to the permitting process. The permitting and regulatory information contained in this memorandum is based on the assumption that the modifications necessary to achieve the project’s purpose will be not be considered maintenance and repair of an existing structure due to the expansion of the bridge proposed under both alternatives under consideration.

Table 4 provides an overview of the anticipated permits and approvals that would be required for both bridge alternatives under consideration, including the name of the permit, issuing agency, permit trigger, and applicability of each permit.

Table 4 Anticipated Permits and Approvals for North Lake Samish Road Bridge No. 107 Replacement Project

Permit or Approval Agency Trigger Applicability Required due to the replacement bridge being located within Lake Samish (a navigable water of the USACE Work within navigable Section 10 Permit* U.S.) (Federal) waters of the U.S. * Note that the USACE may defer to the U.S. Coast Guard Bridge Permitting Process and not require a Section 10 permit. Required due to the replacement Constructing a new bridge bridge being located within Lake or reconstructing or Samish (a navigable water of the Bridge Permit* U.S. Coast Guard modifying an existing bridge U.S.) across the navigable waters * Note that the U.S. Coast Guard may of the U.S. defer to the USACE Section 10 permit and not require a Bridge Permit. Required due to the fill that will USACE Discharge of fill material in Section 404 Permit need to be placed in Lake Samish (Federal) waters of the U.S. for the new bridge abutments Projects with a federal nexus USACE in occurring in the vicinity of Required due to the potential coordination with any threatened or presence of Chinook salmon, ESA Compliance NMFS/USFWS endangered species or steelhead trout, and bull trout in (Federal) destroy or adversely modify Lake Samish critical habitat

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Permit or Approval Agency Trigger Applicability Projects with a federal nexus USACE in that have the potential to Section 106 Required due to a USACE permit coordination with affect cultural, Compliance being required DAHP (Federal) archaeological, and/or historical properties Triggered by projects that Coastal Zone USACE in contain a federal nexus Management Act coordination with Required due to a USACE permit proposed within any of Consistency Ecology being required Washington's 15 coastal Determination (Federal/State) counties Work that uses, diverts, Required due to work that will use, Hydraulic Project obstructs, or changes the divert, obstruct, or change the WDFW (State) Approval natural flow or bed of state natural flow or bed of any of the waters (below OHWM) fresh waters of the state Aquatic Use Required due to the bedlands of Work that occurs on or over Authorization or WDNR Lake Samish being under WDNR WDNR-owned aquatic lands Lease ownership Required as part of state and local permitting process; a mitigated State Environmental Whatcom County Any proposal that requires a determination of non-significance Policy Act Compliance (Local) local agency decision is anticipated to be the SEPA approval mechanism Required in Shoreline Residential and Conservancy Shoreline Development of an Jurisdictions for institutional institutional development development and essential public Shoreline Conditional and essential public facilities facilities, where there is no feasible Use Permit in the Shoreline Residential location outside the shoreline (i.e., and Conservancy Shoreline this project is not a permitted use Jurisdictions per the Whatcom County Shoreline Master Program) Required due to potential wetland Critical Areas Work within designated impacts and being in a wildlife Whatcom County Ordinance critical areas or critical area habitat conservation area (Local) Compliance buffers (waterfowl concentrations/ bald eagle habitat) Alteration or new Whatcom County construction regulated by Required due to bridge Building Permit (Local) the Whatcom County construction Building Code Title 15 Notes: DAHP: Washington Department of Archaeology and SEPA: State Environmental Policy Act Historic Preservation USACE: U.S. Army Corps of Engineers Ecology: Washington State Department of Ecology USFWS: U.S. Fish and Wildlife Service NMFS: National Marine Fisheries Services WDFW: Washington Department of Fish and Wildlife OHWM: Ordinary High Water Mark WDNR: Washington Department of Natural Resources

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4 References Camponelli, K.M., S.M. Lev, J.W. Snodgrass, E.R. Landa, and R.E. Casey, 2010. Chemical fractionation of Cu and Zn in stormwater, roadway dust, and stormwater pond sediments. Environ. Pollut. 158, 2143-2149.

Sandahl, J.F., D.H. Baldwin, J.J. Jenkins, N.L. Scholz, 2007. A sensory system at the interface between urban stormwater runoff and salmon survival. Environ. Sci. Technol. 2007; 41:2998–3004.

WDFW (Washington Department of Fish and Wildlife), 2017. Salmonscape Interactive mapper – Stock Status. Available from: http://wdfw.wa.gov/mapping/salmonscape. Accessed on: May 23, 2017.

Wilson (Wilson Engineering), 2012. Lake Samish Basin Comprehensive Stormwater Plan. Prepared for Whatcom County, Washington. June 1, 2012.

Environmental and Permitting Considerations Assessment 13 May 2017 Appendix D – Cultural Resources Memo

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May 2017 North Lake Samish Road Bridge Replacement

Cultural Resources Assessment

Prepared for Whatcom County Public Works Department

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May 2017 North Lake Samish Road Bridge Replacement

Cultural Resources Assessment

Prepared for Prepared by Whatcom County Public Works Department Anchor QEA, LLC 322 N. Commercial Street, Suite 210 1605 Cornwall Avenue Bellingham, Washington 98225 Bellingham, Washington 98225

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TABLE OF CONTENTS

1 Introduction ...... 1 1.1 Project Description ...... 1 1.2 Regulatory Context ...... 1

2 Environmental and Cultural Context ...... 4 2.1 Environmental Setting ...... 4 2.2 Cultural Setting ...... 4 2.3 Previous Research ...... 7 2.4 Cultural Resource Potential ...... 8 2.4.1 Archaeological Potential ...... 8 2.4.2 Built Environment Potential ...... 8

3 Next Steps and Recommendations ...... 9

4 References ...... 10

FIGURES Figure 1 Project Vicinity ...... 2 Figure 2 Bridge Replacement Alternatives ...... 3 Figure 3 General Land Office Survey Map, 1873 ...... 5 Figure 4 Unidentified Logging Operation, Samish Lake, Washington, 1910 ...... 7

APPENDICES Appendix A Washington State Department of Transportation Bridge Data Appendix B Cultural Resources Survey Work Plan

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ABBREVIATIONS APE Area of Potential Effects CFR Code of Federal Regulations DAHP Department of Archaeology and Historic Preservation LSA Lake Samish Association NRHP National Register of Historic Places Project North Lake Samish Bridge Replacement Project RCW Regulatory Code of Washington Section 106 Section 106 of the National Historic Preservation Act SHPO State Historic Preservation Officer TSL Type, Size, and Location (study) USACE United States Army Corps of Engineers

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1 Introduction Anchor QEA, LLC is supporting TranTech Engineering, LLC in developing a Type, Size, and Location (TSL) study for the North Lake Samish Road Bridge No. 107 Replacement Project (Project) for Whatcom County Public Works. This support includes developing information on cultural resources to identify considerations for use in developing the TSL study. This report describes recorded and potential unrecorded cultural resources in the project area, identifies the laws and regulations that require cultural resources review, and recommends a process for future cultural resources compliance.

1.2 Regulatory Context The Project will require a permit from the U.S. Army Corps of Engineers (USACE). As part of the permit process, the USACE must comply with Section 106 of the National Historic Preservation Act (Section 106), its implementing regulations at 36 Code of Federal Regulations (CFR) 800, and USACE’s Section 106 regulations at 33 CFR 325.

Section 106 requires federal agencies to consider the effects of their undertakings on historic properties, which are prehistoric or historic sites, districts, structures, or objects that are listed in (or eligible for listing in) the National Register of Historic Places (NRHP). Agencies must also consult with the State Historic Preservation Officer (SHPO) and interested and affected Native American tribes.

Washington state law also applies to the Project. Regulatory Code of Washington (RCW) 27.53 prohibits unpermitted disturbance of archaeological sites, and RCW 68.60.055 governs inadvertent discovery of human remains. The State Environmental Policy Act also requires consideration of cultural, historical, and archaeological resources.

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Alternative 1 – Straight Alignment Alternative 2- Curved Alignment

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2 Environmental and Cultural Context

2.1 Environmental Setting The Project area is within the Puget Trough physiographic region, which is characterized by the effects of glaciation (Franklin and Dyrness 1973:6). The region consists of gentle north-south trending ridges and troughs, with troughs often occupied by lakes. Lake Samish is one such natural lake, occupying approximately the same location as when it was first mapped by the General Land Office in 1873 (Figure 3). The lake’s outlet is Friday Creek at the south end, a tributary to the Samish River.

Glaciers began to retreat about 14,500 years ago, leaving deposits of recessional outwash (Heller and Dethier 1981). As the glaciers retreated, marine waters flooded Puget Sound, depositing characteristic glaciomarine sediments (Easterbrook 2003). As the glaciers continued to melt, the global sea level rose while the landmass rebounded. Around 9,000 years ago, isostatic rebound was complete but the sea level was still rising, and early Holocene shorelines began to submerge. Shorelines in the northern Puget Sound area did not stabilize until the mid-Holocene, about 5,000 years ago (Thorson 1980).

