DRAFT. Geotechnical Engineering Services. Army Street Project Bellingham, Washington. for Bellingham Public Development Authority.

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1 Geotechnical Engineering Services Army Street Project Bellingham, Washington for Bellingham Public Development Authority May 16, Dupont Street Bellingham, Washington

2 Geotechnical Engineering Services Army Street Project Bellingham, Washington File No May 16, 2014 Prepared for: Bellingham Public Development Authority 104 West Magnolia Street, Suite 307 Bellingham, Washington Attention: Jim Long, Executive Director Prepared by: GeoEngineers, Inc. 600 Dupont Street Bellingham, Washington Sean W. Cool, PE Senior Geotechnical Engineer J. Robert Gordon, PE Senior Principal SWC:JRG:leh Disclaimer: Any electronic form, facsimile or hard copy of the original document ( , text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.

3 Table of Contents EXECUTIVE SUMMARY... ES INTRODUCTION Project Understanding Scope of Services SITE CONDITIONS Surface Conditions Geology Seismicity Subsurface Exploration Program Geotechnical Borings and Well Installation Environmental Field Screening Archaeological Screening Subsurface Conditions Soil Conditions Groundwater Conditions Archaeological Considerations GEOLOGICALLY HAZARDOUS AREAS AND MITIGATION Designation of Geologic Hazards Erosion Hazard: Landslide Hazard: Seismic Hazard: Mine Hazard: Tsunami Hazard and Sea Level Rise Geologic Hazard Mitigation Erosion Hazard Mitigation Landslide Hazard Mitigation Seismic Hazard Mitigation CONCLUSIONS AND RECOMMENDATIONS General Seismic Design Considerations IBC Seismic Design Information Liquefaction Potential Lateral Spreading Potential Seismic Hazard Mitigation Summary Foundation Support General Shallow Foundations Mat Foundations Pile Foundations Ground Improvement Vibro-Replacement Columns and RAPs May 16, 2014 Page i File No

4 ARMY STREET PROJECT Bellingham, Washington DRAFT Rigid Inclusions Slab-on-Grade Floor Support Permanent Retaining Walls Waterproofing and Drainage Considerations Stormwater Considerations Utilities Construction Considerations Soil Excavation Rock Excavation Temporary Slopes Temporary Shoring Considerations Erosion and Sedimentation Control Dewatering Considerations Additional Geotechnical Services LIMITATIONS REFERENCES LIST OF FIGURES Figure 1. Vicinity Map Figure 2. Site and Exploration Plan Figure 3. Geologically Hazardous Areas Map Figure 4. Bedrock Elevation Contour Map Figures 5 through 9. Subsurface Cross Sections Figure 10. Summary of Geotechnical Considerations APPENDICES Appendix A. Field Exploration Program Figure A-1. Key to Explorations Figures A-2 through A-8. Logs of Borings Appendix B. Laboratory Testing Figures B-1 through B-5. Sieve Analysis Results Figures B-6 and B-7. Atterberg Limits Test Results Appendix C. Logs of Previous Explorations Appendix D. Archaelogcial Review Appendix E. Report Limitations and Guidelines for Use Page ii May 16, 2014 GeoEngineers, Inc. File No

5 ARMY STREET PROJECT Bellingham, Washington DRAFT EXECUTIVE SUMMARY This report summarizes the results of GeoEngineers, Inc. s (GeoEngineers) geotechnical engineering services for the proposed Army Street Project in Bellingham, Washington. The proposed project includes developing most of the site with mid-rise multi-story buildings over several levels of parking structure. The lowest elevation of the parking structure would be near or slightly below the lower existing site grade, which is at about Elevation 20 feet. The following presents a summary of the subsurface conditions encountered and major geotechnical considerations related to developing the site as proposed. GeoEngineers completed a concurrent Phase I Environmental Site Assessment (ESA) that included all the properties comprising the site. The results of the Phase I ESA did not identify any significant environmental contamination concerns at the site, with the exception that the site has a significant quantity of undocumented fill which always represents a potential source of contamination. The historic bluff line is located along the southeast corner of the site. Therefore, most of the site has been filled. The lower portion of the site was originally Bellingham Bay beach and tidelands. The Phase I ESA includes a detailed description of the history of the site and historical land uses. We drilled seven borings at the site for this study. We also included four borings previously completed by GeoEngineers on the site, and incorporated data from seven off-site borings that we have completed for other studies in the immediate vicinity of the site. The subsurface conditions encountered the following: Fill soils were encountered in all the borings except one in the southeast corner of the upland area. The upland fill generally consists of mixed silt, clay and sand of variable consistency; the lowland fill generally consists of more granular soils, some of which may have been derived from dredge/beach sediments. The lower fill soils below the groundwater table are typically loose, liquefiable and not suitable for bearing support of mid-rise structures. Beach deposits underlying the fill soils at the lower elevations of the site. The beach soils generally consist of loose to medium dense sands. The beach deposits are also liquefiable and not suitable for bearing support of mid-rise structures. Glaciomarine drift, consisting of native stiff clay was encountered in the upland borings. This deposit will support smaller structures. This deposit was also encountered in some of the lower borings below the beach deposits and consists of soft, compressible clay. The borings for this project were drilled to refusal into bedrock of the Chuckanut Formation. The bedrock surface dips rather steeply downward to the northwest; it was encountered at about Elevation +37 feet in the southeast corner of the site, and at Elevation -39 feet in our northernmost boring. Monitoring wells were installed in three of the borings. Groundwater was measured at approximately 10 feet below the existing ground surface (bgs) in the lower portion of the site; this corresponds to approximately Elevation 10 to 11 feet. It is likely that the groundwater levels are several feet higher in the winter; during the design life of the structure, the groundwater would also be expected to rise in direct correlation to sea level rise that occurs. Therefore, in order to avoid the extra costs of dewatering and waterproofing of any structure, the lowest parking garage level should be designed with some margin above the maximum May 16, 2014 Page ES-1 File No

6 ARMY STREET PROJECT Bellingham, Washington estimated groundwater level. At this time we suggest a deepest finished floor elevation of about 15 feet. A finished floor elevation of about 20 feet (near lowest existing site grades) will have less risk of being impacted in the long term. An archaeology study was subcontracted for this project site. No anthropogenic soils or artifacts of historic or precontact periods were observed in the soil samples. The site is a known area of modified land with massive fill volumes. A large stormwater vault required significant excavation at the site with no evidence of archeological interest. The archaeologist concluded that it is unlikely that the Department of Archaeology and Historic Preservation (DAHP) will require monitoring of the soils during excavation for development at the site. The presence and need for mitigation of geological hazard areas in accordance with the City of Bellingham Municipal Code were evaluated at the site. The following is a summary with a brief discussion of mitigation strategies: The site is located outside of the known coal mine hazard area and no mitigation is required. Erosion hazard areas were identified because of the steep slope that crosses most of the site. The erosion hazard areas can be completely mitigated by using conventional erosion control procedures and best management practices during construction, and incorporating hard surfaces and vegetation into final design. Steep slope hazard areas were identified across most of the site. The steep slope hazard areas can be completely mitigated by using adequate temporary slopes and/or shoring during construction and incorporating permanent retaining walls into the final design. If individual smaller projects were to be proposed, some alternative mitigation measures might be necessary. The site is in a designated seismic hazard area because it extends beyond the historic bluff line. No known faults are located in the vicinity of the site to represent a risk of surface fault rupture. The fill and beach soils at the lower elevations of the site have a high susceptibility to liquefaction; the Dyson property has a moderate risk of land movement associated with lateral spreading, with lower risk to farther inland properties. The seismic hazard in this environment is typically mitigated by using pile supported foundations for structures, or mat foundations, or mat foundations/shallow foundations on improved ground as described below. Foundation support of structures on the individual properties and for the proposed Army Street project is complex because of the unknown building design details and because of the variability in the subsurface conditions. However, the foundation design considerations are typical for waterfront development projects in Puget Sound. A summary of major foundation support considerations is provided below: Conventional shallow spread footings and slab-on-grade construction can be used for: (a) buildings and building components supported on bedrock; (b) low-rise (one to two story) structures supported on the stiff glaciomarine drift encountered on upland properties; (c) low- to mid-rise structures that are designed with mat foundations; low-rise structures supported on ground improvement. Mat foundations, consisting of monolithic, thick concrete slab with several layers of steel reinforcement to serve as foundation support for the entire structure, can be used for: (a) low-rise (one to two story) structures floated over the liquefiable soils, with the understanding that the life safety design level may not save economic functionality of the building after a design level earthquake; (b) mid-rise structures over improved ground. Page ES-2 May 16, 2014 GeoEngineers, Inc. File No

7 ARMY STREET PROJECT Bellingham, Washington DRAFT Pile foundation support could be used to support mid-rise and heavily loaded structures; pile support in this environment is typically driven H-pile or open-ended steel pipe piles driven through the liquefiable soils into the bedrock. Other pile types may be suitable for less heavily loaded structures. Typically, the lower floor is pile supported as well. Pile support is typically the more expensive alternative because of the higher lateral design loads and required grade beams. Ground improvement in liquefiable soils typically consists of stone columns installed by using vibro-replacement methods or a rammed earth impact pier method, or installing rigid inclusions, which are unreinforced columns of grout typically installed with augercast pile equipment. The stone columns provide higher capacity structural elements and also densify the adjacent soil to provide improved bearing and resistance to liquefaction. The rigid inclusions transfer the foundation loads typically from a mat foundation to a stable bearing layer, in this case the bedrock. Significant excavation would be necessary for the proposed Army Street Project and likely for most individual site development. A summary of the major excavation considerations is provided below: The soil can be excavated with conventional earth moving equipment. Provided that the excavations will not extend below about Elevation +10 feet, no significant dewatering will be required. Bedrock was encountered at Elevation 37 feet in the southeast corner of the site and we expect it will be encountered to achieve parking garage elevation along portions of West Holly Street and Bay Street. Typically, the upper weathered sandstone bedrock (typically 2 to 5 feet) can be excavated with large horsepower excavators. Below the weathered zone, large bulldozers with a ripper tooth or large horsepower excavators with a hydraulic hammer attachment are typically required. This impacts the excavation costs and schedule. Temporary shoring walls will be required for the deeper cuts, likely along West Holly Street and Bay Street. We expect that a combination of cantilevered soldier pile walls, soldier pile walls with tiebacks or soil nail walls would be appropriate depending on the depth. Temporary easements into the City of Bellingham right-of-way would be required for tiebacks and soil nails until the permanent structure walls are completed. If the rock is competent, it may be possible to use a flashcoat of shotcrete; otherwise rock anchors and reinforced shotcrete facing may be required. Additional geotechnical services will be require for property specific or project specific designs. The site has significant ground modification and complex geology such that the soil-structure interaction and building performance will need to be carefully considered during design in a collaborative effort by the architect, structural and geotechnical engineers. This is very typical for this type of multi-story project with below grade parking. The subsurface conditions may be adequately defined such that no additional exploration may be required; that decision would be made based on the owner and design team at that time. This Executive Summary should be used only in the context of the full report for which it is intended. May 16, 2014 Page ES-3 File No

8 ARMY STREET PROJECT Bellingham, Washington DRAFT 1.0 INTRODUCTION This report presents the results of our geotechnical engineering services for the Bellingham Public Development Authority (BPDA) Army Street Project located between West Holly Street, Bay Street, West Chestnut Street and Central Avenue in Bellingham, Washington. A vicinity map showing the project location is provided as Figure 1. The existing site conditions, properties involved in the project, and topography are shown in the Site and Exploration Plan, Figure 2. We provided preliminary geotechnical updates to BPDA as information became available. GeoEngineers, Inc. (GeoEngineers) also completed a concurrent Draft Phase 1 Environmental Site Assessment for the project, results of which have been submitted to BPDA in a separate document Project Understanding The project site is comprised of several different, some non-contiguous parcels with private and public ownership. As currently envisioned, the Army Street Project proposal is to consolidate all the parcels into a single parcel that can be developed into a much more significant project than could be accomplished individually. We understand that the current proposal includes BPDA serving as the developer representative and project lead. Current conceptual plans include an 800-space belowgrade parking garage covering about two-thirds of the southern portion of the site, with hotel and conference center, residences, commercial and office space above. A pedestrian plaza and an elevated walkway over Roeder Avenue and Burlington Northern Santa Fe (BNSF) railroad tracks are also being considered for the site. The owners of the parcels are shown in Figure 2, and are listed below in Table 1 with a brief description of the proposed development that might occur on that particular portion of the site and relevant reference explorations completed within the property. TABLE 1: SUMMARY OF PROPERTIES Property Name/Owner General Location of Parcel(s) on Project Site Proposed Building Type George B. Dyson North Low-Rise (up to 3 stories) Trillium Corporation Central Small Mid-Rise (up to 8 stories) Army Street ROW (City of Bellingham [COB]) Bellingham Public Development Authority Central Central Small Mid-Rise (4 to 8 stories) Large Mid-Rise (up to 15 stories) Wright Angle, LLC Central Large Mid-Rise (up to 15 stories) Port of Bellingham (POB) Central Large Mid-Rise (up to 15 stories) Donna Macdonald Trust Southeast Large Mid-Rise (up to 15 stories) Robert C. Thornburg Decedent s Trust Southeast Large Mid-Rise (up to 15 stories) Reference Explorations BPDA-1 BPDA-2P, B-2 (2006), B-3 (2006) BPDA-3P, B-1 (2006), B-2 (2003) B-1 (2003) None BPDA-4P BPDA-5 BPDA-6, BPDA-7 May 16, 2014 Page 1 File No

9 ARMY STREET PROJECT Bellingham, Washington The project concept includes two mid-rise structures with up to eleven stories of mixed-use structure over four stories of concrete parking garage in the southern portion of the site (BPDA, Wright Angle, Port of Bellingham, MacDonald and Thornberg properties) and an additional mid-rise structure with up to six stories of mixed-use structure over two stories of concrete parking garage in the central portion of the site (Trillium and Army Street right-of-way [ROW] properties). Based on preliminary conversations with BPDA, the lowest parking grade for the mid-rise structures is expected to be at or slightly below lowest existing grades, possibly with a finished floor between approximately Elevations 15 to 18 feet (datum is NAVD88). Excavation into the existing hill slope along West Holly Street and Bay Street will be required for the below-grade parking structure. The lower central structure would have moderate foundation loads and the taller southern structures would have moderate to heavy foundation loads. The Dyson property at the northeast corner of the site at West Holly Street and Central Avenue could be developed as a smaller low-rise one- or two-story structure based on current City codes. This structure would have relatively low foundation loads. We understand that a pedestrian bridge may be incorporated into the project. The pedestrian bridge would cross over the BNSF railroad tracks and connect the site to proposed future waterfront development to the west. Such a bridge would need to be coordinated with BNSF. The bridge would likely require pile foundation support to provide both bearing support and sufficient lateral resistance Scope of Services The purpose of our geotechnical engineering services was to evaluate subsurface soil and groundwater conditions at the site as the basis for developing preliminary conclusions and recommendations for future development. While most of the discussion is focused on the proposed development as previously described, the information is also useful for individual site development which is likely to be much smaller in scale. GeoEngineers has provided geotechnical and environmental services on several of the parcels on the site previously. Our scope of services included drilling seven additional borings and installing groundwater piezometers, completing laboratory testing on the samples obtained from the borings, and providing preliminary geotechnical conclusions and recommendations for design and construction of the proposed improvements. Our specific scope of services is described in our proposal for the project dated February 28, 2014, and included the following tasks: 1. Review all applicable references, in-house materials, and any reports provided by BPDA and property owners. 2. Complete a critical areas evaluation of the applicable geohazards to meet CAO requirements and present a discussion how to mitigate those hazards for individual properties and BPDA program. 3. Call the State one-call utility locate contractor number after field locating borings and subcontract a private locate company to help locate existing utilities. 4. Complete seven new borings and incorporate previous borings at the site into the conclusions and recommendations. Page 2 May 16, 2014 GeoEngineers, Inc. File No

10 ARMY STREET PROJECT Bellingham, Washington DRAFT 5. Complete the exploration program by drilling to refusal in bedrock. Field samples observed for evidence of petroleum contamination, field screening (sheen test and PID). 6. Install 2-inch-diameter open standpipe piezometers (monitoring wells) at three of the boreholes at the lower portion of the site for groundwater monitoring. 7. Develop the monitoring wells the day after well installation by surging and bailing and/or pumping to remove fine sediment and drilling debris from the well screen and filter pack. Install pressure transducers in the three piezometers to evaluate groundwater levels and determine potential tidal influence. 8. Conduct analysis and evaluation of pertinent physical and engineering characteristics of the foundation and subgrade soils based on laboratory tests performed on samples obtained from the explorations. Laboratory testing includes determination of soil moisture content, Atterberg limits, and grain size distribution. 9. Evaluate the influence of groundwater based on experience and review of data logger information. 10. Provide seismic design considerations based on the 2012 International Building Code (IBC). The seismic design includes proposed mitigation strategies as appropriate. 11. Complete an evaluation of foundation support options, wall and shoring options, and other significant geotechnical design considerations, including: Ground improvement strategies and foundation options, and their relation to impacts and mitigations for any identified geohazards. Shallow foundation, mat foundation, pile foundation, slab-on-grade analysis and support conclusions. Hydrostatic pressures and buoyancy/uplift, dewatering considerations, including evaluation and discussion of tidal effects. Wall design considerations, especially with regard to impact of groundwater if an underground parking structure could be included. Temporary and permanent shoring/wall support considerations for West Holly Street. Potential for stormwater infiltration and low impact development opportunities. 12. Provide a draft and final geotechnical report with our conclusions and recommendations. Exploration logs, a site plan, cross sections of the subsurface profile and any supporting test data will be included. 2.0 SITE CONDITIONS 2.1. Surface Conditions The project site is located between the downtown and waterfront (former Georgia Pacific site) areas of Bellingham. The site is bounded by West Holly Street to the northeast, Bay Street to the southeast, West Chestnut Street and the BNSF ROW to the southwest, and Central Avenue to the northwest. West Holly Street slopes down and toward the northwest. The site also slopes steeply down from West Holly Street and Bay Street toward the middle of the site and Bellingham Bay. Based on review of historical information the historical bluff line crossed through the southeastern May 16, 2014 Page 3 File No

