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161031 MAD (Geotech Report).pdf
Geotechnical Engineering Report New Madrona K-8 Project 9300 2361h Street SW Edmonds, Washington Excellence, Innovation. Service. Value. offlVIRM October 31, 2016 Submitted To: Ms. Taine Wilton Edmonds School District #15 20420 68th Avenue West Lynnwood, Washington 98036 By: Shannon & Wilson, Inc. 400 N 34th Street, Suite 100 Seattle, Washington 98103 21-1-22082-004 SHANNON ILA TABLE OF CONTENTS Page 1.0 SITE AND PROJECT DESCRIPTION.................................................................................I 2.0 SITE CONDITIONS..............................................................................................................2 2.1 Regional Geology.......................................................................................................2 2.2 Regional Seismicity....................................................................................................2 3.0 SUBSURFACE EXPLORATION.........................................................................................3 ' 5.0 LABORATORY TESTING...................................................................................................5 6.0 SUBSURFACE CONDITIONS.............................................................................................5 6.1 Site Geology and Subsurface Conditions...................................................................5 6.1.1 Subsurface Conditions at Proposed Building..............................................5 6.1.2 Subsurface Conditions at Proposed Parking Lots and Driveways...............6 6.2 Hydrogeologic Conditions.........................................................................................6 7.0 ENGINEERING STUDIES AND RECOMMENDATIONS................................................6 7.1 General.......................................................................................................................6 7.2 Foundation Design.....................................................................................................7 7.3 Seismic Design...........................................................................................................7 7.4 Lateral Earth Pressures and Retaining Walls.............................................................8 7.5 Lateral Resistance......................................................................................................9 7.6 Slope Stability............................................................................................................9 7.7 Pavement Design......................................................................................................10 7.7.1 Traffic Load...............................................................................................10 7.7.2 Subgrade Conditions..................................................................................10 7.8 Non -Porous Pavement Section Recommendations..................................................10 7.9 Porous Pavement Section Recommendations..........................................................11 7.9.1 Grass Grid Pavers......................................................................................11 7.9.2 Pervious Hot Mix Asphalt (HMA) and Concrete......................................11 7.10 Pavement Sections Near Steep Slopes.....................................................................12 7.11 Frost Susceptibility...................................................................................................12 8.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS.....................................13 8.1 Earthwork and Use of On -site Soils.........................................................................13 8.2 Pervious Pavement Materials...................................................................................14 8.3 Construction and Maintenance Considerations for Pervious Pavement ..................14 8.4 Temporary and Permanent Excavation Slopes.........................................................15 8.5 Erosion Control........................................................................................................16 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 1 TABLE OF CONTENTS (cont.) Page 8.6 Construction Drainage..............................................................................................16 8.7 Subsurface Drainage................................................................................................16 8.8 Utilities.....................................................................................................................16 8.9 Wet Weather Earthwork...........................................................................................1.7 8.10 Plans Review and Construction Observation...........................................................18 9.0 LIMITATIONS....................................................................................................................18 10.0 REFERENCES.....................................................................................................................20 TABLES 1 Recommended Minimum Parking Lot and Driveway Section Thicknesses .........1.1. 2 Recommended Minimum Porous Pavement Section Thicknesses ........................11 3 Imported Backfill Specifications Based on 2016 Washington. State Department of Transportation Standard Specifications.........................................13 FIGURES 1 Vicinity Map 2 Site and Exploration Plan 3 Typical Rockery Detail 4 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-1 5 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-2 6 Measured Water Level, Pilot Infiltration Test, Test Pit PIT-3 APPENDICES A Subsurface Explorations B Laboratory Test Results C Analytical Laboratory Test Results D Important Information About Your Geotechnical/Environmental Report 21-1-22082-004-R1 f.aocx/wp/1kn 21-1-22082-004 11 SHANNON 6WILSON, ING GEOTECHNICAL ENGINEERING REPORT NEW MADRONA K-8 PROJECT 9300 236TH STREET SW EDMONDS, WASHINGTON 1.0 SITE AND PROJECT DESCRIPTION The Edmonds School District No. 15 plans to construct a new Madrona K-8 School on the south side of the property at 9300 236th Street SW in Edmonds, Washington, as shown in the Vicinity Map (Figure 1). The property contains the existing Madrona K-8 School and is bounded by 236th Street to the north, residential developments on the east and south sides, and the former Woodway Elementary School on the west. The site has a number of distinct surface features including a parking lot on the northwest side, track and large open field area on the southwest side, and a baseball field on the southeast side. There is a densely wooded ravine area along the east side of the property and a densely wooded slope on the west side of the property that slopes down to the former Woodway Elementary School. The purpose of this study is to finalize our geotechnical recommendations with data from additional subsurface explorations and testing to aid in the final design of the proposed structure. Geotechnical recommendations were provided previously in a preliminary geotechnical engineering report submitted on August 6, 2015. Our scope of services for the design phase included drilling and sampling 12 geotechnical borings and excavating 5 test pits. However, one of the proposed drilling locations was changed to a test pit exploration for a total of 11 geotechnical borings and 6 test pits. The proposed drilling location was changed to a test pit due to the close proximity to subsurface utilities and access issues. Locations of the subsurface explorations were selected to coincide with the planned location of the proposed building and associated facilities. Descriptions of the subsurface exploration activities are discussed further in Section 3.0. The results of our pilot infiltration testing (PIT) are discussed in Section 4.0. This report presents updated geotechnical engineering recommendations to incorporate the additional subsurface information gathered from the new explorations and information provided by the design team. We have included recommendations for pavement design and a discussion of buffer and setback distances when adjacent to steep slopes and other geologic hazard areas. The results of the soil fertility testing are also provided to aid the design team in evaluating the suitability of on -site topsoil for use in landscaping. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 2.0 SITE CONDITIONS 2.1 Regional Geology SHANNON ING , The site is located in Edmonds, Washington, which is within a region known as the Puget Lowland. The Puget Lowland is a structural depression bordered by the Olympic and Cascade Mountain ranges that is generally within about 500 feet of sea level. The geology of the area has been influenced by repeated cycles of glaciation, which worked to fill the lowland to significant depths with a complex sequence of glacial and nonglacial deposits. The most recent glacier to impact the area, the Vashon Stade of the Fraser Glaciation, overrode the area with up to 3,000 feet of ice in some locations. Following the last glaciations, the erosion of some of the glacially overridden soil deposits, as well as local deposition and human placement of additional soil deposits, have further complicated the local geology (Troost and Booth, 2008). The project site itself is situated on a ridge underlain by Quaternary Vashon till (Qvt) that was observed at relatively shallow depths during the current subsurface investigation. This geologic unit was found to be a very dense, gray to gray -brown deposit consisting of silty sand with variable gravel, cobble, and some boulder content. Other explorations performed on the site (Shannon & Wilson, Inc. [Shannon & Wilson], 2016) encountered deposits of Quaternary Vashon advanced glacial outwash (Qva) at depths of approximately 40 to 50 feet below ground surface (bgs). This geologic unit is characterized by dense to very dense sands and gravels with variable amounts of silt. Qva is typically less compact and more pervious than Qvt. Geologic maps of the Snohomish County region indicate that the contact between the glacial till and advanced outwash material is on the slope on the west side of the property. The Qva at the site may be underlain by pre-Vashon interglacial and glacial soils, predominantly fluvial. 