Climate and vegetation also stabilized around the mid-Holocene; at that time, a wide variety of resources would have become available. These include large and small mammals, fish (including substantial salmon runs), waterfowl, berries, tubers, and roots. Today much of the County is in the Tsuga heterophylla vegetation zone (Franklin and Dyrness 1973:45). Prior to historic and modern logging and development, this zone was characterized by forests of Western hemlock, Douglas fir, and Western red cedar with understories of shrubs, ferns, and grasses (Franklin and Dyrness 1973:72-73).

2.2 Cultural Setting The earliest archaeological sites in the northern Puget Sound and Gulf of Georgia region date to the early to mid-Holocene around 8,100 to 4,400 years ago. The sites are attributed to the Old Cordilleran culture in British Columbia and the Olcott Tradition in northwestern Washington and are classified as Archaic Period (Matson and Coupland 1995:78; Ames and Maschner 1999:67-72). The sites typically consist of stone tools, including leaf-shaped bifacial points and cobble tools, and lack evidence of permanent houses.

By the latter part of the mid-Holocene, larger populations began to organize in complex ways to exploit a wide range of terrestrial and littoral resources, including salmon and shellfish, land mammals, and plant resources such as berries, roots, and bulbs. Cultures around Puget Sound and northward show “an unequivocal adaptation to coastal resources,” though classic Northwest coast developments such as sizeable longhouses and large-scale storage are still absent (Matson and Coupland 1995:97).

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Over time, populations grew and began to reside in large semi-sedentary cedar plank house villages located at river mouths and confluences and on protected shorelines. The artifact tool kits became increasingly complex and specialized, allowing for large takes of resources, which were processed and stored for year-long consumption (Ames and Maschner 1999). Archaeological expressions of late Holocene cultures are consistent with ethnographic descriptions.

The Project area is in the traditional territory of the Nooksack Tribe and the Lummi Nation. Both are Central Coast Salish tribes; the Nooksack speak the Nooksack language and the Lummi speak the Halkomelem language (Suttles 1990). Central Coast Salish peoples traditionally relied on a seasonal round (hunting and gathering based on available plants and animals each season) that focused on fishing and also included hunting for sea and land mammals, gathering plant foods and medicines, and harvesting intertidal invertebrates (Suttles 1990). Villages consisted of large split-plank houses occupied by extended family groups, but seasonal camps used temporary shelters.

Whatcom County communities felt the effects of Euroamerican contact prior to the sustained interaction with Euroamericans. Introduced diseases had already caused shifts in population and settlement patterns by the time the first settlers arrived in the early 1850s (Ruby and Brown 1986:111). The Lummi were signatories to the Point Elliott Treaty of 1855, which assigned them to the Lummi Reservation. The Nooksack Tribe was unable to attend the treaty signing and is not a signatory. The treaty assigns them to the Lummi Reservation as well, but few resettled (Ruby and Brown 1986:153). Just a few years after the treaty signing, gold was discovered along the Fraser River to the north, bringing an influx of settlers and commerce to the area, and “from this time on, Native people were greatly outnumbered in the region” (Suttles 1990:471). Despite demographic and social changes, Nooksack and Lummi people remain in the area today and practice many aspects of their traditional cultures.

The first documented Euroamerican exploration of the region was an expedition by the Spanish in 1791, followed the next year by George Vancouver’s expedition. Settlement was sparse until the 1850s, when sawmills began to be established along the shoreline and gold was discovered in the Fraser River area to the north (Oakley 2005). In the fall of 1851, sawmill worker Nicholas Sheffer visited the Samish area (though closer to the coast than Lake Samish) and reported little evidence of Euroamerican presence in the region (Sheffer 2006).

Whatcom County was carved out of neighboring Island County in 1854. Rail came to the region in the 1890s, including a trestle crossing Lake Samish built by the Fairhaven and Southern Railroad Company and sold to the Great Northern Railway Company (LSA 2016). The trestle washed out in a flood in 1892 and does not appear to have been replaced (Seattle Post-Intelligencer 1892). The earliest homesteads around Lake Samish were patented in 1885, and the settlement of Bluff (formerly Crescent) was founded on the lake in 1902 (LSA 2016). The lake was ringed by shingle mills and logging camps (Figure 4), as well as a coal company (the Samish Lake Coal Company,

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Figure 4 Unidentified Logging Operation, Samish Lake, Washington, 1910

University of Washington Libraries, Darius Kinsey Photograph Collection. PH Coll 126

2.3 Previous Research No cultural resources surveys have occurred in the Project area. Two cultural resources surveys have been conducted with 2 miles of the Project area. Only one was along the lake shoreline: a pedestrian

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DRAFT reconnaissance of the Lutherwood Camp and Retreat Center approximately 0.75 mile west of the Project area (Munsell 2016). The second survey was near South Samish Way, approximately 1.5 miles north of the Project area. It included pedestrian reconnaissance and subsurface testing (Baldwin and Watrous 2009). Neither survey located archaeological or historic built environment resources.

There are no archaeological sites recorded in the Project area or within a 2-mile radius of it. The nearest recorded site is a logging camp in northern Skagit County (45SK450).

There are two historic-age structures within a mile of the Project area, both residences along West Lake Samish Drive (781 W Lake Samish Drive; 851 W Lake Samish Drive). Both have been determined not eligible for listing on the NRHP.

2.4 Cultural Resource Potential

2.4.1 Archaeological Potential According to the Statewide Predictive Model for Archaeological Resources, the Project area is in the High to Very High Risk category (DAHP 2017). The category indicates locations where natural features indicate a high likelihood that precontact archaeological resources are present. The Project area is in this category primarily due to its proximity to a natural shoreline. Precontact or historic archaeological materials could be present in Holocene native sediments. These could include precontact tools, faunal material, and features (such as remains of structures or hearths), or the remains of logging or transportation infrastructure.

The area has likely been disturbed by construction of the road and existing bridge (as well as previous bridges). However, outside the boundaries of demonstrated disturbance, there is significant potential for archaeological materials.

2.4.2 Built Environment Potential The only structure in the Project area is the North Lake Samish Road bridge, which will be demolished. The bridge is older than 50 years and may be eligible for listing in the NRHP. An evaluation would be required to determine if it is NRHP-eligible.

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3 Next Steps and Recommendations Section 106 requires the following actions from the USACE:

1. Identify the Project’s Area of Potential Effects (APE).

2. Inventory and evaluate potential historic properties in the APE (archaeological sites, historic structures, and Traditional Cultural Properties).

3. Determine whether the Project will adversely affect NRHP-eligible historic properties, and mitigate any adverse effects.

4. Consult with DAHP and interested and affected Native American tribes.

The USACE will likely require Whatcom County to provide documentation fulfilling the requirements of the first three steps. The APE will be determined by the footprint of the selected alternative, and is expected to include the existing bridge and the area of ground disturbance for new construction. If the proposed new bridge is significantly different in appearance or prominence than the existing structure, there may also be potential effects to historic structures within view of the Project area.

When an alternative has been selected and the APE determined, a field survey will be required to evaluate the bridge (and possibly other structures within view), and likely to conduct an archaeological survey in areas where native sediments could be disturbed. Appendix B contains a work plan for completing the survey.

If the survey identifies NRHP-eligible historic properties, Whatcom County would need to work with USACE, DAHP, and tribes to avoid, minimize, or mitigate adverse effects.

Compliance with Section 106 will fulfill the requirements of RCW 27.53, and information gained in the Section 106 process will also be used in preparing National Environmental Policy Act and State Environmental Policy Act documentation.

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4 References Ames, Kenneth M., and Herbert D.G. Maschner, 1999. Peoples of the Northwest Coast: Their Archaeology and Prehistory. Thames and Hudson Ltd. London.

Baldwin, Garth L., and Joshua B. Watrous, 2009. Archaeological Investigation at the Emissions Technologies Inc. North Samish Project. Whatcom County, WA. Report on file at the Department of Archaeology and Historic Preservation, Olympia, Washington.

DAHP (Department of Archaeology and Historic Preservation), 2017. Washington Information System for Architectural and Archaeological Records (WISAARD). Restricted-access online database accessed October 2017.

Easterbrook, Don J., 2003. Cordilleran Ice Sheet Glaciation of the Puget Lowland and Columbia Plateau and Alpine Glaciation of the North Cascade Range, Washington. In Western Cordillera and Adjacent Areas, edited by T.W. Swanson, pp. 137-157. The Geological Society of America, Boulder, Colorado.

Franklin, Jerry F., and C.T. Dyrness, 1973. Natural Vegetation of Oregon and Washington. USDA Forest Service Technical Report PNW-8. Portland, OR.

Heller, Paul L., and David P. Dethier, 1981. Surficial and Environmental Geology of the Lower Baker Valley, Skagit County, Washington. Northwest Science 55(2):145-155.

Matson, R.G., and Gary Coupland, 1995. The Prehistory of the Northwest Coast. Academic Press, London.

Munsell, David, 2016. NRCS Cultural Resources Survey for the Lutherwood Camp and Retreat Center Inc. EQIP 2016 Project, Contract No. 74054616VJ. Report on file at the Department of Archaeology and Historic Preservation, Olympia, Washington.

LSA (Lake Samish Association), 2016. Facts and History: Discovering Lake Samish. Electronic document. Accessed: May 2017. Available from: http://www.lakesamish.org/history/discovery.html.

Oakley, Janet, 2005. Whatcom County – thumbnail history. Accessed: October 2014. Available from: http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=7327.