11 ARMY STREET PROJECT Bellingham, Washington portion of the site leading down to the beach. This information is consistent with the subsurface conditions encountered. Existing buildings are located along West Holly Street in the northern and eastern portions of the site, and along Central Avenue in the northwestern portion of the site. A stormwater vault is located within the COB Army Street property. Many utilities are located across the site, including some easements across some of the parcels. Historical conditions at the site are described in detail in our Phase I ESA report; detailed historical and present survey information was prepared by Wilson Engineering, LLC and this information was used as our base maps. We performed a reconnaissance of the site for geotechnical purposes on April 9, The following is a brief summary of our observations. Steep slopes are located along all of the parcels with the exception of Dyson property as shown in Figure 2. The steep slope adjacent to West Holly Street has inclinations ranging between approximately 40 percent (2.5H:1V [horizontal to vertical]) to 75 percent (1.33H:1V); as it extends farther south, the steep slope has inclinations ranging between approximately 65 percent (1.53H:1V) to 85 percent (1.17H:1V). Gradients of the steep slopes were determined using a topographic survey map and inclinometer in the field and therefore should be considered approximate. The steep slope areas are identified in Figure 3. The ground surface in the lower portion of the site is relatively level, near about Elevation 20 feet, and is the result of historical fill placed at the site. Mature conifer and deciduous trees are growing along the steep slopes in the southern portion of the site. No slope failure features or significant evidence of slope instability were observed at the site. Some minor erosion was located where stormwater concentrates. Groundwater seeps were not observed on the ground surface along the slopes Geology Our interpretation of the geologic/hydrogeologic conditions at the site vicinity is based on a review of available references (see Section 8.0), our reconnaissance and subsurface explorations, and our experience in the vicinity of the site. The site is located near the geologic contact between the Bellingham (glaciomarine) Drift (GMD) and the Chuckanut Formation bedrock, and areas of artificial fill that was placed waterward of the historical bluff. The Bellingham GMD consists of unsorted, unstratified silt and clay with varying amounts of sand, gravel, cobbles and occasional boulders. Bellingham Drift is derived from sediment melted out of floating glacial ice that was deposited on the sea floor. This material locally contains shells and wood. Glaciomarine drift was deposited during the Everson Interstade approximately 11,000 to 12,000 years ago while the land surface was depressed 500 to 600 feet resulting from previous glaciations. The upper portion of this unit, sometimes to about 15 feet of depth, can be quite stiff as a result of desiccation or partial ice contact in upland areas. This material typically grades to medium stiff or soft with depth. The entire GMD profile, however, can be stiff when only a thin section of the drift mantles bedrock at shallow depths. Page 4 May 16, 2014 GeoEngineers, Inc. File No

12 ARMY STREET PROJECT Bellingham, Washington DRAFT The Chuckanut Formation is a mixture of sandstone, conglomerate, shale, and coal initially deposited as relatively horizontal surfaces then heavily folded by tectonic forces. The sandstone portion of the unit is relatively hard and strong where unweathered. The formation was partially eroded and weathered prior to the Pleistocene age (about 3 million years ago), where it was subjected to glacial activity. The bedrock surface underlying the GMD deposits can vary in elevation and character significantly over short distances. Beach and intertidal deposits at the site ranges from approximately 10 to 30 feet thick and consist primarily of loose sand and silty sand. The beach/intertidal deposits are moderately compressible, with low shear strength, and the granular zones are highly susceptible to liquefaction. Fill at the site ranges up to approximately 40 feet thick. Fill in the project vicinity is variable in composition and ranges from sand to clay derived from dredging, mining, and some upland sources. The fill is generally loose/soft, compressible, with low shear strength, and the granular zones are moderately to highly susceptible to soil liquefaction below the water table Seismicity The site is located within the Puget Sound region, which is seismically active. Seismicity in this region is attributed primarily to the interaction between the Pacific, Juan de Fuca, and North American plates. The Juan de Fuca plate is subducting beneath the North American plate. It is thought that the resulting deformation and breakup of the Juan de Fuca plate might account for the deep focus earthquakes in the region. Hundreds of earthquakes have been recorded in the Puget Sound area. In recent history, four of these earthquakes were large events: 1) in 1946, a Richter magnitude 7.2 earthquake occurred in the Vancouver Island, British Columbia area; 2) in 1949, a Richter magnitude 7.1 earthquake occurred in the Olympia area; 3) in 1965, a Richter magnitude 6.5 earthquake occurred between Seattle and Tacoma; and 4) in 2001, a Richter magnitude 6.8 earthquake occurred near Olympia. Research has concluded that historical large magnitude subduction-related earthquake activity has occurred along the Washington and Oregon coasts. Evidence suggests several large magnitude earthquakes (Richter magnitude 8 to 9) have occurred in the last 1,500 years, the most recent of which occurred about 300 years ago. No earthquakes of this magnitude have been documented during the recorded history of the Pacific Northwest. Local design practice in Puget Sound and local building codes include local seismic conditions including local known faults in the design of structures. There are no known faults near the site and no known risk of surface rupture Subsurface Exploration Program Geotechnical Borings and Well Installation GeoEngineers subcontracted the drilling of seven borings (BPDA-1, BPDA-2P, BPDA-3P, BPDA-4P, BPDA-5, BPDA-6 and BPDA-7) for this project, which were completed on March 31 and April 1, The borings were completed with a track-mounted drill rig within the various property boundaries of the overall project site; BPDA-3P may actually be slightly outside of the property boundary because the site survey had not been completed at the time of our exploration program. Borings BPDA-2, BPDA-3P and BPDA-4P were completed as monitoring wells that will remain at the site for future measurements of the water table and possible groundwater sampling. May 16, 2014 Page 5 File No

13 ARMY STREET PROJECT Bellingham, Washington GeoEngineers previously subcontracted the drilling of several borings at the project site and for other nearby projects. The locations of the explorations completed for this study and for previous nearby studies are shown in Figure 2. A table providing a summary of borings, depth below ground surface, surface elevation, approximate groundwater elevation based on (a) observation during drilling which should be considered very approximate or (b) measured depth in the piezometer should be considered accurate, and approximate elevation of the bedrock surface, is presented below. Figure 4 is a bedrock elevation contour map based on interpolating between our own-site and off-site borings. Figures 5 through 9 present generalized cross sections based on interpolating conditions from the borings; cross section locations are shown in Figure 2. TABLE 2. SUMMARY OF SUBSURFACE EXPLORATION PROGRAM Boring Number Depth (ft) Approximate Surface Elevation (ft) Approximate Groundwater Elevation (ft) 1 Approximate Bedrock Elevation (ft) Property Name Army Street Development Sites BPDA ND -40 Dyson BPDA--2P Trillium BPDA--3P Army Street ROW BPDA--4P Port of Bellingham BPDA NE 36 MacDonald Trust BPDA ND 3 Thornberg Trust BPDA ND 6 Thornberg Trust B-1 (2006) Army St. ROW B-2 (2006) Trillium B-3 (2006) Trillium B-1 (2003) BPDA B-2 (2003) Army Street ROW Other Nearby Sites B-10 (2005) ND West Holly Street B-11 (2005) ND West Holly Street B-13 (2005) ND West Holly Street B-2 (2009) Chestnut Street ROW Granary-1 (2009) Granary Site Granary-2 (2009) Granary Site B-7 (2014) NE 29 Bay Street ROW Note: 1 Estimated at time of drilling, except where noted. Groundwater at time of drilling may not accurately represent static water table. 2 Measured in piezometer ND/NE = Not Determined/Not Encountered Page 6 May 16, 2014 GeoEngineers, Inc. File No

14 ARMY STREET PROJECT Bellingham, Washington DRAFT Descriptions of our field exploration program and well installation are presented in Appendix A. Soil samples were collected during the drilling and were taken to our laboratory for further evaluation. Selected samples were tested for moisture content, fines content, grain size distribution, and Atterberg limits (soil plasticity). A description of the laboratory testing and the test results are presented in Appendix B. Logs of previous site explorations are presented in Appendix C Environmental Field Screening While onsite, our representative also conducted field screening on selected soil samples within the fill soils obtained from the borings. Field screening results are used as a general guideline to delineate areas of possible petroleum-related contamination in soils. The screening methods employed included (1) visual examination, (2) water sheen testing, and (3) headspace vapor testing using a BW Miroc5 Photoionization Detector (PID). A general description of each screening method is presented in Appendix A. Our field screening did not encounter significant evidence of petroleum contamination. No petroleum associated sheen was observed in the samples collected and screened. PID readings recorded during the field screening were less than 1 part per million (ppm) and therefore are not included on the boring logs. These readings are generally consistent with soil not containing petroleum hydrocarbons or at concentrations less than Model Toxics Cleanup Act (MTCA) cleanup levels. Accordingly, we did not recommend that soil samples be submitted for chemical evaluation Archaeological Screening Select soil samples were screened for the presence of archaeologically significant artifacts by a subcontracted cultural resources consultant from Drayton Archaeology of Bellingham, Washington. No artifacts were identified in the samples screened. The results of Drayton Archeology s sample review and site research are presented in Appendix D. We did not observe any evidence of cultural resources during our exploration program Subsurface Conditions Soil Conditions The borings generally encountered the following four soil layers described in more detail below. As previously mentioned, Figures 4 through 9 show generalized cross sections of the subsurface conditions. A summary of the subsurface conditions is also presented in Figure 10, which is a summary of subsurface conditions and geotechnical considerations. Fill Soils. Significant thicknesses of fill soils were encountered at the ground surface in all borings at the site except BPDA--5, which appears to be behind the historic bluff line. Fill in higher upland areas (above surface Elevation 25 feet) along West Holly Street and Bay Street in the eastern and southern portions of the site, generally consisted of mixed clay, silt and sand of variable density and consistency. The fill was likely derived from various local sources. Fill was quite deep in some areas near BPDA-6 and B-1 (2006) where the fill appeared to have been used to extend the property beyond the historic bluff line. Fill in the lower-lying areas of the site (below surface Elevation 25 feet) was generally more granular in nature, consisting of loose to medium dense, relatively clean sand, sand with silt May 16, 2014 Page 7 File No

15 ARMY STREET PROJECT Bellingham, Washington and silty sand. These lower fill soils may have been partially derived from dredge sediments and is difficult to distinguish between beach deposits described below. Fill in these lower lying areas typically extended to Elevation 10 feet to Elevation 0 feet, and slightly lower toward the northwest. The character of the fill is quite variable. We did not observe evidence of deleterious material, contamination or significant debris. The fill soils were not placed in an engineered manner, and are generally considered to have low shear strength, and the granular fill soils below the water table have a high liquefaction potential. Beach Deposits. Beach deposits were typically encountered underlying the fill soils in the lower borings and consisted of very loose to medium dense fine to medium sand with silt, and occasional wood and shell fragments. This unit was not encountered where the underlying bedrock was above Elevation 10 feet. This layer varied in thickness, but the top of this unit was typically encountered at about Elevation 0 to 10 feet and was not encountered below about Elevation 20 feet within the property boundary. We did not encounter beach deposits in any of the borings in the higher upland areas where underlying bedrock was typically at a higher elevation. The saturated beach deposits have low shear strength and high liquefaction potential. Glaciomarine Drift. Glaciomarine drift was encountered in all the borings with the exception of BPDA-6 and BPDA-7 located at the southeastern margin of the site. As discussed previously, the upper portion of this unit can be quite stiff in upland areas, and possess moderate shear strength and compressibility characteristics. This unit typically grades to medium stiff or soft with depth, and has low shear strength and high compressibility characteristics. The glaciomarine drift was typically brown, stiff to very stiff, moist, clay with sand, grading to gray, medium stiff clay in the upland areas of the site, such as near BPDA--5 and underlying the fill in B-1 (2014). In lower lying areas, the glaciomarine drift encountered was typically gray, soft to medium stiff clay with variable sand content. The glaciomarine drift can have pods of sand and/or gravel that can be saturated even when above the water table. The glaciomarine drift extended to the underlying bedrock within the project boundaries. Bedrock: The bedrock underlying the site is of the Chuckanut Formation. Based on our borings, and review of previous site explorations it consists principally of massive sandstone and siltstone. The boring methods used could not penetrate a significant distance into the bedrock. The rock quality of the local sandstone can be very erratic over short distances. The surface of the sandstone was weathered at some explorations locations, sometimes extending to depths of 6 feet or more before reaching less weathered, more competent sandstone bedrock. The Chuckanut Formation has possible layers of mudstone or coal seams. Interpolated contours illustrating the bedrock surface are shown in Figure Groundwater Conditions Groundwater monitoring piezometers were installed in the recent explorations at BPDA-2P, BPDA-3P, and BPDA-4P, in the lower central portion of the site. Groundwater measurements were completed in May 2014 with water levels measured between about Elevation 9.8 and 11.1 feet. Groundwater levels were also inferred at similar elevations based on observations during drilling of the recent and past site explorations; however, direct measurement of groundwater levels could not be completed during drilling. No groundwater was observed during drilling in BPDA-5 which was terminated at about Elevation 33 in bedrock. The regional groundwater table at the site is near Page 8 May 16, 2014 GeoEngineers, Inc. File No

16 ARMY STREET PROJECT Bellingham, Washington DRAFT the measured groundwater elevation in the piezometers but may fluctuate several feet seasonally. Future site evaluation will include additional monitoring to determine if the groundwater levels are also tidally influenced. Limited groundwater seepage was also encountered in some higher upland borings above this elevation. A perched groundwater condition frequently occurs within silty fill soils, and above dense/stiff low permeability soils. Groundwater conditions should be expected to vary as a function of season, precipitation, tides and other factors Archaeological Considerations The results of Drayton Archeology s (Drayton) evaluation are presented in Appendix D. Their evaluation determined that the present site is a largely manufactured landform that would have been near-shore tidal area until massive quantities of fill were imported to the site and that the soils were composed primarily of marine dredge spoils and native beach deposits, which overlie glaciomarine drift deposits and Chuckanut sandstone bedrock. No anthropogenic soils, formed identifiable or diagnostic artifacts of historic or precontact periods were observed in the soil samples. Based on their archaeological review of collected samples and a review of available historical documentation, Drayton Archeology concluded that the likelihood of encountering cultural deposits or artifacts during construction is low. Additionally, it was Drayton s conclusion that it is unlikely the City or the Department of Archaeology and Historic Preservation (DAHP) will require monitoring at the site during construction, although it is our understanding that the risk increases for excavations that extend through the existing fill into the underlying beach deposits. 3.0 GEOLOGICALLY HAZARDOUS AREAS AND MITIGATION The COB requires a geologically hazardous area site assessment be completed for the proposed project in accordance with Bellingham Municipal Code (BMC) Our geologically hazardous area site assessment included reviewing geologic maps and other relevant references, our previous reports, and evaluating our geotechnical explorations of soil and bedrock conditions at the site, completing a geological reconnaissance at the site, and providing conclusions regarding mitigations that would likely be required for development at the site. Designation of the hazards and their presence/absence at the site is discussed in Section 3.1, and discussion of mitigation strategies is discussed in Section 3.2. The geologically hazardous areas are identified in Figure 3 and summarized for each property owner in Figure Designation of Geologic Hazards The methods of designating specific hazard areas are presented in the BMC and are briefly discussed below: Erosion Hazard: Erosion hazard areas are designated in the BMC using Table 11-Building Site Development of the U.S. Department of Agriculture Soil Conservation Service Soil Survey (SCS) of Whatcom County Area. The soil name and map symbol at the site is mapped as urban land in the SCS and is not May 16, 2014 Page 9 File No

17 ARMY STREET PROJECT Bellingham, Washington rated as an erosion hazard area in Table 11 in the SCS. Erosion hazard areas are also designated in the BMC as areas where the soil type is predominantly (greater than 50 percent) comprised of sand, clay, silt, and/or organic matter and slope is greater than 30 percent. With the exception of the Dyson and Donna MacDonald Trust properties, the other participating properties have slopes greater than 30 percent that are considered erosion hazard areas as designated by the BMC. Our interpretation of erosion hazard areas at the site is presented in the Geologically Hazardous Areas Map, Figure Landslide Hazard: The BMC defines a landslide hazard area as any area with a slope of 40 percent or steeper and over 10 feet high. Historic marine bluffs along historical shorelines of Bellingham Bay and areas depicted as having high landslide potential within the landslide hazard areas section of the Geologic Hazard Areas Map Folio, Bellingham, Washington, 1991 are also designated as landslide hazard areas. With the exception of the Dyson and Donna MacDonald Trust properties, the other participating properties have slopes greater than 40 percent that are considered landslide hazard areas as designated by the BMC. Our interpretation of landslide hazard areas at the site is presented in Figure Seismic Hazard: Seismic hazard areas include areas that are subject to severe risk of damage as a result of earthquake induced ground shaking, slope failure, settlement, soil liquefaction or surface faulting. No faults are shown at the site in the United States Geological Survey (USGS) Quaternary Fault and Fold Database for the United States website, The nearest mapped fault is the Macaulay Creek Fault, located approximately 12 miles northeast of the site. The Vedder Mountain Fault is located approximately 5½ miles northwest of the site based on a map presented in Potential Seismic Hazards of the Sumas and Vedder Mt. Faults (Easterbrook, et. al. Undated). The site is located in an area water-ward of the historic natural coastline of Bellingham Bay which was filled to achieve current grades and is mapped as having a very high response to seismic shaking based on our review of the above referenced COB Geologic Hazard Areas Map Folio. Our interpretation of seismic hazard areas at the site is presented in Figure Mine Hazard: Mine hazard areas are defined by the CAO as those areas underlain by or affected by historical mine workings. Specific hazard areas include areas depicted within the Coal Mine Hazard Areas of the COB Geologic Hazard Areas Map Folio. GeoEngineers reviewed their records and other references including a detailed historical review of historical Bellingham mine activity prepared by Tetra Tech (1984). The closest known mine workings are identified south of Commercial Street. Based on our evaluation, the area does not meet the definition of a mine hazard area. Additionally, no mine hazard areas were identified at the project site. Therefore, no impacts or mitigation are appropriate related to mine hazard areas and mine hazards are not be addressed further in this report Tsunami Hazard and Sea Level Rise Tsunami hazard and impacts of sea level rise are not specifically defined in the City CAO, however, because of the proximity to the shoreline, we evaluated if these potential hazards are present at Page 10 May 16, 2014 GeoEngineers, Inc. File No

18 ARMY STREET PROJECT Bellingham, Washington DRAFT the site. The site is not located in an area that is a mapped tsunami inundation zone (DNR, 2004), therefore, no impacts or mitigation are appropriate related to tsunami hazard and is not addressed further in this report. The reference reviewed for sea level rise in Puget Sound prepared by Washington State Department of Ecology (2006) indicates that the sea level rise in the Bellingham area is generally considered in the range of 2 to 3 feet by the year However, this estimate is subject to considerable study and debate at the present time Geologic Hazard Mitigation Erosion Hazard Mitigation Steep slopes of the site defined as erosion hazard areas will be temporarily disturbed during construction. In our opinion, implementing a temporary erosion and sediment control plan (TESCP) designed by the civil engineer, and use of appropriate best management practices (BMPs) will effectively mitigate the temporary erosion hazard. Long-term hazards will be mitigated by the site development with permanent hard surfacing, vegetation, and retaining walls. It is our opinion that no other mitigation outside of the conventional controls during construction will be necessary for site development Landslide Hazard Mitigation Significant below-grade excavation is planned in the steep slope portions of the site currently defined as a landslide hazard area. The planned excavation will require use of temporary slope or engineered temporary shoring to mitigate risks to the site and adjacent properties during construction. The permanent below-grade walls for the proposed structures will act as retaining walls below West Holly Street and Bay Street after the steep slopes are removed, and provide long-term stabilization of the site. In our opinion, the landslide hazard risk will be completely mitigated during construction and site development by use of engineered shoring and permanent retaining structures. Temporary slopes, shoring and permanent retaining walls are discussed later in this report Seismic Hazard Mitigation All of Puget Sound is a seismic hazard area. As discussed previously, no hazard from surface faulting was identified as the site. Incorporating seismic design in accordance with the 2012 International Building Code (IBC) will adequately mitigate effects of seismic shaking on the proposed structures. As discussed previously, the project site is not believed to be at risk from surface faulting and no mitigation will be required for this risk. The only property not subject to potential liquefaction is the Donna MacDonald Trust property. The fill and beach soils below groundwater at the lower elevations of the site on the other properties are susceptible to earthquake induced soil liquefaction and can be susceptible to lateral spreading. These seismic hazards will require mitigation for site development. In waterfront environments such as this site, a combination of overexcavation and replacement, ground improvement technologies, and/or use of pile supported foundations will effectively mitigate the liquefaction and lateral spreading seismic hazards. These mitigation strategizes are discussed later in this report. May 16, 2014 Page 11 File No