2.2 Regional Seismicity The Puget Sound Lowland is located in the fore arc of the Cascadia Subduction Zone. The seismicity of the region is largely derived from the subduction of the Juan de Fuca Plate beneath the North American Plate. The convergence of these two plates results in a number of generally east -west -trending faults, as well as basin and uplift regions (Troost and Booth, 2008). The seismic hazard of the region comes from three major sources, a major subduction type events, deep intraplate events (such as the 2001 Nisqually earthquake), and earthquakes due to rupture of shallow crustal faults. The site itself is located a reasonable distance from subduction and intraslab sources, and as a result, the more local, crustal faults are believed to drive the seismic hazard for the site. The closest known potentially active fault to the site is the South Whidbey Island Fault (SWIF). The 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 2 SHANNON ING , SWI.F is a shallow, strike -slip fault that is believed to be capable of producing a magnitude 7.5 event, which could impose significant seismic demands on structures at the site. 3.0 SUBSURFACE EXPLORATION Previously, we completed subsurface explorations as a part of a preliminary geotechnical engineering study to aid in the selection of the proposed building location. Previous explorations consisting of 16 test pits on the southern half of the property were completed on June 24, 2015. Logs of the previous subsurface explorations are included in Appendix A. Recent subsurface explorations consisted of test pits and geotechnical borings completed between Monday, July 25, 2016, and Friday, July 29, 2016. Holocene Drilling (Holocene), under subcontract to Shannon & Wilson, completed a total of 11 geotechnical borings with the use of a track -mounted Diedrich D-50 drill rig. Holocene used the hollow -stem auger drilling method to complete the borings to depths ranging from 15.5 to 16.5 feet bgs. Holocene collected samples on approximate 2.5-foot intervals with the use of the Standard Penetration Test. Once the geotechnical borings were completed, Holocene backfilled the holes with bentonite to within approximately 1 to 2 feet bgs. Borings that were drilled in the asphalt parking area were patched with concrete. Clearcreek Contractors (Clearcreek), under subcontract to Shannon & Wilson, completed a total of six test pits to depths ranging from 4 to 10 feet with the use of a rubber -tired John Deere 310SJ backhoe. Three of the test pits were used to characterize infiltration within the near - surface soils. Infiltration testing within the near -surface soils is discussed below in Section 4.0. Following the excavations and testing, Clearcreek backfilled the test pits with the excavated material and tamped the material down using the excavator bucket in approximately 1-foot-thick lifts. Once Clearcreek had completed backfilling the test pits, they rolled the surface for further compaction and replaced the grass layer where it was possible to salvage. The explorations were located throughout the site as shown in the Site and Exploration Plan, Figure 2. Test pits designated with a PIT were the ones in which we performed the in situ infiltration testing/PITs, while the test pits designated with a TP were not used for in situ infiltration testing. During the exploration process, the soil and groundwater conditions were observed by an engineer or a geologist from our office. Soil samples were collected and transported to our Seattle laboratory for analysis and testing. Logs of the explorations are presented in Appendix A. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 SHANNON ING , The geotechnical boring and test pit locations provided in Figure 2 are approximate, being based on hand measurements from site features, and surface elevations shown in the logs are estimated from a topographic survey of the site prepared by PACE Engineers, Inc. 4.0 FIELD INFILTRATION TESTING We performed small-scale PITs within three of the six test pits excavated during the current subsurface explorations. The PIT test pits were designated as PIT-1 through PIT-3, and the locations are shown in the Site and Exploration Plan, Figure 2. All three of the infiltration tests were performed on July 28, 2016. These test pits were over excavated following the PITs on July 29, 2016. Details of the three tests are presented below and are summarized in the PIT data plots (Figures 4 through 6). The PIT-1 test pit bottom during the PIT was approximately 3.8 feet bgs, or about Elevation 440.7 feet. The tested soil unit was fill, consisting of reworked glacial till. After the water flow was terminated, the test pit drained completely overnight. No free water was present below the PIT test depth when we overexcavated it on July 29, 2016. A plot of the PIT-1 test data is presented as Figure 4. The observed (short-term) infiltration rate was approximately 0.80 inch per hour, based on the last hour of the constant head period. If these soils represented the subgrade beneath a bioretention feature constructed with imported bioretention soil, the City of Edmonds (City) will require the application of a correction factor of 2 due to the test being performed during the dry season. This would result in a design (long-term) infiltration rate of 0.4 inch per hour. The PIT-2 test pit bottom during the PIT was approximately 3.3 feet bgs, or about Elevation 452.7 feet. The tested soil unit was glacial till, with a short-term infiltration rate of 0.13 inch per hour, based on the falling head data collected after the water flow into the test pit was terminated. Applying the correction factor would result in a design infiltration of 0.06 inch per hour. The test pit failed to drain completely overnight and this soil is considered to be a hydraulic restriction to infiltration, due to its low infiltration rate. A plot of the PIT-2 test data is presented as Figure 5. The PIT-3 test pit bottom during the PIT was approximately 2.9 feet bgs, or about Elevation 447.1 feet. The tested soil unit was glacial till, with a short-term infiltration rate of 0.07 inch per hour based on the falling head data collected after the water flow into the test pit was terminated. Applying the correction factor would result in a design infiltration rate of 0.03 inch per hour. The test pit failed to drain completely overnight and this soil is considered to be a hydraulic 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 4 SHANNON ING , restriction to infiltration due to its low infiltration rate. A plot of the PIT-3 test data is presented as Figure 6. If a shallow well were installed in the vicinity and read during the wet season, no correction. factor would be required, provided groundwater is at least 3 feet below the bottom of the facility. 5.0 LABORATORY TESTING Laboratory testing was conducted on several soil samples collected from the test pit explorations to assist in classification and characterization of the subsurface soils. The laboratory tests included natural moisture content determination and grain size analysis. The natural moisture contents are indicated on the test pit logs in Appendix A. The results of the grain size analyses are presented in Appendix B. Most of the grain size tests were sieve analyses. Combined sieve and hydrometer tests were performed on two samples (from B-4 at 5 feet deep [about Elevation 440 feet] and from B-5 at 7.5 feet deep [about Elevation 439.5 feet]) so that the U.S. Department of Agriculture (USDA) texture could be identified. Both samples are considered to be "sandy loam," based on the USDA textural system. Based on our discussions with the City, the short-term infiltration rate for these soils is 1 inch per hour. Since the explorations were completed during the dry season, a seasonal correction factor of 2 is required, resulting in a design infiltration rate of 0.5 inch per hour. This assumes that these soils represent the subgrade beneath bioretention features with imported bioretention soil. In order to characterize the existing topsoil within the upper and lower field, we submitted two samples to Spectra Laboratories (Spectra) in Poulsbo, Washington. The samples were tested for soil fertility and the results with recommendations from Spectra are included in Appendix C. 6.0 SUBSURFACE CONDITIONS 6.1 Site Geology and Subsurface Conditions Intact glacial till soils were encountered in all but one of the explorations performed under the current scope of work. The test pit PIT-1 did not encounter intact glacial till, but did encounter weathered till at a depth of approximately 7 feet bgs. 6.1.1 Subsurface Conditions at Proposed Building Explorations performed within or near the proposed building footprint on the existing upper play field in the southeast corner of the site indicate that this area is underlain by a thin layer of topsoil followed by layers of fill, weathered or reworked glacial till, and intact glacial 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 5 SHANNON ING , till. Borings B-7, B-9, B-10, and B-1.2 indicate that there is a layer of fill soils at depths ranging from 4.5 to 7 feet bgs. Fill soils consisted of medium dense to very dense, silty sand to silty sand with gravel. Intact very dense glacial till underlying the building footprint was encountered at depths ranging from approximately 1 to 7 feet bgs. 6.1.2 Subsurface Conditions at Proposed Parking Lots and Driveways Explorations performed within the parking areas west of the existing school building and north of the track indicated that fill soils overlying the glacial till are present at depths ranging from 7 to 9.5 feet bgs. Borings and test pits on the north and east sides of the existing building also encountered fill soils at depths ranging from 4.5 to 6 feet bgs. Intact, very dense glacial till was found to underlie the fill soils. 6.2 Hydrogeologic Conditions Groundwater was not encountered in the recent shallow soil borings and test pits, all of which were performed during the dry season. Moist to wet layers were observed below about 15 feet in. borings B-2, B-3, and B-5, and below about 1.2 feet in boring B-9, which may indicate the presence of perched groundwater. Subsurface explorations performed previously onsite as part of our hydrogeologic study (Shannon & Wilson, 2016) identified a regional groundwater aquifer at the site at about 180 feet deep and between approximate Elevations 276.3 to 277.2 feet. Perched groundwater zones were also encountered during the previous hydrogeologic explorations at depths ranging from 8.5 to 11 feet bgs (Shannon & Wilson, 2016). Note that groundwater is not expected to be encountered during excavations for the new school building. We understand that the project stormwater management system will consist of a series of shallow bioretention swales combined with underground injection control (UIC) wells. The results of our recent hydrogeological testing and analysis are presented in a separate report (Shannon & Wilson, 2016). Please refer to this report for design recommendations regarding UIC construction and infiltration rates. 7.0 ENGINEERING STUDIES AND RECOMMENDATIONS 7.1 General Based on the observations made during the subsurface exploration program and information reviewed for the project, we expect the glacial till material will provide good support for conventional spread footing foundations with minimal settlements. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 6 SHANNON ING , The following subsections provide detailed recommendations on the following topics: ■ Foundation design • Seismic design ■ Lateral earth pressures ■ Lateral resistance ■ Slope stability ■ Pavement design 7.2 Foundation Design The subsurface explorations encountered undisturbed, very dense, native glacial till soils across the entire site. Spread footings founded in the dense, native till material may be designed with an allowable bearing pressure of 10,000 pounds per square foot (psf). Spread footings that are founded in compacted structural backfill placed above the glacial till may be designed for an allowable bearing capacity of 4,000 psf. These allowable bearing values may be increased by one-third for transient seismic loading. Any fill material that is to be reused should be evaluated by a geotechnical engineer to see if they are suitable for use. Use of on -site fill material is discussed in Section 8.1. Based on the subsurface conditions, isolated overexcavation could be required due to the presence of some existing fill within the building footprints. As an alternative to overexcavation of fill material encountered at footing subgrade elevations, in situ densification of the fill could be accomplished with the use of heavy vibratory compaction equipment (i.e., excavator -mounted "ho-pac"). Footing subgrades should be observed by a qualified geotechnical engineer or geologist. If the native glacial till material or compacted structural backfill is used as the foundation bearing soils, it is anticipated that any settlement that occurs will be essentially instantaneous as the load is applied during construction. If the footings are designed for the bearing pressures noted above, then the total footing settlements will be less than '/z inch. Differential settlements would be about one-half of the total settlement. However, if the entire structure is founded on the glacial till, then differential settlements would be insignificant. 