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REVIEWED BLD2022-0923+Geotechnical_Report+7.13.2022_11.08.17_AM+2986715THESE PLANS COVER ALL THESE PERMITS BLD2022-0921 BLD2022-0922 BLD2022-0923 RECEIVED Jul 19 2022 CITY OF EDMONDS DEVELOPMENT SERVICES DEPARTMENT ,.,. REVIEWED BY CITY OF EDMONDS BUILDING DEPARTMENT Prepared for: Seattle Luxury Homes, LLC G R A T E D GEOTECHNICAL REPORT PROPOSED TOWNHOMES 614 & 616 - 5T" AVENUE SOUTH EDMONDS, WASHINGTON Project No. 21-372 September 2021 Geotechnical & Earthquake Engineering Consultants 3213 Eastlake Avenue East, Ste B Seattle, Washington 98102-3513 Tel: 206.262.0370 Fax: 206.262.0374 Iran ■ c o a r o e w r e o Geotechnical & Earthquake Engineering Consultants September 21, 2021 Project No. 21-372.200 Mr. Jonathan Kurth 557 Roy St, Suite 125 Seattle, WA 98109 Subject: Geotechnical Report Proposed Townhomes 614 & 616 — 5" Avenue South, Edmonds, Washington Dear Mr. Kurth: Attached please find our geotechnical report for the proposed development at the above site in Edmonds, Washington. This report documents the subsurface conditions at the site and presents our geotechnical engineering design recommendations for the proposed townhome development. In summary, based on test pits excavated at the site, the east portion of the site is generally underlain by between 8 to 10 feet of fill overlying native, medium dense to dense poorly graded sand. At the west portion of the site, fill soils were encountered up to about 4 feet below existing grade overlying native medium dense to dense sand. In our opinion, the proposed buildings may be supported on conventional shallow footings, bearing on the dense native soils or compacted structural fill placed on the native dense soils. Alternatively, a deep foundations system consisting of small diameter steel pipe piles (pin piles) may be used to support the east buildings, to avoid deep over -excavations below the building foundations. Temporary unsupported excavations may be sloped as steep as 1 H:1 V (Horizontal: Vertical). We appreciate the opportunity to work on this project. Please call if there are any questions. Sincerely, Michael H. Xue, P.E. Principal Geotechnical Engineer 3213 Eastlake Avenue East, Suite B Seattle, WA 98102 Tel (206) 262-0370 TABLE OF CONTENTS 1.0 INTRODUCTION...................................................................................................................1 2.0 PROJECT AND SITE DESCRIPTION............................................................................... 1 3.0 SUBSURFACE EXPLORATIONS....................................................................................... 2 3.1 CURRENT SUBSURFACE EXPLORATION.................................................................................. 2 3.2 PREVIOUS SUBSURFACE EXPLORATION.................................................................................. 3 4.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS.................................................... 3 4.1 SITE GEOLOGY....................................................................................................................... 3 4.2 SOIL CONDITIONS.................................................................................................................. 3 4.3 GROUNDWATER..................................................................................................................... 4 5.0 CRITICAL AREAS AMF SITE STABILITY..................................................................... 5 5.1 EROSION HAZARD AREA........................................................................................................ 5 5.2 SITE STABILITY...................................................................................................................... 5 6.0 GEOTECHNICAL RECOMMENDATIONS...................................................................... 6 6.1 SEISMIC DESIGN PARAMETERS.............................................................................................. 6 6.2 BUILDING FOUNDATIONS....................................................................................................... 6 6.2.1 General........................................................................................................................... 6 6.2.2 Conventional Footings................................................................................................... 6 6.2.3 Allowable Bearing Pressure........................................................................................... 7 6.2.4 Foundation Performance................................................................................................ 7 6.2.5 Lateral Resistance.......................................................................................................... 7 6.2.6 Perimeter Footing Drains............................................................................................... 8 6.2.7 Footing Subgrade Preparation and Protection............................................................... 8 6.2.8 Pin Piles......................................................................................................................... 8 6.3 CONCRETE RETAINING WALL DESIGN PARAMETERS........................................................... 11 6.3.1 Lateral Earth Pressures................................................................................................. 11 6.3.2 Wall Surcharge............................................................................................................. 12 6.3.3 Lateral Resistance........................................................................................................ 12 6.3.4 Wall Drainage.............................................................................................................. 12 6.3.5 Wall Backfill................................................................................................................ 13 6.4 CONCRETE SLAB-ON-GRADE............................................................................................... 13 7.0 CONSTRUCTION CONSIDERATIONS..........................................................................13 7.1 DEMOLITION & SITE PREPARATION..................................................................................... 13 7.2 MATERIAL REUSE................................................................................................................ 14 7.3 TEMPORARY EXCAVATIONS................................................................................................. 14 7.4 STRUCTURAL FILL PLACEMENT AND COMPACTION............................................................. 15 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page i PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 7.5 PERMANENT CUT AND FILL SLOPES ............. 7.6 EROSION AND DRAINAGE CONSIDERATIONS 7.7 WET EARTHWORK RECOMMENDATIONS ...... ...................................................................... 15 ...................................................................... 15 ...................................................................... 16 8.0 ADDITIONAL SERVICES..................................................................................................17 9.0 LIMITATIONS.....................................................................................................................17 10.0 REFERENCES.................................................................................................................... 19 LIST OF ATTACHMENTS Figure 1 Figure 2 Appendix A Figure A-1 Figure A-2 Figure A-3 Figure A-4 Figure A-5 Figure A-6 Figure A-7 Appendix B Vicinity Map Site and Exploration Plan Summary Test Pit Logs Terms and Symbols for Boring and Test Pit Logs Log of Test Pit PIT-1 Log of Test Pit PIT-2 Log of Test Pit PIT-3 Log of Test Pit TP-1 Log of Test Pit TP-2 Log of Test Pit TP-3 Previous Test Boring Logs and Laboratory Results 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page ii PanGEO, Inc. GEOTECHNICAL REPORT PROPOSED TOWNHOMES 614 & 616 - 5TH AVENUE SOUTH EDMONDS, WASHINGTON 1.0 INTRODUCTION This report presents the results of a geotechnical study that was undertaken to support the design and construction of the proposed development in Edmonds, Washington. Our study was performed in general accordance with our mutually agreed -upon scope of work as outlined in our proposal dated August 2, 2021. Our service scope included reviewing readily available geologic and geotechnical data at the subject site and in the site vicinity, conducting a site reconnaissance, excavating six (6) test pits, and developing the geotechnical design recommendations presented in this report. 