Ruby, Robert H., and John A. Brown, 1986. A Guide to the Indian Tribes of the Pacific Northwest. University of Oklahoma Press. Norman, Oklahoma.

Seattle Post-Intelligencer, 1892. A Storm in Whatcom County. November 21, 1892.

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Sheffer, Nicholas V., 2006. A Story of Pioneering: Being a Personal Narrative of Early Days in Northwest Washington, told to the Tribune by N.V. Sheffer, of 1854. HistoryLink.org Essay 7975. Electronic document. Accessed: May 2017. Available from: http://www.historylink.org/File/7975.

Suttles, Wayne, 1990. Central Coast Salish. In Northwest Coast, edited by W. Suttles, pp. 453-475. Handbook of North American Indians Volume 7. Smithsonian Institution, Washington D.C.

Thorson, Robert M., 1980. Ice-sheet Glaciation of the Puget Lowland, Washington, During the Vashon Stade (late Pleistocene). Quaternary Research 13: 303-312.

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Appendix A Washington State Department of Transportation Bridge Data

Appendix B Cultural Resources Survey Work Plan

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Cultural Resources Survey Work Plan, North Lake Samish Bridge Replacement

Introduction The North Lake Samish Bridge Replacement Project (Project) will replace the existing 250-foot bridge that conveys North Lake Samish Road over Lake Samish in a north-south direction across the narrow strait that connects the two basins of the lake. Cultural resources review has indicated that there is potential for cultural resources in the Project area. Precontact and historic archaeological resources may be present in the area of ground disturbance, and the North Lake Samish Bridge may be historic. This plan describes how potential cultural resources should be located and evaluated.

Historic Structures Evaluation A qualified architectural historian will review the Project plans. The historian will conduct background research to determine the historic context of the North Lake Samish Bridge and properties in its viewshed.

Potentially historic properties that could be affected will be field surveyed and recorded on a Department of Archaeology and Historic Preservation (DAHP) Historic Property Inventory Form, and evaluated for National Register of Historic Places (NRHP) eligibility and Project effects. If there will be adverse effects to NRHP-eligible properties, the historian will assist in consultation to resolve them. This will likely also include coordination with the Project team regarding compliance with Section 4(f).

Archaeological Survey A qualified professional archaeologist will review project plans, as well as geotechnical information and other relevant literature. Where Project work could encounter native Holocene sediments, archaeological testing will be conducted. Testing is expected to include subsurface tests excavated by hand. Sediment will be screened and GPS coordinates will be collected. Deep testing is not expected because Holocene sediments in the Project area are expected to be relatively thin.

Survey Logistics The historian and archaeologist will conduct the survey together for safety and efficiency. Any required Rights of Entry should be secured prior to the survey, and a utilities locate will be performed. A Health and Safety Plan will be prepared for the survey, and a tailgate safety meeting will be held. Fieldwork is expected to take 1 to 2 days, depending on Project design.

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Reporting The historian and archaeologist will collaborate to produce a report meeting DAHP and U.S. Army Corps of Engineers (USACE) guidelines for Section 106 reporting. The report is expected to become an attachment to the USACE permit application, and USACE will distribute it to Native American tribes and DAHP as part of Section 106 consultation.

Cultural Resources Assessment B-2 May 2017 Appendix E - Hydrology & Geomorphology Memo

1605 Cornwall Avenue Bellingham, Washington 98225 DRAFT 360.733.4311

Memorandum May 26, 2017

To: Khashayar Nikzad, PhD., P.E., TranTech Engineering From: Adam Hill, P.E., and Jerry Bibee, P.E., Anchor QEA, LLC cc: Tom Weller, P.E., TranTech Engineering; Derek Koellmann, AICP CEP, Anchor QEA, LLC

Re: Summary of Hydrologic/Hydraulic Data and Preliminary Analysis and Assessment, North Lake Samish Road Bridge No. 107 Replacement Project

This memorandum summarizes available hydrologic and hydraulic data and preliminary analysis and assessment conducted by Anchor QEA, LLC for the TranTech design team for the North Lake Samish Road Bridge No. 107 Replacement (Project) Type, Size, and Location (TSL) study.

Hydrologic and Hydraulic Data Review and Prior Evaluation Findings Available hydrologic data and prior analysis work for the Lake Samish watershed relevant to the Project has been reviewed including lake drainage subbasin areas; watershed hydrologic characteristics; lake surface area, volumes, and level variation; hydrologic modeling for lake stage (elevation) fluctuation and peak inflow/outflow estimates; and downstream flow records. The available data and previous key watershed analysis results are briefly summarized below.

The Project is located within the Lake Samish Basin, an 8,005-acre watershed at the lake outlet that consists of forested hillsides, valleys, ravines, and the 816-acre Lake Samish waterbody. This basin is part of Water Resource Inventory Area (WRIA) 3 (Lower Skagit-Samish). The bridge to be replaced crosses Lake Samish at a sill between two arms of the lake. The smaller West Arm lies upstream of the bridge and the larger East Arm is located downstream of the bridge. The West Arm affecting the Project hydrology is reported to have the following approximate characteristics (Wilson 2012; Wilson 2010):

• 130 acres of lake surface area (16 percent of the total lake area) • 9,200 acre-feet of total lake storage volume (30 percent of total lake volume) • 2,320 acres of contributing drainage area (32 percent of the total tributary drainage area, not including the lake area)

As part of the comprehensive stormwater plan previously prepared (Wilson 2012), a hydrologic model of the Lake Samish Basin watershed was developed. The modeling effort was completed based on subbasins within the Lake Samish Basin to simulate watershed runoff response to precipitation records; estimate lake water level fluctuations based on lake inflows, lake storage volume-stage characteristics, and lake stage-discharge characteristics at the outflow weir (adjusted seasonally). For that plan, the modeling results were calibrated to available lake stage and

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The hydrologic model applied to the prior lake watershed modeling (Wilson 2012) was the HEC-HMS continuous simulation model. The model uses hourly precipitation data, evapotranspiration data, physical subbasin data, and observed lake levels to simulate hydrology in the basin. Watershed runoff was simulated from April 2001 through December 2009 but was not further extrapolated beyond the simulation period to estimate peak flow and lake stage recurrence interval values (i.e., for the 100-year event).

The reported peak flow results from the HEC-HMS model simulation for the drainage areas tributary to the West Arm (not including the lake area) are shown in Table 1. An additional eight subbasins contribute to the East Arm downstream of the Project and upstream of the lake outlet. These values are peak inflow estimates to the lake during the period of simulation only and do not reflect hydrologic routing effects that occur through the lake storage volume that significantly reduces peak outflows from the lake (this also applies to the Project site). The hydrologic modeling did estimate peak discharges from subbasins for a “wet year,” specifically 2001. The reported cumulative peak inflow estimate for the largest event that year into the lake’s West Arm (upstream of the Project) totaled approximately 660 cubic feet per second (cfs). Similarly, for the lake’s East Arm watershed area downstream of the Project, the cumulative reported peak inflow value was approximately 1,805 cfs.

Table 1 Simulated Peak Flows for Lake Samish Subbasins Tributary to the West Arm (2001 “Wet Year”)

Subbasin Drainage Area (acres) Peak Discharge (cfs) Mud 1,040 258.9 Roy East 495 123.8 Roy West 415 95.5 North 372 181.6 Source: Wilson 2010. cfs: cubic foot per second

During the simulation period, observed lake levels at the outlet ranged from 272.4 feet to 276.4 feet (NAVD88), with an average lake level of 273.6 feet (Wilson 2010). Modeled simulated lake stages do generally follow with the observed values, but comparative results show that there is some variability, particularly during larger flow events. For example, review of Figure 9 (Wilson 2010) shows that the model appears to under-simulate the lake stage by approximately 1.0 foot compared to observed lake stage data during the largest event in the simulation period (January 2009). This variability may May 26, 2017 DRAFT Page 3 be associated with the actual watershed event precipitation record compared to the compiled model precipitation time series (that partially uses adjusted Bellingham Airport records). It may also be affected by actual lake outlet conditions that differ from modeling assumptions during that event.

Simulated flows at the lake outlet are compared to measured flows at a downstream stream gage at the Friday Creek Fish Hatchery (between December 2005 and September 2009), as adjusted for drainage area differences. That comparison is shown in Figure 10 (Wilson 2010). For that period of comparison, lake outlet peak outflows were predicted to not exceed approximately 230 cfs. However, because of the under-simulation of lake stage during the largest event in January 2009, significantly higher lake outlet flows are expected to have occurred during that event.

Preliminary Hydrologic and Hydraulic Evaluation for Assessment of Bridge Replacement Alternatives As another basis of hydrologic assessment, flows from the nearest USGS active gage, USGS #12201500 (Samish River near Burlington) were reviewed to relate observed lake water levels to peak storm events in the basin. This gage has a significantly larger drainage area than the Lake Samish outlet (87.8 versus 12.5 square miles). Although the USGS gage is significantly downstream, observed peak water levels in Lake Samish were found to generally occur during peak storm events recorded at the USGS gage. Table 2 compares peak storm event flows and their estimated recurrence intervals at the USGS gage to observed Lake Samish water levels.