7.3 Seismic Design The seismic design of the structure should be in accordance with the International Code Council, Inc. 2015 International Building Code (IBC) (International Code Council, Inc., 2014). The IBC design criteria are based on a target risk of structural collapse of 1 percent in 50 years. The soil 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 7 SHANNON ING , profile is assessed by assigning a site class definition. It is our opinion that based on the soil classification, i.e., very dense, the site can be classified as Site Class C. Seismic inputs are the short -period maximum spectra acceleration, Ss, and spectral acceleration at a period of one second, Si. Using the map provided in the IBC, which corresponds to Site Class B sites, the mapped values of Ss and Si are approximately 1.262 and 0.493g, respectively. The site coefficients for the given spectral acceleration values and site class C are 1.0 and 1.31 for Fa and F, respectively. Seismic hazards such as liquefaction and fault rupture are not present at the project site. 7.4 Lateral Earth Pressures and Retaining Walls Lateral earth pressures will act on portions of the building as well as on retaining walls. The magnitude and distribution of these lateral pressures will depend on many factors, including, but not limited to, the type of backfill, the method of backfill placement, level of backfill compaction, slope of backfill, drainage, and characteristics of the wall itself. If the wall is allowed to move at least 0.001 times the wall height, the wall is considered flexible and active earth pressures can be used. If the wall is considered to be inflexible then at -rest earth pressures must be used. The active and at -rest earth pressures, evaluated using an equivalent fluid unit weight, are estimated to be on the order of 30 and 50 pounds per cubic feet (pcf), respectively. The values given above assume a permanent wall structure, the ground surface behind the wall is level, and that proper drainage is installed to prevent the buildup of pore water pressure behind the wall. The total earth pressures should be analyzed for seismic loading conditions using a dynamic load increment equal to a percentage of the static earth force. The percentage load increase for seismic condition was developed to be consistent with a pseudo -static analysis using the Mononobe-Okabe equation for lateral earth pressures (Kramer, 1996) and a horizontal seismic coefficient of 0.2. The load increase for seismic conditions is recommended to be a uniformly distributed load equal to 8H, where H is the height of the wall. Note the seismic coefficient is not equal to the peak ground acceleration (PGA) expected to be encountered at the site in a design event. The PGA is experienced only a few times within the record of earthquake shaking, and the actual earthquake ground motion is cyclic in nature, not static. Values of the seismic coefficient are thus typically one-third to one-half the value of the PGA that may be experienced at the site during a design level event. We understand that rockery walls may be installed. Rock walls have been used in numerous locations around Puget Sound area primarily to provide erosion protection to cuts in stable 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 8 SHANNON ING , materials. Rockeries have also been used to retain fill slopes; however, this practice is not as prevalent. In our opinion, rockeries could be used to retain cut slopes made in dense to very dense native soil that are less than 6 feet high. Rockeries should be constructed in accordance with the recommendations shown in Figure 3. Rockeries could be used to retain fill slopes provided they are 5 feet high or less, or if they are reinforced. If used with a reinforced slope, the rockery would form a fagade or erosion protection facing on an otherwise stable slope. Rockeries that are used to retain fill slopes that are 5 feet high or less should be built in accordance with the recommendations shown in Figure 3. We recommend that the fill be built out beyond the planned wall location and then cut back. With this procedure, the fill can be fully compacted, as compared with the difficulty of compacting the edge of a fill slope. 7.5 Lateral Resistance Footings may resist lateral loads using a combination of base friction and passive pressure against the buried or embedded portion of the footings and buried wall. We recommend that base sliding resistance be determined using an allowable coefficient of friction of 0.7 for a concrete foundation founded on on -site glacial till or compacted structural fill. Passive earth pressures can be evaluated using an equivalent unit weight of 400 pcf. This value includes a factor of safety of 1.5. 7.6 Slope Stability The slope along the eastern perimeter of the property is mapped as a critical area by the City due to the steepness of the slope and the presence of wetlands. We recommend that the Madrona K-8 school footprint be set back at least 1.0 feet from the top of slope. While we did not observe active landsliding on this slope, the Edmonds Community Development Code requires that buildings or other structures constructed near an environmentally critical area maintain a setback of 15 feet from the edge of the critical area which in this case is the top of the slope (Edmonds, Wash., 2016). However, the code also allows for setbacks to be determined by a Geotechnical Engineering Report. In our opinion, after review of the subsurface conditions and the current condition of the slope, a setback of 10 feet would not cause an increased potential for landslides or surficial soil instability on the steep slope. In our opinion, buried utilities within this setback distance are acceptable and will not be at risk due to slope instability. We understand that dead or diseased tree removal is planned along the east, west, and south perimeter of the property near the top of the slopes. We made a site visit on September 20, 2016, 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 9 SHANNON ING , to observe the slope areas where tree removal is planned. In our opinion, the planned tree removal will not cause instability of the slope and the trees may be felled and chipped in -place. 7.7 Pavement Design Pavement analyses were conducted using the American Association of State Highway and Transportation Officials (AASHTO) method for flexible and rigid pavement design (AASHTO, 1993). The AASHTO method is a widely used empirical design procedure for the design of flexible and rigid pavement structures. It considers strength of the base course materials, traffic stresses, and the strength of the pavement subgrade. The pavement design life is assumed to be 20 years. 7.7.1 Traffic Load Average daily traffic counts, including delivery trucks, school buses, and occasional heavy vehicles such as fire trucks, were based on assumed conditions for similar projects. Assumed traffic volumes were then converted into equivalent single -axle loads by using equivalent load factors. We assume that there will not be a significant increase in traffic at this location, but did include a 1 percent growth factor in the design life traffic counts for our analysis. 7.7.2 Subgrade Conditions The subgrade conditions at the proposed pavement locations are medium dense, silty sand to silty sand with gravel fill suitable for pavement support. If loose or soft subgrade is observed during construction, we recommend that it be removed and replaced with at least 1 foot of compacted structural fill. A Resilient Modulus, MR, of 15,000 pounds per square inch is recommended for pavement design where existing medium dense fill and newly placed compacted structural fill are present. 7.8 Non -Porous Pavement Section Recommendations For support of the proposed parking and driveway areas we propose pavement section thicknesses shown in Table 1 below. Recommendations have been separated into lightly loaded and heavily loaded pavement sections. Lightly loaded pavement sections are assumed to be those that are utilized primarily by car and other passenger vehicle traffic. Heavily loaded pavement sections are assumed to be those that are utilized by heavy vehicles such as buses, delivery, and fire trucks. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 10 SHANNON ING , TABLE 1 RECOMMENDED MINIMUM PARKING LOT AND DRIVEWAY SECTION THICKNESSES ?" rnteut Jght -!:"Heavy' +- Pavement I,a er. ; Lodi I .trsdih " Asphalt 3 inches 4 inches Flexible Base Course 4 inches 6 inches Concrete 4 inches 6 inches Rigid Base Course 4 inches 4 inches Base course should correspond to crushed surfacing in accordance with the Washington State Department of Transportation (WSDOT) Standard Specifications (WSDOT, 2016). Placement, compaction, and material specification for crushed surfacing is discussed in Section 8.1 of this report. 7.9 Porous Pavement Section Recommendations 7.9.1 Grass Grid Pavers Grass grid pavers will be a proprietary product and should be designed in accordance with the manufacturer's recommendations. For design of the porous pavement sections, we recommend that the compacted subgrade be assumed to have a California Bearing Ratio of approximately 20. 7.9.2 Pervious Hot Mix Asphalt (HMA) and Concrete As we understand, porous pavement sections consisting of pervious HMA or concrete underlain by an underdrain are being considered within the fire lane to collect surface drainage. Pervious pavement consists of porous asphalt or concrete overlying a stone bed. For support of the proposed fire lane areas, we propose porous pavement section thicknesses shown in Table 2 below. TABLE 2 RECOMMENDED MINIMUM POROUS PAVEMENT SECTION THICKNESSES Pavement T Pmeiita `r Th>i Pervious HMA Porous Asphalt 5 inches Stone Bed 10 inches Rigid Porous Concrete 9 inches Stone Bed 12 inches 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 11 SHANNON ING , Please note that porous asphalt is susceptible to considerable wear due to heavy vehicle loading especially in vehicle turning areas. Rutting due to surface abrasion is known to occur between the wheel and the pavement during breaking and turning. Also note that pervious concrete pavement is sensitive to the means and methods used in. mix design and placement. We recommend following the American Concrete Institute (ACI) Specification for Pervious Concrete Pavement, ACI 522.1-13 for design and installation practices of porous concrete pavement systems (ACI, 2013). This specification covers materials, preparation, forming, placing, finishing, jointing, curing, and quality control of pervious concrete pavement. Provisions governing testing, evaluation, and acceptance of pervious concrete pavement are included. Pervious concrete pavement will require annual cleaning to maintain its infiltration function. We recommend vacuum cleaning once or twice a year (depending on conditions) with a regenerative sweeper and pressure washing as needed. 7.10 Pavement Sections Near Steep Slopes Pavements constructed near the steep slopes on the east and west perimeters of the property should have the same minimum pavement sections shown above in Table 1. Subsurface conditions encountered in the explorations indicate that the site is underlain by glacial till at relatively shallow depths, so slope stability is not an issue with regard to pavement construction. 