2.0 PROJECT AND SITE DESCRIPTION The project site consists of two adjacent parcels located at 614 and 616 — 5th Avenue South in Edmonds, Washington (see Figure 1, Vicinity Map). The combined site is an approximate 0.39 acre lot. It is bordered by 5th Avenue South to the east, multi -family residences to the west, retail establishments to the north, and an improved private alley to the south. The site is currently occupied by a single -story retail building at the north portion of the site and a single -story retail building with full basement at the southern portion of the site, with a surface parking lot between the two buildings. The site generally slopes down from east to west with an approximate grade change of 10 feet to a vacant vegetated area at the western portion of the site. According to the City, an erosion hazard (slope gradient between 15% and 40%) is present at the approximate central portion of the lot, associated with previous grading at the site. No other geologic hazards are mapped on the property by the City or County. We understand that you plan to remove the existing buildings, and construct three buildings at the site, consisting of two live -work townhome buildings (Buildings A and B) along the east property line and a townhome building (Building C) in the western portion of the site (see Figure 2). Based on review of the preliminary plans, the proposed buildings will be 3-story, wood -frame structures with concrete slabs on grade. We envisage that site grading for the proposed project will include cuts and fill up to about 8 to 10 feet for the foundation construction. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 1 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 BUILDING A BUILDING C u Plate 1. Typical East-West Building Section, looking North. The conclusions and recommendations outlined and provided in this report are based on our understanding of the proposed development, which is in turn based on the project information provided. If the above project description is incorrect, or the project information changes, we should be consulted to review the recommendations contained in this study and make modifications, if needed. 3.0 SUBSURFACE EXPLORATIONS 3.1 CURRENT SUBSURFACE EXPLORATION Our current subsurface exploration consisted of excavating six (6) test pits (PIT-1, PIT-2, PIT-3 and TP-1, TP-2, TP-3) at the project site on August 4 and August 6, 2021. PIT-1 was initially excavated to 5.5 feet for infiltration testing and was then excavated to about 9 feet deep after the test. PIT-2 was initially excavated to 6 feet for infiltration testing and was then excavated to at about 9 feet deep after the test. PIT-3 was initially excavated to 12 feet for infiltration testing and was then excavated to practical digging refusal at about 15 feet deep after the test. TP-1 was excavated to practical digging refusal at 13 feet below grade and TP-2, and TP-3 were each excavated to about 11 feet below the existing grade. The approximate test pit locations are shown on the attached Figure 2. The relative in -situ density of cohesionless soils, or the relative consistency of fine-grained soils, was estimated from the excavating action of the excavator, probing the sidewalls with a 1/2-inch diameter steel rod, and the stability of the test pit sidewalls. Where soil contacts were gradual or undulating, the average depth of the contact was recorded in the log. After the test pits were 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 2 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 completed, the excavations were backfilled with the excavated soils and the surface was tamped and re -graded smooth. A geologist from our firm was present throughout the explorations to assist in sampling, and to document the soil samples obtained from the explorations. The summary test pit logs are included in Appendix A. 3.2 PREVIOUS SUBSURFACE EXPLORATION In addition to the current explorations at the site, we also reviewed readily available subsurface data in the site vicinity. Specifically, we reviewed five boring logs (B-1 through B-5) at the subject site by Zipper Geo Associates, LLC (ZGA) in October 2015. The previous test boring logs and laboratory results are included in Appendix B for reference. We also observed two existing monitoring wells (Department of Ecology Well Tags BKH-527 and BKH-528) installed by others at the site. Details of these monitoring wells are not known, and they could not be found on the Department of Ecology Well Report Viewer. These groundwater monitoring wells will need to be decommissioned per the Washington State Department of Ecology's standards prior to, or during construction. 4.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS 4.1 SITE GEOLOGY Based on our review of the Composite Geologic Map of the Sno-King Area, Central Puget Lowland (Booth, 2004), the site is underlain by Pre -Fraser Deposits (geologic map unit Qpf). Pre -Fraser Deposits generally consist of interbedded sand, gravel, and silt that has been glacially overridden and typically dense to very dense. This unit is similar to the younger Vashon Advance Outwash but is characterized by its stratigraphic position and generally heterogenous grain size. 4.2 SOIL CONDITIONS For a detailed description of the subsurface conditions encountered at each exploration location, please refer to our summary test pit logs provided in Appendix A and previous test boring logs in Appendix B. The stratigraphic contacts indicated on the logs represent the approximate depth to boundaries between soil units. Actual transitions between soil units may be more gradual or 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 3 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 occur at different elevations. The descriptions of groundwater conditions and depths are likewise approximate. The following is a generalized description of the soils encountered in the test pits. UNIT 1: Fill — Test pits PIT-1, PIT-2, and TP-1, excavated in the western portion of the site, test pits, generally encountered approximately 4 to 4.5 feet of fill below surface vegetation. The fill encountered in these test pits generally consisted of loose to medium dense silty to poorly graded sand with some plastic, asphalt, and brick debris. Test pits PIT- 3, TP-2, and TP-3, excavated in the central and eastern portion of the site, encountered approximately 8 to 10 feet of fill below the surface asphalt. The fill generally consisted of loose to medium dense silty sand with gravel with varying amounts of wood, concrete, and construction debris. UNIT 2: Pre -Fraser Deposits — Directly below the fill in each test pit, medium dense to dense poorly graded sand was observed in the test pits extending to the bottom of test pits. We interpreted this unit as the mapped pre -Fraser Deposits within the project vicinity. Our subsurface descriptions are based on the conditions encountered at the time of our exploration. Soil conditions between our exploration locations may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, PanGEO should be requested to reevaluate the recommendations in this report and to modify or verify them in writing prior to proceeding with earthwork and construction. Previous Test Borings: The previous test borings by ZGA generally encountered fill up to 13 feet overlying medium dense to dense native sand that extended to a maximum depth of about 24 feet below the surface. 4.3 GROUNDWATER Groundwater or seepage was not observed in our test pits or previous test borings by ZGA at the time of exploration. Groundwater was measured in the previously installed groundwater monitoring wells on August 5, 2021 at a level of approximately 25 feet below ground surface in the parking lot area (approximate EL 59 feet) and 16.5 feet below ground surface in the lower vegetated area (approximate EL 57.5 feet). No groundwater was encountered within the drilling depths in the borings by ZGA. It should be noted that groundwater elevations may fluctuate depending on the seasonal rainfall, local subsurface and groundwater conditions, and other factors. In general, the water level is the 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 4 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 highest and the seepage rate in the greatest during the winter and early spring (typically October through May). 