Table 2 Lake Samish Water Levels Compared to Downstream Samish River Peak Flows at USGS Gage

Water Year Lake Samish Water Level USGS Gage #12201500 Estimated Recurrence (Date of Event) (feet, NAVD88)1 Peak Flow (cfs)2 Interval 2001 NA 1,280 < 2-year (June 12) 2002 276.2 2,980 2-year (December 14, 2001) 2003 275.5 1,050 < 2-year (February 21) 2004 275.6 4,050 5-year (November 19, 2003) 2005 NA 4,820 7-year (November 25, 2004) 2006 275.7 2,290 < 2-year (January 10) 2007 NA 2,050 < 2-year (November 6, 2006) 2008 274.5 1,470 < 2-year (February 8) May 26, 2017 DRAFT Page 4

Water Year Lake Samish Water Level USGS Gage #12201500 Estimated Recurrence (Date of Event) (feet, NAVD88)1 Peak Flow (cfs)2 Interval 2009 276.4 9,870 80-year (January 8) 2010 NA 2,880 2-year (November 26, 2009) Notes: 1. Wilson 2010: Data reported from Figure 6 where peaks in water levels are noticeable. 2. USGS 2017a NA: Not Available

Table 2 shows that the highest observed lake level (elevation 276.4 NAVD 88) in the model-simulated time series correlates with the January 9, 2009, event with recorded USGS gage peak flow of 9,870 cfs, estimated to be approximately an 80-year event. Adjusting that downstream recorded peak flow to the Lake Samish outlet using proportional drainage areas and regional regression exponents results in an estimate of lake peak outflow for that event of approximately 1,460 cfs. However, because the lake watershed area is regulated by the lake storage volume, and the downstream watershed is unregulated, it is expected that the actual lake peak outflow would have been significantly lower.

A log-Pearson III flood frequency analysis (USGS 1982) was completed for the USGS gage using the full period of gage flow records (see Attachment A). This analysis estimated the 100-year event peak flow at the USGS gage to be approximately 10,270 cfs. This flow is 4 percent higher than the 2009 recorded event (9,870 cfs), so for purposes of this preliminary analysis, it is assumed that the 100-year event flow at the lake outlet would also be approximately 4 percent higher than the 2009 recorded event.

A StreamStats (USGS 2017b) hydrologic analysis based on regional regression equations was also completed for the Lake Samish drainage area tributary to the lake outlet to comparatively estimate peak flows for the 100-year event (see Attachment A). The 100-year event peak flows at the lake outlet and Project site, computed from StreamStats, were estimated to be 771 cfs and 241 cfs, respectively. This analysis method was used only for comparative assessment of peak flows because it only addresses certain regional runoff factors and does not account for watershed-specific factors including lake storage flow regulation effects.

Table 3 summarizes the various estimates of peak flows at the Lake Samish outlet for the 2009 and 100-year events. May 26, 2017 DRAFT Page 5

Table 3 Peak Flow Estimates – Lake Samish Outlet

Peak Flow Peak Flow Estimate Method Estimate (cfs) Analysis Basis and Comments Source 2009 event; lake peak stage and HEC-HMS peak flow from outlet 230 associated peak outflow were Wilson 2010 under-simulated USGS gage recorded peak flow, 2009 event; not including lake adjusted to lake outlet based on 1,460 USGS 2017a storage flow regulation effects relative drainage areas 100-year event; not including StreamStats regression analysis 771 lake storage flow regulation USGS 2017b effects

As Table 3 summarizes, there is a wide range of estimated peak flows for the Lake Samish outlet using different analysis methods. To provide a more reliable lake outflow estimate, a preliminary lake stage- discharge rating estimate for the lake outlet controls was developed (see Attachment A). This was based on the description of the Lake Samish Retention Dam outlet control structure under its reported winter configuration (Wilson 2010). The center bay was not fully described in that plan, so it was assumed that the weir crest in that bay is 1 foot lower than the inner bays for the winter configuration. Using this assumption and the reported outlet control configuration for the remainder of the weir, Table 4 presents the computed estimates of lake outlet peak flows at various lake stage elevations.

Table 4 Lake Samish Outlet Preliminary Stage-Discharge Rating Peak Flow Estimates

Lake Stage Elevation Assumed Flow Depth above Estimated Lake Outlet (feet, NAVD88) Center Bay Weir Crest (feet) Peak Flow (cfs) 271.4 0.0 0 272.41 1.0 11 273.4 2.0 79 273.62 2.2 103 274.4 3.0 239 275.4 4.0 468 276.43 5.0 747 277.4 6.0 1,070 278.4 7.0 1,430 Notes: 1. Minimum depth during data collection period (Wilson, 2010) 2. Average depth during data collection period (Wilson, 2010) 3. Maximum depth during data collection period (Wilson, 2010) cfs: cubic foot per second

May 26, 2017 DRAFT Page 6

Using the preliminary stage-discharge rating reported in Table 4, and the recorded lake stage during the January 2009 event (largest event in record), the lake outlet peak flow estimate for that event would have been approximately 750 cfs. This flow is much higher than the HEC-HMS simulated peak flow at the outlet (230 cfs, at a lower simulated stage) but much lower than the unregulated peak flow estimate as adjusted from the USGS gage (1,460 cfs). This peak flow rate based on the preliminary discharge rating is relatively close to the StreamStats analysis peak flow estimate (771 cfs for 100-year event). Therefore, the lake outlet discharge rating analysis computed peak flow of 750 cfs for the January 2009 event was the basis for further adjustment to the Project site.

Using the 4 percent increase described previously above the January 2009 event, the 100-year event peak flow estimate at the lake outlet would be 780 cfs. The corresponding lake stage water surface elevation would be about 276.5 feet NAVD88 (based on the Table 4 discharge rating). Translating the lake outlet peak flow back to the replacement bridge Project site requires an adjustment based on the relative drainage areas, but also with a consideration of associated active storage volumes in the West and East arms of the lake. Considering those factors, the 100-year peak flow at the replacement bridge was conservatively assumed to be approximately 40 percent of the computed value at the lake outlet, or 310 cfs.

For preliminary hydraulic analysis of the proposed bridge alternatives, the 100-year peak flow estimate of 310 cfs and the 100-year estimated lake stage elevation of 276.5 feet NAVD88 were applied to the proposed bridge section using ManningSolver program (Current Applications 2000) (see Attachment A). Because the bridge alternatives sections are similar, only a single computation for the linear bridge replacement section was conducted (the curvilinear alignment hydraulic section is very similar). The analysis assumed an irregular bridge opening section including lake bed elevations taken from available topographic mapping, proposed bridge abutment and pier locations and sizes, and an assumed Manning’s roughness coefficient of 0.035. The resulting 100-year event compute average velocity through the bridge section was about 0.11 foot per second. The corresponding hydraulic slope through the replacement bridge was 0.000017 percent. At this very low average velocity through the replacement bridge opening, scour of the channel bed and banks is not expected, although localized maximum velocities near the channel piers is expected to be somewhat higher (likely still not problematic though). Other potential shoreline scour due to boat wakes/prop wash should be further reviewed in next project phases.

There are several uncertainties and assumptions included in these preliminary analyses as presented. During future design phases, it is recommended that a detailed review of flow at the lake outlet and at the proposed replacement bridge be completed to confirm or further adjust the 100-year lake stage and peak flow estimate. Additionally, detailed hydraulic modeling of the recommended bridge section should be completed in combination with the updated flows to confirm velocities and any lake bed, pier/abutment, or adjacent shoreline scour protection measure needs. May 26, 2017 DRAFT Page 7

References Current Applications, 2000. ManningSolver. Computer program, version 2.02.

USGS (U.S. Geological Survey), 1982. Guidelines for Determining Flood Flow Frequency. Bulletin #17B of the Hydrology Subcommittee. March 1982.

USGS, 2017a. Peak Streamflow for the Nation. USGS 12201500 Samish River near Burlington, WA. Accessed on: March 28, 2017. Available at: https://nwis.waterdata.usgs.gov/nwis/peak?site_no=12201500&agency_cd=USGS&format=html.

USGS, 2017b. StreamStats for Washington. Accessed on: May 25, 2017. Available at: https://water.usgs.gov/osw/streamstats/Washington.html.

Wilson (Wilson Engineering), 2010. Lake Samish Comprehensive Stormwater Plan Hydrologic Modeling – Summary of Results and Recommendations. Technical Memorandum prepared for Kraig Olason, Whatcom County Stormwater Division. October 6, 2010.

Wilson, 2012. Lake Samish Basin Comprehensive Stormwater Plan. Prepared for Whatcom County, Washington. June 1, 2012.