19 ARMY STREET PROJECT Bellingham, Washington 4.0 CONCLUSIONS AND RECOMMENDATIONS 4.1. General It is our opinion that the site is suitable for the proposed development. The individual sites are also suitable for development. A summary of subsurface conditions and preliminary geotechnical considerations for each property are presented in Figure 10. A generalized discussion of site development considerations is provided bellow. The properties have some combination of geohazard areas present, with the exception of the small upland Donna MacDonald Trust property that has shallow bedrock and no slope. The geohazard areas can be mitigated by incorporating appropriate design and construction practices, including temporary erosion control BMPs, temporary shoring and permanent walls, and a foundation strategy that mitigates the soft and/or liquefiable soils at the lower elevations of the site. Bedrock was encountered at a relatively high elevation in the southeast boring (approximately Elevation 37 in BPDA-5), and then dips downward rather steeply to the west as shown in Figure 4. If a uniform parking garage elevation is used across the site, considerable excavation into bedrock will be required along Bay Street and West Holly Streets. Temporary shoring of the soils will be required for vertical cuts to support the adjacent roadways, with possibly shotcrete and/or rock anchors in the rock faces. Foundation designs will be variable across the site: Conventional foundations and slab-on-grade design could be used where rock is encountered at the subgrade elevations. This is also true for light buildings founded on stiff glaciomarine drift. At the lower elevations across the site, the foundation design must mitigate the liquefaction potential. For large, heavily loaded structures, it may be appropriate to use piles driven down to bedrock. Another alternative could be a mat foundation over ground improvement, which is typically some kind of rock column or rigid grout column (rigid inclusions). Specific design can t be provided until specific structures are proposed with associated loads and settlement tolerances. Therefore, we have presented an overview of foundation design considerations at this time. At this time, a parking structure is considered for the basement level(s) of the structure. We anticipate that the parking structure would be designed near the existing site grades (about Elevation 20 feet). Based on our current knowledge of groundwater conditions, a lowest subgrade elevation of about +15 feet could be used to avoid dewatering and substantial waterproofing. Considering long term sea level rise, it may be appropriate to stay near the present ground surface elevation Seismic Design Considerations IBC Seismic Design Information The 2012 IBC is the appropriate building code for any development at the site. Because of the variable site conditions from shallow bedrock to liquefiable fill/beach soils, the seismic Site Class is also variable. The Site Class can also vary as a function of building height and land use. The following discussion of Site Class is provided for preliminary planning purposes only; project Page 12 May 16, 2014 GeoEngineers, Inc. File No

20 ARMY STREET PROJECT Bellingham, Washington DRAFT specific information such as building type and height, location at the site (various soils under the foundation) will need to be considered to determine the actual Site Class for design. Sites with liquefiable soils, such as the saturated fill and beach deposits at the site would be classified as Site Class F, and require a site specific seismic evaluation. We assume that the new structures will not be constructed on these soil deposits without liquefaction mitigation, and this mitigation can change the Site Class to not require a site specific seismic evaluation. It is our experience on large mid-rise buildings (over eight stories) that site specific spectral analyses can result in more cost effective structural design and construction costs. This decision would be made by the structural engineer and geotechnical engineer based on the type of building proposed. At the present time, we recommend that the existing site fill soils and beach deposits be classified at Site Class E (Soft Soil Profile) based on presence of loose fill and beach deposits. The areas of the site with stiff native glaciomarine drift overlying bedrock would be defined classified as Site Class D (Stiff Soil Profile). Structures founded directly on underlying sandstone bedrock would be classified as Site Class C (Very Dense Soil and Soft Rock). The design parameters for the 2012 IBC based on the various Site Classifications are summarized in Table 3. These values are based on an earthquake event that has a 2 percent chance of exceedance in a 50-year period. TABLE 3: SPECTRAL RESPONSE ACCELERATIONS (SRA) (SRA) and Site Coefficients Short Period 1 Second Period Soil Profile Type E Description: Soft Soil Profile (N < 15) Mapped SRA SS = S1 = Max. Considered Earthquake SRA SMS = SM1 = Design SRA SDS = SD1 = Soil Profile Type D Description: Stiff Soil Profile (15 < N < 50) Mapped SRA SS = S1 = Max. Considered Earthquake SRA SMS = SM1 = Design SRA SDS = SD1 = Soil Profile Type C Description: Very Dense Soil and Soft Rock (N > 50) Mapped SRA SS = S1 = Max. Considered Earthquake SRA SMS = SM1 = Design SRA SDS = SD1 = Liquefaction Potential Liquefaction is a phenomenon where soils experience a rapid loss of internal strength as a consequence of strong ground shaking. Ground settlement, lateral spreading and/or sand boils may result from liquefaction. Structures supported on liquefied soils could suffer foundation settlement or lateral movement that could be severely damaging to the structures. Conditions favorable to liquefaction occur in loose to medium dense, clean to moderately silty sand that is below the groundwater level. Dense soils/bedrock or soils that exhibit cohesion are generally considered not to be susceptible to liquefaction. May 16, 2014 Page 13 File No

21 ARMY STREET PROJECT Bellingham, Washington The evaluation of liquefaction potential is complex and is dependent on numerous site parameters, including soil grain size, soil density, site geometry, static stresses, and the magnitude and ground acceleration of the design earthquake. Typically, the liquefaction potential of a site is evaluated by comparing the cyclic shear stress ratio (the ratio of the cyclic shear stress to the initial effective overburden stress) induced by an earthquake to the cyclic shear stress ratio required to cause liquefaction. The cyclic shear stress ratio required to cause liquefaction was estimated using an empirical procedure based on the in-situ static ground stresses, the blow count data obtained during sampling in the borings, and a design earthquake with a Richter magnitude of 6.7 and a peak horizontal ground acceleration of 0.41g. The design earthquake parameters were developed using published hazard maps associated with an earthquake event that has a 2 percent chance of exceedance in a 50-year period (2,475 year event) as required by IBC. Based on the blowcounts obtained in our explorations, our analysis indicates that most of the saturated granular fill material and the underlying beach deposits have a moderate to high potential for liquefaction during the design earthquake. We estimate that the liquefaction-induced settlement will on the order of about 8 to 12 inches in the northern portion of the site near boring BPDA-1 (Dyson property), and 3 to 9 inches in the central portion of the site near borings BPDA-2, BPDA-3, and BPDA-4 (Trillium, Army Street ROW, BPDA and Port of Bellingham properties). Limited liquefaction and settlement could occur under the western portion of the Wright Angle and Thornberg properties only. It is standard practice to assume that differential settlement will be about half of the total settlement, therefore on the order of 4 to 6 inches and 1½ to 4½ inches in the northern and central portions of the site respectively. These magnitudes of settlement are typically not tolerable for most structures, therefore we have recommended mitigation by using pile foundations or mat foundations with/without ground improvement depending on project specific circumstances Lateral Spreading Potential Lateral spreading involves lateral displacements of large volumes of liquefied soil during an earthquake. Lateral spreading occurs as blocks of surface soils are displaced toward a nearby slope or shoreline free face by movement of the underlying liquefied soil. This condition exists in the northwest portion of the site near Whatcom Creek at Bellingham Bay. Lateral spreading can also occur on moderately sloping ground as blocks of surface soils displace relative to adjacent blocks. The evaluation of lateral spreading at the site was completed using an empirical model that incorporates earthquake, geological, topographical and soil factors that affect ground displacement. The model was developed from compiled data collected at sites where lateral spreading was observed. The key parameters are the Richter magnitude, the distance from the source zone, the horizontal ground acceleration, the thickness of the liquefied zone, the grain size distribution of the liquefied deposit, and the inclination of the adjacent dike slope. We estimate that the lateral spreading could be up to about 6 inches in the northern portion of the site near boring BPDA-1 (Dyson property), and more likely on the order of 4 inches or less in the central portion of the site near borings BPDA-2, BPDA-3, and BPDA-4 (Trillium, Army Street ROW, and Port of Bellingham properties). Typically the mitigation strategy for liquefaction will serve as sufficient mitigation for these magnitudes of lateral spreading. Ground improvement by rock columns is typically very effective in this regard and has been used successfully on other projects along Bellingham Bay. Page 14 May 16, 2014 GeoEngineers, Inc. File No

22 ARMY STREET PROJECT Bellingham, Washington DRAFT Seismic Hazard Mitigation Summary Using the IBC seismic design is sufficient for all buildings founded directly on bedrock. However, seismic hazard mitigation will be required for all structures at the site not founded directly on the underlying bedrock or those buildings that traverse from bedrock to non-bedrock conditions. There are many options available for mitigation of the seismic hazards such as liquefaction at the site. The most cost-effective strategies include ground improvement (typically densification with rock or grout columns) or pile support of new structures. For smaller structures, sometimes use of a rigid mat foundation without ground improvement is sufficient mitigation. Ground densification of liquefiable soils, typically with stone columns or other proprietary similar methods is a cost-effective means to mitigate seismic hazards associate with soil liquefaction. This method of ground improvement includes installation of higher strength granular fill to the soil profile that results in a composite soil matrix that will provide improved soil bearing capacity. A similar means of ground improvement that does not provide significant densification, but does improve the overall soil matrix, is grouted columns (rigid inclusions). Both of these measures would allow for construction of a shallow foundation system of spread footings and/or mat foundation, depending on final loads and tolerable foundation settlement. Stone columns and grouted columns are discussed in additional detail in the Ground Improvement section of this report. Seismic hazards can also be mitigated by deep pile foundations extending to the underlying bedrock. Appropriate use and placement of piles could likely mitigate both liquefaction and lateral spreading hazard for the building. However, the soil can liquefy around the building and piles, creating problems at connections. Pile foundations are also discussed later in this report Foundation Support General Foundation support options will depend on the location, elevation on the site(s), design elevations of the building(s), and building design details. The foundation conditions will be variable because bedrock was observed at about Elevation 37 feet in the southeast corner of the site, and fill/liquefiable soils are located at the lower portion of the site with bedrock to about Elevation -25 to -40 feet at the northern corner where structures are currently planned. As currently envisioned, the excavation for the below-grade parking for the mid-rise structures will extend at the deepest to approximately Elevation 15 feet (approximately 5 feet below existing lower site grades) to stay above groundwater. Where encountered in the excavation, the bedrock will likely be competent for foundation support of the proposed buildings; however, the soils at the site are not adequate to support the type of heavy, multi-story structures that are currently envisioned for most of this site. As previously described, seismic hazard/liquefaction mitigation will also require supporting the buildings on the lower portion of the site on a pile foundation or performing ground improvement prior to construction. We are not able to present specific foundation design conclusions and recommendations because no specific structure, foundation loading, or settlement tolerances can be identified at this stage. Conceptual level foundation design recommendations are provided in the following sections. May 16, 2014 Page 15 File No

23 ARMY STREET PROJECT Bellingham, Washington Shallow Foundations Conventional shallow isolated spread and continuous footings will be appropriate for portions of the site. Conventional shallow footings are placed under concentrated column and wall loads. Conventional shallow foundations are not recommended for use in areas of existing fill or liquefiable beach deposits, and could be appropriate on the upland sites if small individual structures are considered outside of the steep slope and fill zone. Conventional shallow foundations could be appropriate for the following design scenarios: Low- to mid-rise structure on bedrock: The current design concept will include excavation to bedrock for the below-grade parking structure on the southeast portion of the site. Shallow foundations for low- to mid-rise structures bearing directly on bedrock, or compacted structural fill or lean concrete control density fill (CDF) extending to bedrock will provide suitable foundation support. Allowable bearing pressures will depend on the quality of rock, foundation loads, footings sizes, and type of overexcavation and replacement (if any) that is required to reach the bedrock bearing surface. Allowable bearing pressures on the order of 5,000 pounds per square foot (psf) to 20,000 psf could be expected. Additional exploration including rock coring below the proposed foundation elevation would be necessary to establish an actual design bearing pressure. Low-rise structures on glaciomarine drift: Shallow foundations may also be constructed on undisturbed native stiff glaciomarine drift, which is located on the upland sites. Allowable bearing pressures for this unit will depend on stiffness of the soil unit, foundation loads, footings sizes and settlement tolerance; we expect allowable bearing pressures on the order of 2,000 to 4,000 psf would be appropriate. Low-rise structures or small-mid-rise structures on ground improved soils: Shallow foundations may also be constructed directly on ground improved soils. Because of the relatively high loads for the large mid-rise structures, it is likely that this option will only be feasible for smaller mid-rise structure with one or two levels of concrete parking and up to five levels of wood framing, or one- to two-story low-rise structures. Heavier structures will have larger loads and footing sizes such that a mat foundation would likely be required to reduce bearing pressures, and control total and differential settlements. Allowable bearing pressures for ground improvement will depend on the type and spacing of the improvement; we expect allowable bearing pressures on the order of 4,000 to 6,000 psf based on previous experience. Non-inhabited appurtenant and non-critical structures on existing fill: Non-critical appurtenant structures might be supported adequately on the existing fill soils in some circumstances. Some overexcavation and replacement with structural fill may be required to create uniform support of the foundations and improve settlement performance. We recommend that this option only be considered for not critical structures that could be subject to severe distress during a seismic event. Allowable bearing pressures for this scenario would be relatively low, on the order of 1,500 psf. Where shallow foundations span the various soil/rock conditions described above, the design will need to consider the potential for differential settlement across this transition. It is our experience that significant/large structures with this kind of transition will require significant collaboration with the architect, structural and geotechnical engineers. Page 16 May 16, 2014 GeoEngineers, Inc. File No

24 ARMY STREET PROJECT Bellingham, Washington DRAFT Mat Foundations A mat foundation typically consists of a monolithic, thick concrete slab with several layers of steel reinforcement that serves to distribute the column loads and provide support of the lower floor. The purpose of a mat foundation is to tie the foundations into a rigid unit that will distribute foundation loads over a wider area and reduce differential settlement between individual foundation elements. In some instances, a mat foundation can be designed to float and bridge expected differential settlement resulting from variable magnitudes of static and liquefactioninduced settlement. The mat foundation is typically thick, 24-inches or more, with multiple layers of steel reinforcement. The mat foundation will require construction over a uniform subgrade, typically 12 to 24 inches of crushed rock. Mat foundations may be appropriate for the following design scenarios: Low- to mid-rise structure on ground improved soils: It will likely be feasible to construct a mat foundation over ground improved soils where the foundation elevation is above existing fill, beach deposits, or soft glaciomarine drift. Because of the relatively heavy foundation loads, it will be necessary to extend the ground improvement through all unsuitable soil and down to the bedrock surface, the elevation of which is shown in Figure 4. Detailed design will be required to evaluate differential settlement where mat foundations span between areas of ground improvement and direct support on bedrock surfaces. Low-rise structures on unimproved soils: Low-rise structures might be constructed on mat foundation with or without ground improvement. A mat foundation for a lightly-loaded structure could be designed that is sufficiently rigid that it will prevent collapse and provide life safety standards even when supported over existing liquefiable soils. Significant damage to the structure would be expected during a design-level earthquake, possibly with total economic loss of the structure. Alternatively, partial-depth ground improvement could be used mitigate the liquefaction even if soft soils remain below the structure. In this instance, the structure would be expected to withstand a design-level earthquake with more limited damage Pile Foundations Pile foundations transfer foundation loads through the loose and liquefiable soils where present to the bedrock. This technique does not stabilize the ground below or around a pile supported building, so some settlement below and around a building could occur such that the connections to surrounding infrastructure can be compromised during a large earthquake. The incremental increase in cost for a pile foundation from a shallow or mat foundation system can be significant because of the required grade beams and higher lateral load design requirements. We would expect that the bottom floor will also be a structural slab. A pile foundation would also be the preferred option for support of the pedestrian bridge connection to the waterfront area. Since pile foundations would extend through the potentially liquefiable soils, new pile foundation design must include the effects of downdrag loads. New piles will offer some lateral resistance for the buildings and to resist the effects of lateral spreading. Driven piles will likely be the preferred piles at the site because of the ability to confirm adequate bearing considering the variable conditions across the site. Additionally, driven piles do not generate soil cuttings, which require disposal. For the heavier mid-rise structures proposed at the site, steel H-pile, or open-ended steel May 16, 2014 Page 17 File No

25 ARMY STREET PROJECT Bellingham, Washington pipe piles will provide higher bearing capacities. For lighter low-rise structures, timber and drilled augercast piles may also be appropriate. Lateral pile capacity will be a significant component of final design. For the larger structures, it will be necessary to use sufficient piles to resist lateral loads or ground improvement may be required to densify the soil around the piles to provide better lateral resistance Ground Improvement In absence of pile foundations, ground improvement will likely be required for shallow foundation support of the mid-rise structures in areas of existing fill or beach deposits. The purpose of ground improvement at the site can be four-fold: 1) to improve bearing capacity and reduce settlement under static conditions resulting from the newly imposed structural loads; 2) to reduce settlement resulting from liquefaction of loose saturated foundation soils; 3) to densify loose/soft soils under structures or waterward of structures to provide suitable static and seismic stability and reduce deformation associated with lateral spreading; and 4) improve soils around pile foundations to provide additional lateral pile resistance. Numerous methods of ground improvement are available such as vibro-replacement, Rammed Aggregate Piers (RAPs), timber compaction piles, compaction grouting, soil mixing, deep dynamic compaction, wick drains, and blast densification. Some of these techniques are likely not suitable considering the location, high groundwater table and other factors. A combination of these techniques has been used to allow creative and more cost-effective foundation alternatives; however, such evaluation was beyond the scope of this preliminary study. For this level of planning, we focused on two common waterfront ground improvement technique that mitigates liquefaction impacts and could be used to provide adequate foundation support for moderately loaded structures. GeoEngineers has successfully used vibro-replacement (stone columns) in the Bellingham area on other projects including the Bellwether hotel and for mitigation of lateral spreading at the CH2M Hill Building Vibro-Replacement Columns and RAPs Stone columns and proprietary systems like the RAP (Geopier Impact System) are common ground improvement techniques that could be designed to mitigate the seismic hazards at the site. Conventional shallow foundations for lighter low-rise structures could be supported on the stone columns directly, or, for heavily loaded structures, the columns could be used in combination with mat foundations or pile foundations. It may be beneficial and/or necessary to use a ground improvement technique to stiffen the bearing soils for lateral resistance around the pile foundations and/or resist lateral spreading. These techniques are typically one of the more cost effective methods of ground improvement. Therefore, we have focused on this approach. Construction of vibro-replacement columns or RAPS involves the displacement of loose/soft soils by installation of vertical columns of compacted stone. Typically, a hollow tube or probe is vibrated, or jetted into the ground to the desired depth for stone columns. As the tube or probe is withdrawn, crushed stone is fed to the bottom of the hole and compacted. With RAPS below groundwater, a casing can be used to the bearing depth and then a mandrel is used to compact layers of stone. The end result is a column of dense stone which penetrates through the loose/soft unsuitable soil and is capable of transferring loads into the underlying competent soils or bedrock. Page 18 May 16, 2014 GeoEngineers, Inc. File No