5.0 CRITICAL AREAS AMF SITE STABILITY 5.1 EROSION HAZARD AREA The site is mapped as an erosion hazard area in accordance with the City of Edmonds Critical Areas Map and City of Edmonds Development Code Section 23.80.020, due to presence of slopes with gradient between 15 and 40 percent. Based on the USDA Soil Survey data and the test pits/borings, the site soils (Alderwood/Everett series) are anticipated to exhibit low to moderate erosion potential when disturbed and left unprotected. However, in our opinion, the potential erosion hazards at the site can be effectively mitigated with the best management practice during construction and with properly designed and implemented landscaping for permanent erosion control. During construction, the temporary erosion hazard can be effectively managed with an appropriate erosion and sediment control plan, including but not limited to installing silt fence at the construction perimeter, limiting removal of vegetation near the construction area, placing rocks or hay bales at the disturbed/traffic areas and on the downhill side of the project, covering stockpile soil or cut slopes with plastic sheets, constructing a temporary drainage pond to control surface runoff and sediment trap if needed, placing rocks at the construction entrance, etc. Permanent erosion control measures should include establishing vegetation, landscape plants, and hardscape established at the end of project. 5.2 SITE STABILITY As part of our study, we conducted a site reconnaissance on August 4, 2021 to observe the conditions of the slope. Based on our observations, the slope follows the east -west grade break located at the approximate center of the two parcels. The earthen slope at the center of the two parcels has a gradient of approximately 35 to 40 percent with a vertical height of about 7 feet. The slope area is currently heavily vegetated. No evidence of groundwater seepage was observed on or near the slope. Based on the results of our field exploration and our field observations, it is our opinion that the site is currently stable. It is also our opinion that the proposed development as currently planned will not adversely impact the subject site and surrounding properties, provided that the proposed project is properly designed and constructed. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 5 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.0 GEOTECHNICAL RECOMMENDATIONS 6.1 SEISMIC DESIGN PARAMETERS We understand that the project will be designed in conformance with the 2018 edition of the International Building Code (IBC). The 2018 International Building Code (IBC) is based on a design level earthquake event having a 2% probability of occurrence in 50 years (return interval of 2,475 years), and the 2008 USGS seismic hazard maps. Based on site soils conditions, it is our opinion that Site Class D (Stiff Soil) may be assumed for the seismic design of the proposed structures. 6.2 BUILDING FOUNDATIONS 6.2.1 General Based on the subsurface conditions and current design plans, it is our opinion that the proposed buildings may be supported by conventional shallow footings, bearing on dense native soils or structural fill/controlled density fill (CDF) placed on the competent native soils. However, use of this foundation system will require over -excavation of fill/loose soils and backfill of structural fill/CDF. Over -excavations of existing fill below foundations will be up to about 4 feet for the west building and will be up to about 10 to 12 feet for the two east buildings. Alternatively, to avoid deep over-excavations/structural backfill and the need for temporary shoring, it is our opinion that a deep foundation system consisting of small diameter steel pipe piles (pin piles) may be considered to support the east buildings. It should be noted that large concrete pieces were encountered in the test pits in the existing fill. As such, obstructions may be encountered during pin pile installation and pile locations may need to be moved to avoid obstructions. Alternatively, the obstructions may be removed by the excavator, where encountered, to facilitate pile installation. The following sections present our design recommendations for shallow conventional footings and pin piles. 6.2.2 Conventional Footings In our opinion, the proposed west building may be supported on conventional footings bearing on the medium dense to dense, undisturbed native soils (Soil Unit 2: Pre -Fraser Deposits). Footings may also be founded on properly compacted structural fill placed on undisturbed native soil. The structural backfill should extend horizontally with an approximately I H: IV line beyond the footing edges. It is our opinion that it will be more appropriate to support the two east buildings with pin piles. Please note that the competent bearing soil depths in the vicinity of our test pits are approximate. The actual amount of over -excavation required will need to be 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 6 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 determined during construction based on actual soil conditions found at the proposed footing locations and elevations. In designing the footings, the shape of footings will need to be considered regarding the available space for temporary excavations. Where space may be limited for an unsupported open cut, it may be necessary to use L-shaped perimeter footings to conserve space and to allow the temporary excavations to be made within the property limits. 6.2.3 Allowable Bearing Pressure We recommend that an allowable soil bearing pressure of 2,500 pounds per square feet (psf) be used to size the footings, bearing on medium dense to dense native soil, or structural fill/lean- mix concrete placed on the competent native soils. Continuous and individual spread footings should have minimum widths of 18 and 24 inches, respectively. Footings should be placed at least 18 inches below final exterior grade. Interior footings should be placed at least 12 inches below the top of slab. 6.2.4 Foundation Performance Total and differential settlements are anticipated to be within tolerable limits for foundation designed and constructed as discussed above. For the proposed buildings supported by conventional footings bearing on competent native soils and structural fill/lean-mix concrete, the building settlement under static loading conditions is estimated to be approximately one inch, and differential settlement should be on the order of about 1/2 inch. Most settlement should occur during construction as loads are applied. 6.2. S Lateral Resistance Lateral forces from wind or seismic loading may be resisted by a combination of passive earth pressures acting against the embedded portions of the foundations and walls, and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf). This value includes a factor safety of at least 1.5 assuming that densely compacted structural fill will be placed adjacent to the sides of the foundation. A friction coefficient of 0.35 may be used to determine the frictional resistance at the base of the foundation. This coefficient includes a factor of safety of approximately 1.5. Unless covered by pavements or slabs, the passive resistance in the upper 12 inches of soil should be neglected. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 7 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.2.6 Perimeter Footing Drains Footing drains should be installed around the perimeter of the building, at or just below the invert of the footings. The footing drains should consist of 4-inch diameter, schedule 40 PVC or SDR 35, perforated pipe embedded in washed drain rock/pea gravel and wrapped in filter fabric. Under no circumstances should roof downspout drain lines be connected to the footing drain systems. Roof downspouts must be separately tightlined to appropriate discharge locations. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. 6.2.7 Footing Subgrade Preparation and Protection All footing subgrades should be carefully prepared. The adequacy of footing subgrade should be verified by a representative of PanGEO, prior to placing forms or rebar. The footing subgrade at should be in a firm/dense condition prior to concrete pour. Any over -excavations in the footing areas should be backfilled with compacted structural fill. Footing excavations should be observed by PanGEO to confirm that the exposed footing subgrade is consistent with the expected conditions and adequate to support the design bearing pressure. It should be noted that site soils are highly moisture sensitive and can be easily disturbed when exposed to moisture. As such, the exposed footing subgrade should be adequately protected. This may be accomplished with placing quarry spalls or crushed surfacing base course (CSBQ on the footing subgrade immediately after excavations if excavations are planned during inclement weather. 