Attachment A Preliminary Hydrologic and Hydraulic Analyses Supporting Project Assessment

5/26/2017

FREQUENCY ANALYSIS

year flow, cfs log(flow) rank P=m/(N+1) T=1/P 1944 998 3.00 59 0.967 1.03 1945 2,820 3.45 29 0.475 2.10 1946 4,310 3.63 13 0.213 4.69 1947 2,750 3.44 30 0.492 2.03 1948 1,210 3.08 56 0.918 1.09 1949 4,990 3.70 9 0.148 6.78 1950 5,830 3.77 5 0.082 12.20 1951 4,030 3.61 16 0.262 3.81 1952 1,210 3.08 56 0.918 1.09 1953 2,150 3.33 40 0.656 1.53 1954 2,330 3.37 37 0.607 1.65 1955 2,420 3.38 35 0.574 1.74 1956 2,000 3.30 42 0.689 1.45 1957 3,670 3.56 22 0.361 2.77 1958 1,490 3.17 49 0.803 1.24 1959 2,670 3.43 32 0.525 1.91 1960 2,690 3.43 31 0.508 1.97 1961 3,770 3.58 19 0.311 3.21 1962 1,220 3.09 55 0.902 1.11 1963 1,590 3.20 47 0.770 1.30 1964 1,540 3.19 48 0.787 1.27 1965 3,740 3.57 20 0.328 3.05 1966 1,280 3.11 53 0.869 1.15 1967 2,200 3.34 39 0.639 1.56 1968 3,300 3.52 24 0.393 2.54 1969 2,590 3.41 33 0.541 1.85 1970 891 2.95 60 0.984 1.02 1971 3,980 3.60 17 0.279 3.59 1972 3,790 3.58 18 0.295 3.39 1973 3,730 3.57 21 0.344 2.90 1974 3,380 3.53 23 0.377 2.65 1975 1,940 3.29 43 0.705 1.42 1976 6,090 3.78 4 0.066 15.25 1977 1,650 3.22 46 0.754 1.33 1978 3,090 3.49 26 0.426 2.35 1979 1,340 3.13 52 0.852 1.17 1980 6,340 3.80 3 0.049 20.33 1981 1,490 3.17 49 0.803 1.24 1982 5,590 3.75 7 0.115 8.71 1983 8,440 3.93 2 0.033 30.50 1997 3,110 3.49 25 0.410 2.44 1998 1,740 3.24 44 0.721 1.39 1999 2,480 3.39 34 0.557 1.79 2000 4,240 3.63 14 0.230 4.36 2001 1,280 3.11 53 0.869 1.15 2002 2,980 3.47 27 0.443 2.26 2003 1,050 3.02 58 0.951 1.05 2004 4,050 3.61 15 0.246 4.07 2005 4,820 3.68 10 0.164 6.10 2006 2,290 3.36 38 0.623 1.61 2007 2,050 3.31 41 0.672 1.49 2008 1,470 3.17 51 0.836 1.20 2009 9,870 3.99 1 0.016 61.00 2010 2,880 3.46 28 0.459 2.18 2011 5,700 3.76 6 0.098 10.17 2012 4,780 3.68 11 0.180 5.55 2013 1,680 3.23 45 0.738 1.36 2014 2,360 3.37 36 0.590 1.69 2015 5,150 3.71 8 0.131 7.63 2016 4,680 3.67 12 0.197 5.08 average 3153 3.43 std.dev. 1836 0.25 skew 1.36 0.04 log-Pearson III return(yr) p zp K log(Q) Q 1.58 0.367 -0.337 -0.343 3.35 2224 2 0.500 0.000 -0.007 3.43 2690 2.33 0.571 0.177 0.171 3.47 2974 5 0.800 0.839 0.837 3.64 4330 10 0.900 1.281 1.285 3.75 5580 25 0.960 1.757 1.770 3.87 7337 50 0.980 2.064 2.085 3.94 8763 100 0.990 2.337 2.367 4.01 10273 500 0.998 2.874 2.922 4.15 14054 83.4 0.988 2.268 2.296 3.99 9870

1 FloodFreqAnalysis_Samish_12201500 StreamStats Version 3.0 Flow Statistics Ungaged Site Report Date: Thurs May 25, 2017 8:04:11 AM GMT‐7 Study Area: Washington NAD 1983 Latitude: 48.6456 ( 48 38 44) NAD 1983 Longitude: ‐122.3718 (‐122 22 19) Drainage Area: 12.78 mi2

Peak‐Flow Basin Characteristics

100% Region 2 (12.8 mi2) Regression Equation Valid Range Parameter Value Min Max Drainage Area (square miles) 12.8 0.08 3020 Mean Annual Precipitation (inches) 46 23 170

Peak‐Flow Statistics 90‐Percent Prediction Interval Statistic Value Unit Standard Error (percent) Equivalent years of record Min Max PK2 273 cfs 56 1 PK10 480 cfs 53 1 PK25 589 cfs 53 2 PK50 688 cfs 53 2 PK100 771 cfs 54 3 PK500 1000 cfs

http://pubs.er.usgs.gov/usgspubs/wri/wri974277 (http://pubs.er.usgs.gov/usgspubs/wri/wri974277) Sumioka_ S.S._ Kresch_ D.L._ and Kasnick_ K.D._ 1998_ Magnitude and Frequency of Floods in Washington: U.S. Geological Survey Water‐Resources Investigations Report 97‐4277_ 91 p.

Peak‐Flow Basin Characteristics

100% Region 2 (3.85 mi2) Regression Equation Valid Range Parameter Value Min Max Drainage Area (square miles) 3.85 0.08 3020 Mean Annual Precipitation (inches) 42.5 23 170

Peak‐Flow Statistics 90‐Percent Prediction Interval Statistic Value Unit Standard Error (percent) Equivalent years of record Min Max PK2 84.4 cfs 56 1 PK10 150 cfs 53 1 PK25 184 cfs 53 2 PK50 215 cfs 53 2 PK100 241 cfs 54 3 PK500 315 cfs

Accessibility FOIA Privacy Policies and Notices U.S. Department of the Interior | U.S. Geological Survey URL: http://streamstatsags.cr.usgs.gov/v3_beta/FTreport.htm Page Contact Information: StreamStats Help Streamstats Status News Page Last Modified: 08/09/2016 11:34:10 (Web1) Section 1 Section 2 Section 3 Section 4 Section 5 Depth from bottom of 0 1 1 2 2 active outlet (ft) Width (ft) 3.5 7.5 7.5 7.5 7.5 Depth (ft) Flow - Section 1 (cfs) Flow - Section 2 (cfs) Flow - Section 3 (cfs) Flow - Section 4 (cfs) Flow - Section 5 (cfs) Total Flow (cfs) Elevation (ft) 0 0 0 0 0 0 0 271.4 0.2 1.01 0 0 0 0 1.01 271.6 0.4 2.82 0 0 0 0 2.82 271.8 0.6 5.17 0 0 0 0 5.17 272 0.8 7.94 0 0 0 0 7.94 272.2 1 11.08 0 0 0 0 11.08 272.4 1.2 14.55 2.16 2.16 0 0 18.87 272.6 1.4 18.32 6.05 6.05 0 0 30.42 272.8 1.6 22.37 11.08 11.08 0 0 44.53 273 1.8 26.68 17.02 17.02 0 0 60.72 273.2 2 31.23 23.76 23.76 0 0 78.75 273.4 2.2 36.01 31.2 31.2 2.16 2.16 102.73 273.6 2.4 41.02 39.3 39.3 6.05 6.05 131.72 273.8 2.6 46.24 47.99 47.99 11.08 11.08 164.38 274 2.8 51.66 57.24 57.24 17.02 17.02 200.18 274.2 3 57.27 67.02 67.02 23.76 23.76 238.83 274.4 3.2 63.07 77.3 77.3 31.21 31.21 280.09 274.6 3.4 69.06 88.06 88.06 39.3 39.3 323.78 274.8 3.6 75.22 99.27 99.27 48 48 369.76 275 3.8 81.55 110.92 110.92 57.25 57.25 417.89 275.2 4 88.05 123 123 67.03 67.03 468.11 275.4 4.2 94.71 135.48 135.48 77.31 77.31 520.29 275.6 4.4 101.53 148.35 148.35 88.07 88.07 574.37 275.8 4.6 108.5 161.61 161.61 99.29 99.29 630.3 276 4.8 115.63 175.24 175.24 110.94 110.94 687.99 276.2 5 122.9 189.23 189.23 123.02 123.02 747.4 276.4 5.2 130.32 203.57 203.57 135.5 135.5 808.46 276.6 5.4 137.87 218.26 218.26 148.38 148.38 871.15 276.8 5.6 145.57 233.28 233.28 161.64 161.64 935.41 277 5.8 153.4 248.64 248.64 175.28 175.28 1001.24 277.2 6 161.37 264.31 264.31 189.28 189.28 1068.55 277.4 6.2 169.47 280.3 280.3 203.63 203.63 1137.33 277.6 6.4 177.69 296.59 296.59 218.32 218.32 1207.51 277.8 6.6 186.04 313.19 313.19 233.35 233.35 1279.12 278 6.8 194.52 330.09 330.09 248.71 248.71 1352.12 278.2 7 203.12 347.27 347.27 264.39 264.39 1426.44 278.4

Flow Calculations Lake Samish Outlet Lake Samish Bridge Manning's Equation - Irregular Section

Flow 310 cfs WSElev 276.450 ft Slope 0.00000017 ft/ft

Sta Elev n Sta Elev n Sta Elev n Sta Elev n 1300.00 284.05 .035 1305.60 284.03 .035 1325.00 272.50 .035 1350.00 262.50 .035 1375.00 258.50 .035 1389.41 257.36 .035 1389.42 285 .035 1401.42 285 .035 1401.43 257.36 .035 1425.00 257.25 .035 1450.00 258.00 .035 1454.68 258.37 .035 1475.00 260.90 .035 1477.41 260.90 .035 1477.42 285 .035 1489.42 285 .035 1489.43 262.43 .035 1500.00 263.00 .035 1525.00 267.40 .035 1550.00 272.70 .035 1567.19 283.75 .035 1569.43 283.75 .035