26 ARMY STREET PROJECT Bellingham, Washington DRAFT These techniques densify surrounding granular soil deposits; no soil cuttings need to be generated with these techniques. The presence of the column creates a composite material of lower overall compressibility and higher shear strength than the native soil alone. Confinement of the stone is provided by the lateral stress within the densified loose/soft soils. As loads are applied, the stone columns and soft soil move downward together, resulting in transfer of the majority of the load to the stone column. Additional analyses of stone columns will be required during design to determine the specific amount of ground improvement (replacement ratio and depth) that will be necessary to meet the project needs. This type of ground improvement method is typically satisfactory to mitigate liquefaction and support low-rise structures that can then be designed using conventional shallow foundation and slab-on-grade techniques, or mid-rise structures with mat foundations. A slightly higher allowable bearing pressure can oftentimes be used to help off-set some of the ground improvement costs At this site, we would expect the stone columns would extend through the liquefiable fill and beach deposits and soft clay to bedrock. The depth of these units was discussed previously, and the bedrock elevations are shown in Figure 4. The thicker deposits extend toward the Whatcom Waterway. For smaller, lightly loaded structures, it may not be necessary to install ground improvement the full depth of the liquefiable soils. Typically, the area in which stone columns are installed extend at least 10- to 20-feet (one to two rows) laterally beyond the edges of buildings Rigid Inclusions Rigid inclusions are another ground improvement technique that could be designed to mitigate the seismic hazards at the site. Rigid inclusions are formed by constructing unreinforced lean concrete piles beneath the shallow foundations, typically using the same equipment that installs augercast piles. This type of installation does generate soil cuttings, which may be an archaeological consideration. The intent of the rigid inclusions is to provide foundation bearing by transferring foundation loads to the underlying bedrock when the surrounding soil liquefies during a design earthquake event. Rigid includes could likely be used in the same areas as the stone columns; this technique typically results in lower post-construction settlements and would be used for larger structures. GeoEngineers designed a similar foundation system for a large tank at the COB wastewater treatment plant Slab-on-Grade Floor Support Where conventional shallow spread footings are used, buildings may also be constructed with a conventional slab-on-grade. In the lower, northern and central portions of the site, the slab would overly existing fill soils, and would likely require overexcavation and replacement to create uniform support of the slab. The slab-on-grade may also be supported on ground improvement. In the southern, higher portions of the site, it is more likely that the slab on grade would be constructed overlying stiff native soils or bedrock and conventional construction techniques would be appropriate. In all cases, use of a typical capillary break layer below the slab, and sufficient drainage provisions is recommended. May 16, 2014 Page 19 File No

27 ARMY STREET PROJECT Bellingham, Washington 4.6. Permanent Retaining Walls Permanent retaining walls would most likely be included with most new site development scenarios. The envisioned Army Street Project includes multiple levels of parking below multi-story buildings. It is assumed that the lowest floor for the parking will be near the existing lower site grades or possibly to about Elevation 15 feet (one-half floor below grade at the lowest site grades). The parking structure would include permanent retaining walls along West Holly Street and Bay Street, and could be as high as 40 feet. Conventional design of permanent walls would be appropriate for the site where they are located above the maximum groundwater level. It will likely be appropriate to consider potential effects of tsunami and sea level rise when choosing a lowest floor elevation for the parking garage or any other structures at the lower elevation of the site. Any walls below even temporary high groundwater will need to be designed to prevent seepage as described in the Waterproofing and Drainage section of this report. Depending on location on the site, depth below grade, and location relative to the property line boundary, permanent retaining walls will either be constructed in front of temporary slopes or against temporary shoring. Walls constructed in front of temporary slopes and backfilled are typically cast-in-place concrete walls that will be designed for typical lateral earth pressures assuming granular backfill and either active or at-rest earth pressures, and will include surcharge pressures and seismic forces. Drainage for backfilled cast-in-place retaining walls is typically provided by placing a free-draining layer behind the wall and collection pipe tightlined to the stormwater system. The deeper excavations expected at or near the property line will likely be completed with temporary shoring. As such, permanent retaining walls will be constructed against the temporary wall face. Earth pressures will depend on the wall height, shoring type, and nature of the permanent structure (i.e. bracing) and may be triangular, uniform, or trapezoidal load distribution, with surcharge and seismic earth pressures. It is possible that a reduced earth pressure could be used for the walls that are constructed against bedrock. Drainage for permanent walls constructed against temporary shoring is typically provided by geocomposite drainage mats placed between the temporary and permanent wall. The drainage mat will be tied into the footing drain Waterproofing and Drainage Considerations As currently envisioned, the lower floor of the parking garage will be constructed near the lower existing site grade or possibly to about Elevation 15 feet. If the lowest final grades are at about Elevation 15 feet or above, it is unlikely that special waterproofing will be required; however, as previously mentioned, long term sea level rise could impact groundwater levels at this site such that a lower floor level near Elevation 20 feet would have less risk of long-term impact. Typical water control measures above these elevations include installation of a capillary break layer and moisture vapor barrier below slabs-on-grade, and drainage provisions behind retaining walls and waterproofing coatings on exterior walls. We expect that random but limited perched groundwater will be encountered in the cuts that would be necessary along West Holly Street and Bay Street. Below about Elevation 15 feet, construction of a completely watertight basement that resists buoyancy and hydrostatic forces as well as water penetration may be required. Waterproofing can Page 20 May 16, 2014 GeoEngineers, Inc. File No

28 ARMY STREET PROJECT Bellingham, Washington DRAFT be accomplished with a concrete additive for the floor slab and a concrete additive and/or an applied product for the buried walls. A water stop joint sealer is required between the walls and the floor slabs including the ramps down to the garage floor elevation, usually with a monolithic mat foundation that has no joints. Below this elevation it may be appropriate to install an underslab drainage system connected to a sump and pump to serve as a dewatering mechanism during construction and as an emergency backup during the building operation in the event that groundwater penetration into the garage becomes a concern Stormwater Considerations Stormwater requirements will need to be evaluated by a civil engineer when a specific project is in the planning stages. As previously mentioned, a buried concrete stormwater vault presently exists in the Army Street ROW. It may be possible to incorporate this or an additional below grade stormwater vault as part of the project. We do not expect that significant infiltration will be appropriate at this site because of the groundwater table and likely presence of below grade building components for this project. However, some limited low impact development (LID) strategies such as rain gardens could be evaluated during design. We recommend that the ground surface be sloped away from the buildings to the extent practical. Due to the poorly draining site conditions, we recommend that perimeter-footing drains be included around all buildings. The footing drains should be tightlined to the storm drain system or other suitable discharge point. All downspouts should also be tightlined away from the building foundation areas and should be discharged into a stormwater disposal system. Downspouts should not be connected to footing drains Utilities The utilities at the lower elevations will experience settlement from liquefaction, likely differential in nature between the ground improved soil under buildings or pile supported buildings. Therefore, we recommend critical and rigid utilities such as gas, water, sewer lines and drains be attached to the building via flexible fittings to allow for differential settlement between the building and the surrounding ground supporting the utilities. Also, we recommend that gas and water lines be equipped with automatic shutoff valves that are activated by ground shaking to reduce the potential for gas leaks or water leaks during an earthquake Construction Considerations The proposed Army Street Project is a typical multi-story project with below grade parking that is not unusual in the Puget Sound region. It would require significant excavation along West Holly and Bay Streets, which would include temporary shoring. The bedrock was encountered at about Elevation 37 in boring BPDA-5, so significant excavation into bedrock would be required which is discussed below. As previously described, foundation construction in the lower portion of the site would involve installation of piles or ground improvement. These foundation practices are common for buildings located in waterfront developments. Therefore, we conclude that construction for this project would be reasonably conventional. May 16, 2014 Page 21 File No

29 ARMY STREET PROJECT Bellingham, Washington Soil Excavation We expect that any site developments will include excavations below present site grades. The proposed Army Street Project would include a lowest parking garage floor elevation near existing lowest site grades. Based on our preliminary conclusions, the parking garage could extend approximately ½-story below grade to about Elevation 15 feet without being impacted by groundwater. However, excavation to this lower level could require archaeological monitoring, and groundwater levels may rise during the design life of the structure, such that planning on a lower finished floor at about Elevation 20 feet would limit potential future impacts. Project excavations would extend through existing fill soils, the native glaciomarine drift (sandy clay) and bedrock. The site soils can be excavated with conventional equipment. Large cobbles and boulders can be encountered in the glaciomarine drift. The clay and clayey fill soils are highly moisture sensitive and easily susceptible to disturbance by construction equipment during wet weather. The clay fill soils will not support rubber-tired construction equipment during wet conditions. However, vehicular travel will be good during extended periods of warm dry weather. We did not observe evidence of contamination at the site based on the results of our explorations; however, the undocumented nature of the fill always represents a potential for random buried contamination or past undocumented underground storage tanks. It may be necessary to perform some chemical testing for disposal of fill soils at the contractor s disposal site. As discussed, based on the archaeological review, the likelihood of encountering cultural deposits or artifacts during construction is low. Because the artifacts would generally be associated with soils below the existing fill horizon, planning development at or above existing site grades would reduce the risk encountering the artifacts and associated costs of triggering onsite archaeological monitoring requirements during construction Rock Excavation Based on our exploration program and the proposed Army Street Project below-grade parking, excavation of bedrock will likely be required in the southeast portion of the property to achieve the proposed finished floor grades. Depending on whether a stepped approach is taken, on the order of 20 feet of rock excavation may be required for the lower floor elevation anticipated. Figure 4 shows the interpreted bedrock elevations to allow a preliminary determination of the rock excavation that might be required for various design elevations. The character of the Chuckanut Formation varies tremendously with location in terms of surface elevation, grain size, weathering, bedding, and other factors. Based on experience, the upper several feet of the bedrock is typically weathered and can be excavated with conventional large horsepower excavators. As the rock becomes unweathered, more mechanical effort is required. Bulldozers with rock rippers, large horsepower excavators with special rock teeth and/or hydraulic rams or hydropunches are typically able to excavate the local bedrock, although it slows the excavation process. This consideration would need to be included in the cost estimate and schedule for excavation. Other options of rock excavation include predrilling numerous holes using an air track rig, blasting, or using hydraulic rock splitters or expansive grout. All of these methods fracture the bedrock so that conventional excavators can remove the material. Page 22 May 16, 2014 GeoEngineers, Inc. File No

30 ARMY STREET PROJECT Bellingham, Washington DRAFT Blasting is allowed by the COB codes, although it would be carefully scrutinized considering the urban density around the site. Based on our experience, we expect that excavators with special rock ripping equipment would be the contractor s preferred method of excavation. Further evaluation during design would be appropriate Temporary Slopes The excavation necessary to achieve a uniform lower parking elevation across most of the site would encounter mixed granular and clayey fill soils, stiff native clayey soils and bedrock. Regardless of the soil type encountered in the excavation, either shoring, trench boxes, or sloped sidewalls will be required for excavations deeper than 4 feet under Washington State Administrative Code (WAC) , Part N. The native stiff sandy clay would be classified as a Type A soil with a temporary slope at 0.5H:1V. The existing fill, however, is considered a Type C soil with a temporary slope at 1.5H:1V. Flatter slopes would be required in areas of seepage. Any excavations below groundwater would need to be dewatered for safety. The contractor is typically responsible for temporary slopes because they are able to observe subsurface conditions continuously throughout the construction process and can respond to the soil and groundwater conditions. Construction site safety is generally the sole responsibility of the contractor, who also is solely responsible for the means, methods, and sequencing of the construction operations and choices regarding temporary excavations and shoring. We expect that the excavations will be made as open cuts in conjunction with the use of a trench box and/or sloped sidewalls for shielding workers, or temporary shoring as described below. The stability of open-cut slopes is a function of soil type, ground water level, slope inclination and nearby surface loads. The use of inadequately designed open cuts could impact the stability of adjacent structures and existing utilities, and endanger personnel. The above regulations assume that surface loads such as construction equipment and storage loads will be kept a sufficient distance away from the top of the cut so that the stability of the excavation is not affected. Flatter slopes and/or shoring will be necessary for those portions of the excavations which are subjected to significant seepage in order to maintain the stability of the cut. Temporary slopes in wet/saturated sand will be susceptible to sloughing, raveling and running conditions. It should be expected that unsupported cut slopes will experience some sloughing and raveling if exposed to surface water. Berms, hay bales or other provisions should be installed along the top of the excavation to intercept surface runoff to reduce the potential for sloughing and erosion of cut slopes during wet weather. The stability of temporary cuts in the bedrock will depend on the bedrock conditions. Vertical cuts are suitable in competent, non-jointed rock. It would be necessary to perform rock cores below the base of the proposed excavation to determine if primarily competent, uniform sandstone is present such that it may be possible to make unsupported excavations. Oftentimes the local sandstone has discontinuities, clay infill, coal and other conditions that still require some kind of stabilization. This can vary from a simple flashcoat of shotcrete for safety purposes, or reinforced shotcrete facing with rock bolts if fractures, joints adverse bedding or other non-conformities are encountered. May 16, 2014 Page 23 File No

31 ARMY STREET PROJECT Bellingham, Washington Temporary Shoring Considerations If the project is designed using zero lot line practices (edge of building extends to property line, i.e., adjacent sidewalks along West Holly Street and Bay Streets) and the lower floor will be several floors below existing adjacent site grades, then temporary shoring walls will be required to support adjacent properties and/or public ROWs. It is typically required that shoring walls adjacent to public ROWs be designed to limit deflections to less than 1 inch. The deflections will depend on the proximity of critical infrastructure. The typical temporary shoring types in this application include soil nail walls where a soil profile is present that allows temporary short vertical excavation, cantilevered soldier piles, or soldier piles and tiebacks when two stories below grade or more are to be constructed. These types of walls are not appropriate below groundwater; thus dewatering would need to be accomplished if they extend below groundwater at about Elevation 10 feet. The use of tiebacks, soil nails and/or rock anchors will require easements from adjacent property owners, most likely the City of Bellingham for the West Holly and Bay Street ROWs.. Soil nail walls are a top down construction method and are typically less expensive than tieback soldier pile walls. Soil nail walls are constructed by excavating a vertical face in the soil, installing near horizontal anchors (typically 15 degrees below horizontal) into the exposed face and then placing steel reinforcing and shotcrete against the exposed face. Once the concrete wall has achieved adequate strength, another section of soil can be excavated from beneath the previous lift and the process repeated. This technique is limited to the capacity of the soil to stand near vertical for a short period of time. It may be necessary to include vertical elements or use other wall types along West Holly Street or Bay Street where existing fill soils are not suitable for vertical face excavation and/or existing utilities may conflict with soil nail layout. Temporary soldier pile walls may be appropriate in places to limit conflicts with existing utilities. Soldier piles consist of vertical shafts with a steel wide flange section full depth drilled on typically about 8-foot spacing along the perimeter of the excavation. The portion of the annular space below the excavation depth is backfilled with structural concrete; the upper portion of the annular space is backfilled with lean concrete. As the excavation proceeds, typically timber lagging is placed between the soldier piles. Equipment can be used that can penetrate the bedrock where necessary, although significant penetration into the bedrock is typically expensive. This type of system typically requires tiebacks to be more cost effective when the height approaches 15 feet below adjacent grade. As mentioned above, bedrock was encountered in the southeast corner of the site. It is possible that shoring could be avoided in this area, although typically at least some kind of rock fall protection is required. The rock may be competent enough to stand vertical without any temporary shoring, although oftentimes there are enough discontinuities in the local rock that a shotcrete facing with at least some rock bolts should be expected for temporary excavations. We suggest that a contingency be included for shotcrete and rock anchors should stabilization of the rock be required. Typically a shoring monitoring and instrumentation program is recommended when a significant shoring system extends below an adjacent public ROW. This includes a series of survey points to Page 24 May 16, 2014 GeoEngineers, Inc. File No

32 ARMY STREET PROJECT Bellingham, Washington DRAFT monitor horizontal and vertical movements of the shoring, surrounding streets, buildings, and any other adjacent facilities. Locations of the monitoring points should be established when the final shoring design is complete. Monitoring points are typically established within a lateral distance of half the height of the shoring, and on all adjacent structures. In addition to survey monitoring points, a complete inspection of the site and adjacent facilities should be completed prior to construction. The inspection should include photographic documentation and complete notes or diagrams of the condition of all adjacent facilities Erosion and Sedimentation Control The site soils have a high susceptibility to erosion when disturbed. Temporary erosion control measures should be used during construction depending on the water, location, soil type, and other factors. Surface water should be prevented from flowing across disturbed areas and not directed toward slopes during construction. Temporary erosion protection (e.g., straw, plastic, or rolled erosion control products [RECPs]) may be necessary to reduce sediment transport until vegetation is established or permanent surfacing applied. Appropriate best management practices (BMPs) should be incorporated into the temporary erosion and sediment control plan by the civil engineer. We are available to provide additional input if desired Dewatering Considerations As previously discussed the groundwater elevation was encountered at approximately Elevation 10 feet, and could vary by several feet based on seasonal fluctuation during the winter months and tidal events. Based on the information collected to date: We conclude that a ½-story below grade basement (4 to 6 feet below existing lower site grades to about Elevation 15 feet) is likely feasible without significant dewatering based on present information. Constructing a full basement (typically 8 to 10 feet below existing lower site grades) may require some dewatering during construction except in the later summer/early fall months. If a full basement is constructed, the floor slab and lower walls must be designed watertight, with appropriate waterproofing details and hydrostatic pressures incorporated into the design. This has been done for other waterfront projects in the Bellingham area. Localized groundwater conditions are affected by adjacent sea levels. If below grade basements will be constructed, it will be appropriate to consider the possible effect of sea level rise based on best available information at the time of design. It should be noted that extensive use of construction dewatering and permanent waterproofing usually adds significant expense to a project. Detailed dewatering design is typically completed by a specialty subcontractor based on planned locations and depths of excavation. We anticipate that dewatering would consist of a combination of sumps and pumps, wells, or a well point system discharging to the COB storm drain system with specialty permits. It may be necessary to perform chemical analytical testing of groundwater to discharge to the storm drain system. May 16, 2014 Page 25 File No