7.11 Frost Susceptibility Frost -susceptible soil is regarded as having greater than 3 percent finer that 0.02 millimeter (mm). Soil with a fines content not exceeding 7 percent passing the No. 200 sieve, based on the minus 3/4-inch fraction, can normally be expected to have 3 percent or less finer than 0.02 turn. The current subsurface explorations indicate the subgrade soil has an average fines content of about 30 percent, which should be considered frost -susceptible. The measured frost depth during cold winters of 1949 and 1950 was about 15 inches near Edmonds, Washington. In accordance with the WSDOT Pavement Policy (WSDOT, 2015), pavement can be designed for frost protection by providing a pavement section that is equal to or thicker than half of the anticipated frost depth. The pavement section includes pavement and non -frost susceptible base course. In our opinion, the minimum recommended pavement sections presented in Table 1 above should provide adequate frost protection. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 12 SHANNON ING , 8.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS 8.1 Earthwork and Use of On -site Soils Fill placed beneath structures such as floor slabs, pavements, sidewalks, or backfill against footings should be structural fill. Structural fill should be placed and compacted upon native soil surfaces observed during construction by a geotechnical engineer or the engineer's representative. The fill soils encountered onsite generally contain sufficient fines to make them moisture -sensitive. In our opinion, on -site soils may be difficult to place and compact to adequate relative compaction levels, particularly during wet weather or in wet conditions. The on -site glacial till soils may be used as structural fill material provided the following conditions are met: ■ The soil is free from organics, debris, or other deleterious material. ■ The water content of the on -site soil at the time of compaction is close to its optimum as determined by a Modified Proctor Test (ASTM International [ASTM], 2012). ■ On -site soils used for fills and backfills that become wet and unstable after placement should be removed and replaced with suitable material. ■ Stockpiled on -site soils are protected when rainfall is anticipated in accordance with Section 2-09.3(1)E (WSDOT, 2016). If on -site soil becomes too difficult to compact or construction site space limitations prevent stockpiling, we recommend using imported, granular, structural backfill. Imported backfill should meet gradation requirements of the WSDOT Standard Specifications (WSDOT, 2016). Table 3 provides material specifications for various backfill applications. On -site soil not suitable for structural backfill could be used as backfill within landscaped areas. TABLE 3 IMPORTED BACKFILL SPECIFICATIONS BASED ON 2016 WASHINGTON STATE DEPARTMENT OF TRANSPORTATION STANDARD SPECIFICATIONS A ' lic�ti©n Maternal eifictt®n Structural Fill 9-03.14(1) Gravel Backfill for Walls 9-03.12(2) Gravel Backfill for Pipe Zone Bedding 9-03.12(3) Crushed Surfacing Base Course 9-03.9(3) Structural fill should be placed in horizontal, uniform lifts and compacted to a dense and unyielding condition, and to at least 95 percent of the Modified Proctor maximum dry density (ASTM D155'7 [ASTM, 2012]). Subgrades to receive structural fill should be dense and unyielding and should be evaluated by the geotechnical engineer prior to the placement of fill. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 13 SHANNON ING , Preparation of subgrades should be in accordance with Section 2-06 of the WSDOT Standard Specifications (WSDOT, 2016). In general, the thickness of soil layers before compaction should not exceed 1.0 inches for heavy equipment compactors or 6 inches for hand -operated mechanical compactors. The most appropriate lift thickness should be determined in the field using the Contractor's selected equipment and fill, and verified with in situ soil density testing (nuclear gauge methods). All compacted surfaces should be sloped to drain to prevent ponding. Structural fill placement operations should be observed and evaluated by an experienced geotechnical engineer or technician. 8.2 Pervious Pavement Materials We recommend the following material specifications for pervious pavement: Porous Bituminous Asphalt. The bituminous surface course shall be a bituminous mix of 6 percent by weight dry aggregate. Porous asphalt uses the same mixing and application equipment as for conventional asphalt. A neat asphalt binder modified with an elastomeric polymer is recommended. The polymer modified asphalt binder shall be heat and storage stable. Aggregate shall be minimum 90 percent crushed material and have a recommended gradation of: U.S. Standard Sieve Size Percent Passing 1/2 (12.5 millimeter [mm]) 100 % (9.5 mm) 92 to 98 4 (4.75 mm) 34 to 40 8 (2.36 mm) 14 to 20 16(1.18mm) 7to13 30 (0.60 mm) 0 to 4 200 (0.075 mm) 0 to 2 ■ Stone Bed. Stone bed course aggregate shall be a crushed, %- to 1-inch uniformly graded coarse aggregate conforming to AASHTO size number 67 (or equivalent). Stone bed aggregate shall be placed immediately after approval of subgrade preparation. Clean (washed) stone bed aggregate should be in maximum 8-inch lifts. Each layer shall be compacted to a dense condition with a smooth drum roller. 8.3 Construction and Maintenance Considerations for Pervious Pavement Pervious pavement is susceptible to damage and clogging during construction and afterward. We recommend that the construction be undertaken in such a way as to prevent: 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 14 SHANNON ING , • Compaction of Subgrade: If the existing subgrade under the stone bed is to be used for infiltration, then the subgrade shall not be compacted or subject to excessive construction equipment traffic prior to stone bed placement. Contamination of Stone Bed and Pervious Pavement with Sediment and Fines: Control of sediment is critical and rigorous installation and maintenance of erosion and sediment control measures is required to prevent sediment deposition on the pavement surface or within the stone bed. Staging, construction practices, and erosion and sediment control must all be taken into consideration when using pervious pavements. Due to the nature of construction sites, pervious pavement and other infiltration measures should be installed at the end of the construction period. All pervious pavement installations must have a backup method for water to enter the stone storage bed in the event that the pavement fails or is altered. In uncurbed lots, this backup drainage may consist of an unpaved 2-foot-wide stone edge drain connected directly to the bed between the wheel stop. In curbed lots, inlets with 12-inch sediment traps may be required at low spots. Backup drainage elements will ensure the functionality of the infiltration system if the pervious pavement is compromised. These systems should be designed by the project civil engineer. 8.4 Temporary and Permanent Excavation Slopes Safe temporary excavations are the responsibility of the Contractor and depend on the actual site conditions at the time of construction. Temporary cuts are the responsibility of the Contractor and should comply with applicable Occupational Safety and Health Administration (OSHA) and Washington Industrial Safety and Health Administration Standards. For trench safety purposes, the fill material at the site should be considered as OSHA "Class U material, which requires side slopes no steeper than 1.5 Horizontal to 1 Vertical (1.5H:1V). Cut slopes during construction, particularly during wet weather, should be compacted to achieve a dense surface and covered with plastic sheeting to reduce erosion. All traffic and/or construction equipment loads should be set back from the edge of the cut slopes a minimum of 5 feet. Excavated material, stockpiles of construction materials, and equipment should not be placed closer to the edge of any excavation than the depth of the excavation, unless the excavation is shored and such materials are accounted for as a surcharge load on the shoring system. Permanent slopes excavated in dense native soils should be no steeper than 1.5H:IV. We recommend that permanent slopes in on -site fill materials be no steeper than 2H:IV. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 15 SHANNON ING , 8.5 Erosion Control Erosion control for the site will include the Best Management Practices incorporated in the civil design drawings and may incorporate the following recommendations: ■ Limit exposed cut slopes. ■ Route surface water through temporary drainage channels around and away from exposed slopes. ■ Use silt fences, straw, and temporary sedimentation ponds to collect and hold eroded material on the site. ■ Seed or plant vegetation on exposed areas where work is completed and no buildings are proposed. ■ Retain existing vegetation to the greatest possible extent. 8.6 Construction Drainage Even during dry weather, we recommend that site drainage measures be incorporated into the project construction. Perched water in the excavations (if present) and surface runoff can be controlled during construction by careful grading practices. Typically, these include the construction of shallow perimeter ditches or low earthen berms, and the use of temporary sumps to collect runoff and prevent water from damaging slopes and exposed subgrades. All collected water should be directed, under control, to a positive and permanent discharge system. The site will need to be graded at all times to facilitate drainage and minimize the ponding of water. 8.7 Subsurface Drainage We recommend installing a subdrain system along the outside of the perimeter footings to prevent pooling of stormwater against the building foundations. The subdrain system should consist of a perforated or slotted, 4-inch (minimum) -diameter plastic pipe bedded in %-inch to No. 8 size washed pea gravel. Where a perforated or slotted drain pipe from a subdrain system connects into a tightline, we recommend that a low permeability concrete collar or dam be placed along the first 2 feet of the tightline to force all water into the tightline. Cleanouts should be provided at convenient locations along all drain lines, such as at the building corners. 8.8 Utilities In general, utilities at the site can be installed within the existing site soils, provided they are not underlain by extremely loose, soft, or organic materials. Maintaining safe utility excavations is 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 16 SHANNON ING , the responsibility of the Contractor. Conventional excavation equipment can be used to excavate the soils. The utility trenches should be backfilled as noted in Section 8.1. We recommend utilities placed under the roadway have a minimum cover of 2 feet from the crown of the pipes or conduits to the top of the pavement subgrade. Catch basins, utility vaults, and other structures installed flush with the pavement should be designed and constructed to transfer wheel loads to the base of the structure. 