Velocity 0.107 fps Velocity Head 0.000179 ft Flow Area 2,890 sf Wetted Perimeter 287 ft Hydraulic Radius 10.1 ft Top Width 213 ft Froude Number 0.00515 Critical WSElev 258.487 ft Critical Slope ft/ft

LakeSamishBridge.msd 5/25/2017 User: Unregistered ManningSolver v2.02 Appendix F – Utility Coordination Memo

Appendix G – Public Involvement Memo

Lake Samish Bridge Phase 1 Report

Public Engagement and Architectural Design

To identify the local community’s design preferences for the Lake Samish Bridge, the design team conducted two public work sessions and a web-based survey. The general purpose of these efforts was to:  Establish community based objectives and preferences for the bridge’s design, particularly the architectural elements and the visual aspects of the structural elements.  Identify preferences for the different architectural and pedestrian oriented bridge elements, and  Arrive at a design solution that meets the community’s objectives

At the first work session, held on December 7, 2016, the approximately 25 participants identified design objectives for the visual character and pedestrian functions. Then, working in small groups, they reviewed photos of relevant bridge elements such as railings, walkways, pavement, piers, and lighting, and noted their preferences. These two exercises provided the design team with a preliminary picture of the range of bridge design alternatives that should be considered.

Following the first work session, the County conducted a web-based survey with questions framed to test the work session’s results. The 70 responses to the survey generally confirmed the work session 1 results favoring a visually low key bridge with simple architectural elements, low-level or no lights, minimal or no art and a modest pedestrian walkway.

Example of survey results illustrated to present at Work Session #2

MAKERS architecture and urban design Page 1 Based on this public input, the design team prepared three design alternatives that illustrated: 1. A simple straight bridge with multiple piers, minimal abutment structures, and an overlook 2. A horizontal curved bridge with single piers, steel railing, low level pedestrian lights and no art. 3. A straight bridge with multiple piers, and panels to give the bridge a sense of tying into the abutments with some artwork. The team then refined these alternatives and prepared several 3 dimensional renderings of each.

MAKERS architecture and urban design Page 2 On February 23, 2017 the team conducted Work Session #2 at which they presented the results of the survey and the three design alternatives. The approximately 25 participants reviewed the alternatives and then indicated their preferences for the individual elements (e.g.: railing, structural configuration, lighting, etc.) with dots and preferences for the alternatives as a whole with another sized dot.

The results of this exercise are presented in the chart below. Participants were also given the opportunity to discuss the bridge design in general to help the design team determine how to combine the preferred elements into a preferred design. The numbers in the pink circles indicate the number of responses that favored that alternative.

MAKERS architecture and urban design Page 3 As a result of this input, the team prepared a preferred design that features:  A horizontal curve (provided that an agreement can be reached with the property owners of the submerged land over which the bridge would extend).  Single piers at two points in the lake.  A minimal abutment structure.  A steel railing with the barrier incorporated into the design. (The railing must also meet the height requirement for bicycles on the east side.)  Low level pedestrian lighting mounted on the railing.  Plain walkway pavement.  No art.

Some of the preferred design renderings are shown below:

MAKERS architecture and urban design Page 4

MAKERS architecture and urban design Page 5

MAKERS architecture and urban design Page 6 Appendix H – Roadway Alignment & Profile Preliminary Plans

XREF LIST: 2016026-BASE-SV G G G G G G G G G G G G G G G

270 G G G 270 G G G G

PC STA=15+67.19

280 COUNTY290 PARK 260 280 260 P P P P P P P P P P P P P P PT STA=13+05.60 P SS SS P SS P SS

290 16 P

ROY ROAD 15

P FO + SS P

14 +

00 P

13 +

00 SS 258 280

CP P

270

SS 280 260 N LAKE SAMISH RD

270 17 SS

LAKE SAMISH +

P PT STA=17+33.98 PT

SS 260 12 +00 SS

290

P SS DESCRIPTION:

P · THIS ALTERNATIVE ANGLES THE ROAD SOUTH EASTERLY SS 270 FROM THE PC OF THE NORTH CURVE. 260

· IT HAS A DESIGN SPEED OF 25 MPH EXCEPT FOR THE 290 SS 280 SS W LAKE SAMISH RD SOUTH CURVE WHICH HAS A DESIGN SPEED OF 20 MPH.. · THE MAX SUPERELEVATION RATE FOR THE CURVES IS 4%. LEGEND

BRIDGE ABUTMENT BRIDGE STRUCTURE

20' 10' 0 20' 40' PIER ROADWAY SCALE IN FEET 350 350

HIGH PT STA: 14+54.68 HIGH PT ELEV: 286.40 PVI STA:14+36.38 325 PVI ELEV:287.00 325 K:80.41 LVC:200.00 GRADE BREAK STA = 11+50.00 300 ELEV = 282.787 300 BVCE: 285.53 FINISHED GRADE EVCE: 285.98 BVCS: 13+36.38 EVCS: 15+36.38 STA: 15+67.19 BRIDGE END STA: 13+05.60 BRIDGE END 1.47% -1.02%

EXISTING BRIDGE DECK 275 275 BRIDGE ABUTMENT BRIDGE ABUTMENT

EXISTING GROUND

N LAKE SAMISH ROAD PROFILE SCALE: 1"=20' HORIZ., 1"=20' VERT. P:\2016\2016026 - WHATCOM COUNTY NORTH LAKE SAMISH BRIDGE\000 CAD\010 DRAWING\D-EXHIBIT\LAKE EXHIBIT 2.DWG - PROJECT NO.: #### REFERNCE WHATCOM COUNTY N LAKE SAMISH ROAD BRIDGE REPLACEMENT SHEET NO.

1:29 PM FED. AID NO.: ####

- PUBLIC WORKS E2 DEPARTMENT DATUM: ####

SCALE: 1" = 20' SHEET July 21, 2017 322 N COMMERCIAL STREET, SUITE 210 ALTERNATIVE - 1 - 2 BELLEVUE OFFICE: BELLINGHAM, WA 98225 DESIGNED BY: #### DRAWN BY: #### STRAIGHT ALIGNMENT 121011 NE 1st ST, STE 305, BELLEVUE, WA 98005 1 INCH SCALE BAR OF RBRAR PH: 425-453-5545 FAX: 425-453-6779 360-7786200 NO. DATE REVISION ADJUST SCALE ACCORDINGLY CHECKED BY: #### APPROVED BY: #### 2 CP

XREF LIST: 2016026-BASE-SV

G G G G G G G G G

G G G G G G

270 G STA=15+67.86 PT G G G G 270 G G G G COUNTY PARK

280 290 260

PCC STA=12+97.10280 260 P STA=16+14.22 PC P P P P P P

P P P P P P P 15

14 P +

+ 00 SS SS 00 P SS P SS

FO ROY ROAD 16 P

290 P

+ P FO 13 SS P

00 P +

00 SS 258 280

CP P

P 270 N LAKE SAMISH RD

SS 280 LAKE SAMISH 260

270 17 SS

P PT STA=17+30.18 PT

SS 260 12 SS +00

290

P DESCRIPTION: SS

P · THIS ALTERNATIVE HAS A SET OF COMPOUND CURVE WITH SS

155' RADIUS CURVES AT EITHER END AND A 400' RADIUS 270 CURVE IN MIDDLE. 260 · IT HAS A DESIGN SPEED OF 25 MPH . 290 · THE MAX SUPERELEVATION RATE FOR THE CURVES IS 4%. LEGEND W LAKE SAMISH RD BRIDGE ABUTMENT BRIDGE STRUCTURE 20' 10' 0 20' 40' PIER ROADWAY SCALE IN FEET

350 350

HIGH PT STA: 14+48.43 HIGH PT ELEV: 288.27 PVI STA:14+32.48 PVI ELEV:289.30 325 K:47.51 325 LVC:200.00

300 BVCE: 286.86 EVCE: 287.53 300

BVCS: 13+32.48 FINISHED GRADE EVCS: 15+32.48 STA: 15+67.86 BRIDGE END STA: 12+97.10 BRIDGE END -1.77% 2.44%

EXISTING BRIDGE DECK 275 275 BRIDGE ABUTMENT BRIDGE ABUTMENT

EXISTING GROUND

N LAKE SAMISH ROAD PROFILE SCALE: 1"=20' HORIZ., 1"=20' VERT. P:\2016\2016026 - WHATCOM COUNTY NORTH LAKE SAMISH BRIDGE\000 CAD\010 DRAWING\D-EXHIBIT\LAKE EXHIBIT 1.DWG - PROJECT NO.: #### REFERNCE WHATCOM COUNTY N LAKE SAMISH ROAD BRIDGE REPLACEMENT SHEET NO.