6.2.8 Pin Piles In the eastern portion of the site where upwards of 13 feet of fill was observed in our test pits and previous borings, it is our opinion that 3- and 4-inch diameter driven pin piles may be considered in -lieu of deep over -excavation and structural backfill. Three- and four -inch diameter pin piles are typically driven with a hammer mounted to a small excavator. Pin Pile Capacity — The number of piles required depends on the magnitude of the design load and the pile size. Table 1, below, provides the allowable axial capacities in compression for pin piles with an approximate factor of safety of at least 2.0. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 8 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 Table 1— Pin Pile Capacities Pile Diameter (in) Allowable Axial Capacity in Compression (tons) 3 6 4 10 Penetration resistance required to achieve the capacities will be determined based on the hammer used to install the pile. The tensile and lateral capacities of pin piles should be ignored in design calculations. It is our experience that the driven pipe pile foundations should provide adequate support with total settlements on the order of 1/2-inch or less. Pin Pile Specifications — We recommend that the following specifications be included on the foundation plan: 1. 3-inch and 4-inch diameter piles should consist of Schedule-40, ASTM A-53 Grade "A" pipe. 2. 3-inch piles shall be driven to refusal with a minimum 600-lb hydraulic hammer. We recommend the following refusal criteria based on the size of hammer utilized: Table 2 — Three-inch Pile Refusal Criteria Hammer Approx. Refusal Criteria Blows per Size Minute (3-inch pile) 600 lbs 1000 12 seconds per inch 850 lbs 900 10 seconds per inch 1100 lbs 900 6 seconds per inch The driving criteria recommended in the table above will be verified by a static load test program (see discussion in Item 5). 3. 4-inch piles shall be driven to refusal with a minimum 850-lb hydraulic hammer. We recommend the following refusal criteria based on the size of hammer utilized: 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 9 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 Table 3 — Four -inch Pile Refusal Criteria Hammer Approx. Refusal Criteria Blows per Size Minute (4-inch pile) ) 850 lbs 900 16 seconds per inch 1100 lbs 900 10 seconds per inch 2000 lbs 600 4 seconds per inch The driving criteria recommended in the table above will be verified by a static load test program (see discussion in Item 5). 4. Piles shall be driven in nominal sections and connected with compression fitted sleeve couplers (see detail below — Courtesy of McDowell Pile King, Kent, WA). We discourage welding of pipe joints, particularly when galvanized pipe is used, as we have frequently observed welds broken during driving. Pipe 10 2" to 6" New Steel Pipe Section to 1�� S 1 1/4" to 2" wide X-Strong Steel Ring 1/4" filet welded to pipe sleeve Driven Steel Pipe Section Beveled End to aid insertion 5. At least 3 percent (but no more than 5) of the 3-inch and 4-inch pin piles should be load tested. All load tests shall be performed in accordance with the procedure outlined in ASTM D1143. The maximum test load shall be 2 times the design load. The objective of the testing program is to verify the adequacy of the driving criteria, and the efficiency of the hammer used for the project. 6. The geotechnical engineer of record or their representative shall provide full time observation of pile installation and testing. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 10 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 The quality of a pin pile foundation is dependent, in part, on the experience and professionalism of the installation company. We recommend that a company with experienced personnel be selected to install the piles. Lateral Resistance — Lateral capacity of vertical pin piles should be ignored in design calculations. Some resistance to lateral loads may be accomplished by battering the piles to a slope of l (H):4(V), or steeper. Passive soil resistance values for embedded pile caps and grade beams may be determined using an equivalent fluid weight of 250 pounds per cubic foot (pcf). This value includes a factor of safety of at least 1.5 assuming that a properly compacted structural fill will be placed adjacent to the sides of the pile caps and grade beams. Friction at the base of pile cap should be ignored in the design calculations. For the seismic condition, the recommended passive pressure may be increased by one third. Estimated Pile Length — The subsurface conditions at the site may vary across the site. Based on the soil conditions at the site and our experience in the project area, for planning and cost estimating purposes, we estimate that pile length may range from about 20 to 25 feet. A minimum pile length of 10 feet should also be specified in the project plans. Obstructions — Construction and concrete debris was encountered in test pits PIT-3, TP-2, and TP-3 beneath the existing parking area. In so, obstructions may be encountered during pile driving. Where possible, the obstructions should be removed to facilitate the pile driving. If obstructions cannot be removed, the structural engineer of record should be notified to revise the pile layout to accommodate the adjustment. 6.3 CONCRETE RETAINING WALL DESIGN PARAMETERS Retaining walls should be properly designed to resist the lateral earth pressures exerted by the soils behind the wall. Proper drainage provisions should also be provided behind the walls to intercept and remove groundwater that may be present behind the wall. Our geotechnical recommendations for the design and construction of the retaining and below -grade walls are presented in the sections below. 6.3.1 Lateral Earth Pressures We recommend that concrete cantilever walls that are free to rotate be designed for an equivalent fluid pressure of 35 pcf for level backfills behind the walls; and 50 pcf with a backslope no steeper than 2H:IV. Restrained walls such as basement walls should be designed for 50 and 60 pcf for level and 2H:1 V backslope, respectively. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 11 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 For the seismic condition, we recommend a uniform lateral earth pressure of 8H psf (where H is the wall height) be added to the static pressure for sizing the retaining and basement walls. The recommended lateral pressure assumes that adequate wall drainage will be incorporated into the design and construction of the walls to prevent the development of hydrostatic pressure. 6.3.2 Wall Surcharge The retaining and basement walls should be designed to accommodate traffic surcharge pressures if the traffic load is located within the height dimension of the wall. As a minimum, the traffic surcharge should be considered equivalent to 2 feet of soils surcharge (i.e., 80 psf of horizontal uniform pressure). Similarly, surcharge loads from construction equipment or soil/material stockpiles should be considered in the retaining and basement wall design. We recommend that a lateral load coefficient of 0.4 be used to compute the lateral pressure on the wall face resulting from surcharge loads located within a horizontal distance of one-half wall height. 6.3.3 Lateral Resistance Lateral forces from wind or seismic loading and unbalanced lateral earth pressures may be resisted by a combination of passive earth pressures acting against the embedded portions of the foundations and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 300 pounds per cubic foot (pcf). This value includes a factor of safety of 1.5, assuming the footing is poured against recompacted native soil or properly compacted structural fill adjacent to the sides of footing. A friction coefficient of 0.35 may be used to determine the frictional resistance at the base of the footings. This coefficient also includes a safety factor of at least 1.5. 6.3.4 Wall Drainage Provisions for wall drainage should consist of a 4-inch diameter perforated drainpipe behind and at the base of the wall footings, embedded in 12 to 18 inches of clean crushed rock and pea gravel wrapped with a layer of filter fabric. Where applicable, in -lieu of conventional footing drains, weep holes (2" diameter of 10 feet on center) may be used for site retaining walls. A minimum 18-inch-wide zone of free draining granular soils (i.e., pea gravel or washed rock) is recommended to be placed adjacent to the wall for the full height of the wall. Alternatively, a composite drainage material, such as Miradrain 6000, may be used in lieu of the clean crushed rock or pea gravel. The drainpipe at the base of the wall should be graded to direct water to a suitable outlet. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 12 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 6.3. S Wall Backfill Wall backfill should consist of free draining granular soils. In our opinion, the on -site fill soils have a high fines content, and are not suitable to be re -used as wall backfill. Imported wall backfill such as Gravel Borrow (Section 9.03.14 (1) of the 2020 WSDOT Standard Specifications) should be assumed for this project. The fill should be moisture conditioned to near its optimum moisture content, placed in loose, horizontal lifts less than about a foot in thickness, and systematically compacted to a dense and relatively unyielding condition. The adequacy of the compaction should be verified by PanGEO. If density tests will be performed, the test results should indicate at least 95 percent of the maximum dry density, as determined using test method ASTM D 1557. Within 5 feet of the wall, the backfill should be compacted to 90 percent of the maximum dry density. 6.4 CONCRETE SLAB -ON -GRADE The floor slabs for the proposed buildings may be constructed using conventional concrete slab - on -grade floor construction. The floor slabs should be supported on competent native soil or compacted structural fill. Any loose soils at the slab subgrade should be either recompacted to a dense condition or over -excavated to expose dense undisturbed native soils. Over -excavation should be replaced with compacted structural fill. Interior concrete slab -on -grade floors should be underlain by a capillary break consisting of at least of 4 inches of pea gravel or compacted 3/4-inch, clean crushed rock (less than 3 percent fines). The capillary break material should also have no more than 10 percent passing the No. 4 sieve and less than 5 percent by weight of the material passing the U.S. Standard No. 100 sieve. The capillary break should be placed on the subgrade that has been compacted to a dense and unyielding condition. A 10-mil polyethylene vapor barrier should also be placed directly below the slab. We also recommend that construction joints be incorporated into the floor slab to control cracking. 7.0 CONSTRUCTION CONSIDERATIONS 7.1 DEMOLITION & SITE PREPARATION We envisage site preparation for the proposed project includes demolishing the existing structures, stripping and clearing of surface vegetation, and excavations to the design subgrade. All footings and floor slabs of the existing buildings, as well as building debris and concrete rubble should be removed from the site prior to the start of excavations or grading. All stripped 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 13 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 surface materials should be properly disposed off -site or be "wasted" on site in non-structural landscaping areas. Following site clearing and excavations, the adequacy of the subgrade where foundations, slabs, or pavements are to be placed should be verified by a representative of PanGEO. The subgrade soil in the improvement areas, if recompacted and still yielding, should be over -excavated and replaced with compacted structural fill or CDF/lean-mix concrete. The test pits for this study were backfilled with the excavated soils. The backfill was tamped with the excavator bucket and the ground surface leveled. The backfill was not compacted to the requirements of structural fill. During construction of the project, the earthwork contractor should locate the test pits, remove the loose backfill and replace it with properly compacted structural fill. 7.2 MATERIAL REUSE In the context of this report, structural fill is defined as compacted fill placed under footings, concrete stairs and landings, and slabs, or other load -bearing areas. The contractor should be aware that the site soils are poorly graded and may be difficult to compact to the requirements of structural fill. As a result, the excavated site materials may not be suitable for use as structural backfill, particularly during periods of wet weather. If import structural fill is needed, it should consist of a well -graded granular material, such as WSDOT CSBC, Gravel Borrow or approved equivalent. Well -graded recycled concrete may also be considered as a source of structural fill. Use of recycled concrete as structural fill should be approved by the geotechnical engineer. The on -site soil can be used as general fill in the non-structural and landscaping areas. If use of the on -site soil is planned, the excavated soil should be stockpiled and protected with plastic sheeting to prevent softening from rainfall in the wet season. 7.3 TEMPORARY EXCAVATIONS As currently planned, excavations on the order of 10 feet are needed for the foundation construction. As such, we anticipate that unsupported slope cuts may be incorporated into the excavation design. All temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 14 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 In general, vertical cuts should be limited to 4 feet in areas not close to the property lines. The vertical cuts should be limited to 2 feet along the property lines. Temporary excavations deeper than a total of 4 feet should be sloped, benched, or shored. Excavations more than 2 feet along property lines, will also need to be sloped or supported if sufficient space is not available to lay back the excavations without encroaching into neighboring properties. If temporary shoring is needed to support the excavations, PanGEO can provide shoring design recommendations if requested. For planning purposes, the temporary unsupported excavation may be sloped as steep as 1 H:1 V (Horizontal: Vertical). The cut slopes may also need to be flattened in the wet seasons and should be covered with plastic sheets. We also recommend that heavy construction equipment, building materials, excavated soil, and vehicular traffic should not be allowed within a distance equal to 1/3 the slope height from the top of any excavation. 7.4 STRUCTURAL FILL PLACEMENT AND COMPACTION Structural fill should be moisture conditioned to within about 3 percent of optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and systematically compacted to a dense and relatively unyielding condition and to at least 95 percent of the maximum dry density, as determined using test method ASTM D 1557. Depending on the type of compaction equipment used and depending on the type of fill material, it may be necessary to decrease the thickness of each lift to achieve adequate compaction. PanGEO can provide additional recommendations regarding structural fill and compaction during construction. 7.5 PERMANENT CUT AND FILL SLOPES Based on the anticipated soil that will be exposed in the planned excavation, we recommend permanent cut and fill slopes be constructed no steeper than 2H:1V (Horizontal:Vertical). 7.6 EROSION AND DRAINAGE CONSIDERATIONS Surface runoff can be controlled during construction by careful grading practices. Typically, this includes the construction of shallow, up -grade perimeter ditches or low earthen berms to collect runoff and prevent water from entering the excavation. All collected water should be directed to a positive and permanent discharge system such as an approved City storm sewer. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 15 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 It should be noted that the site soils are prone to surficial erosion. Special care should be taken to avoid surface water on open cut excavations. As previously mentioned in Section 7.3, we recommend that the exposed temporary slopes be covered with plastic sheeting. Permanent control of surface water and roof runoff should be incorporated in the final grading design. In addition to these sources, irrigation and rainwater infiltrating into landscape and planter areas adjacent to paved areas or building walls should also be controlled. All collected runoff should be directed into conduits that carry the water away from the pavement or structure and into City storm drain systems or other appropriate outlets. Adequate surface gradients should be incorporated into the grading design such that surface runoff is directed away from structures. 7.7 WET EARTHWORK RECOMMENDATIONS General recommendations relative to earthwork performed in inclement weather or in wet conditions are presented below: • All surface of the foundation subgrade should be protected against inclement weather. It is the contractor's responsibility to protect the footing subgrade from disturbance. One option is to place a 2- to 3-inch-thick layer of lean -mix concrete on the footing subgrade as soon as the subgrade is exposed. • Earthwork should be performed in small areas to minimize subgrade exposure to wet weather. Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. The size and type of construction equipment used may have to be limited to prevent soil disturbance. • During wet weather, the allowable fines content of the structural fill should be reduced to no more than 5 percent by weight based on the portion passing 3/4-inch sieve. The fines should be non -plastic. • The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. • Geotextile silt fences should be strategically located to control erosion and the movement of soil. Erosion control measures should be installed along all the property boundaries. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 16 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 • Excavation slopes and soils stockpiled on site should also be covered with plastic sheets. 8.0 ADDITIONAL SERVICES To confirm that our recommendations are properly incorporated into the design and construction of the proposed development, PanGEO should be retained to conduct a review of the final project plans and specifications, and to monitor the construction of geotechnical elements. Modifications to our recommendations presented in this report may be necessary, based on the actual conditions encountered during construction. 9.0 LIMITATIONS We have prepared this report for use by Jonathan Kurth and the project design team. Recommendations contained in this report are based on a site reconnaissance, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed -upon scope of work. Variations in soil conditions may exist between the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors' methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our work specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. We are not mold consultants nor are our recommendations to be interpreted as being preventative of mold development. A mold specialist should be consulted for all mold -related issues. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 17 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on -site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor's option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. We appreciate the opportunity to be of service. Sincerely, Spenser P. Scott, L.G. Staff Geologist Michael H. Xue, P.E. Principal Geotechnical Engineer 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 18 PanGEO, Inc. Geotechnical Report Proposed Townhomes: 614 & 616 — 5th Avenue South, Edmonds, Washington September 21, 2021 10.0 REFERENCES ASTM D2488-17, Standard Practice for Description and Identification of Soils (Visual -Manual Procedures), ASTM International, West Conshohocken, PA, 2017, www.astm.org. International Code Council, 2018, International Building Code (IBC). Booth, D. B., Cox, B. F., Troost, K. G., Shimel, S. A., 2004, Composite Geologic Map of the Sno-King Area, Central Puget Lowland, Washington: Seattle -Area Geologic Mapping Project, University of Washington, and the United States Geological Survey, scale 1:24000. Washington Administrative Code (WAC), 2016, Chapter 296-155 - Safety Standards for Construction Work, Part N - Excavation, Trenching, and Shoring, Olympia, Washington. Washington State Department of Transportation, 2020, Standard Specifications for Road, Bridge and Municipal Construction, M 41-10, Washington State Department of Transportation. Zipper Geo Associates, LLC., February 2016, Geotechnical Engineering Report, Proposed Home Street Bank, 614 & 616 5' Avenue South, Edmonds, Consultant report prepared for Home Street Bank. 21-372 - 614 & 616 5th Ave S - Geotech Rpt.doc Page 19 PanGEO, Inc. :: z zoom sl SW z a � Y R R L E 7" PUGET O cl i SOUND C Daley St rvrc CoNor 1 A� 3' Rid" Pbyt"a s/r Park Craq* (Edmonds W r n St o rn Dayton St Q f > W Pk St Yo N Park Alder St M n dnwrd> > r, LO Shel/, walnut St Nbt sh y v �s� i wooin dmonds Q ?� Wa r rn t3rk C, L 216th St SW to, Project Site 21eth s1 sw a2201h St SW40 Q > Q L m L G G m a o ' a� L = ; 0 2261h St SW - o 0 22eth St SW t\SW Geer Creek �s9 0"r Park %se ve Edmonds' Esperance z3zro s1 Wact,,ir .'r? rr Hrkman Park Woodway %$Ila*" � 1 Marysville n,, Pon Hael,ck l—dn le n Whidbey '_. N., r 1 sland Everett wmorr Gole F'. 0--d r�r . Xf �y„ 1. NORTH r� Redm1 nd ?- A Not to Scale z st Sw R Base Map: ESRI Topographic Proposed Townhomes VICINITY MAP RnGEO614 & 616 5thA�/ve S r N C o R P o R A.rE D Edmonds, V ,1A Project No. 21-372 Figure No. 1 t-j()TE: LE,;-J,AL DESCF-IF71--�Dh ;-j-'--/EFL."`-'P'-. ll,jTc-i FIC"HT CIF 1,1VA i' 171F 47H '.-TREE-T Legend: N A CONDO 4CIF-1 P HA L T P4PK'--'1E'11'11' T'%,',IN. A CONDOMINIt p-.4 517 47H AVE S 131.37 ONE B,ALLARD LLC/ 610 5TH AVE S WAL� ............... P ONE S70BUILDING:.S... 614 5TAVE:::•: FF ..84-.05: ........... -1 z z z z� �I Building A z z .......... . I M .7z82.22-' TP �-ON*--)N IE=80,42. " 4 CONC zE---jE=B0.62' ... .......... ': BKH-5281 ....... .. .......... ASPHALT PA-RKi ........... ........... 50 FT P - 31; 11 z z B-2 . z ....... ....... ...... �W z z M PIT-3 z ................. Building B 9 tp 2 STi--)PY CONC, BI- 16 5TH A� FFE=85,26' FFE=76.59' --z<;'44H RIM = 69,68 CHAPARCa B: Ifj 6;5, 08 Approximate Test Pit Location Approximate Parcel Boundary PanGEO, Inc., August 2021 F-1 - ----- Previous Test boring Location Zipper Geo Associates, October 2015 F-1 Approximate Proposed Building Approximate Observed Monitoring Well Approx. Scale: 1 inch = 20 fee - ACft 11 P Base map modified from ALTA/ACSM Land Title Survey by PACE Engineering, dated July 17, 2015 APPENDIX A SUMMARY TEST PIT LOGS RELATIVE DENSITY / CONSISTENCY SAND / GRAVEL SILT / CLAY SPT Approx. Relative SPT Approx. Undrained Shear DensityN-values Density (%) Consistency N-values Strength (psf) Very Loose <4 <15 Very Soft <2 <250 Loose 4 to 10 15 - 35 Soft 2 to 4 250 - 500 Med. Dense 10 to 30 35 - 65 Med. Stiff 4 to 8 500.1000 Dense 30 to 50 65 - 85 Stiff 8 to 15 1000 - 2000 Very Dense >50 85.100 Very Stiff 15 to 30 2000 - 4000 Hard >30 >4000 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS •�' GW: Well -graded GRAVEL Gravel GRAVEL (<5% fines) .. .....: ...................................................... 50% or more of the coarse o ° GP : : Poorly -graded GRAVEL fraction retained on the #4 sieve. Use dual symbols leg. o ° GM ...................................................... Silty GRAVEL GP -GM) for 5% to 12% fines. GRAVEL (>12% fines) •••••••••••••••••••••••••••••• GC : ........................••• Clayey GRAVEL ...................................................................... .......................................................... SW: Well -graded SAND Sand SAND (<5 /° fines) '' 50% or more of the coarse ....................................:....> % SP Poorly -graded raded SAND y-g fraction passing the #4 sieve. Use duals leg. SP-SM ) ; ":r" ............................................................ SM: Silt SAND y %fin for s%to12%fines.g SAND (>1 2% fines) , ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• SC : Clayey SAND ...................................................................... ............................................................. ML : SILT Liquid Limit < 50 ............................................................ CL : Lean CLAY Silt and Clay ............................................................ OL : Organic SILT or CLAY == — 50%or more passing #200 sieve :.................................. :...................................................... MH : Elastic SILT Liquid Limit > 50 CH Fat CLAY OH Organic SILT or CLAY — , ........................... ...................................... Highly Organic Soils ............................................................ PT : PEAT Notes: 1. Soil exploration to s contain material descriptions based on visual observation and field tests using a system modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been conducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to the discussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole to s. Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. DESCRIPTIONS OF SOIL STRUCTURES Layered: Units of material distinguished by color and/or Fissured: Breaks along defined planes composition from material units above and below Slickensided: Fracture planes that are polished or glossy Laminated: Layers of soil typically 0.05 to 1 mm thick, max.1 cm Blocky: Angular soil lumps that resist breakdown Lens: Layer of soil that pinches out laterally Disrupted: Soil that is broken and mixed Interlayered: Alternating layers of differing soil material Scattered: Less than one per foot Pocket: Erratic, discontinuous deposit of limited extent Numerous: More than one per foot Homogeneous: Soil with uniform color and composition throughout BCN: Angle between bedding plane and a plane normal to core axis COMPONENT DEFINITIONS COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder: > 12 inches Sand Cobbles: 3 to 12 inches Coarse Sand: #4 to #10 sieve (4.5 to 2.0 mm) Gravel Medium Sand: #10 to #40 sieve (2.0 to 0.42 mm) Coarse Gravel: 3 to 3/4 inches Fine Sand: #40 to #200 sieve (0.42 to 0.074 mm) Fine Gravel: 3/4 inches to #4 sieve Silt 0.074 to 0.002 mm Clay <0.002 mm TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. ATT AtterbergLimit Test Comp Compaction Tests Con Consolidation DD Dry Density DS Direct Shear %F Fines Content GS Grain Size Perm Permeability PP Pocket Penetrometer R R-value SG Specific Gravity TV Torvane TXC Triaxial Compression UCC Unconfined Compression SYMBOLS Sample/In Situ test types and intervals 2-inch OD Split Spoon, SPT (140-lb. hammer, 30" drop) H3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core ® Vane Shear MONITORING WELL SZ Groundwater Level at time of drilling (ATD) 1 Static Groundwater Level Cement / Concrete Seal Bentonite grout / seal Silica sand backfll Slotted tip Slough Bottom of Boring MOISTURE CONTENT Dry Dusty, dry to the touch Moist Damp but no visible water Wet Visible free water GPmE® Terms and Symbols for I IN C 0 R P 0 R A T E D Boring and Test Pit Logs Figure A-1 Phone: 206.262.0370 Test Pit No. PIT-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297653, 1260821 Death ft Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0-2 with gravel; trace plastic, asphalt, and brick debris, some angular rock, trace ----------------------- rootlets; disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2 — 4.5 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4.5 — 9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet o• JI -Av_ _ - � � l _ yy 1 ti_ s eve Photo PIT-1 (left): Shows PIT-1 at approximately 5.5 feet in depth before testing Photo PIT-1 (right): Shows spoils from PIT-1 at approximately 9 feet in depth after testing PIT-1 was terminated approximately 5.5 feet below grade for infiltration testing. After the test, PIT-1 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-2 PanGEO, Inc. Test Pit No. PIT-2 Approximate ground surface elevation (NAVD88): 73.5 feet Coordinates (Washington State Plane - North): 297574, 1260814 Death ftj Material Description Light vegetation above loose to medium dense, gray -brown, silty fine SAND 0 — 2.5 with gravel; trace asphalt debris, some angular rock, trace rootlets; disrupted ----------------------- texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2.5-4 rock, some roots, burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine SAND; trace gravel, trace silt; non- 4-9 plastic, moist [Qpf — Pre -Fraser Deposits] - Becomes dense, gray, poorly graded fine SAND from 7 to 9 feet ..!t r a. V.. W Photo PIT-2 (left): Shows PIT-2 at approximately 6 feet in depth before testing Photo PIT-2 (right): Shows spoils from PIT-2 at approximately 9 feet in depth after testing PIT-2 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-2 was over -excavated to 9 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-3 PanGEO, Inc. Test Pit No. PIT-3 Approximate ground surface elevation (NAVD88): 83.5 feet Coordinates (Washington State Plane - North): 297594, 1260886 De th ft Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 7 — 8.5 debris, some concrete and construction debris; disrupted texture; non -plastic, moist ----------------------- ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8.5 — 10 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown, poorly graded fine to medium SAND; trace gravel, trace silt, 10-15 trace iron -oxide staining; non -plastic, moist [Qpf— Pre -Fraser Deposits] tip " 1 ` � _ '7 • . Ate. �,� t}K' : � �' ; AL Photo PIT-3 (left): Shows PIT-3 at approximately 12 feet in depth before testing Photo PIT-3 (right): Shows spoils from PIT-3 at approximately 10 feet in depth after testing PIT-3 was terminated approximately 6 feet below grade for infiltration testing. After the test, PIT-3 was over -excavated to 15 feet in depth to check for shallow groundwater or groundwater mounding. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-4 PanGEO, Inc. Test Pit No. TP-1 Approximate ground surface elevation (NAVD88): 74 feet Coordinates (Washington State Plane - North): 297615, 1260818 Death ftj Material Description Light vegetation and gravel above loose to medium dense, gray -brown, silty 0-2 fine SAND with gravel; trace concrete debris, some angular rock, trace rootlets; ----------------------- disrupted texture, non -plastic, dry to moist ---------------------------------------------------------------------------------------------------------------------------- Medium dense, light brown, poorly graded fine SAND; trace silt, trace angular 2-4 rock, trace roots, burnt wood fragments; iron -oxide staining; disrupted texture non -plastic, moist [Fill] Dense, gray -brown to gray, poorly graded fine to medium SAND; trace gravel, trace silt; non -plastic, moist 4 —13 • Top approximate 2 feet weathered to red -brown w/ iron -oxide staining • Cobble layer from approximately 11 to 12 feet below ground surface [Qpf — Pre -Fraser Deposits] i ! ,t 1.4 1 � l v Photo TP-1 (left): Shows TP-1 at approximately 13 feet in depth Photo TP-1 (right): Shows spoils from TP-1 at approximately 10 feet in depth TP-1 was terminated approximately 13 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-5 PanGEO, Inc. Test Pit No. TP-2 Approximate ground surface elevation (NAVD88): 84 feet Coordinates (Washington State Plane - North): 297617, 1260919 Death ftj Material Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-8 ----------------------- slightly silty SAND with gravel and cobble; trace wood debris; non -plastic, moist ---------------------------------------------------------------------------------------------------------------------------- Loose, dark brown to black, slightly organic silty SAND; trace brick debris, wood 8-9 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 9-11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] • r '• i Photo TP-2 (left): Shows TP-2 at approximately 11 feet in depth Photo TP-2 (right): Shows spoils from TP-2 at approximately 10 feet in depth TP-2 was terminated approximately 11 feet below grade. No groundwater seepage was encountered during explorations. 21-372 Test Pit Logs Figure A-6 PanGEO, Inc. Test Pit No. TP-3 Approximate ground surface elevation (NAVD88): 83 feet Coordinates (Washington State Plane - North): 297651, 1260854 PeiqthftjMaterial Description Approximate 2-inch asphalt overlay above loose to medium dense, gray -brown, 0-7 slightly silty SAND with gravel and cobble, layers of gray, sandy SILT; metal ---------------------------- debris, wood debris, large fragments of concrete slab; non -plastic, moist ------------------------------------------------------------------------------------------------------------------------------------------------------ Loose, dark brown to black, slightly organic silty SAND; metal debris, wood 7-8 debris, some concrete and construction debris; disrupted texture; non -plastic, moist [Fill] Medium dense, light brown to red -brown, poorly graded fine SAND; trace silt, 8 —11 burnt wood fragments; trace iron -oxide staining; disrupted texture non -plastic, moist [Qpf — Pre -Fraser Deposits] f 4 Photo TP-3 (left): Shows TP-3 at approximately 10 feet in depth Photo TP-3 (right): Shows spoils from TP-3 at approximately 10 feet in depth TP-3 was terminated approximately 10 feet below grade. No groundwater seepage was encountered during explorations. Date of Test Pit Excavations: August 4 and August 6, 2021 Excavations Logged by: S. Scott and J. Manke 21-372 Test Pit Logs Figure A-7 PanGEO, Inc. APPENDIX B PREVIOUS TEST BORING LOGS AND LABORATORY RESULTS 10 El SB-1 a (10 °°TSB-2� B-3 `n 1 1 _ O oaf °°" po cl IB-rJ u° low=.11�:>!11 ao 0 od o pO LEGEND B-1 BORING NUMBER AND APPROXIMATE LOCATION 30 0 15 30 APPROXIMTATE SCALE IN FEET w 0q Fi.. ' 'd o BASE DRAWING PROVIDED BY HOMESTREET BANK, UNDATED. Boring Location: See Figure 1, Site and Exploration Plan Drilling Companv: Environmental Bore Hole Dia.: 8" Top Elevation: - Drilling Method: Hollow Stem Auger Hammer Type: Auto B-1 Date Drilled: 10/19/2015 Drill Rig: Truck Logged by.. TAJ aThe ° SOIL DESCRIPTION /^ 9 vJ E J Q n (6 0 C PENETRATION RESISTANCE (blows/foot) o U ° m 0) W stratification lines represent the approximate boundaries between soil types. The transition may be gradual. Refer to report text and appendices for additional information. Standard Penetration Test Hammer Weight and Drop: 0 20 40 60 -0 2 inches asphalt over about 2 inches Crushed Surfacing Base Course over gravelly SAND with trace to some silt —i +✓-+tip+I-++ IIIIIIIII I I -I I l l-I-I IIIIIIIII I I��+�� I... IIIIIIII- Loose, wet, gray -brown, gravelly SAND with some silt Fill ( ) S-1 18 I IIIIIIIII +t��th1�� 1.J 1 1Ii rr IIIIIIIII ��I I I I -I -I IIIIII --, rrl-i-I IIIIIIII -1-4-4-4�Probable 1 1 1 1 1 II1111� 10 -5 - IIIIII IIIIIIII, I 1I- __ 4 _ __ .._. _I I __ ... Loose, wet, gray, SAND with silt and gravel (Probable Fill) T S-2 11 181, 10 GSA Loose, moist, gray, gravelly SAND with trace to some silt Probable Filo__________________________________ 1.o9Se,maiSi.dlsbravyn.