8.9 Wet Weather Earthwork In the project area, wet weather generally begins about mid -October and continues through about May, although rainy periods may occur at any time of the year. Therefore, it would be advisable to schedule earthwork during the dry weather months of June through mid -October. Most of the soils at the site contain sufficient fines to produce an unstable mixture when wet. Such soils are highly susceptible to changes in water content, and may become muddy, unstable, and difficult to compact if their moisture content significantly exceeds the optimum. Performing earthwork during dry weather would reduce these problems and costs associated with rainwater, trafficability, and handling of wet soil. However, should wet weather/wet condition earthwork be unavoidable, the following recommendations are provided: Earthwork should be accomplished in small sections to minimize exposure to wet conditions. That is, each section should be small enough such that the removal of unsuitable soils and the placement and compaction of clean structural fill can be accomplished on the same day. If there is to be traffic over the exposed subgrade, the subgrade should be protected with a compacted layer (generally 8 inches or more) of clean crushed rock. ■ Fill material should consist of clean, well -graded granular soil, of which not more than 5 percent by dry weight passes the No. 200 mesh sieve, based on wet sieving the fraction passing the 3/4-inch mesh sieve. The fines should be non -plastic. ■ The ground surface in the construction area should be sloped and sealed with a smooth -drum roller to promote the rapid runoff of precipitation, to prevent surface water from flowing into excavations, and to prevent ponding of water. ■ No soil should be left uncompacted and exposed to moisture. A smooth -drum vibratory roller, or equivalent, should be used to seal the ground surface. Soils which become too wet for compaction should be removed and replaced with clean granular soil. ■ Excavation and placement of structural fill material should be observed on a full-time basis by a geotechnical engineer or his/her representative, experienced in wet -weather earthwork, to determine that all work is being accomplished in accordance with the project plans and specifications, and our recommendations. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 17 SHANNON ING , • Covering of work areas, soil stockpiles, or slopes with plastic; sloping, ditching, and installing sumps; dewatering; and other measures should be employed, as necessary, to permit proper completion of the work. Bales of straw and/or geotextile silt fences should be aptly located to control soil movement and erosion. Grading and earthwork should not be accomplished during periods of heavy, continuous rainfall. 8.10 Plans Review and Construction Observation We recommend that Shannon & Wilson be retained to review those portions of the plans and specifications that pertain to the geotechnical aspects of the project to determine if they are consistent with our recommendations. We also recommend that we be retained to observe the geotechnical aspects of construction, particularly the pavement and shallow footing subgrade preparation, drainage installation, and earthwork (structural fill placement and compaction). This observation would allow us to witness the subsurface conditions as they are exposed during construction and to determine that the work is accomplished in accordance with our recommendations. 9.0 LIMITATIONS This report was prepared for the exclusive use of the Edmonds School District No. 15 for specific application to the design of the Madrona K-8 School project at this site as it relates to the geotechnical aspects discussed in this report. The data and report should be provided to prospective contractors and/or the Contractor for factual information only. Our judgments, conclusions, and interpretations presented in the report should not be construed as a warranty of subsurface conditions and should not be relied upon by prospective contractors. Construction period observation by our firm is necessary to confirm recommendations and interpretations made in this report. The analyses, conclusions, and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical engineering principles and practice in this area at this time. No other warranty, either express or implied, is made. The analyses, conclusions, and recommendations contained in this report are based on site conditions as they existed during our site visits and explorations, and further assume that the explorations are representative of the subsurface conditions throughout the site; i.e., the subsurface conditions everywhere are not significantly different from those disclosed by the explorations. If subsurface conditions different from those described in this report are observed 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 18 SHANNON 6WILSON, or appear to be present during construction, we should be advised at once so that we can review these conditions and reconsider our recommendations, where necessary. If there is a substantial lapse of time between the submission of this report and the start of work at the site, or if conditions have changed because of natural causes or construction operations at or adjacent to the site, we recommend that this report be reviewed to determine the applicability of the conclusions and recommendations, considering the changed conditions and time lapse. Unanticipated soil conditions are commonly encountered and cannot be fully determined by merely taking soil samples or completing test pits. Such unexpected conditions frequently require that additional expenditures be made to attain a properly constructed project. Therefore, some contingency fund is recommended to accommodate such potential extra costs. Shannon & Wilson has prepared the enclosed Appendix D, "Important Information About Your Geotechnical/Environmental Proposal," to assist you and others in understanding the use and limitations of our proposals. Kevin Wood Geotechnical Staff Martin W. Page, PE, LEG Vice President Geotechnical Engineer, LEED AP, DBIATM KJW:MWP/kjw 21-1-22082-004-R 1 f/tvp/tkn 21-1-220 82-004 19 SHANNON ING , 10.0 REFERENCES American Association of State Highway and Transportation Officials (AASHTO), 1993, AASHTO guide for design of pavement structures, Washington, D.C., AASHTO, 2 v. American Concrete Institute (ACI), 2013, Specification for pervious concrete pavement (ACI 522.1): Farmington Hills, Mich., American Concrete Institute, ACI 522.1-13, 7 p. ASTM International (ASTM), 2012,.Standard test methods for laboratory compaction characteristics of soil using modified effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3)), D1557- 1.2e1: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 14 p., available: www.astm.org. Edmonds, Wash., 2016, Natural resources: Edmonds, Wash., Edmonds City Code and Development Code Title 23, available: htt1�://wwwacode�ulishin.com1WA/Edmonds/. International Code Council, Inc., 2014,.International building code 2015: Country Club Hills, Ill., International Code Council, Inc., 700 p. Kramer, S.L., 1996, Geotechnical earthquake engineering: Upper Saddle River, N.J., Prentice Hall, 653 p. Shannon & Wilson, Inc. (Shannon & Wilson), 2016, Hydrogeologic report, new Madrona K-8 project, Edmonds, Washington: Report prepared by Shannon & Wilson, Inc., Seattle, Wash., 21-1-22082-003, for Edmonds School District No. 15, Edmonds, Wash., November. Troost, K.G., and Booth, D.B., 2008, Geology of Seattle and the Seattle area, Washington, in Baum, R.L., Godt, J.W. and Highland, L.M., eds., Landslides and Engineering Geology of the Seattle, Washington, Area: Geologic Society of America Reviews in Engineering Geology XX, p. 1-35. Washington State Department of Transportation (WSDOT), 2015, WSDOT Pavement Policy: Olympia, Washington, WSDOT, 131 p., available: ham://www.wsdot,wao gov/NRlydonl�res/EF9AAC9E-6323-4B09-A3D 1- DD2E2C905D02/0/WSDOTPave entPolicyJune20l5.p f Washington Department of Transportation (WSDOT), 2016, Standard specifications for road, bridge, and municipal construction: Olympia, Wash., WSDOT, Manual M 41-10, 1 v., January, available: http:/Iwww.wsdot.wa.govlPublicationslManualslM4I-l0.htm. 21-1-22082-004-R1 f.docx/wp/lkn 21-1-22082-004 20 Filename: J:\211\22082-004\2-1-22084-004 Fig 2 - Site Plan.dwg Layout: Layout Date: 10-04-2016 Login: SAC co 0 0 0 H = 6 Ft. Max. 4 Medium 12" Min. dense to Very Dense Native Soil 6" Min. 16" Min. Width for Top Rock —� H/3 Min. Width for Base Rock All loose soil at rockery foundation subgrade should be overexcavated down to medium dense to very dense soil and replaced with compacted backfill as described above. The excavation shall be kept free of water. The prepared foundation subgrade shall be evaluated by a soils engineer prior to placement of rock. If•IILIII►U[II]JimingEel -kIma 10141 / Rock shall be sound and have a minimum density of 160 pounds per cubic foot. Not to Scale Ditch Drain to Appropriate Outlets 8" Compacted Native or Imported Soil (Impervious Surface Layer) Stable Excavation Slope in Very Dense Native Soil (Contractor's Responsibility) Opening Chinked with 2 to 4-inch Quarry Spalls Very Dense Undisturbed Native Soil Backfill Clean, well -graded sand and gravel or crushed rock, 2-inch maximum size, 40 to 60% gravel, less than 5% fines (passing #200 sieve). Fines shall be non -plastic. Compact in 4" lifts with minimum of 4 coverages by hand -operated tamper. Compact to at least 92% of Modified Proctor maximum dry density (ASTM D-1557). Backfill and rock placement should be built up together. 6" Diameter Slotted Pipe Bedded in washed 3/8" to No.8 sieve size pea gravel (6" cover around pipe), sloped to drain and connected by tightline to storm drain outfall or other appropriate outlets. No fabric around pipe. Maximum slot width is 1/8". 1.6 0.8 Transducer 1.4 __ Reading (Feet) _ -0.7 -tt�,ot} tf tqr, - Manual Reading - 1.2 Oil �sn��,� � _ (Feet) 0.6 0 .... _ .... 10 Inflow Rate (GPM) ._. �3 - LL 0 1 "}tfr 0.5 Residual water -'ifir=t t,t . .. perched on silt o muck at test 0 0'8 (` ��{`' pit bottom. Soils 0.4 0 m - -�, - immediately below jr,, -, - {p tx{ were moist. c,> 0.6 0.3 CU Q 41 .. .... _0.4Transducer #4 was inside a stilling tube. 4i ytt}i r, Approx. 5" mud accumulated and t hetube bottomby end of to test. ,t 0.2 Water level in tube fell below 0.1 .. - - - surroundin ding mud level. it { _ O4-0 0 200 400 600 800 1000 1200 1400 Time Since Start of Saturation (Minutes) ► W 1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 10:31 to 19:28. Approximate grade elevation 444.5 feet (NAVD88). Test pit floor depth 3.8 feet deep. A flow rate of 0.75 to 0.12 gallons per minute (gpm) was maintained for the initial saturation period. During the last hour of saturation, the flow rate was 0.11 gpm, with a water level of 14.25 inches above the test pit bottom. Test test pit drained from 19:28 on 7/28/16 to about 6:00 on 7/29/16. Test pit dimensions during the PIT were approximately 2.4 feet (north -south) by 5.5 feet (east - west), or 13.2 square feet. The test pit was over -excavated on 7/29/16 (starting at 8:30) to 10 feet deep. No sign of water was observed during over -excavation. PIT Results -Figure 4 PIT-1 Plot-9/28/2016-pvh Time Since Start of Saturation (Minutes) ►9W 1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 11:28 to 18:53. Approximate grade elevation 456 feet (NAVD88). Test pit floor depth 3.3 feet deep. A flow rate of 3.75 to 0.04 gallons per minute (gpm) was maintained for the initial saturation period. During the last hour of saturation, the flow rate was 0.04 gpm, with a water level of 15.75 inches above the test pit bottom. Test test pit drained from 18:53 on 7/28/16 to about 11:50 on 7/29/16. Test pit dimensions during the PIT were approximately 2.1 feet (north -south) by 6.3 feet (east - west), or 13.2 square feet. The test pit was over -excavated on 7/29/16 to 4.5 feet deep. The back hoe scooped out the residual PIT water and found that it had been perched on moist till. PIT Results -Figure 5 PIT-2 Plot-9/28/2016-pvh 1.6 0.8 1.4 - _ _ ___ 0.7 ' Rir s, iFt tii i}#}d} 2i! FF iP2Y .