1:32 PM FED. AID NO.: ####

- PUBLIC WORKS E1 DEPARTMENT DATUM: ####

SCALE: #### SHEET July 21, 2017 322 N COMMERCIAL STREET, SUITE 210 ALTERNATIVE 2A & 2B - 1 BELLEVUE OFFICE: BELLINGHAM, WA 98225 DESIGNED BY: #### DRAWN BY: #### CURVED ALIGNMENT 121011 NE 1st ST, STE 305, BELLEVUE, WA 98005 1 INCH SCALE BAR OF RBRAR PH: 425-453-5545 FAX: 425-453-6779 360-7786200 NO. DATE REVISION ADJUST SCALE ACCORDINGLY CHECKED BY: #### APPROVED BY: #### 3 Appendix I – Bridge Alternatives Plans

Appendix J – Bridge Alternatives Opinion of Cost

Lake Samish Road Bridge Replacement

3 Span Concrete Girder.‐ 3 Span Concrete Girder‐ Item No. Description Straight Curved 3 Span Steel Girder‐ Curved Mobilization $485,959 $486,212 $533,650

1 Foundations $325,920 $325,920 $325,920

2Work Access Trestle $1,386,000 $1,386,000 $1,386,000

3 Substructure Concrete $492,271 $492,271 $492,271 Shoring/Excavation‐ Abutment and 4 $180,089 $180,089 $180,089 Interior Piers 5 Bridge Superstructure $1,093,063 $1,295,592 $1,769,971 6 Approach Slab $52,200 $52,200 $52,200 7 Bridge Demolition $174,900 $174,900 $174,900 8 Approach Fill $155,150 $155,150 $155,150 9 Civil Items $1,000,000 $800,000 $800,000 10 Contingency‐ 30% $1,603,666 $1,604,500 $1,761,045

Total Construction Cost $6,949,218 $6,952,835 $7,631,196

Total 2019 Construction Cost with $7,661,513 $7,665,500 $8,413,394 Inflation @ 5%/ Yr.

Maintenance Cost (75‐yr window) $500,000 $500,000 $1,000,000 Item 1 Analysis Lake Samish Rd Bridge Replacement

3 Span Concrete Girder Alternative ‐ Straight Abutment with Drilled Shaft

Drilled Shaft at Abutment ‐ 3' Diameter ‐ 3 each x 72' Deep per Abutment

Location Description Quantity Unit of Measure Unit Price Total Pier 1 and 4 Drill and Excavate 113 CY $350 $39,584 Pier 1 and 4Place Concrete 113 CY $350 $39,584 Pier 1 and 4 Rebar 25,447 LBS $1.25 $31,809 Pier 1 and 4CSL Tubes 1,296 LF $5 $6,480 Pier 1 and 4CSL Test 4 EA $1,500 $6,000 Shaft Obstruction Provision 10% of Total 1 LS $12,346 $12,346 Subtotal: $135,802

Pier 2 ‐6' Diameter ‐ 1 each x 72' Deep , Pier 3‐ 6' Diameter ‐1 each x 72' Deep

Location Description Quantity Unit of Measure Unit Price Total Pier 2,3 Drill and Excavate 151 CY $350 $52,779 Pier 2,3 Place Concrete 151 CY $350 $52,779 Pier 2,3 Rebar 33,929 LBS $1.25 $42,411 Pier 2,3 CSL Tubes 864 LF $5 $4,320 Pier 2,3 CSL Test 4 EA $1,500 $6,000 Pier 2,3 Shaft Casing Shoring 40 LF $400 $16,000 Shaft Obstruction Provision 10% of Total 1 LS $15,829 $15,829 Subtotal $190,118

Total $325,920

Item 2 Analysis Lake Samish Rd Bridge Replacement Work Access Trestle

Unit Price Temporary Work Trestle‐ $140/SF

Trestle Footprint Main Spine ‐ 250'x 30' = 7500 SF Trestle Pier Footprint‐ Pier 2, 3 Finger‐ 30'x40'x2= 2400 SF

Temporary Work Trestle ‐ Cost Analysis‐ Furnish ‐ Install‐ Remove Description Quantity Unit of Measure Unit Price Total Temporary Work Trestle 9,900 SF $140 $1,386,000

Item 3 Analysis Lake Samish Rd Bridge Replacement Substructure Concrete

Description Quantity Unit of Measure Unit Price Total Abutment Footing‐ Pier 1 and 4 83 CY $550 $45,833 Abutment Footing Rebar‐ Pier 1 and 4 18,750 LBS $1.25 $23,438 Abutment Wall ‐ Wingwall‐Pier 1 and 4 222 CY $700 $155,556 Abutment Wall Rebar ‐ Wingwall‐Pier 1 and 4 50000 LBS $1.25 $62,500 Column Concrete Pier 1, 4 24 CY $800 $18,850 Column Rebar Pier 1,4 5301 LBS $1.25 $6,627 Column Concrete ‐ Pier 2,3 31 CY $800 $25,133 Column Rebar‐ Pier 2,3 7,069 LBS $1.25 $8,836 Pier Cap Concrete ‐ Pier 2,3 120 CY $900 $108,000 Pier Cap Rebar‐ Pier 2,3 30,000 LBS $1.25 $37,500

Total $492,271

Item 4 Analysis Shoring and Excavation Analysis ‐ Samish Bridge Replacement Pier 1 and 4 Unit Price Shoring ‐ $20/SF Extra Ex Unit Price Strucural Excavation‐ $30/CY‐ Gravel Backfill ‐ $20/CY Piers 1,2,3,4 Temp Casing $200/LF Description Quantity Unit of Measure Unit Price Total Shoring Pier 1 and 4 1,920 SF $20 $38,400 Structural Excavation Pier 1 and 4 160 CY $30 $4,800 Gravel Backfill Pier 1 and 4 1244 CY $20 $24,889 Temp Casing 560 LF $200 $112,000 Total $180,089

Item 5 Analysis Bridge Supersrtucture

Description Quantity Unit of Measure Unit Price Total 53 Decked Bulb Tee Girder‐ Furnish and Install 1560 LF $450 $702,000 Bearings 12 EA $750 $9,000 Intermediate and End Diaphragm Concrete ‐Spans 1‐ 32 CY $1,000 $32,000 3 Intermediate and End Diaphragm Rebar ‐Spans 1‐3‐ 3,840 LBS $1.25 $4,800 120#/CY HMA Deck‐ Span 1‐3 135 TON $150 $20,263 Sidewalk Concrete 29 CY $1,000 $29,000 Deck Rebar‐ Span 1‐3 23,200 LBS $1.25 $29,000 Concrete Barrier 520 LF $175 $91,000 Metal Railing 260 LF $100 $26,000 Expansion Joints 2 EA $10,000 $20,000 Utilities 260 LF $300 $78,000 Pedestrian Railing 260 LF $200 $52,000

Total $1,093,063

Item 6 Analysis Approach Slab‐47' x 25' x 2 each Unit Price‐ $200/SY Description Quantity Unit of Measure Unit Price Total Approach Slabs 261 SY $200 $52,200

Item 7 Analysis Bridge Demolition Surface Area‐250'x42'= 10500 sf (1166 SY) Unit Price‐ $150/SY Description Quantity Unit of Measure Unit Price Total Existing Bridge Demolition 1166 SY $150 $174,900

Item 8 Analysis Approach Fills South Approach ‐ Length‐ 200' x Average Height ‐ 2' High North Approach‐ Length ‐ 200'x Average Height ‐ 2' High

Description Quantity Unit of Measure Unit Price Total Gravel Backfill 2200 TON $20 $44,000 HMA Pavement‐ 400' x 50'Wide x 6" Thick 741 TON $150 $111,150 Guardrail Both Sides ‐ 400 * 2 400 LF $50 $20,000 Total $155,150 Item 1 Analysis Lake Samish Rd Bridge Replacement

3 Span Concrete Girder Alternative ‐ Curved Abutment with Drilled Shaft

Drilled Shaft at Abutment ‐ 3' Diameter ‐ 3 each x 72' Deep per Abutment

Pier 2 ‐6' Diameter ‐ 1 each x 72' Deep , Pier 3‐ 6' Diameter ‐1 each x 72' Deep

Total $325,920

Item 2 Analysis Lake Samish Rd Bridge Replacement Work Access Trestle

Unit Price Temporary Work Trestle‐ $140/SF

Trestle Footprint Main Spine ‐ 250'x 30' = 7500 SF Trestle Pier Footprint‐ Pier 2, 3 Finger‐ 30'x40'x2= 2400 SF

Temporary Work Trestle ‐ Cost Analysis‐ Furnish ‐ Install‐ Remove Description Quantity Unit of Measure Unit Price Total Temporary Work Trestle 9,900 SF $140 $1,386,000

Item 3 Analysis Lake Samish Rd Bridge Replacement Substructure Concrete

Description Quantity Unit of Measure Unit Price Total

Abutment Footing‐ Pier 1 and 4 83 CY $550 $45,833

Abutment Footing Rebar‐ Pier 1 and 4 18,750 LBS $1.25 $23,438

CY $700 Abutment Wall ‐ Wingwall‐Pier 1 and 4 222 $155,556

Abutment Wall Rebar ‐ Wingwall‐Pier 1 and 4 50000 LBS $1.25 $62,500 Column Concrete Pier 1, 4 24 CY $800 $18,850 Column Rebar Pier 1,4 5301 LBS $1.25 $6,627 Column Concrete ‐ Pier 2,3 31 CY $800 $25,133 Column Rebar‐ Pier 2,3 7,069 LBS $1.25 $8,836 Pier Cap Concrete ‐ Pier 2,3 120 CY $900 $108,000 Pier Cap Rebar‐ Pier 2,3 30,000 LBS $1.25 $37,500