33 ARMY STREET PROJECT Bellingham, Washington Additional Geotechnical Services We recommend project specific geotechnical design studies for any future development at the individual properties and for the Army Street Project. The site has significant ground modification and complex geology such that the soil-structure interaction and building performance will need to be carefully considered during design in a collaborative effort by the architect, structural and geotechnical engineers. This is very typical for this type of multi-story project with below grade parking. The subsurface conditions at the site are adequately defined for this level of planning and pre-design effort. However, it may be appropriate to perform additional exploration for individual projects and/or for a large project to better define transitions, or better define the bedrock character. The local bedrock can have non-conformities and has a significant slope across the site. If a large building will be supported with at grade elements (shallow footings) on the bedrock, we recommend that the bedrock be cored to at least 20 feet below the foundation level to confirm that the bedrock is adequately competent and stable for the foundation loads. The subsurface information in this report may be adequate for future development of individual geotechnical reports for individual property development considering that the buildings would likely be much smaller. 5.0 LIMITATIONS We have prepared this report for the exclusive use of the Bellingham Public Development Authority, and individual property owners identified in this report for use on the Army Street Development project to be located in Bellingham, Washington. It also provides background development considerations for individual properties at the site. This report should not be used for design purposes. The subsurface information contained herein may be adequate to prepare a design level report during design; however, since no specific project and buildings were identified at this time, this report is suitable for planning and pre-design purposes. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. Any electronic form, facsimile or hard copy of the original document ( , text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. Please refer to Appendix E titled Report Limitations and Guidelines for Use for additional information pertaining to use of this report. 6.0 REFERENCES City of Bellingham Geologic Hazard Areas Map Folio, Bellingham, Washington. Page 26 May 16, 2014 GeoEngineers, Inc. File No

34 ARMY STREET PROJECT Bellingham, Washington DRAFT Easterbrook, D.J., 1976, Geologic Map of Western Whatcom County, Washington, United States Geological Survey, Map I-854-B. Easterbrook, D.J., et. al. Undated, Potential Seismic Hazards of the Sumas and Vedder Mt. Faults report accessed on International Building Code, Copyright 2012, International Code Council, Inc. Tetra Tech, December Final Report: Bellingham Abandoned Mine Land Survey, prepared for the U.S. Department of the Interior, Office of Surface Mining. United States Department of Agriculture Soil Conservation Service. May Soil Survey of Whatcom County Area, Washington. United States Geological Survey. Quaternary Fault and Fold Database for the United States website Washington State Department of Ecology. June Coastal Zone Atlas of Washington, Whatcom County. Washington State Department of Ecology and Washington State Department of Community, Trade and Economic Development, November 2006, Impacts of Climate Change on Washington s Economy: A Preliminary Assessment of Risks and Opportunities Washington State Department of Natural Resources Division of Geology and Earth Resources. June Tsunami Hazard Map of the Bellingham Area, Washington: Modeled Tsunami Inundation from a Cascadia Subduction Zone Earthquake. Washington State Department of Natural Resources Division of Geology and Earth Resources. Online Washington Interactive Geologic Map website May 16, 2014 Page 27 File No

35 Lynn St Ellis St Franklin St West St Elizabeth St Grant St Humboldt St Iron St James St King St Path: \\BAM\Projects\18\ \GIS\ _VicinityMap.mxd Map Revised: 07 May 2014 mformolo Eldridge Ave Coho Way S Harbor Loop Dr Bellingham Bay San Juan Island Monroe St Washington St S State St Victor St Roeder Ave Boulevard Forest Ln Utter St S Garden St Walnut St Park St Hilton Ave SITE Pine St Elm St Highland Dr Broadway J St I St H St W Holly St C St N Forest St N Garden Ter Morey Ave Bancroft St Astor St G St Cornwall Ave Wharf St Pine St 21St St W Campos Way Girard St Ellsworth St E St W Laurel St E Pine St Oak St D St E Ivy St Jenkins St Cornwall Ave N State St N Garden St High St F St Irving St Halleck St Bay St Girard St C St Lottie St Prospect St Commercial St N Forest St Western Washington University A St E St Central Ave Flora St E Holly St E Maple St Indian St B St Young St Railroad Ave E Chestnut St Jersey St Liberty St Dean Ave New St York St E Magnolia St Key St Mason St Newell St 32Nd St Dean Ave 33Rd St Texas St Iowa St Ohio St Kansas St Ellis St E Laurel St Carolina St Otis St N 34Th St W Byron St Virginia St Kentucky St York St Gladstone St Franklin St Franklin St ha t Potter St N Samish Way tcom Fraser St Mead or Lakeway Dr 37Th St C rreek Humboldt St 5 5 Iron St Ave Fraser St E Maple St µ 5 W a s h i n g t o n 2,000 2,000 Bellingham! Whatcom Skagit Notes: 1. The locations of all features shown are approximate. 2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. can not guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. 3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. Data Sources: ESRI Data & Maps Projection: NAD 1983 UTM Zone 10N DRAFT 0 Feet Vicinity Map BPDA - Army Street Project Bellingham, Washington Figure 1 King St King St Lincoln St Byron Ave Lincoln Blvd

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44 PROPERTY NAME (LISTED BY OWNER) TOPIC ANTICIPATED BUILDING TYPE George B. Dyson Trillium Corporation Army Street ROW/ City of Bellingham BPDA Port of Bellingham Wright Angle, LLC Donna McDonald Trust Robert C. Thornberg Decedent s Trust Low-rise Small mid-rise Small to large mid-rise Large mid-rise Large mid-rise Large mid-rise Large mid-rise Large mid-rise APPROXIMATE GROUNDWATER ELEVATION ~ +10 feet ~ +10 feet Seepage in cut slopes ~ +10 feet Seepage in cut slopes ~ +10 feet Seepage in cut slopes ~ +10 feet Seepage in cut slopes Seepage in cut slopes Seepage in cut slopes ~ +10 feet Seepage in cut slopes SUBSURFACE CONDITIONS Soils Fill and beach deposits Soft glaciomarine drift Fill and beach deposits Soft glaciomarine drift Fill and beach deposits Soft glaciomarine drift Fill and possible beach deposits Soft glaciomarine drift Fill and beach deposits Soft glaciomarine drift Fill beach deposits Stiff glaciomarine drift Fill deposits Stiff glaciomarine drift Fill deposits Stiff glaciomarine drift Bedrock Bedrock at approximately Elevation -20 to -45 feet Bedrock at approximately Elevation +0 to -25 feet Bedrock at approximately Elevation +20 to -25 feet Bedrock at approximately Elevation +40 to +0 feet Bedrock at approximately Elevation +5 to-10 feet Bedrock at approximately Elevation +40 to -+0 feet Bedrock at approximately Elevation >40 to -20 feet Bedrock at approximately Elevation >40 to -5 feet GEOLOGIC HAZARDS AND MITIGATION Erosion No erosion hazard Erosion hazard use BMPs Erosion hazard use BMPs Erosion hazard use BMPs Erosion hazard use BMPs Erosion hazard use BMPs No erosion hazard Erosion hazard use BMPs Landslide No landslide hazard Landslide hazard use engineered slopes/walls Landslide hazard use engineered slopes/walls Landslide hazard use engineered slopes/walls Landslide hazard use engineered slopes/walls Landslide hazard use engineered slopes/walls No landslide hazard Landslide hazard use engineered slopes/walls Seismic Seismic hazard requires mitigation - use pile or mat foundation/ground improvement Seismic hazard requires mitigation - use pile or mat foundation/ground improvement Seismic hazard requires mitigation - use pile or mat foundation/ground improvement Seismic hazard requires mitigation - use pile or mat foundation w/ground improvement Seismic hazard requires mitigation - use pile or mat foundation w/ground improvement Seismic hazard requires mitigation IBC code sufficient Seismic hazard requires mitigation IBC code sufficient Seismic hazard requires mitigation IBC code sufficient except southwest corner SEISMIC DESIGN CONSIDERATIONS IBC Site Class Class E, F Class E, F Class E, F Class E, F Class E, F Class C, D, E Class C, D Class C, D, E Liquefaction Potential High liquefaction potential (8 to 12 inches settlement) High liquefaction potential (3 to 9 inches settlement) High liquefaction potential (3 to 9 inches settlement) Low liquefaction potential lower portion of site only (less than 1 inch) High liquefaction potential (3 to 9 inches settlement) Low liquefaction potential lower portion of site only (less than 1 inch) Non-liquefiable Low liquefaction potential lower portion of site only (less than 1 inch) Lateral Spreading Potential Slight lateral spreading potential (less than 6 inches) Slight lateral spreading potential (less than 4 inches) Slight lateral spreading potential (less than 4 inches) Low lateral spreading potential (less than 1 inch) Slight lateral spreading potential (less than 4 inches) Low lateral spreading potential (less than 1 inch) No lateral spreading Low lateral spreading potential (less than 1 inch) TYPES OF FOUNDATION SUPPORT AND POSSIBLE GROUND IMPROVEMENT STRATEGY Pile foundation Mat foundation with or without ground improvement Shallow foundations with ground improvement Pile foundation Mat foundation with ground improvement Shallow foundations with ground improvement (smaller structure only) Pile foundation Mat foundation with ground improvement Shallow foundations with ground improvement (smaller structure only) Pile foundation Mat foundation with ground improvement Shallow foundations not recommended Pile foundation Mat foundation with ground improvement Shallow foundations not recommended Pile foundation (lower site elevation) Mat foundation with ground improvement (lower site elevation) Shallow foundations on bedrock Pile foundation (lower site elevation) Mat foundation with ground improvement (lower site elevation) Shallow foundations on bedrock Pile foundation (lower site elevation) Mat foundation with ground improvement (lower site elevation) Shallow foundations on bedrock Summary of Geotechnical Considerations Army Street Project Bellingham, Washington DRAFT Figure 10

45 Topic RETAINING WALLS George B. Dyson Trillium Corporation Army Street ROW/ City of Bellingham PROPERTY NAME (LISTED BY OWNER) BPDA Port of Bellingham Wright Angle, LLC Donna McDonald Trust Robert C. Thornberg Decedent s Trust Temporary No temporary shoring Temporary shoring Temporary shoring Temporary shoring Temporary shoring Temporary shoring Temporary shoring Temporary shoring Permanent No permanent walls unless below grade parking constructed Permanent walls Permanent walls Permanent walls Permanent walls Permanent walls Permanent walls Permanent walls DEWATERING Unlikely Possibly required below Elevation +10 feet Possibly required below Elevation +10 feet Possibly required below Elevation +10 feet Possibly required below Elevation +10 feet Unlikely Unlikely Unlikely EARTHWORK Soil Excavation Limited soil excavation expected for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Soil excavation for below grade parking Rock Excavation No rock excavation expected No rock excavation expected No rock excavation expected Rock excavation likely along West Holly Street Rock excavation unlikely Rock excavation for below grade parking Rock excavation for below grade parking Rock excavation for below grade parking Notes: 1. See text for detailed discussion. 2. Low-rise building is height less than 35 feet. 3. Small mid-rise building is up to 6 stories over 2 levels of parking. 4. Large mid-rise building is up to 11 stories above 4 levels of parking. 5. Base elevation for parking structure is assumed at about Elevation +15 feet for all properties. Summary of Geotechnical Considerations Army Street Project Bellingham, Washington DRAFT Figure 10

46 APPENDIX A Field Exploration Program

47 ARMY STREET PROJECT Bellingham, Washington DRAFT APPENDIX A FIELD EXPLORATION PROGRAM Soil Exploration Subsurface soil and groundwater conditions were evaluated across the site by completing seven borings on March 31 and April 1, The borings were completed using hollow-stem auger techniques to a depth of approximately 20 to 65 feet below existing ground surface (bgs) using a track-mounted drill rig subcontracted to GeoEngineers. The approximate locations of the explorations are shown in the Site and Exploration Plan, Figure 2. Piezometers were installed into three of the borings and completion details are summarized on the boring logs. The boring locations were surveyed after the borings were completed by a licensed surveyor, and therefore the locations should be considered accurate to the degree implied by the method used. Logs of previous site explorations and nearby explorations reviewed for this project are reproduced in Appendix C. Soil samples from the borings were obtained using the Standard Penetration Test (SPT) method. This method involves driving a split spoon sampler a total of 18 inches using a 140 pound rope and cat-head hammer free falling 30 inches. The number of blows required to drive the sampler the last 12 inches are recorded on the boring logs. The samples were placed in plastic bags to maintain the moisture content and transported back to our laboratory for analysis and testing as described in Appendix B. The borings were continuously monitored by a geotechnical engineer from our firm who examined and classified the soils encountered, obtained representative soil samples, observed groundwater conditions and prepared a detailed log of each exploration. Soils encountered were classified visually in general accordance with ASTM D , which is described in Figure A-1. An explanation of our boring log symbols is also shown on Figure A-1. The logs of all the borings completed at the site are presented in Figure A-2 through A-8. The exploration logs are based on our interpretation of the field and laboratory data and indicate the various types of soils encountered. It also indicates the depths at which these soils or their characteristics change, although the change might actually be gradual. If the change occurred between samples in the boring, it was interpreted. Piezometer Installation and Groundwater Monitoring Piezometers were installed in three of the borings, BPDA-2P, BPDA-3B, and BPDA-4P, in the central portion of the site. Details regarding the piezometer construction are shown in the individual logs in this appendix. Groundwater levels were subsequently measured in the piezometers, and are shown in Table 2 in the body of this report. The groundwater levels measured in May 2014 are indicated by an open triangle on the piezometer logs. If groundwater was interpreted at other locations (without piezometer installation) based on observations during drilling, it is noted in the comments section of the logs. Our services included installation of vibrating wire pressure transducers in the piezometers to monitor if the groundwater table is affected by tidal fluctuation. The pressure transducers have been installed are currently collecting data, but have not been analyzed at the time of this report. May 16, 2014 Page A-1 File No

48 ARMY STREET PROJECT Bellingham, Washington The pressure transducer data and our interpretation of tidal influence will be included in the final version of this report. Environmental Field Screening Our representative conducted field screening on selected soil samples obtained from the borings, mostly within the fill soils. Field screening results are used as a general guideline to delineate areas of possible petroleum-related contamination in soils. The screening methods employed included (1) visual examination, (2) water sheen testing, and (3) headspace vapor testing using a BW Miroc5 Photoionization Detector (PID). Visual screening consists of inspecting the soil for stains indicative of petroleum-related contamination. Visual screening is generally more effective when contamination is related to heavy petroleum hydrocarbons such as motor oil, or when hydrocarbon concentrations are high. Water sheen screening and headspace vapor screening are more sensitive screening methods which can be effective in detecting petroleum based products in concentrations lower than regulatory cleanup guidelines. However, field screening results are site-specific. The effectiveness of field screening results will vary with temperature, moisture content, soil lithology, organic content and type of contaminant. The presence or absence of a sheen or headspace vapors does not necessarily indicate the presence or absence of petroleum hydrocarbons. Water sheen testing involves placing soil in water and observing the water surface for signs of sheen. The results of water sheen testing on soil samples from the borings are presented on the boring logs. Sheens are classified as follows: No Sheen (NS) Slight Sheen (SS) Moderate Sheen (MS) Heavy Sheen (HS) No visible sheen on water surface Light colorless film, spotty to globular; spread is irregular, not rapid; areas of no sheen remain; film dissipates rapidly Light to heavy film, may have some color or iridescence, globular to stringy, spread is irregular to flowing; few remaining areas of no sheen on water surface. Heavy colorful film with iridescence; stringy, spread is rapid; sheen flows off the sample; most of water surface may be covered with sheen. Headspace vapor screening involves placing a soil sample in a plastic bag. Air is captured in the bag and the bag is shaken to expose the soil to the air trapped in the bag. The probe of the PID is inserted into the bag and the instrument measures the concentration of organic vapors in the sample bag headspace. The PID is calibrated to isobutylene and measures vapor concentrations in parts per million (ppm) with a quantification range between 0 and 5,000 ppm. Page A-2 May 16, 2014 GeoEngineers, Inc. File No

49 MAJOR DIVISIONS SOIL CLASSIFICATION CHART SYMBOLS GRAPH LETTER TYPICAL DESCRIPTIONS ADDITIONAL MATERIAL SYMBOLS SYMBOLS TYPICAL GRAPH LETTER DESCRIPTIONS GRAVEL AND GRAVELLY SOILS CLEAN GRAVELS (LITTLE OR NO FINES) GW GP WELL-GRADED GRAVELS, GRAVEL - SAND MIXTURES POORLY-GRADED GRAVELS, GRAVEL - SAND MIXTURES AC CC Asphalt Concrete Cement Concrete COARSE GRAINED SOILS MORE THAN 50% RETAINED ON NO. 200 SIEVE FINE GRAINED SOILS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE SAND AND SANDY SOILS MORE THAN 50% OF COARSE FRACTION PASSING NO. 4 SIEVE SILTS AND CLAYS GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) CLEAN SANDS (LITTLE OR NO FINES) SANDS WITH FINES (APPRECIABLE AMOUNT OF FINES) LIQUID LIMIT LESS THAN 50 GM GC SW SP SM SC ML CL OL SILTY GRAVELS, GRAVEL - SAND - SILT MIXTURES CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES WELL-GRADED SANDS, GRAVELLY SANDS POORLY-GRADED SANDS, GRAVELLY SAND SILTY SANDS, SAND - SILT MIXTURES CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS, ROCK FLOUR, CLAYEY SILTS WITH SLIGHT PLASTICITY INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY CR TS Crushed Rock/ Quarry Spalls Topsoil/ Forest Duff/Sod Groundwater Contact Measured groundwater level in exploration, well, or piezometer Measured free product in well or piezometer Graphic Log Contact Distinct contact between soil strata or geologic units Approximate location of soil strata change within a geologic soil unit Material Description Contact MORE THAN 50% PASSING NO. 200 SIEVE SILTS AND CLAYS LIQUID LIMIT GREATER THAN 50 MH CH OH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS SILTY SOILS INORGANIC CLAYS OF HIGH PLASTICITY ORGANIC CLAYS AND SILTS OF MEDIUM TO HIGH PLASTICITY Distinct contact between soil strata or geologic units Approximate location of soil strata change within a geologic soil unit HIGHLY ORGANIC SOILS NOTE: Multiple symbols are used to indicate borderline or dual soil classifications 2.4-inch I.D. split barrel Standard Penetration Test (SPT) Shelby tube Piston Direct-Push Bulk or grab Blowcount is recorded for driven samplers as the number of blows required to advance sampler 12 inches (or distance noted). See exploration log for hammer weight and drop. A "P" indicates sampler pushed using the weight of the drill rig. PT Sampler Symbol Descriptions PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS %F AL CA CP CS DS HA MC MD OC PM PI PP PPM SA TX UC VS NS SS MS HS NT Laboratory / Field Tests Percent fines Atterberg limits Chemical analysis Laboratory compaction test Consolidation test Direct shear Hydrometer analysis Moisture content Moisture content and dry density Organic content Permeability or hydraulic conductivity Plasticity index Pocket penetrometer Parts per million Sieve analysis Triaxial compression Unconfined compression Vane shear Sheen Classification No Visible Sheen Slight Sheen Moderate Sheen Heavy Sheen Not Tested NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to be representative of subsurface conditions at other locations or times. KEY TO EXPLORATION LOGS FIGURE A-1 DRAFT