-.. Stt'4L ... _ .._ . .... 5+<F.,, 314))Y. Y, t{ cS(,{#,;lft r }tf +Yf}f}ft,.liitti,l $lis -- tr 1„{r(ttt#,risiP3�{tji()tft+`.`#ttt7ititritlt t2l;F��ti3 ri.,?�tiiiF# (3) .. iSi�i,Y}„ f . 1.2 0.6 o Cn r,; TTransduuc(er a� o Reading (Feet) E 0.8 0.4 0 o y Y� Manual h Reat'ng C m + (Feet) -, �. 0.3 Q �. + -. - - - Inflow Rate (GPM) - Residual water CU remaining in test pit z 0.4 over 16 hours after- 0.2 - 1 T 1 T - -. __ ow. fl . ceasing infl � _ T -. 0 2 0.1 - 4, - OL-------------- 1 U J I I_—i J i J ._ 0 0 200 400 600 800 1000 1200 1400 Time Since Start of Saturation (Minutes) ► W 1. This small-scale pilot infiltration test (PIT) was performed on 7/28/16. Water was added from 13:07 to 20:38. Approximate grade elevation 450 feet (NAVD88). Test pit floor depth 2.9 feet deep. A flow rate of 3.33 to 0.06 gallons per minute (gpm) was maintained for the initial saturation period. During the last hour of saturation, the flow rate was 0.06 gpm, with a water level of 16.2 inches above the test pit bottom. Test test pit drained from 20:38 on 7/28/16 to about 12:36 on 7/29/16 when we removed the transducer. Inital ponded area dimensions during the PIT were approximately 2.2 feet (east -west) by 8 feet (north -south), or 17.6 square feet. Due to sidewall slumping during the falling head test period, the final ponded dimensions were approximate 2.5 feet by 8.2 feet (20.5 square feet). The test pit was over -excavated on 7/29/16 to 3.4 feet deep. The back hoe scooped out the residual PIT water and found that it had been perched on moist till. PIT Results -Figure 6 PIT-3 Plot-9/28/2016-pvh SUBSURFACE EXPLORATIONS 21-1-22082-004 PARTICLE SIZE DEFINITIONS Shannon & Wilson, Inc. (S&W), uses a soil identification system modified from the Unified Soil Classification System (USCS). Elements of the USCS and other definitions are provided on this and the following pages. Soil descriptions are based on visual -manual procedures (ASTM D2488) and laboratory testing procedures (ASTM D2487), if performed. S&W INORGANIC SOIL CONSTITUENT DEFINITIONS CONSTITUENT s -------------- Major FINE-GRAINED SOILS (50% or more fines)' __ __ -- Silt, Lean Clay, Elastic Silt, or Fat Clay COARSE -GRAINED SOILS (less than 50%fines' _ - Sand or Gravely Modifying (Secondary) 30% or more More than 12% Precedes major coarse -grained: fine-grained: constituent Sandy or Gravelly' Silty or Clayey3 15% to 30% 5% to 12% coarse -grained: fine-grained: Minor with Sand or with Silt or With Gravel ° with Clay Follows major 30 or more total /o constituent coarse -grained and 15% or more of a lesser coarse- second coarse - grained constituent grained constituent: is 15% or more: with Sand or with Sand or with Gravels with Gravels 'All percentages are by weight of total specimen passing a 3-inch sieve 2The order of terms is: Modifying Major with Minor. 'Determined based on behavior. °Determined based on which constituent comprises a larger percentage 'Whichever is the lesser constituent. MOISTURE CONTENT TERMS Dry Absence of moisture, dusty, dry to the touch Moist Damp but no visible water Wet Visible free water, from below water table STANDARD PENETRATION TEST (SPT) SPECIFICATIONS 140 pounds with a 30-inch free fall. Rope on 6- to 10-inch-diam. cathead 2-1/4 rope turns, > 100 rpm NOTE: If automatic hammers are used, blow counts shown on boring logs should be adjusted to account for efficiency of hammer. Sampler: 10 to 30 inches long Shoe I.D. = 1.375 inches Barrel I.D. = 1.5 inches Barrel O.D. = 2 inches N-Value: Sum blow counts for second and third 6-inch increments. Refusal: 50 blows for 6 inches or less; 10 blows for 0 inches. NOTE. Penetration resistances (N-values) shown on', boring logs are as recorded in the field and have not been corrected for hammer efficiency, overburden, or other factors. DESCRIPTION SIEVE NUMBER AND/OR APPROXIMATE SIZE FINES < #200 (0.075 mm = 0.003 in.) SAND Fine #200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.) Medium #40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.) Coarse #10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.) GRAVEL Fine #4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.) Coarse 3/4 to 3 in. (19 to 76 mm) COBBLES 3 to 12 in. (76 to 305 mm) BOULDERS > 12 in. (305 mm) RELATIVE DENSITY / CONSISTENCY COHESIONLESS SOILS COHESIVE SOILS N, SPT, RELATIVE N, SPT, RELATIVE BLOWS/FT. DENSITY BLOWS/FT. CONSISTENCY < 2 Very soft < 4 Very loose 4-10 Loose 2-4 Soft 10-30 Medium dense 4-8 Medium stiff 30-50 Dense 8 - 15 Stiff > 50 Very dense 15 - 30 Very stiff > 30 Hard MBentonite Cement Grout FM Bentonite Grout Bentonite Chips Silica Sand E] Perforated or Screened Casing %o a" Surface Cement Seal Asphalt or Cap - Slough Inclinometer or Non -perforated Casing mVibrating Wire Piezometer PERCENTAGES TERMS'' z Trace < 5% Few 5 to 10% Little -------------- _ Some 15 to 25% -- - 30 to 45% Mostly 50 to 100% 'Gravel, sand, and fines estimated by mass. Other constituents, such as organics, cobbles, and boulders, estimated by volume. 2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org. MAJOR DIVISIONS GROUP/GRAPHIC TYPICAL IDENTIFICATIONS SYMBOL GW .'• Well -Graded Gravel; Well -Graded Gravel with Sand Gravel GP Poorly Graded Gravel; Poorly Graded Gravels (less than 5% fines) (more than 50% o Gravel with Sand of coarse fraction retained on No. 4 sieve) Silty or Clayey GM Silty Gravel; Silty Gravel with Sand Gravel GC i Clayey Gravel; Clayey Gravel with COARSE- (more than 12% fines) GRAINED Sand SOILS SW Well -Graded Sand; Well -Graded Sand (more than 50% retained on No. 200 sieve) Sand with Gravel (less than 5% fines) Sp Poorly Graded Sand; Poorly Graded Sands Sand with Gravel (50% or more of coarse fraction passes the No. 4 Silty or SM Silty Sand; Silty Sand with Gravel sieve Clayey Sand (more than 12% fines) SC ✓ Clayey Sand; Clayey Sand with Gravel ML Silt; Silt with Sand or Gravel; Sandy or Gravelly Silt Inorganic CL 0010/11/ Lean Clay; Lean Clay with Sand or Silts and Clays (liquid limit less Gravel; Sandy or Gravelly Lean Clay than 50) Organic OL — — Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or FINE-GRAINED SOILS — — Gravelly Organic Silt or Clay (50% or more MH Elastic Silt; Elastic Silt with Sand or passes the 200 sieve)) Gravel; Sandy or Gravelly Elastic Silt Inorganic CH Fat Clay; Fat Clay with Sand or Silts and Clays (liquid limit 50 or Gravel; Sandy or Gravelly Fat Clay more) Organic Silt or Clay; Organic Silt or Organic OH Clay with Sand or Gravel; Sandy or / Gravelly Organic Silt or Clay HIGHLY- Primarily organic matter, dark in PT Peat or other highly organic soils (see ORGANIC SOILS color, and organic odor ASTM D4427) NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in. NOTES Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand with Silt) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Graphics shown on the logs for these soil types are a combination of the two graphic symbols (e.g., SP and SM). Borderline symbols (symbols separated by a slash, i.e., CL/ML, Lean Clay to Silt, SP-SM/SM, Sand with Silt to Silty Sand) indicate that the soil properties are close to the defining boundary between two groups. Poorly Graded Narrow range of grain sizes present or, within the range of grain sizes present, one or more sizes are missing (Gap Graded). Meets criteria in ASTM D2487, if tested. Well -Graded Full range and even distribution of grain sizes present. Meets criteria in ASTM D2487, if tested. CEMENTATION TERMS' Weak Crumbles or breaks with handling or slight finger pressure. Moderate Crumbles or breaks with considerable finger pressure. Strong Will not crumble or break with finger pressure. DESCRIPTION APPROX. PLASITICITY VISUAL -MANUAL CRITERIA INDEX RANGE Nonplastic A 1/8-in. thread cannot be rolled < 4 at any water content. Low A thread can barely be rolled and 4 to 10 a lump cannot be formed when drier than the plastic limit. Medium A thread is easy to roll and not 10 to 20 much time is required to reach the plastic limit. The thread cannot be rerolled after reaching the plastic limit. A lump crumbles when drier than the plastic limit. High It takes considerable time rolling > 20 and kneading to reach the plastic limit. A thread can be rerolled several times after reaching the plastic limit. A lump can be formed without crumbling when drier than the plastic limit. Mottled Irregular patches of different colors. Bioturbated Soil disturbance or mixing by plants or animals. Diamict Nonsorted sediment; sand and gravel in silt and/or clay matrix. Cuttings Material brought to surface by drilling. Slough Material that caved from sides of borehole. Sheared Disturbed texture, mix of strengths. Angular Sharp edges and unpolished planar surfaces. Subangular Similar to angular, but with rounded edges. Subrounded Nearly planar sides with well-rounded edges. Rounded Smoothly curved sides with no edges. Flat Width/thickness ratio > 3. Elongated Length/width ratio > 3. ATD At Time of Drilling Diam. Diameter Elev. Elevation ft. Feet FeO Iron Oxide gal. Gallons Horiz. Horizontal HSA Hollow Stem Auger I.D. Inside Diameter in. Inches lbs. Pounds MgO Magnesium Oxide mm Millimeter MnO Manganese Oxide NA Not Applicable or Not Available NP Nonplastic O.D. Outside Diameter OW Observation Well pcf Pounds per Cubic Foot PID Photo -Ionization Detector PMT Pressuremeter Test ppm Parts per Million psi Pounds per Square Inch PVC Polyvinyl Chloride rpm Rotations per Minute SPT Standard Penetration Test USCS Unified Soil Classification System qu Unconfined Compressive Strength VWP Vibrating Wire Piezometer Vert. Vertical WOH Weight of Hammer WOR Weight of Rods Wt. Weight Interbedded Alternating layers of varying material or color with layers at least 1/4-inch thick; singular: bed. Laminated Alternating layers of varying material or color with layers less than 1/4-inch thick; singular: lamination. Fissured Breaks along definite planes or fractures with little resistance. Slickensided Fracture planes appear polished or glossy; sometimes striated. Blocky Cohesive soil that can be broken down into small angular lumps that resist further breakdown. Lensed Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay. Homogeneous Same color and appearance throughout. 'Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org. 2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A Geotechnical Report New Madrona K-8 Project Edmonds, Washington October 2016 21-1-22082-004 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants www.astm.org. Total Depth: 16.5 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: - 449 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Asphalt_ ............................................................... 0.4 Dense, red -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; 2 few organics. Topsoil/Weathered Glacial Till :.: % 4 4.5 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to T angular gravel; fine to coarse sand; nonplastic 21 6 94/9`" fines; diamict. Glacial Till 3 m 8 L 0 90/10" 0 10 z a 088/10" O c 0 z 12 5� 50/4^ 14 - Moist to wet below about 15 feet. 6 :. 16 16.5 BOTTOM OF BORING COMPLETED 7/26/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-2 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-2 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.9 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 447.5 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Asphalt_ ............................................................... 