Total $492,271

Item 5 Analysis Description Quantity Unit of Measure Unit Price Total 53 Decked Bulb Tee Girder‐ Furnish and Install 1620 LF $550 $891,000 Bearings 12 EA $750 $9,000 Intermediate and End Diaphragm Concrete ‐Spans 1‐ 32 CY $1,000 $32,000 3 Intermediate and End Diaphragm Rebar ‐Spans 1‐3‐ 3,840 LBS $1.25 $4,800 120#/CY HMA Deck‐ Span 1‐3 140 TON $150 $21,042 Sidewalk Concrete 30 CY $1,000 $30,000 Sidewalk and Barrier Rebar‐ Span 1‐3 25,000 LBS $1.25 $31,250 Concrete Barrier 540 LF $175 $94,500 Metal Railing 270 LF $100 $27,000 Expansion Joints 2 EA $10,000 $20,000 Utilities 270 LF $300 $81,000 Pedestrian Railing 270 LF $200 $54,000

Total $1,295,592

Item 6 Analysis Approach Slab‐47' x 25' x 2 each Unit Price‐ $200/SY Description Quantity Unit of Measure Unit Price Total Approach Slabs 261 SY $200 $52,200

Item 8 Analysis Approach Fills South Approach ‐ Length‐ 200' x Average Height ‐ 2' High North Approach‐ Length ‐ 200'x Average Height ‐ 2' High

3 Span Steel Girder Alternative ‐ Curved Abutment with Drilled Shaft

Drilled Shaft at Abutment ‐ 3' Diameter ‐ 3 each x 72' Deep per Abutment

Pier 2 ‐6' Diameter ‐ 1 each x 72' Deep , Pier 3‐ 6' Diameter ‐1 each x 72' Deep

Total $325,920

Item 2 Analysis Lake Samish Rd Bridge Replacement Work Access Trestle

Unit Price Temporary Work Trestle‐ $140/SF

Trestle Footprint Main Spine ‐ 250'x 30' = 7500 SF Trestle Pier Footprint‐ Pier 2, 3 Finger‐ 30'x40'x2= 2400 SF

Temporary Work Trestle ‐ Cost Analysis‐ Furnish ‐ Install‐ Remove Description Quantity Unit of Measure Unit Price Total Temporary Work Trestle 9,900 SF $140 $1,386,000

Item 3 Analysis Lake Samish Rd Bridge Replacement Substructure Concrete

Description Quantity Unit of Measure Unit Price Total

Abutment Footing‐ Pier 1 and 4 83 CY $550 $45,833

Abutment Footing Rebar‐ Pier 1 and 4 18,750 LBS $1.25 $23,438

CY $700 Abutment Wall ‐ Wingwall‐Pier 1 and 4 222 $155,556

Total $492,271

Description Quantity Unit of Measure Unit Price Total Item 5 Analysis Steel Girder and Diaphragms 317,100 LBS $2.75 $872,025 Bearings 20 EA $5,000 $100,000 Concrete Deck‐ Span 1‐3 358 CY $1,000 $357,778 Deck Rebar‐ Span 1‐3 99,334 LBS $1.25 $124,168 Concrete Barrier 560 LF $175 $98,000 Metal Railing 280 LF $100 $28,000 Expansion Joints 2 EA $25,000 $50,000 Pedestrian Railing 280 LF $200 $56,000 Utilities 280 LF $300 $84,000

Total $1,769,971

Item 6 Analysis Approach Slab‐47' x 25' x 2 each Unit Price‐ $200/SY Description Quantity Unit of Measure Unit Price Total Approach Slabs 261 SY $200 $52,200

Item 8 Analysis Approach Fills South Approach ‐ Length‐ 200' x Average Height ‐ 2' High North Approach‐ Length ‐ 200'x Average Height ‐ 2' High

Engineer's Preliminary Opinion of Cost

ALT‐1 ‐ 3‐span PS Concrete Slab Bridge on Straight Alignment

ITEM UNITS QUANTITY UNIT PRICE AMOUNT

Mobilization LS 1$ 451,680 $ 451,680 Clearing and Grubbing AC 0.2$ 20,000 $ 3,000 Roadway Survey LS 1$ 20,000 $ 20,000 Structure Surveying LS 1$ 15,000 $ 15,000 Project Temporary Traffic Control LS 1$ 100,000 $ 100,000 Removing Existing Bridge LS 1$ 150,000 $ 150,000 Removal of Structure and Obstruction LS 1$ 10,000 $ 10,000 Work Trestle LS 1$ 1,400,000 $ 1,400,000 Roadway Excavation Incl. Haul CY 1,100$ 30 $ 33,000 Gravel Borrow Incl. Haul TON 300$ 20 $ 6,000 Crushed Surfacing Base Course TON 1000$ 35 $ 35,000 HMA CL. 1" PG 64‐22 TON 500$ 120 $ 60,000 Structural Earth Wall SF 475$ 35 $ 16,625 Bridge Structure SF 10800$ 250 $ 2,700,000 Temporary Structural Shoring LS 1$ 20,000 $ 20,000 Erosion Control LS 1$ 50,000 $ 50,000 Shoreline Restoration LS 1$ 50,000 $ 50,000 Utility Relocation LS 1$ 150,000 $ 150,000 Approach Improvements LS 1$ 150,000 $ 150,000 Repair/Restoration of Public & Private Faciliti LS 1$ 50,000 $ 50,000 Subtotal:$ 5,470,305

Contingency @30%:$ 1,641,092

Total Construction Cost:$ 7,111,397

Total 2019 Construction Cost $ 7,840,315 with Inflation @5% / Year

Future Maintenance Cost$ 500,000 North Lake Samish Road

Engineer's Preliminary Opinion of Cost

ALT‐2 ‐ 3‐span PS Concrete Bridge

ITEM UNITS QUANTITY UNIT PRICE AMOUNT

Mobilization LS 1$ 457,680 $ 457,680 Clearing and Grubbing AC 0.2$ 20,000 $ 3,000 Roadway Survey LS 1$ 20,000 $ 20,000 Structure Surveying LS 1$ 15,000 $ 15,000 Project Temporary Traffic Control LS 1$ 100,000 $ 100,000 Removing Existing Bridge LS 1$ 150,000 $ 150,000 Removal of Structure and Obstruction LS 1$ 10,000 $ 10,000 Work Access Trestle LS 1$ 1,400,000 $ 1,400,000 Roadway Excavation Incl. Haul CY 750$ 30 $ 22,500 Gravel Borrow Incl. Haul TON 750$ 20 $ 15,000 Crushed Surfacing Base Course TON 1000$ 35 $ 35,000 HMA CL. 1" PG 64‐22 TON 500$ 120 $ 60,000 Structural Earth Wall SF 650$ 35 $ 22,750 Bridge Structure SF 11200$ 260 $ 2,912,000 Temporary Structural Shoring LS 1$ 20,000 $ 20,000 Erosion Control LS 1$ 50,000 $ 50,000 Shoreline Restoration LS 1$ 50,000 $ 50,000 Utility Relocation LS 1$ 150,000 $ 150,000 Repair/Restoration of Public & Private Faciliti LS 1$ 50,000 $ 50,000

Subtotal:$ 5,542,930

Contingency @30%:$ 1,662,879

Total Construction Cost:$ 7,205,809

Total 2019 Construction Cost $ 7,944,404 with Inflation @5% / Year

Future Maintenance Cost$ 500,000 North Lake Samish Road

Engineer's Preliminary Opinion of Cost

ALT‐2B ‐ 3‐span Steel Girder Bridge

ITEM UNITS QUANTITY UNIT PRICE AMOUNT

Mobilization LS 1$ 498,000 $ 498,000 Clearing and Grubbing AC 0.2$ 20,000 $ 3,000 Roadway Survey LS 1$ 20,000 $ 20,000 Structure Surveying LS 1$ 15,000 $ 15,000 Project Temporary Traffic Control LS 1$ 100,000 $ 100,000 Removing Existing Bridge LS 1$ 150,000 $ 150,000 Removal of Structure and Obstruction LS 1$ 10,000 $ 10,000 Work Access Trestle LS 1$ 1,400,000 $ 1,400,000 Roadway Excavation Incl. Haul CY 750$ 30 $ 22,500 Gravel Borrow Incl. Haul TON 750$ 20 $ 15,000 Crushed Surfacing Base Course TON 1000$ 35 $ 35,000 HMA CL. 1" PG 64‐22 TON 500$ 120 $ 60,000 Structural Earth Wall SF 650$ 35 $ 22,750 Bridge Structure SF 11200$ 300 $ 3,360,000 Temporary Structural Shoring LS 1$ 20,000 $ 20,000 Erosion Control LS 1$ 50,000 $ 50,000 Shoreline Restoration LS 1$ 50,000 $ 50,000 Utility Relocation LS 1$ 150,000 $ 150,000 Repair/Restoration of Public & Private Faciliti LS 1$ 50,000 $ 50,000

Subtotal:$ 6,031,250

Contingency @30%:$ 1,809,375

Total Construction Cost:$ 7,840,625

Total 2019 Construction Cost $ 8,644,289 with Inflation @5% / Year

Future Maintenance Cost$ 1,000,000

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