50 Drilled Start 4/1/2014 End 4/1/2014 Total Depth (ft) 65.2 Logged By Checked By MWR SWC Driller Boretec Drilling Method Hollow-Stem Auger Surface Elevation (ft) Vertical Datum 20.8 NAVD88 Hammer Data Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment EC 55 Track Easting (X) Northing (Y) System Datum NAD88 Groundwater Date Measured Depth to Water (ft) Elevation (ft) Notes: FIELD DATA Elevation (feet) 20 0Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification AC SM MATERIAL DESCRIPTION 2.5-inches asphalt concrete Gray-brown silty fine to coarse sand with gravel (medium dense, moist) (fill) Moisture Content (%) Fines Content (%) REMARKS <1/NS a 2b SP Brown fine to medium sand, trace silt (loose, moist) <1/NS SP-SM Dark brown fine to medium sand with silt and occasional gravel, trace shell fragments (very loose to loose, moist) <1/NS a 4b 5 SA ML SP/SP-SM Brown clayey silt with sand and interbedded sand lenses, trace shell fragments (medium stiff, moist) Gray-brown fine to medium sand with gravel and shell fragments (loose, moist) (beach deposits) <1/NS Becomes gray and medium dense With increasing silt content Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD * 10 30* 7a SA 7b 8 9 SA Note: See Figure A-1 for explanation of symbols. SP-SM Gray fine to coarse sand with silt and gravel (medium dense, wet) Becomes fine to coarse sand with silt Trace wood fragments With increasing coarse sand and gravel content Log of Boring BPDA-1 Project: Project Location: Project Number: Army Street Development Bellingham, Washington *Blow count overstated Light brown wood piece in sampler shoe *Blow count overstated DRAFT Figure A-2 Sheet 1 of 2

51 FIELD DATA Elevation (feet) Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification MATERIAL DESCRIPTION Moisture Content (%) Fines Content (%) REMARKS * 10 *Blow count overstated SM Gray silty fine to medium sand with silt pockets (loose, wet) CL Gray silty clay with interbedded sand and occasional gravel (stiff, wet) (glaciomarine drift) AL CL Gray silty clay with sand and occasional gravel (medium stiff, wet) 18 AL (LL = 29; PI = 14) With decreased sand content, no gravel and trace shell fragments Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD /2" 50/2" Note: See Figure A-1 for explanation of symbols. RX Gray siltstone (hard, wet Log of Boring BPDA-1 (continued) Project: Army Street Development Project Location: Bellingham, Washington Project Number: DRAFT Figure A-2 Sheet 2 of 2

52 Drilled Start End 4/1/2014 4/1/2014 Total Depth (ft) 40.2 Logged By MWR Checked By SWC Driller Boretec Drilling Method Hollow-Stem Auger Hammer Data Surface Elevation (ft) 19.8 Vertical Datum NAVD88 Easting (X) Northing (Y) Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment Top of Casing Elevation (ft) Horizontal Datum EC 55 Track NAD88 DOE Well I.D.: BHX 351 A 2 (in) well was installed on 4/1/2014 to a depth of 23 (ft). Groundwater Date Measured 5/7/2014 Depth to Water (ft) 9.7 Elevation (ft) 10.1 Notes: FIELD DATA WELL LOG Elevation (feet) 0Depth (feet) Interval Recovered (in) 9 Blows/foot 6 Collected Sample Sample Name Testing 1 %F Water Level Graphic Log Group Classification ML MATERIAL DESCRIPTION Gray to gray-brown interbedded and mixed silty fine to medium sand to sandy silt with occasional gravel and shell fragments (very loose to loose/very soft to medium stiff, moist) (fill) <1/SS Moisture Content (%) 22 Fines Content (%) Steel surface monument Concrete surface seal Bentonite <1/NS With organics 21 2-inch Schedule 40 PVC well casing a 4b 5 SA 6 SP-SM SM Becomes wet <1/NS Large brown wood piece Gray-brown fine to coarse sand with silt and occasional gravel (loose, wet) Gray silty fine to coarse sand with shell fragments and occasional gravel, trace brick fragment (medium dense, wet) Medium sand backfill Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_WELL * SA Note: See Figure A-1 for explanation of symbols. 8 9 SP-SM CL RX With silt lenses *Blow count overstated Gray fine to medium sand with silt and occasional gravel, trace shell fragments (medium dense, wet) (beach deposits) Gray silty clay with occasional sand, gravel and small sand pockets (medium stiff, wet) (glaciomarine drift) Log of Boring BPDA-2 Project: Project Location: Project Number: 22 Army Street Development Bellingham, Washington inch Schedule 40 PVC screen, inch slot width Bentonite DRAFT Figure A-3 Sheet 1 of 2

53 FIELD DATA WELL LOG Elevation (feet) Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification MATERIAL DESCRIPTION Moisture Content (%) Fines Content (%) /4" 10 Gray-brown weathered siltstone/sandstone (hard, wet) /2" RX Gray sandstone (hard, wet) Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_WELL Note: See Figure A-1 for explanation of symbols. Log of Boring BPDA-2 (continued) Project: Army Street Development Project Location: Bellingham, Washington Project Number: DRAFT Figure A-3 Sheet 2 of 2

54 Drilled Start End 4/1/2014 4/1/2014 Total Depth (ft) 40.3 Logged By MWR Checked By SWC Driller Boretec Drilling Method Hollow-Stem Auger Hammer Data Surface Elevation (ft) 19.2 Vertical Datum NAVD88 Easting (X) Northing (Y) Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment Top of Casing Elevation (ft) Horizontal Datum EC 55 Track NAD88 DOE Well I.D.: BHX 350 A 2 (in) well was installed on 4/1/2014 to a depth of 20 (ft). Groundwater Date Measured 5/7/2014 Depth to Water (ft) 9.4 Elevation (ft) 9.8 Notes: FIELD DATA WELL LOG Elevation (feet) 15 0Depth (feet) Interval Recovered (in) 10 Blows/foot 10 Collected Sample Sample Name Testing 1a 1b Water Level Graphic Log Group Classification SM SP-SM MATERIAL DESCRIPTION Dark brown silty fine to coarse sand with gravel (loose, moist) (fill) <1/NS Brown fine to medium sand with silt (loose to medium dense, moist) Moisture Content (%) Fines Content (%) 1.5 Steel surface monument Concrete surface seal Bentonite Interbedded with silt lenses <1/NS 2-inch Schedule 40 PVC well casing SA <1/NS With iron staining and shell fragments a 4b SP-SM Becomes wet Gray fine to medium sand with silt and shell fragments (loose, wet) (beach deposits) 10.0 Medium sand backfill Slight sulphur odor <1/NS Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_WELL a 6b 7a 7b 8 SA Note: See Figure A-1 for explanation of symbols. 9 SP-SM ML <1/NS Wood piece encountered Gray fine to coarse sand with silt, gravel and shell fragments; lense of coarse sand and fine gravel (loose to medium dense, wet) <1/NS Gray sandy silt with clay (stiff, wet) (glaciomarine drift) Log of Boring BPDA-3 Project: Project Location: Project Number: 19 Army Street Development Bellingham, Washington inch Schedule 40 PVC screen, inch slot width Bentonite DRAFT Figure A-4 Sheet 1 of 2

55 FIELD DATA WELL LOG Elevation (feet) Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification MATERIAL DESCRIPTION Moisture Content (%) Fines Content (%) RX Gray-brown weathered siltstone (hard, wet) /3" Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_WELL Note: See Figure A-1 for explanation of symbols. Log of Boring BPDA-3 (continued) Project: Army Street Development Project Location: Bellingham, Washington Project Number: DRAFT Figure A-4 Sheet 2 of 2

56 Drilled Start End 4/1/2014 4/1/2014 Total Depth (ft) 25.1 Logged By MWR Checked By SWC Driller Boretec Drilling Method Hollow-Stem Auger Hammer Data Surface Elevation (ft) 18.3 Vertical Datum NAVD88 Easting (X) Northing (Y) Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment Top of Casing Elevation (ft) Horizontal Datum EC 55 Track NAD88 DOE Well I.D.: BHX 349 A 2 (in) well was installed on 4/1/2014 to a depth of 17.5 (ft). Groundwater Date Measured 5/7/2014 Depth to Water (ft) 7.2 Elevation (ft) 11.1 Notes: FIELD DATA WELL LOG Elevation (feet) 0Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification SP-SM MATERIAL DESCRIPTION Brown fine to coarse sand with silt and gravel (medium dense, moist) (fill) Moisture Content (%) Fines Content (%) 1.5 Steel surface monument Concrete surface seal a 1b 2 SA 3 SP-SM/SP <1/NS Brown fine to medium sand with silt to trace silt (loose to medium dense, moist) <1/NS Becomes wet Bentonite 2-inch Schedule 40 PVC well casing Medium sand backfill SA SP Gray fine to coarse sand with shell fragments, trace silt (loose to medium dense, wet) <1/NS SA SM <1/SS Becomes fine to medium sand with silt Gray silty fine to medium sand with shells and 1-inch organic woody layer (loose, wet) ( beach deposits) <1/SS inch Schedule 40 PVC screen, inch slot width Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_WELL /1" Note: See Figure A-1 for explanation of symbols. 7 8 RX With soft woody fragments Gray sandstone (hard, wet) Log of Monitoring Well BPDA-4 Project: Project Location: Project Number: Army Street Development Bellingham, Washington Bentonite DRAFT Figure A-5 Sheet 1 of 1

57 Drilled Start 4/1/2014 End 4/1/2014 Total Depth (ft) 20.2 Logged By Checked By MWR SWC Driller Boretec Drilling Method Hollow-Stem Auger Surface Elevation (ft) Vertical Datum 52.8 NAVD88 Hammer Data Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment EC 55 Track Easting (X) Northing (Y) Notes: System Datum NAD88 Groundwater Date Measured Depth to Water (ft) Not encountered Elevation (ft) FIELD DATA Elevation (feet) 50 0Depth (feet) Interval Recovered (in) 18 Blows/foot 40 Collected Sample Sample Name Testing 1 Water Level Graphic Log Group Classification AC SM CL/CH MATERIAL DESCRIPTION 1-inch asphalt concrete Brown silty sand with gravel (meidum dense, moist) (fill) Brown silty clay with occasional fine sand (hard, moist) (glaciomarine drift) Moisture Content (%) Fines Content (%) REMARKS <1/NS AL With iron staining and occasional fine sand; very stiff 30 AL (LL = 58; PI = 30) <1/NS With sand; stiff * 4 CL Brown silty clay with sand and gravel (stiff, moist) *Blowcount overstated a 5b AL CL Gray silty clay, trace sand (soft to medium stiff, moist) 28 AL (LL = 31; PI = 14) 15 P 6 Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD /2" 50/2" 7 8 Note: See Figure A-1 for explanation of symbols. RX Gray sandstone (hard, dry) Log of Boring BPDA-5 Project: Army Street Development Project Location: Bellingham, Washington Project Number: DRAFT Figure A-6 Sheet 1 of 1

58 Drilled Start 4/1/2014 End 4/1/2014 Total Depth (ft) 55.3 Logged By Checked By MWR SWC Driller Boretec Drilling Method Hollow-Stem Auger Surface Elevation (ft) Vertical Datum 51.5 NAVD88 Hammer Data Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment EC 55 Track Easting (X) Northing (Y) System Datum NAD88 Groundwater Date Measured Depth to Water (ft) Elevation (ft) Notes: FIELD DATA Elevation (feet) 50 0Depth (feet) Interval Recovered (in) 6 Blows/foot 5 Collected Sample Sample Name Testing 1 Water Level Graphic Log Group Classification AC SM/ML MATERIAL DESCRIPTION 8-inches asphalt concrete Brown silty fine to medium sand to sandy silt with occasional gravel (loose/medium stiff, moist) (fill) Moisture Content (%) Fines Content (%) REMARKS <1/NS a 2b CL SM Brown silty clay with sand and occasional gravel (stiff, moist) Dark brown silty fine to medium sand with occasional gravel (medium dense, moist) <1/NS SM/ML Brown to red-brown silty fine to medium sand to sandy silt (medium dense/stiff, moist) With increased gravel content, trace rootlets SA SM Light brown silty fine to medium sand with pockets of sandy silt, trace dark brown organics (medium dense, moist) Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD a 8b 9 AL Note: See Figure A-1 for explanation of symbols. SP-SM CH SP-SM Becomes dark brown; with woody organics Brown-gray fine to medium sand with silt and occasional gravel (medium dense, moist) Brown-gray sandy silty clay with organic lenses and 1/4 inch wood piece; mottled with distorted bedding (medium stiff to stiff, moist) Gray-brown fine to coarse sand with silt and occasional gravel, trace shell fragments (medium dense, moist) Log of Boring BPDA-6 Project: Project Location: Project Number: 31 Army Street Development Bellingham, Washington AL (LL = 60; PI = 32) DRAFT Figure A-7 Sheet 1 of 2

59 FIELD DATA Elevation (feet) 15 Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification MATERIAL DESCRIPTION Moisture Content (%) Fines Content (%) REMARKS SA With iron staining SA SP-SM Dark gray fine to coarse sand with silt, silt inclusions and shell fragments (loose, wet) (beach deposits) RX Gray sandstone (hard, wet) /2" /3" 14 Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD Note: See Figure A-1 for explanation of symbols. Log of Boring BPDA-6 (continued) Project: Army Street Development Project Location: Bellingham, Washington Project Number: DRAFT Figure A-7 Sheet 2 of 2

60 Drilled Start 3/31/2014 End 3/31/2014 Total Depth (ft) 20.1 Logged By Checked By MWR SWC Driller Boretec Drilling Method Hollow-Stem Auger Surface Elevation (ft) Vertical Datum 22 NAVD88 Hammer Data Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment EC 55 Track Easting (X) Northing (Y) System Datum NAD88 Groundwater Date Measured Depth to Water (ft) Elevation (ft) Notes: FIELD DATA Elevation (feet) 20 0Depth (feet) Interval Recovered (in) 6 Blows/foot 14 Collected Sample Sample Name Testing 1 Water Level Graphic Log Group Classification SM MATERIAL DESCRIPTION Dark brown silty fine to coarse sand with gravel and woody organics (medium dense, moist) (fill) Moisture Content (%) Fines Content (%) REMARKS <1/NS Mixed dark and light brown With organics, trace brick fragments <1/NS ML Brown sandy silt with gravel, clay and organics, trace brick (medium stiff to stiff, moist) <1/NS a 4b CL Grades to rusty brown; moist to wet Gray silty clay with organics (medium stiff, wet) <1/NS a 5b 5c SM RX Brown-gray silty fine to coarse sand with woody pieces and gravel (medium dense, wet) Gay siltstone/sandstone (hard, wet) <1/NS Bellingham: Date:5/13/14 Path:\\BAM\PROJECTS\18\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD /1" Note: See Figure A-1 for explanation of symbols. Log of Boring BPDA-7 Project: Project Location: Project Number: Army Street Development Bellingham, Washington DRAFT Figure A-8 Sheet 1 of 1

61 APPENDIX B Geotechnical Laboratory Testing

62 ARMY STREET PROJECT Bellingham, Washington DRAFT APPENDIX B LABORATORY TESTING Soil samples obtained from the explorations were transported to our laboratory and examined to confirm or modify field classifications, as well as to evaluate index properties of the soil samples. Representative samples were selected for laboratory testing consisting of the determination of the moisture content, and sieve analysis. The tests were performed in general accordance with test methods of the American Society for Testing and Materials (ASTM) or other applicable procedures. Moisture Content Testing The natural moisture contents of selected soil samples obtained from the exploratory borings were determined in general accordance with ASTM D 2216 test procedures. The results from the moisture content determinations are displayed in the column labeled Moisture Content % adjacent to the corresponding samples on the summary logs. Sieve Analyses Sieve analyses were performed on selected samples in general accordance with ASTM D 422 to determine the sample grain size distribution. The wet sieve analysis method was used to determine the percentage of soil greater than the U.S. No. 200 mesh sieve. The results of the sieve analyses were plotted, classified in general accordance with the Unified Soil Classification System (USCS), and are presented in Figures B-1 through B-5. Atterberg Limits Testing Atterberg limits tests were performed on selected fine-grained soil samples. The tests were used to classify the soils as well as to evaluate index properties. The liquid limit and the plastic limit were estimated through a procedure performed in general accordance with ASTM D The results of the Atterberg limits tests are summarized in Figures B-6 and B-7. May 16, 2014 Page B-1 File No

63 U.S. STANDARD SIEVE SIZE /4 3/8 #4 #10 #20 #40 #60 #100 # PERCENT PASSING BY WEIGHT GRAIN SIZE IN MILLIMETERS COBBLES COARSE GRAVEL FINE SAND COARSE MEDIUM FINE SILT OR CLAY Exploration Sample Depth Symbol Number (feet) Soil Classification BPDA Gray fine to medium sand (SP) Gray fine to coarse sand with silt and gravel BPDA-1 20 (SP-SM) Gray fine to coarse sand with silt and gravel BPDA-1 30 (SP-SM) Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. Sieve Analysis Results BPDA Army Street Development Bellingham, Washington Figure B-1

64 U.S. STANDARD SIEVE SIZE /4 3/8 #4 #10 #20 #40 #60 #100 # COBBLES GRAVEL SAND COARSE FINE COARSE MEDIUM FINE Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes SILT OR CLAY PERCENT PASSING BY WEIGHT. GRAIN SIZE IN MILLIMETERS Symbol Exploration Number BPDA BPDA-2 20 Sample Depth (feet) Soil Classification Gray-brown fine to coarse sand with silt and occasional gravel (SP-SM) Gray silty fine to coarse sand with occasional gravel (SM) Sieve Analysis Results BPDA Army Street Development Bellingham, Washington Figure B-2

65 U.S. STANDARD SIEVE SIZE /4 3/8 #4 #10 #20 #40 #60 #100 # COBBLES GRAVEL SAND COARSE FINE COARSE MEDIUM FINE Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes SILT OR CLAY PERCENT PASSING BY WEIGHT. GRAIN SIZE IN MILLIMETERS Symbol Exploration Number BPDA BPDA-3 25 Sample Depth (feet) Soil Classification Gray-brown fine to medium sand with silt (SP- SM) Gray fine to coarse sand with silt and gravel (SP-SM) Sieve Analysis Results BPDA Army Street Development Bellingham, Washington Figure B-3

66 U.S. STANDARD SIEVE SIZE /4 3/8 #4 #10 #20 #40 #60 #100 # COBBLES GRAVEL SAND COARSE FINE COARSE MEDIUM FINE Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes SILT OR CLAY PERCENT PASSING BY WEIGHT. GRAIN SIZE IN MILLIMETERS Symbol Exploration Number Sample Depth (feet) Soil Classification BPDA-4 5 Brown-gray fine to medium sand with silt (SP-SM) BPDA-4 10 Gray fine to coarse sand with shells, trace silt (SP) BPDA-4 15 Gray silty fine to medium sand with shells (SM) Sieve Analysis Results BPDA Army Street Development Bellingham, Washington Figure B-4