0.4 Dense, gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; 2 nonplastic fines; diamict. Weathered Glacial Till 4 4.5 Very dense, gray -brown, Silty Sand (SM) to Silty Sand with Gravel (SM); moist; fine, z� 50/6" subrounded to subangular gravel; fine to 6 coarse sand; nonplastic fines; diamict. Glacial Till - Diamict pockets from 7.5 to 9 feet. 8 s c c O 10 a1 N 50/6" O 0 z 12 T 51 50/5" 14 - Moist to wet below about 15 feet. 6� 50/5" 15.9 16 BOTTOM OF BORING COMPLETED 7/26/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-3 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-3 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.8 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: - 445 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Asphalt_ ___ ________ _________ _________ _________________ 0.4 Medium dense, brown, Silty Sand (SM) to Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to angular gravel; fine to coarse 2 sand; nonplastic fines; trace to few organics; trace diamict pockets below about 7 feet. Fill 4 v` ' 2 6 8 _ s c 9'5 Very dense, gray -brown, Silty Sand (SM) to Silty Sand with Gravel (SM); moist; fine, z 10 subrounded to subangular gravel; fine to 4 a 90 0 coarse sand; nonplastic fines; diamict. O Glacial Till Z 12 5 78 14 a. s� 50/3" 15 8 16 BOTTOM OF BORING COMPLETED 7/26/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-4 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-4 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 16 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 447 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Topsoil. 0.5 Medium dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to angular gravel; fine to coarse sand; nonplastic 2 fines; trace organics. Fill 4 4.5 Loose, red -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; 2 6 trace organics. Topsoil/Weathered Glacial Till 7.0 Dense to very dense, gray brown, Silty Sand • (SM) to Silty Sand with Gravel (SM); moist; 3 m 8 fine, subrounded to subangular gravel; fine to 0 coarse sand; nonplastic fines; diamict. Glacial Till o - Slight iron oxide staining from 7 to 9 feet. 10 41 50/5° 0 0 z 12 s� 83/9" 14 - Moist to wet below about 15 feet. 061 50/6" 16.0 16 BOTTOM OF BORING COMPLETED 7/26/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-5 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-5 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.9 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 455 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Medium dense to very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; diamict. 2 Weathered Glacial Till of 4 2 6 8 3 c 9'0 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to 10 angular gravel; fine to coarse sand; nonplastic z fines; diamict. a a 68l11" 0 Glacial Till 0 z 12 51 84/10" 14 6� 50/5" 15.9 16 BOTTOM OF BORING COMPLETED 7/25/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-6 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-6 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.9 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 454 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Asphalt. 0•2 Medium dense, brown, Silty Sand (SM); moist; few fine, subrounded to subangular gravel; fine to coarse sand; nonplastic to low plasticity 2 fines; diamict; trace organics. Topsoil/Weathered Glacial Till 4 4.5 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded 2 50/3" to subangular gravel; fine to coarse sand; 6 nonplastic fines. Glacial Till 3_ 50/5^ 8 0 0 a 10 a. 4 � 50I4`" 0 0 z 12 T s1 50/5" 14 - Trace pockets of poorly graded sand with silt s� 50/5" below about-1 5 feet --- --------- - 15.9 16 BOTTOM OF BORING COMPLETED 7/26/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-7 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-7 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.8 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: - 456 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Asphalt. 0•2 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to angular gravel; fine to coarse sand; 2 nonplastic fines; diamict. Glacial Till 50/3„ 4 2� 50/5" 6 3� $ c c O 10 L 4]:a 50I3" a 0 0 z 12 - Gray below about 12 feet. 5I 50/2" 14 6� 50/4" 15 8 16 BOTTOM OF BORING COMPLETED 7/25/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-8 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-8 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.5 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: - 456 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Topsoil. 0.5 Dense to very dense, brown and gray, Silty Sand with Gravel (SM); dry to moist; fine to coarse, subrounded to angular gravel; fine to 2 coarse sand; nonplastic fines; trace organics; diamict pockets. Fill/Weathered Glacial Till 4 2 6 78 7'0 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded $ 91/11" to subangular gravel; fine to coarse sand; 3 m c nonplastic fines; diamict. Glacial Till `- 0 10 z 41 2 62 0 0 z 12 - Few pockets of poorly graded, fine to medium sand with silt pockets below about 5� 50/4" 12 feet; moist to wet from about 12 to 14 feet. 14 15.5 ° s= 50/6" BOTTOM OF BORING COMPLETED 7/25/2016 16 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-9 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-9 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 15.8 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 454.5 ft, Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Topsoil. 0.5 Medium dense, brown, Silty Sand (SM); dry to moist; few fine, subrounded to subangular gravel; fine to medium sand; nonplastic fines; 2 diamict pockets; trace organics. Fill 4 - Roots at about 5 feet. 2 6 7'0 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded $ to angular gravel; fine to coarse sand; . .e 3T nonplastic fines; diamict. Glacial Till `- - Mottled orange and gray -brown with pockets a 10 of iron oxide staining from 7 to 9 feet. 41 N 50/51, 0 0 z 12 5T 50/3" 14 a. 6T 50/4" 15.8 16 BOTTOM OF BORING COMPLETED 7/25/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-10 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-10 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 16.4 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 456 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Topsoil. 0.5 Dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; 2 diamict. Weathered Glacial Till 4 4.5 Very dense, gray -brown, Silty Sand (SM) to Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to 2 6 $4l11" coarse sand; nonplastic fines; diamict. Glacial Till 3 m 8 62 0 c 10 a1 N 50/6tt O 0 z 12 T 51 50/5" 14 s 85/5" 16 16.4 BOTTOM OF BORING COMPLETED 7/25/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-11 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-11 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal Total Depth: 16.3 ft. Northing: Drilling Method: Hollow Stem Auger Hole Diam.: 6 in. Top Elevation: — 456 ft. Easting: Drilling Company: Holocene Drilling Rod Diam.: 2-inch Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Diedrich D-50 Hammer Type: Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a 4� PENETRATION RESISTANCE (blows/foot) Refer to the report text for a proper understanding of the Q E Q t cz A Hammer Wt. & Drop: 140 Ibs / 30 inches subsurface materials and drilling methods. The stratification Q E o 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Topsoil. 0.5 Medium dense, brown, Silty Sand with Gravel (SM); dry to moist; fine, subrounded to subangular gravel; fine to medium sand; 2 nonplastic fines; trace organics. Fill 4 4.5 Very dense, gray -brown, Silty Sand with Gravel (SM); moist; fine, subrounded to J. subangular gravel; fine to coarse sand; :. 2 6 nonplastic fines; diamict. Glacial Till - Trace organics from about 4.5 to 8.5 feet. TT 31 m $ c c O 10 e 41 L 50/51. 0 o z 12 A. sI 50/2° 14 '. s� 90/9° 16.3 16 BOTTOM OF BORING COMPLETED 7/25/2016 18 0 20 40 60 LEGEND * Sample Not Recovered O % Fines (<0.075mm) Z 2.0" O.D. Split Spoon Sample • % Water Content Geotechnical Report New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF BORING B-12 September 2016 21-1-22082-004 SHANNON & WILSON, INC. FIG. A-12 Geotechnical and Environmental Consultants REV 3 - Approved for Submittal 22 r 22 ,_ 3',4 2 1 22. . 00 4 T"Ps . "ev,, ,�., tKl: 0 ., 2 . i3 Aulhor a"aG =111SHANNON&WILSONTAL N.INC JOB NO: 21-1-22082-004 DATE: 7-28-16 to LOCATION: See Site and Exploration Plan GEOTEC-LOG OF TEST PIT PIT-1 PROJECT: Madrona K-8 7-29-16 _0c a u Sketch of North Pit Side Surface Elevation: Approx. 445 Ft. SOIL DESCRIPTION 0 m `� o Q E Horizontal Distance in Feet (D o U U) 0 0 2 4 6 8 10 12 OTopsoil and - 0 , 1 1 grass. 0 Dense, brown, Silty Sand with Gravel (SM); moist. ; 0 Fill (Reworked Till) 0) c 2 Fine Roots_- O Very loose to dense, brown -gray, O Z ` Silty Sand with Gravel and Cobbles .; (SM); moist; few cobbles, fine to coarse subrounded to subangular gravel; fine to coarse sand; S-1 I , .... "00 3 non -plastic fines; minor iron -oxide 47 % . m -- �" T-Probe 1" Penetration (before PIT) T-Probe 17" Penetration (after PIT) staining at 3.8 feet; diamict pockets. Test Pit Floor During Fill S-2 Pilot Infiltration Test (PIT) 4 Medium dense to dense, brown to S-3 red -brown, Silty Sand with Gravel 1 (SM); moist; fine to coarse S-4= 4 L T-Probe 2.5" Penetration (after PIT) O subrounded to angular gravel; fine S-5I 6 •�_T-Probe 1.5" Penetration (after PIT) to coarse sand; non -plastic fines. Roots and Conifer L T-Probe 0.5" Penetration (after PIT) Fill Duff/Needles 05 Medium dense to dense, red -brown to brown, Silty Sand with Gravel S-6 and Cobbles (SM); moist; few rounded cobbles; fine to coarse subrounded to subangular gravel; 8 05 fine to coarse sand; non -plastic fines; roots and conifer duff at top. Weathered Till S-7 10 NOTES -n 1. Small-scale PIT performed Test Pit Floor After PIT at 3.8 feet on 7-28/7-29-16. D W2. PIT ponded area 2.4' x 5.5'. 12 22 r 22 ,_ 3',4 2 1 22. . 00 4 T"Ps . "ev,, ,�., tKl: 0 ., 2 . i3 Aulhor a"aG =111SHANNON&WILSONTAL N.INC JOB NO: 21-1-22082-004 DATE: 7-28-16 to LOCATION: See Site and Exploration Plan GEOTEC-LOG OF TEST PIT PIT-2 PROJECT: Madrona K-8 7-29-16 _0c a u Sketch of North Pit Side Surface Elevation: Approx. 456 Ft. SOIL DESCRIPTION 0 m `� o Q E Horizontal Distance in Feet (D o U U) 0 0 2 4 6 8 10 12 O Topsoil. 0 / ,� 0Very dense, brown to gray-brown,Silty Sand with Gravel and Cobbles -0 O� / 2 (SM); dry to moist; few cobbles; fine to Y coarse subrounded to subangular o2 gravel; fine to medium sand; Z 1 Test Pit Floor During non -plastic fines; diamict. Pilot Infiltration Test (PIT) Till S-ij\.yy ♦� S-2I T-Probe 0.5" Penetration (after PIT) L T-Probe 0" Penetration (after PIT) 4 Test Pit Floor After PIT 6 8 10 -n NOTES 1. Small-scale PIT performed ' at 3.3 feet on 7-28/7-29-16. 2. PIT ponded area 2.1' x 6.3'. 12 ` , : J s2 r 22 ,_ 3',4 2 1 22. . 00 4 T"Ps . "ev,, ,�., tKl: 0 ., 2 . i3 Aulhor a"aG =111SHANNON&WILSONTAL N.INC JOB NO: 21-1-22082-004 DATE: 7-28-16 to LOCATION: See Site and Exploration Plan GEOTEC-LOG OF TEST PIT PIT-3 PROJECT: Madrona K-8 7-29-16 _0c a u Sketch of West Pit Side Surface Elevation: Approx. 450 Ft. SOIL DESCRIPTION 0 m `� m o Q E Horizontal Distance in Feet (D o U o) 0 0 2 4 6 8 10 12 O Topsoil. 0 Medium dense to dense, brown, Silty 02 Sand with Gravel (SM); dry to moist; -0 scattered cobbles and boulders. Test Pit Floor During Fill (Reworked Till) 0 2 - Pilot Infiltration Test (PIT)Je Z O Very dense, gray -brown, Silty Sand S-1TTest Pit Floor After PIT with Gravel and Cobbles and 1 Boulders (SM); dry to moist; few S-2I cobbles and boulders; fine to coarse subrounded to subangular gravel; 4 __ __ _ T-Probe 0" Penetration (after PIT) L fine to coarse sand; non -plastic fines; T-Probe 0.5" Penetration (after PIT) diamict. Weathered Till to Till 6 NOTES 8 1. Small-scale PIT performed at 2.9 feet on 7-28/7-29-16. 