�aodkSll_T�E�Ii�I�s9il�-------- S3 18" � I� I I -rrrrrrr IIIIIII I I I I I I I I I rrr�rl�� 111ii1 I I I I I �� 11 7 Loose, moist, orange -brown, SAND with gravel, some silt 111 c L L L1_I I IIII 111111I11 I_L_I hill IIIIIIII- T S-4 1151, 9 GSA LL I IIIIIIIII I I I I I I I I I I I S-5 18 I + IIII I I I I I IIIIIIIII I I I I I I IIIIIIII 8 III IIIII IIIIIIIII IIIIIIIII IIIIIIIII IIIIIIII IIIII '..- •15 IIIIIIIII IIIIIIIII IIIIII -------------------------------------------- Dense, moist, light brown, SAND with some silt, some gravel S-6 I 15" IIIIII 1 1 1 1 I I I 1 j 1 34 IIIIII �♦-�FFI IIIIIIIII III II '....� I I I 1-1 - IIIIII IIIII -111� .... IIIIIIII- Dense, wet, brown, gravelly SAND with silt Boring completed at approximately 24 feet. • 25 No groundwater observed ATD. SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits T- T-F L_L L.LLI I ._.I_. I I _J__ IIIIIII IIIIII IIIIIIII' -1 I I IIIIII IIIIIIII- S-7 18" II q6 I IIIII I IIIII 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 1 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 2 - 2.5 inches asphalt over about 2.5 inches CSBC over dark brown, moist, silty SAND Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-2 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Medium dense, moist, brown -gray, SAND with silt and gravel S-1 151• I (Possible Fill) - 5 Medium dense, moist, brown, SAND with silt and gravel T (Possible Fillj._Blowcounts ov_erstated_due to gravel- _ _ _ _ _ _ _ _ S-2 I 181, Very dense, moist, brown, sandy GRAVEL with some silt and cobbles (Possible Fill) T Loose, moist, brown, SAND with some silt to with silt, trace to S-3 I 3" some gravel T Loose, moist, brown, SAND with some silt to with silt, trace to S-4 I 19 some gravel (2 inches wood at 11 feet; root?) (Wood in cuttings) Dense, moist, gray, SAND with silt and gravel to silty SAND s-5 18^ with gravel (Glacial Till -like) •15 Dense, moist, gray, interbedded fine SAND with trace silt and S-6 I 18" silty SAND with some gravel Boring completed at approximately 19 feet. No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 12 1 GSA 14 _ 9 JJJJ� I I I I I I I I I I 1-4 -4 -4 -4 33 Illli II i 41 (IIIII (IIIII III illlillll Iilill IIIIIIII IIIIIIII 1 l i lllll!' iIIlI11 till II11 i r FF jlll --i LLL1 ------------ Illlili 111 Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 2 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 2.5 inches asphalt over about 2.5 inches CSBC over brown, moist, SAND with silt some gravel Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-3 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Loose, moist, gray, SAND with silt, trace gravel (Probable Fill) s 1 I 18" -5 1 Medium dense, moist, gray, silty SAND with trace gravel s 2 16" (Probable Fill) Loose, damp to moist, gray, SAND with trace to some silt and T gravel (Probable Fill) _ _ _ _ _ _ _ _ _ _ s-s 18" I Loose, damp to moist, dark brown, silty SAND (Relic Topsoil?) --------------------------------------------- Medium dense, damp to moist, orange -brown grading to yellow -gray, SAND with trace to some silt trace gravel S-4 T 181, Medium dense, damp to moist, gray, fine SAND with silt S-5 181, •15 -------------------------------------------- Very dense, moist, gray, sandy GRAVEL with some silt S-6 15" Boring completed at approximately 19 feet. No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis VGroundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 50/5" IIIIII IIIIII IIIII -..... illllll - IIIIII (IIIIIII- (IIIIIII I II I llll'�- IIIIIII till (III I r F_F (LILII - -L i IIIIIII IIIIII Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B-3 Lynnwood, WA Page 1 of 1 Boring Location: See Figure 1, Site and Exploration Plan Drilling Companv: Environmental Bore Hole Dia.: 8" Top Elevation: - Drilling Method: Hollow Stem Auger Hammer Type: Auto B-4 Date Drilled: 10/19/2015 Drill Rig: Truck Logged by.. TAJ SOIL DESCRIPTION PENETRATION RESISTANCE (blows/foot) /^ 9 vJ E J (6 0) Standard Penetration Test aThe stratification lines represent the approximate boundaries Hammer Weight and Drop: o U ° between soil types. The transition may be gradual. Refer to Q o W report text and appendices for additional information. n ° m C0 0 20 40 60 -0 _Vyeed�LaysidarkJ)rQvyrl dBDV_tomaiat. siUy-S8UD�IQpwJ Encountered 1/2-inch diameter PVC pipe at 14 inches 1 IIIIIIIII IIIIIIIII IIIIIIII- Medium dense, damp to moist, brown grading to orange- S-1 18 I IIIIIIIII IIIIIIIII IIIIIIII 12 GSA brown, SAND with some silt and 9ravel ! 11 IIIIIIIII _ IIIIIIII -5 Loose, damp to moist, yellow -brown, SAND with silt to SAND S-2 18 with some silt Medium dense, moist, light brown, silty fine SAND S-3 Dense, moist, brown -gray, SAND with some silt S-4 18" Boring completed at approximately 11.5 feet No groundwater observed ATD. •15 • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis V Groundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 38 T IIIIII T TI I I i l IIIIIIIII 11 IIIIIIII- LLL11 JL LIII LLLJLI-I-I J JJJJ� I I I 1 1 1 I I I I I I I I I I I I I I IIIIIIIII I I I I I I IIIIIIIII I I I I I I IIIIIIII- IIIIIIIII tt�ti-�FF� IIIIIIIII FFI I I -I -I -I I IIIIIIII- 1�11��-I - - - - 7 7 F . I i_I_I 11T_ Illllll -I IIIIII IIIIII '..- IIIIIIIII - IIIIII IIIIIIII- �Illll I it I FI FJ L _ L..L L I I . _.!..._. IIIIII IIIIII IIIIIIII' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B_ 4 Lynnwood, WA Page 1 of 1 See Figure 1, Site and Exploration Plan 10/19/2015 SOIL DESCRIPTION Z The stratification lines represent the approximate boundaries a) between soil types. The transition may be gradual. Refer to report text and appendices for additional information. -0 JYeeds_aysi Ioospa, soaisL dk.brawrr silty SAND 4Zap3oi - - - - Medium dense, damp, orange -brown, fine SAND with silt to silty fine SAND with trace gravel 5 Medium dense, damp to moist, orange -brown and gray, fine SAND with silt to silty fine SAND •15 Drilling Company: Environmental Bore Hole Dia.: 8" Drilling Method: Hollow Stem Auger Hammer Type: Auto B-5 Drill Rig: Truck Logged by.. TAJ PENETRATION RESISTANCE (blows/foot) U) Standard Penetration Test J o c Hammer Weight and Drop: U F= <0 o o H U 0 20 40 60 Medium dense, moist, gray, SAND with silt --------------------------------------- Very dense, moist, gray, sandy GRAVEL, with some silt s-s 1e Boring completed at approximately 11.5 feet No groundwater observed ATD. • 25 ' SAMPLE LEGEND GROUNDWATER LEGEND I2-inch O.D. split spoon sample ❑ Clean Sand 3-inch I.D. Shelby tube sample ® Bentonite Grout/Concrete ® Screened Casing TESTING KEY ❑ Blank Casing GSA = Grain Size Analysis V Groundwater level at time of drilling (ATD) or 20OW = 200 Wash Analysis ti on date of Consol. = Consolidation Test N measurement. Att. = Atterberq Limits 12 21 51 illll�llI lilt hill llilll l ililllll �Illll I l i illjll till 111 i r FF 111 --i LLLI I ._.i_. Illlili 111 Illll' 0 % Fines (<0.075 mm) O % Water (Moisture) Content Plastic Limit Liquid Limit Natural Water Content Homestreet Bank 614 & 616 5th Ave S. Edmonds, WA Date: - Project No.: 1527.01 Zipper Geo Associates BORING 19023 36th Ave. W, Suite D LOG; B'.ri Lynnwood, WA Page 1 of 1 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-1 S-2 5 - 6.5 ft. 9.9 26.0 SAND with silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-1 S-4 10 - 11.5 ft. 6.1 7.4 SAND with gravel, some silt Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-2 S-1 2.5 - 4 ft. 8.2 21.7 SAND with silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422 100 90 = 80 W ?� 70 In W 60 W Z 50 Z W U W 40 W a 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 PARTICLE SIZE IN MILLIMETERS BOULDERS COBBLES Coarse Fine Coarse Medium Fine Silt Clay GRAVEL SAND FINE GRAINED Comments: Exploration Sample Depth (feet) Moisture (%) Fines (%) Description B-4 S-1 2.5 - 4 ft. 6.6 12.0 SAND with some silt and gravel Project No.: 1527.01 Project Name: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants Date of Testing: 10/21/2015 Edmonds HomeStreet Bank