67 U.S. STANDARD SIEVE SIZE /4 3/8 #4 #10 #20 #40 #60 #100 # COBBLES GRAVEL SAND COARSE FINE COARSE MEDIUM FINE Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes SILT OR CLAY PERCENT PASSING BY WEIGHT. GRAIN SIZE IN MILLIMETERS Symbol Exploration Number Sample Depth (feet) Soil Classification BPDA-6 15 Light brown silty fine to medium sand (SP-SM) BPDA-6 35 Gray-brown fine to coarse sand with silt (SP-SM) BPDA-6 45 Dark gray fine to coarse sand with silt (SP-SM) Sieve Analysis Results BPDA Army Street Development Bellingham, Washington Figure B-5

68 PLASTICITY CHART CH or OH OH and MH 20 Plasticity Index CL or OL 10 CL-ML ML or OL Liquid Limit Symbol Exploration Number Sample Depth (feet) Moisture Content (%) Liquid Limit (%) Plasticity Index (%) Soil Description BPDA Gray silty clay with sand (CL) BPDA Brown-gray sandy silty clay (CH) Atterberg Limits Test Results Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. BPDA Army Street Development Bellingham, Washington Figure B-6

69 PLASTICITY CHART CH or OH OH and MH 20 Plasticity Index CL or OL 10 CL-ML ML or OL Liquid Limit Symbol Exploration Number Sample Depth (feet) Moisture Content (%) Liquid Limit (%) Plasticity Index (%) Soil Description BPDA Gray silty clay with trace sand (CL) BPDA Gray silty clay with sand (CH) Atterberg Limits Test Results Note: This report may not be reproduced, except in full, without written approval of GeoEngineers, Inc. Test results are applicable only to the specific sample on which they were performed, and should not be interpreted as representative of any other samples obtained at other times, depths or locations, or generated by separate operations or processes. BPDA Army Street Development Bellingham, Washington Figure B-7

70 APPENDIX C Previous Site Explorations

71 ARMY STREET PROJECT Bellingham, Washington DRAFT APPENDIX C PREVIOUS SITE EXPLORATIONS Selected logs from previous studies completed in the project vicinity are included in this appendix: City of Bellingham Stormwater Vault. Borings B-1 (2003) and B-2 (2003) Boss Tweed Restaurant Site. Borings B-10 (2005), B-11 (2005), and B-13 (2005) Trillium West Holly Street. Borings B-1 (2006), B-2 (2006) and B-3 (2006) City of Bellingham Peak Flow Storage Facility Project. Borings Granary-1 (2009) and Granary 2 (2009) Central Avenue Intersection. Boring log B-2 (2009) Chestnut Bay at RR Rehabilitation. Boring B-1 (2014) May 16, 2014 Page C-1 File No

72 SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP SYMBOL GROUP NAME GRAVEL CLEAN GRAVEL GW WELL-GRADED GRAVEL, FINE TO COARSE GRAVEL COARSE GP POORLY-GRADED GRAVEL GRAINED More Than 50% SOILS of Coarse Fraction GM SILTY GRAVEL GRAVEL Retained WITH FINES on No. 4 Sieve GC CLAYEY GRAVEL SAND CLEAN SAND SW WELL-GRADED SAND, FINE TO COARSE SAND More Than 50% SP POORLY-GRADED SAND Retained on More Than 50% No. 200 Sieve SM SILTY SAND of Coarse Fraction SAND Passes No. 4 Sieve WITH FINES FINE SILT AND CLAY INORGANIC SC ML CLAYEY SAND SILT GRAINED CL CLAY SOILS Liquid Limit Less Than 50 More Than 50% SILT AND CLAY INORGANIC ORGANIC OL ORGANIC SILT, ORGANIC CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT Passes CH CLAY OF HIGH PLASTICITY, FAT CLAY No. 200 Sieve Liquid Limit 50 or More ORGANIC OH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: SOIL MOISTURE MODIFIERS: 1. Field classification is based on visual examination of soil in general accordance with ASTM D Dry. Absence of moisture, dusty, dry to the touch 2. Soil classification using laboratory tests is in Moist- Damp, but no visible water general accordance with ASTM D Wet Visible free water or saturated, usually soil is obtained 3. Descriptions of soil density or consistency are from below water table based on interpretation of blow count data, visual appearance of soils, and/or test data. f: soila-j.doc ~~,,.. SOIL CLASSIFICATION SYSTEM Geo ~p Engineers FIGURE 3

73 LABORATORY TESTS SOIL GRAPH: AL CP cs OS GS %F HA SK SM MD SP TX UC CA Atterberg Limits Compaction Consolidation Direct shear Grain size Percent fines Hydrometer Analysis Permeability Moisture Content Moisture and density Swelling pressure Triaxial compression Unconfined compression Chemical analysis BLOW COUNT/SAMPLE DATA: SM SZ... Soil Group Symbol (See Note 2) Distinct Contact Between Soil Strata Gradual or Approximate Location of Change Between Soil Strata Water Level Bottom of Boring Blows required to drive a 2.4-inch l.d. split-barrel sampler 12 inches or other indicated distances using a 300-pound hammer falling 30 inches ~ 170 Location of relatively undisturbed sample Location of disturbed sample Location of sampling attempt with no recovery Blows required to drive a 1.5-inch l.d. (SPT) split-barrel sampler 12 inches or other indicated distances using a 140-pound hammer falling 30 inches. "P" indicates sampler pushed with weight of hammer or against weight of drill rig. rn II 26 m Location of SPT sampling attempt with no recovery Location of sample obtained in general accordance with Standard Penetration Test (ASTM ) procedures Location of grab sample <fl c ~ ~ u 2 c.. 10'. ~ NOTES: 1. The reader must refer to the discussion in the report text, the Key to Boring Log Symbols and the exploration logs for a proper understanding of subsurface conditions. 2 Soil classification system is summarized in Figure 3. ~1~~~~~~~~~~~~~~~~~~~~... ~~~~~~~~~~~~~~~~~~~~~~---1 ro D. ~«itl Geo ~~Engineers KEY TO BORING LOG SYMBOLS FIGURE 4

74 Date(s) Drilled Drilling Contractor Auger Data Total Depth (ft) Datum/ System Logged 3/21/03 RMB By Subterranean, Inc Drilling Method Hammer Data Surface Elevation (ft) Mud Rotary Checked By 2 inch OD Split Spoon Sampler Drilling 140 (lb) hammer/ 30 (in) drop B-61 Truck Mounted Drill Rig Equipment Sampling Methods Groundwater Level (ft. bgs) DRAFT AKM SAMPLES Elevation feet Depth feet 0 Interval Number Recovered (in) Blows/foot Water Level Graphic Log Group Symbol GP-GW SP MATERIAL DESCRIPTION 3 inch gravel surfacing Brown fine to medium sand with occasional gravel, and shell fragments (medium dense, moist) (fill) Water Content, % Dry Unit Weight, lbs/ft 3 OTHER TESTS AND NOTES CL Brown clay with fine sand (medium stiff, moist) (fill) SP-SM Black fine to medium sand with silt, brick fragments, and occasional wood (medium dense, wet) (fill) 30 %F= GEI_GTBORING_2.1.0 P:\0\ \00\FINALS\ GPJ GEIV2_2.GDT 8/13/ /1" CL RX Note: See Figure 4 for explanation of symbols Gray clay with trace sand and layers of silty fine sand (medium stiff, moist) Note: Occasional wood Gray sandstone LOG OF BORING B-1 (2003) Project: Project Location: Project Number: City of Bellingham Stormwater Vault Bellingham, Washington Figure: 5 Sheet 1 of 1

75 Date(s) Drilled Drilling Contractor Auger Data Total Depth (ft) Datum/ System Logged 3/26/03 EMG By Subterranean, Inc Drilling Method Hammer Data Surface Elevation (ft) Mud Rotary Checked By 2 inch OD Split Spoon Sampler Drilling 140 (lb) hammer/ 30 (in) drop B-61 Truck Mounted Drill Rig Equipment Sampling Methods Groundwater Level (ft. bgs) DRAFT AKM SAMPLES Elevation feet Depth feet 0 Interval Number Recovered (in) Blows/foot Water Level Graphic Log Group Symbol GP-GW MATERIAL DESCRIPTION 12 inches of gravel surfacing Water Content, % Dry Unit Weight, lbs/ft 3 OTHER TESTS AND NOTES SP Brown fine to medium sand with occasional gravel, shells, and layers of silt (medium dense, moist) (fill) %F= SP-SM Dark gray fine to medium sand with silt and occasional gravel and shells (medium dense, wet) (fill) 19 %F= GEI_GTBORING_2.1.0 P:\0\ \00\FINALS\ GPJ GEIV2_2.GDT 8/13/ /3" SM WD SM SW RX Note: See Figure 4 for explanation of symbols Dark gray silty sand with occasional gavel and organic matter (loose, wet) (fill) Wood shavings Dark gray silty sand with occasional gravel (loose, wet) Gray well graded fine to coarse sand with gravel (dense, wet) Gray sandstone LOG OF BORING B-2 (2003) Project: Project Location: Project Number: City of Bellingham Stormwater Vault Bellingham, Washington %F=27 GS, %F=4 Figure: 6 Sheet 1 of 1

76 (2005) DRAFT

77 (2005) DRAFT

78 (2005) DRAFT

79 (2006) DRAFT

80 (2006) DRAFT

81 (2006) DRAFT

82 (2009) DRAFT

83 ~ ~ c 0 ~ > <D [jj ~ ~.<:: Cil 15. c: <D <D 0,E 25 FIELD DATA c. " I., E VJ "fil 0 't:i <D., > 'iii ti -c io 0 ;:,SI E~ " <D 0 0 "'<D a: O'i u UH _, c CJ) Q; 0 0 > -~ <D _, " " 2 E o..~ c. 5~ ~ ~.!!l ~ "' (,'.) (,'.)(,) R, Ell DESCRIPTION Q)E' " "- "-- "' c: Q) 'O "'~ 0 Q) "'"- Q)"' (/) "" I> M 0,1 DRAFT REMARKS CL Brown-gray clay with pockets of sand (medium stiff, wet) NS 0,1 44 CL Gray clay with fine sand and occasional gravel (stiff, wet) (glaciomarine drift) NS 0, NS 0,5 22 blowcount overstated NS fine sand lense encountered 42 O' " :ij i ~ I i Note: See Figure A-1 for explanation of symbols, Gray siltstone 0, ~:::=================================================================================================================~ ~ Log of Boring GRANARY-1 (continued) ~!--~~~~~~~~~~~~~~~~~~~~...-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--; ~ Project: Peak Flow Storage Facility E i ~ GEoENGINEERS Project Location: Bellingham, Washington Project Number: Figure A-2 Sheet 2 of 3

84 ~ :!!?.. c 0 ~ Q) [ij I ~.,,!!' :!!?.. Q)..c cu > 2: 0 c. Q) (.) Q) Q) 0.E a: FIELD DATA., ii., l E (ii "' > ' 0...J 0 'C Q)...J (.) 'iii ~ -c E ;:.!! E "ti a. 0 0 ~ "'Q) ~ id (.) UH- 3:: 0 c 0." (.) g.~ e~ (.'.)() 'E' " C\l 0. o.- c "'~ Ql "O 0 (J) C\l 0..c Ql C\l UJ I> DRAFT REMARKS " 14 O' " a: g ~ 2 z ~ ~ i il Note: See Figure A-1 for explanation of symbols. ~::::==========================================================================================================:::::::: GEoENGINEERS Project: Peak Flow Storage Facility Project Location: Bellingham, Washington Project Number: Figure A-2 Sheet 3 of 3

85 (2009) DRAFT

86 ~ Jg, c 0 ~ > Q) w ~ Jg,.!::: a. Q) 0 25 (ii ~ ~ c FIELD DATA., 'li = E 1 (jj O> "O en "' 0 > ~ 'ti Q)...J 0 Q)...J (j > ~ ~ -c E 0 ;;: (j ~ E"fil Q) 0 0 "'Q) ~ 0: Ci5 u (/lf- ~ (.'.) * Q. c 0 15 (j 0. :E 5~ ~.!!1 (.'.) (.) <DE " c. "' c.- c: "'~ <!> "O 0 <!> "' c..r;;; <!>«> (/) I> 9.0 DRAFT REMARKS 34 SC Gray clayey sand with organic matter (very loose, wet) 30 4 NS NS CL Gray clay with fine sand, occasional gravel and shells (medium stiff, moist) NS blowcount overstate 38 0 a: ( z ~I ;o z w " z ~ > t5 ~' w 30 (!) ~ a: w z a t5 :il (!) l " Ii ~ c. " ~ 0 ~ (!) a: 2 i ~ I lo ~ Note: See Figure A-1 for explanation of symbols. ll CL Gray fine sandy clay (hard, moist) (glaciomarine drift/bedrock Gray siltstone a_ ~:::================================================================================================================::::::: ~ Log of Boring GRANARY-2 (continued) ~... ~~~~~~~~~~~~~~~~~~~~..-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Project: Peak Flow Storage Facility Project Location: Bellingham, Washington Project Number: Figure A-5 Sheet 2 of 2

87 MAJOR DIVISIONS GRAVEL AND GRAVELLY SOILS SOIL CLASSIFICATION CHART CLEAN GRAVELS (LITTLE OR NO FINES) SYMBOLS GRAPH LETTER GW GP TYPICAL DESCRIPTIONS WELL-GRADED GRAVELS, GRAVEL - SAND MIXTURES POORLY-GRADED GRAVELS, GRAVEL - SAND MIXTURES ADDITIONAL MATERIAL SYMBOLS SYMBOLS GRAPH LETTER CC AC TYPICAL DESCRIPTIONS Cement Concrete Asphalt Concrete DRAFT COARSE GRAINED SOILS MORE THAN 50% RETAINED ON NO. 200 SIEVE FINE GRAINED SOILS MORE THAN 50% PASSING NO. 200 SIEVE MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE SAND AND SANDY SOILS MORE THAN 50% OF COARSE FRACTION PASSING NO. 4 SIEVE SILTS AND CLAYS SILTS AND CLAYS GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) CLEAN SANDS (LITTLE OR NO FINES) SANDS WITH FINES (APPRECIABLE AMOUNT OF FINES) LIQUID LIMIT LESS THAN 50 LIQUID LIMIT GREATER THAN 50 GM GC SW SP SM SC ML CL OL MH CH OH SILTY GRAVELS, GRAVEL - SAND - SILT MIXTURES CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES WELL-GRADED SANDS, GRAVELLY SANDS POORLY-GRADED SANDS, GRAVELLY SAND SILTY SANDS, SAND - SILT MIXTURES CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS, ROCK FLOUR, CLAYEY SILTS WITH SLIGHT PLASTICITY INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS SILTY SOILS INORGANIC CLAYS OF HIGH PLASTICITY ORGANIC CLAYS AND SILTS OF MEDIUM TO HIGH PLASTICITY CR TS Crushed Rock/ Quarry Spalls Topsoil/ Forest Duff/Sod Measured groundwater level in exploration, well, or piezometer Groundwater observed at time of exploration Perched water observed at time of exploration Measured free product in well or piezometer Stratigraphic Contact Distinct contact between soil strata or geologic units Gradual change between soil strata or geologic units Approximate location of soil strata change within a geologic soil unit HIGHLY ORGANIC SOILS PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS NOTE: Multiple symbols are used to indicate borderline or dual soil classifications Sampler Symbol Descriptions 2.4-inch I.D. split barrel Standard Penetration Test (SPT) Shelby tube Piston Direct-Push Bulk or grab Blowcount is recorded for driven samplers as the number of blows required to advance sampler 12 inches (or distance noted). See exploration log for hammer weight and drop. A "P" indicates sampler pushed using the weight of the drill rig. %F AL CA CP CS DS HA MC MD OC PM PP SA TX UC VS NS SS MS HS NT Laboratory / Field Tests Percent fines Atterberg limits Chemical analysis Laboratory compaction test Consolidation test Direct shear Hydrometer analysis Moisture content Moisture content and dry density Organic content Permeability or hydraulic conductivity Pocket penetrometer Sieve analysis Triaxial compression Unconfined compression Vane shear Sheen Classification No Visible Sheen Slight Sheen Moderate Sheen Heavy Sheen Not Tested NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to be representative of subsurface conditions at other locations or times. KEY TO EXPLORATION LOGS Figure A-1

88 Date(s) Drilled Drilling Contractor Auger Data Total Depth (ft) Vertical Datum Logged Checked 3/24/2009 By A. Hartvigsen By S. Cool Boretec, Inc. 3½ in ID Drilling Method Hammer Data Datum/ System Hollow-stem auger 140 lb hammer Two wraps on cathead Sampling Methods Drilling Equipment M-55 Track-mounted drill rig Surface Groundwater Elevation (ft) Elevation (ft) 10 Easting(x): Northing(y): DRAFT SPT SAMPLES Elevation feet Depth feet 0 Interval Recovered (in) Blows/foot Sub-Sample Sample Number Water Level Graphic Log Group Symbol SP MATERIAL DESCRIPTION Light brown fine to medium sand, trace silt to with silt (loose, moist) (fill) Moisture Content % Dry Unit Weight, lbs/ft 3 OTHER TESTS AND NOTES grades to wet trace shell fragments encountered 21 %F= * 22 %F=3, *California sampler V6_GTBORING P:\0\ \00\ GEOTECHNICAL\GINT\ B.GPJ GEIV6_1.GDT 4/9/ * 5* 6* 7 SW-SM SM 25 Note: See Figure A-1 for explanation of symbols. Gray fine to coarse sand with silt, occasional gravel and shell fragments (loose, wet) (beach deposits) Gray silty fine to coarse sand with occasional gravel (loose, wet) - with 2-inch thick clayey layer LOG OF BORING B-2 (2009) Project: Project Location: Project Number: SA, %F=5, *California sampler %F=15, *California sampler SA, %F=5, *California sampler %F=30 Proposed Central Avenue Intersection Improvements Bellingham, Washington Figure: A Sheet 1 of 3

89 SAMPLES DRAFT Elevation feet Depth feet 25 Interval Recovered (in) 24 Blows/foot 32 Sub-Sample Sample Number 8 Water Level Graphic Log Group Symbol SP MATERIAL DESCRIPTION Gray fine to medium sand with occasional shell fragments (medium dense, wet) Moisture Content % 19 Dry Unit Weight, lbs/ft 3 OTHER TESTS AND NOTES SA, %F=3 Blowcounts overstated - 2-foot heave encountered Blowcounts overstated Blowcounts overstated CL Gray clay with sand (soft to medium stiff, wet) (Bellingham [glaciomarine] Drift) with occasional gravel V6_GTBORING P:\0\ \00\ GEOTECHNICAL\GINT\ B.GPJ GEIV6_1.GDT 4/9/ a 13b 14-3-inch thick silty sand layer LOG OF BORING B-2 (continued) Project: Project Location: Project Number: Proposed Central Avenue Intersection Improvements Bellingham, Washington Figure: A Sheet 2 of 3

90 SAMPLES DRAFT Elevation feet Depth feet Interval Recovered (in) Blows/foot Sub-Sample Sample Number Water Level Graphic Log Group Symbol MATERIAL DESCRIPTION Moisture Content % Dry Unit Weight, lbs/ft 3 OTHER TESTS AND NOTES /5" 17 SSTN Gray siltstone (very dense, moist) (Chuckanut Formation) /5" V6_GTBORING P:\0\ \00\ GEOTECHNICAL\GINT\ B.GPJ GEIV6_1.GDT 4/9/ LOG OF BORING B-2 (continued) Project: Project Location: Project Number: Proposed Central Avenue Intersection Improvements Bellingham, Washington Figure: A Sheet 3 of 3

91 MAJOR DIVISIONS SOIL CLASSIFICATION CHART SYMBOLS GRAPH LETTER TYPICAL DESCRIPTIONS ADDITIONAL MATERIAL SYMBOLS SYMBOLS TYPICAL GRAPH LETTER DESCRIPTIONS DRAFT GRAVEL AND GRAVELLY SOILS CLEAN GRAVELS (LITTLE OR NO FINES) GW GP WELL-GRADED GRAVELS, GRAVEL - SAND MIXTURES POORLY-GRADED GRAVELS, GRAVEL - SAND MIXTURES AC CC Asphalt Concrete Cement Concrete COARSE GRAINED SOILS MORE THAN 50% RETAINED ON NO. 200 SIEVE FINE GRAINED SOILS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE SAND AND SANDY SOILS MORE THAN 50% OF COARSE FRACTION PASSING NO. 4 SIEVE SILTS AND CLAYS GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) CLEAN SANDS (LITTLE OR NO FINES) SANDS WITH FINES (APPRECIABLE AMOUNT OF FINES) LIQUID LIMIT LESS THAN 50 GM GC SW SP SM SC ML CL OL SILTY GRAVELS, GRAVEL - SAND - SILT MIXTURES CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES WELL-GRADED SANDS, GRAVELLY SANDS POORLY-GRADED SANDS, GRAVELLY SAND SILTY SANDS, SAND - SILT MIXTURES CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS, ROCK FLOUR, CLAYEY SILTS WITH SLIGHT PLASTICITY INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY CR TS Crushed Rock/ Quarry Spalls Topsoil/ Forest Duff/Sod Groundwater Contact Measured groundwater level in exploration, well, or piezometer Measured free product in well or piezometer Graphic Log Contact Distinct contact between soil strata or geologic units Approximate location of soil strata change within a geologic soil unit Material Description Contact MORE THAN 50% PASSING NO. 200 SIEVE SILTS AND CLAYS LIQUID LIMIT GREATER THAN 50 MH CH OH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS SILTY SOILS INORGANIC CLAYS OF HIGH PLASTICITY ORGANIC CLAYS AND SILTS OF MEDIUM TO HIGH PLASTICITY Distinct contact between soil strata or geologic units Approximate location of soil strata change within a geologic soil unit HIGHLY ORGANIC SOILS NOTE: Multiple symbols are used to indicate borderline or dual soil classifications 2.4-inch I.D. split barrel Standard Penetration Test (SPT) Shelby tube Piston Direct-Push Bulk or grab Blowcount is recorded for driven samplers as the number of blows required to advance sampler 12 inches (or distance noted). See exploration log for hammer weight and drop. A "P" indicates sampler pushed using the weight of the drill rig. PT Sampler Symbol Descriptions PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS %F AL CA CP CS DS HA MC MD OC PM PI PP PPM SA TX UC VS NS SS MS HS NT Laboratory / Field Tests Percent fines Atterberg limits Chemical analysis Laboratory compaction test Consolidation test Direct shear Hydrometer analysis Moisture content Moisture content and dry density Organic content Permeability or hydraulic conductivity Plasticity index Pocket penetrometer Parts per million Sieve analysis Triaxial compression Unconfined compression Vane shear Sheen Classification No Visible Sheen Slight Sheen Moderate Sheen Heavy Sheen Not Tested NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they are not warranted to be representative of subsurface conditions at other locations or times. KEY TO EXPLORATION LOGS FIGURE A-1

92 Drilled Start 4/11/2014 Surface Elevation (ft) Vertical Datum End 4/11/2014 Total Depth (ft) 49.2 NAVD Logged By Checked By Hammer Data MWR AJH Driller Boretec Rope & Cathead 140 (lbs) / 30 (in) Drop Drilling Equipment Drilling Method DRAFT Hollow-Stem Auger Trailer-mounted Easting (X) Northing (Y) Notes: System Datum Groundwater Date Measured Depth to Water (ft) Not encountered Elevation (ft) FIELD DATA Elevation (feet) Depth (feet) Interval Recovered (in) Blows/foot Collected Sample Sample Name Testing Water Level Graphic Log Group Classification MATERIAL DESCRIPTION Moisture Content (%) Fines Content (%) REMARKS AC CC SM 6 inches of asphalt concrete 8 inches of portland cement concrete Gray-brown silty fine to coarse sand with gravel (loose, moist) (fill) SM Brown silty fine to coarse sand with occasional gravel, trace organics (wood fragment in sampler shoe) (loose, moist) ML Gray-brown sandy silt, trace organics (soft, moist) A 3B CL Blue-gray silty clay with sand (medium stiff, moist) (glaciomarine drift) CL Gray-brown silty clay with sand, trace gravel (stiff, moist) Bellingham: Date:4/18/14 Path:P:\0\ \GINT\ GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARD /3" 100/1" 5A 5B Note: See Figure A-1 for explanation of symbols. 6 SM RX Brown silty clayey fine to coarse sand with gravel Brown to gray sandstone (hard, moist) Project: Log of Boring B-1 Project Location: Project Number: Bay Street Bridge Bellingham, Washington (2014) Figure A-2 Sheet 1 of 1

93 APPENDIX D Archaeological Review

94 Sean Cool, P.E. Senior Geotechnical Engineer 600 Dupont Street Bellingham, WA May 15, 2014 DA Letter 0414B Re: An Archaeological Review of the Bellingham Public Development Authority - Army Street Site Exploration Feasibility Study, Bellingham WA Mr. Cool, Under a contract with GeoEngineers, Drayton Archaeology (DA) conducted an archaeological review in support of the Bellingham Public Development Authority (BPDA), Army Street Site Exploration Feasibility Study. Based on archaeological review of collected samples and a review of available historical documentation, the likelihood of encountering cultural deposits or artifacts during construction is low. This letter will serve as a complete record of the archaeological oversight and is our final address of the study. Project Location and Description The present subsurface testing boreholes and piezometer wells were excavated along the former the Bellingham shoreline (now filled) in west Whatcom County in the SW ¼, NW¼¼, SE¼¼¼ of Section 30, Township 38N, Range 3E, illustrated on Figure 1. Material from seven boreholes were collected and inspected at the GeoEngineers lab facility. Soil samples were collected from undeveloped parcels, parking lots and one location along W. Holly Street (Figures 2-3). The intent of the excavations was to determine if there are any contaminants present and examine the subsurface sediment profile in the specific open area, but with some testing of developed locations as well to aid in construction planning. GeoEngineers have investigated the subsurface sediments in the area with previous borehole excavations, which also consisted of primarily dredged fill and beach deposits (Gordon 2003). The current project concept includes three mid-rise structures with six to eleven stories of mixeduse structure over two to four stories of concrete parking garage in the southern and central portions of the site (Figures 4). The lowest parking grade for the mid-rise structures will be at or slightly below lowest existing grades. Excavation below site grades and into the existing hill slope along West Holly Street and Bay Street will be required for the partially below-grade parking structure. A smaller low-rise one- or two-story structure or possible open green space is envisioned for the northern corner of the site. A pedestrian bridge may be incorporated into the project crossing over the Burlington Northern Santa Fe (BNSF) railroad tracks and connecting the subject property to new waterfront development to the west.

95 Figure 1. Portions of the Ferndale and Bellingham North, WA 7.5' USGS map illustrating the project location. Drayton Archaeology Letter 0414B 2

96 Drayton Archaeology Report 0314B 3 Figure 2. An aerial photo of the project location with geologic testing and monitoring locations noted.

97 Drayton Archaeology Report 0314B Figure 3. The draft site plan with exploration locations noted. 4

98 Drayton Archaeology Report 0314B 5 Figure 4. An illustration of the larger proposed development.

99 Geomorphologic Context The project area is located within western Whatcom County at the northern end of the Puget Lowland. The Puget Lowland is a geological and physiographic province that was shaped by at least four periods of extensive glaciation during the Pleistocene (Easterbrook 2003; Lasmanis 1991). The bedrock was depressed and deeply scoured by glaciers and sediments were deposited and often reworked as the glaciers advanced and retreated. A thick mantle of glacial drift and outwash deposits were left across much of Whatcom County at the end of the last of these glacial periods: the Fraser Glaciation (Easterbrook 2003). The Vashon Stade of the Fraser Glaciation began around 18,000 B.P. with an advance of the Cordilleran ice sheet into the lowlands (Porter and Swanson 1998). The Puget Lobe of the ice sheet flowed down into the Puget Lowland and reached its terminus just south of Olympia between 14,500 and 14,000 BP (Clague and James 2002; Easterbrook 2003; Waitt and Thorson 1983). The Puget Lobe was thicker towards the north and thinned towards its terminus. The depth of the ice near Bellingham is estimated to have been about 1900 meters (~6,330 feet) (Easterbrook 2003). The Puget Lobe began to retreat shortly after reaching its terminus. Marine waters entered the lowlands that had been carved out by the glacier and filled Puget Sound. The remaining ice was floated and wasted away rapidly. Everson glaciomarine drift deposits dating between 12,500 and 11,500 BP were released from the melting glacial ice and deposited on the sea floor across the northern and central Puget Lowland (Easterbrook 2003). The enormous weight of the ice had depressed the land but as the crust rebounded relative sea levels fell and exposed some of the drift deposits (Clague and James 2002; Easterbrook 2003). The Cordilleran ice sheet advanced once again during the Sumas Stade of the Fraser Glaciation from ca. 11,600 to 10,000 BP, leaving glacial till and outwash deposits in northwestern Washington (Kovanen and Easterbrook 2002). Bedrock along the south side of Bellingham Bay is mapped as the Padden Member of the Chuckanut Formation. The surficial geology east of Bellingham Bay is mapped as Everson glaciomarine drift deposits (Lapen 2000). Soils within the project area have been mapped as Urban land because identification of a soil series was not practical due to the ground being covered by streets, buildings, and other structures (USDA-NRCS 2004). However, previous work in this area have demonstrated that the landform beyond the steep bluff is composed entirely of fill. Drayton Archaeology Letter 0314B 6

100 Historic Context The first recorded European to visit the Bellingham Bay area was Francisco Eliza who visited briefly in Joseph Whidbey, serving under George Vancouver, surveyed the bay very shortly after that and it was named in honor of Sir William Bellingham. The first settler on Bellingham Bay, William Prattle, arrived in 1852 and other settlers soon followed. Four communities sprung up: Whatcom, Sehome, Bellingham, and Fairhaven. These eventually merged into modern day Bellingham. The subject review area encompasses portion of a block along and within the former shoreline near the mouth of Whatcom Creek, what became the town of Whatcom. The entrepreneurs Captain Henry Roeder and Russell Peabody settled the land surrounding Whatcom Falls and the mouth of the creek in December of By the following year they had built a mill and established the Whatcom Milling Company, which operated sporadically for twenty years before burning down. Due to sparse business at the mill Henry Roeder established connections abroad (Joffrion et al. 2003). In 1854 Roeder built the 70-foot scow H.C. PAGE, the first ship launched on Bellingham Bay and the third in the Puget Sound registry. Roeder was the captain of H.C. PAGE, which provided the upper Puget Sound villages with the only dependable mail and freight service in the mid-1850s (Edson 1968). Henry C. Page was Roeder and Peabody s other partner in the Whatcom Milling Company and was later appointed the inspector of Customs for the port of Whatcom (Bourasaw 2000). Roeder established the first industry in Whatcom County around Whatcom Creek and the shoreline of Bellingham Bay. In 1853 he purchased land south of Bellingham along the shoreline, which later became the site of the Chuckanut Stone Quarry. He also sold his property containing coal seams to the Bellingham Bay Coal Company (BBCC) in 1854, which opened the Sehome Mine the following year (Joffrion et al. 2009). The site of the BBCC wharf is less than ¼ mile south of the project area. After the mill burnt down in 1873 Roeder concentrated on further settling and developing the lands around Whatcom and Squalicum Creeks. He convinced a group of settlers from a utopian colony in Kansas to travel to Whatcom and re-settle at the site of the mill. These members of the Washington Colony rebuilt the sawmill and a wharf into Bellingham Bay but eventually abandoned the colony in 1885 due to a lack of incoming migrants (Joffrion et al. 2003). Development of the shoreline continued into the 20th Century establishing development area for much of the present waterfront. Figure 5 is a good illustration of the magnitude of landform alteration that has taken place at the site since development in the Bellingham Downtown began. Drayton Archaeology Letter 0314B 7

101 Figure 5. A portion of the 1887 US Coast and Geodetic Survey T-Sheet with the project area approximated. Previous Archaeology The earliest archaeological surveys completed in Whatcom County have focused along the shoreline of Bellingham Bay. The first investigations in this area were undertaken by the American Museum of Natural History s Jesup North Pacific Expedition ( ). Harlan Smith and Gerald Fowkes, members of the Jesup expedition, noted the presence of shell midden sites along the northern shoreline of Bellingham Bay (Smith and Fowkes 1901 and Smith 1907). A decade later Albert Reagan conducted archaeological investigations in the Bellingham area. Reagan also identified several shell midden sites along the northern perimeter of Bellingham Bay (Reagan 1917). These early investigations did not offer much detail regarding the location or Drayton Archaeology Letter 0314B 8

102 composition of these sites. Following these early surveys very few archaeological investigations were conducted in the area until the 1970 s. During the early 1970 s Garland Grabert, with help from Western Washington University students, conducted the first systematic archaeological survey of western Whatcom County. Between 1970 and 1990 Grabert recorded more than 100 archaeological sites in western Whatcom County (Wesson 2007). Recently, several cultural resource surveys have been completed in close proximity to the GP property. One cultural resource assessment conducted within a quarter mile to the northeast, along Holly Street, concluded that the waterfront area surrounding the mouth of Whatcom Creek to be a high probability area for encountering prehistoric or historic archaeological materials (Larson 2004). The present project location should be considered beyond that high probability area however. In 2007 Gary Wesson conducted archaeological testing along the banks of Whatcom Creek in Maritime Heritage Park at the precontact site (45WH735) located there (Wessen 2007). The Washington Information System for Architectural and Archaeological Records Data (WISAARD) database lists numerous cultural resources studies in the immediate vicinity of the project area. In addition, there are several recorded precontact archaeological sites, eligible historic properties and a potential Historic District within one mile of the project area (Sullivan 2012); Wessen 2009; Wessen The nearest archaeological site, 45WH838, the Central Avenue piling site was recorded by Wessen (2009). The site is a set of piles along a wharf extension, west of the present review area. A well-known, multi-component site of note is located along the banks of Whatcom Creek (45WH735 Xwotquem, the source of the word/name Whatcom). The site consists of an exposure of organic rich soils, fragmented shell and fire modified rock eroding out of the riverbank (Wessen 2007). Several historic properties are also present within the area which are recorded on the National Register of Historic Places (NRHP). Six properties recently recorded by Artifacts Consulting (Sullivan 2012) are either eligible for the National Register individually or are being considered as contributing structures to a Historic District. Of the formally recorded properties the Bellingham Bay Coal Company wharf and a sunken wreck of what is believed to be the TYEE tugboat (lying on the bottom of the bay at the end of the wharf) is located a quarter mile to the south of the current project area (Major 2008). To the north and west lie other NRHP eligible buildings. Notable structures include, but are not limited to, the Old City Hall/Whatcom Museum of History and Art (1892), the Barlow Building (1925) Old Main Building (1896, located on Western Washington University s campus), the Alfred L. Black home (1903), the Morse Hardware Co. Building (1902), the Sanitary Meat Market Building (1902), and). And most recently eligibility determinations for some of the the defunct Georgia Pacific Mill structures were assessed and determined eligible as well. Drayton Archaeology Letter 0314B 9

103 Methods and Results The present review was conducted in support of a feasibility study for a potential multi-use development. The scope of the present work was to assess the geologic deposits recovered from borings at the open parcels (Photos 1-2). Methods employed included background literature review, pedestrian survey and inspection of geotechnical boring samples in the GeoEngineers' lab. Background review of previous cultural resources work and historic documentation helped characterize the geologic and historic context. Pedestrian survey was conducted to corroborate the observations of the soils from borings. The geotechnical samples were thoroughly inspected. Materials collected by geologists from the borings at regular intervals were placed into zip-top bags which were analyzed for organic materials, artifacts (such as fire modified rock and historic materials). Numerous cultural resource reviews have been conducted in the vicinity. One analogous review by Baldwin (2009) was conducted immediately south of the present site in During that geotechnical analysis soils recovered from borings were nearly identical to those returned from the present work. Most of the reviews from the area have not employed subsurface testing due to issues such as project scope (structural and cell tower reviews), context (wharf/dock projects) and the potential for hazardous waste. The present site is a largely manufactured landform that would have been near-shore tidal area until massive quantities of fill were imported to the site. It appears that the most eastern portion of the larger project area was likely natural upland area. Fill is visible on the southern slope of the upland area and that suggest that some of those sediments are composed of historic fill (Photo 3). Drayton Archaeology Letter 0314B 10

104 Photo 1. A view of the unoccupied section of the review area to the southeast. Photo 2. An overview from the W Chestnut Bridge at Bay Ave of the review area. Drayton Archaeology Letter 0314B 11

105 Photo 3. A photograph of the slope along Bay Street at the abutment of the overpass (west side), note copious brick, metal and other historic fragments. While there are at least six potentially significant structures within the larger project area (as opposed to the scoped area for the geotech locations only). Those structures will require additional review and assessment with possible mitigation should development of the site move forward. Disturbances associated with the project will take place across the larger project area, but the present study was not tasked with assessing anything outside of the geotechnical work. However, it is quite unlikely that significant archaeological deposits are present within any portion of the parcels considered for development. Historic structures are definitely a future concern for considering the feasibility of developing the site as presently designed. Drayton Archaeology reviewed a series of soil samples at the GeoEngineer lab that were returned from borings at the BPDA Army Street project area. The boreholes were excavated adjacent to the former Georgia Pacific Paper Mill property and BNSF Rail Line. The excavated material was composed of primarily of dredge fill and native beach deposits. The materials were consistent with previous geological testing operations in the area undertaken by GeoEngineers (Gordon 2003). The soils were composed primarily of marine dredge spoils and native beach deposits, which overlie glacio-marine drift deposits and Chuckanut sandstone bedrock. No anthropogenic soils, formed identifiable or diagnostic artifacts of historic or precontact periods Drayton Archaeology Letter 0314B 12