2. PIT ponded area 2.2' x 8.0' on 7-28-16. PIT ponded area 2.5' x 8.2' on 7-29-16. 10 .n 25 12 R.., 22 r 229,_ 3,4 T Us r16-09- G 5 _^20_ 4 004 P FF r6wg Da,",_,, 09 C 016 LAU! !,tE.wnp =111SHANNON&WILSOTAL N.INC JOB NO: 21-1-22082-004 DATE: 7-28-16 LOCATION: Edmonds, WA GEOTEC-LOG OF TEST PIT TP-1 F PROJECT: Madrona K-8 _0c a u Sketch of East Pit Side Surface Elevation: Approx. SOIL DESCRIPTION 0 o E Horizontal Distance in Feet (D o U o) 0 0 2 4 6 8 to 12 O Topsoil 0 Loose to medium dense, brown a� Silty Sand with Gravel (SM); moist. o Fill W Broke/Repaired 2 Storm Drain Pipe OVery dense, gray to gray -brown, Z Silty Sand with Gravel, Cobbles, and Boulders (SM); moist; fine to 02 coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; diamict. 4 Till 6 C� S-1 8 NOTES 1. 9 feet long and 4'-6" wide. 2. 6-inch diameter concrete storm drain encountered 3 feet below 10 "7 ground surface. Repaired with SDR 35 pipe and rubber coupling. D 12 R.., 22 r 229,_ 3',4 T Us r16-09- G 5 _^20_ 4 004 P FF r6wg Da,",_,, 09 C 016 LAU! !,tE.wnp =111SHANNON&WILSOTAL N.INC JOB NO: 21-1-22082-004 DATE: 7-28-16 LOCATION: Edmonds, WA GEOTEC-LOG OF TEST PIT TP-2F PROJECT: Madrona K-8 _0c a u Sketch of East Pit Side Surface Elevation: Approx. SOIL DESCRIPTION 0 o E Horizontal Distance in Feet (D o U o) 0 0 2 4 6 8 10 12 O Topsoil 0 Loose to medium dense, brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse 2 sand; nonplastic fines. Fill Very dense, gray to gray -brown, O Silty Sand with Gravel (SM); moist; diamict. 4 Till Cobbles present. c 0 Z S-1 6 O 8 NOTES 1. 9 Feet long and 4'-6" wide. 10 "n_ t7 D y 12 R: J s2 r 2298_ 3,4 T U-s s rIs-09- G 5 _^20_ 4 004 P FF r6wg Da,",_,, 09 C 016 LAU!s !,tE.wnp =111SHANNON&WILSOTAL N.INC JOB NO: 21-1-22082-004 DATE: 8-25-16 LOCATION: Edmonds, WA GEOTEC-LOG OF TEST PIT TP-3F PROJECT: Madrona K-8 _0c a u Sketch of South Pit Side Surface Elevation: Approx. SOIL DESCRIPTION 0 : cm o E Horizontal Distance in Feet (D o U o) 0 0 2 4 6 8 10 12 Loose to medium dense, brown, 1 J Poorly Graded Sand with Silt and --- 0 . Roofs Gravel (SP-SM); dry to moist, few roots. o O Fill W W S-1 2 02 Very dense, gray -brown; Silty Sand Z with Gravel (SM); moist; diamict. Till S-2 C2 4 6 8 NOTES 10 "n_ D 00 12 -111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-1 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 454 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant plant roots. 7.0 S-0 Topsoil to 2 Very dense, gray brown, Silty O Sand with Gravel (SM); moist. c Till z 4 6 8 10 -n_ D co 12 IAffim SHANNON & WILSON, INC. JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan =I11 MF Geotechnical and Environmental Consultants LOG OF TEST PIT TP-2 PROJECT: Madrona Elementary School, Edmonds, Washington U- Sketch of East Pit Side Surface Elevation: 451 Ft. SOIL DESCRIPTION 0 M (D —C= 0- E Horizontal Distance in Feet 0 can o 0 2 4 6 8 10 12 Loose, brown to gray brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant tree a) and plant roots. Topsoil a) 5.3 S-0 2 Medium dense to dense, brown, 0 Poorly Graded Sand with Silt and a) C: (_1 � Gravel (SP-SM); dry to moist. 0 Z Fill Very dense, gray brown, Silty 4 Sand with Gravel (SM); moist. Till 6 8 10 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-3 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of West Pit Side Surface Elevation: 445 Ft. SOIL DESCRIPTION o co M a) � � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant tree and plant roots. Topsoil 2 Medium dense to dense, brown, O Poorly Graded Sand with Silt and Gravel (SP-SM); dry to moist. z Fill Very dense, gray brown, Silty 4 �> Sand with Gravel (SM); moist. 9.7 S-0 Till 6 8 NOTE 1. Boulder encountered at 1.5 10 feet below ground surface. D N 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-4 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of East Pit Side Surface Elevation: 452 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant tree and plant roots. Topsoil 2 Dense, light brown, Silty Sand O with Gravel (SM); dry to moist. 0 4.0 S-0 3 Fill z Very dense, dark brown, Silty Sand with Gravel (SM); moist. 4 Till 6 8 10 D N N 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-5 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 454 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant plant roots. Topsoil 5.2 S-0 2 Very dense, gray brown, Silty O Sand with Gravel (SM); moist. c Till z 4 6 8 10 -n_ D N w 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-6 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of West Pit Side Surface Elevation: 450 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel 2 (SP); dry to moist; abundant tree and plant roots. Topsoil 2 Medium dense to dense, light Zn O 7.7 S-0 �g brown, Poorly Graded Sand with c Silt and Gravel (SP-SM); dry to z moist. Fill 4 Very dense, dark brown to brown, Silty Sand with Gravel (SM); moist. Till 6 8 10 'rI 17 D N 46 12 IAffim SHANNON & WILSON, INC. JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan =I11 MF Geotechnical and Environmental Consultants LOG OF TEST PIT TP-7 PROJECT: Madrona Elementary School, Edmonds, Washington Sketch of West Pit Side Surface Elevation: 445 Ft. SOIL DESCRIPTION 0 M a) —C= 0- E Horizontal Distance in Feet 0 can o 0 2 4 6 8 10 12 0 Cl) Loose, gray brown, Poorly Graded Sand (SP); trace gravel; dry to moist; abundant tree and plant roots. a) Topsoil a) 2 Medium dense to dense, brown, 0 Poorly Graded Sand with Silt a) C 7.7 S-0 and Gravel (SP-SM); trace 0 Z cobbles; moist. Fill 4 Very dense, brown, Silty Sand with Gravel (SM); trace cobbles; moist. Till 6 8 NOTE 1. Boulder encountered at 2 10 feet below the ground surface. au cri 1 1 121 -111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-8 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of East Pit Side Surface Elevation: 452 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to 5.2 S-0 moist; abundant tree and plant roots. Topsoil 2 Very dense, gray brown, Silty O Sand with Gravel (SM); moist. c Till z 4 6 8 10 D N ca 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-9 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 454 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel 5.5 S-0 O (SP); dry to moist; abundant plant roots. Topsoil 2 OVery dense, gray brown, Silty O Sand with Gravel (SM); moist. Till z 4 6 8 10 -n_ D N V 12 -111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-10 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 446 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel 2 O (SP); dry to moist; abundant tree and plant roots. Topsoil 10.8 S-0 2 Medium dense to dense, brown, O Poorly Graded Sand with Silt and Gravel (SP-SM); dry to moist. z Fill Very dense, gray brown, Silty 4 Sand with Gravel (SM); abundant cobbles; moist. Till 6 8 10 -n_ D N 00 12 -111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-11 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of East Pit Side Surface Elevation: 452 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant tree and plant roots. 5.0 S-0 Topsoil 2 Very dense, gray brown, Silty Zn O Sand with Gravel (SM); moist. c Till z 4 6 8 10 -n_ D N co 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-12 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of West Pit Side Surface Elevation: 446 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel (SP); dry to moist; abundant tree and plant roots. \ Topsoil 2 Medium dense to dense, brown, O 6.1 S-0 Poorly Graded Sand with Silt and o Gravel (SP-SM); dry to moist. z Fill Very dense, gray brown, Silty 4 Sand with Gravel (SM); moist. Till 6 8 10 D w 0 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-13 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 454 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 1 ('1J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to 5.4 S-0 moist; abundant plant roots. Topsoil 2 Very dense, gray brown, Silty O Sand with Gravel (SM); moist. c Till z 4 6 8 10 -n_ D w 12 IAffim SHANNON & WILSON, INC. JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan =I11 MF Geotechnical and Environmental Consultants LOG OF TEST PIT TP-14 PROJECT: Madrona Elementary School, Edmonds, Washington Sketch of North Pit Side Surface Elevation: 448 Ft. SOIL DESCRIPTION 0 M a) —C= 0- E Horizontal Distance in Feet 0 can o 0 2 4 6 8 10 12 0 1 (1) Loose, gray brown, Poorly Graded Sand (SP); trace gravel,- dry to moist; abundant plant roots. Topsoil a) a 16.8 S-0 2 Medium dense to dense, brown, 0 Poorly Graded Sand with Silt and 21) Gravel (SP); trace cobbles; moist. Zo Fill Very dense, dark brown, Silty 4 Sand with Gravel (SM); trace cobbles; dry to moist. Till 6 8 10 tV 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-15 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 454 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown, Poorly Graded Sand with Gravel (SP); dry to 6.5 S-0 moist; abundant plant roots. Topsoil 2 Very dense, gray brown, Silty O Sand with Gravel (SM); moist. c Till z 4 6 8 10 -n_ D w w 12 �111 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-16 JOB NO: 21-1-22082-001 DATE: 6-24-2015 LOCATION: See Site and Exploration Plan PROJECT: Madrona Elementary School, Edmonds, Washington u Sketch of North Pit Side Surface Elevation: 448 Ft. SOIL DESCRIPTION o co M a) � a- E Q Horizontal Distance in Feet O o U co 0 0 2 4 6 8 10 12 0 �11 J Loose, brown to gray brown, Poorly Graded Sand with Gravel 2 O (SP); dry to moist; abundant tree and plant roots. Topsoil 5.2 S-0 2 Medium dense to dense, brown, O Silty Sand with Gravel (SM); dry 3 to moist. o z Fill Very dense, gray brown, Silty 4 Sand with Gravel (SM); abundant cobbles; moist. Till 6 8 10 'rI 17 D w 4h 12 21-1-22082-004 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project BORING B-3 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV �a ti �ro o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory Q M O' O' O' O' O' O' 100 0 95 5 90 ......... .... ...... ........... ......... .. .......... .... ....... ........ ... ........ .. ......... ............10 85 .... .... ..... ... .... , ...... ._ 15 80, ... .. .... ...... ......... .... ... ........... ....... ....................... ...... ......... ....,.... ........ ., ..,,,,,,,,. ..20 75 ..... �� . ... .. ..... ... -_ . ... -25 65 ... .... ... ... ,. ... .. , .... " "" 35 co 60 _ .. -. N ' 40 CD Z3 55 . ... ... ... ... .... .... ... - ..48 n = 80 .. ........ ......... .. ..... ...... ..... ........ ... ..,...... _. .,, 50 N IL N G 45 �� . ... .. ... ... ... " "" 55 (D 40 .......... ...... .. .. ....., .. .. ............................... ............ . .................. . . ... . , .. ------ .. ......... .... 60 � N 35 . _ ...._. . _._65 N 25 _.. 75 20 ......... ..... ..... ............ . .. ._ ,. .. ..... ........ .......... .......... ... ...... , <......., . ... ... 80 15 10 ..... ... ..... ... """""""" ." 90 5 _.. 95 0100 ry o 0 0 0 o ro <o h a M N �° �` M ry p v co a M ry O Q, O O O O y ¢i O^ o a M ry ro o a ry 0 0 ^0• o o 11 o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. B-3, S-3' 7.5 SM Silty Sand 11 55 34 8.7 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project BORING B-4 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters �b ti �ro o 0 0 0 00 00 0° oa o' o� o oo' o00 00° ooM oory Q ^� ti M M P ti b ro �. O' O' O' O' O' O' O' O' O' O' O' 100 0 95 5 90 ......... ........... ...... .. ................ ..................... ................. . . ........ ... ........ .......................... ......... ............10 85 ..._. ......... ..... ... .... , ...... ._ 15 80 ........ ......... ................. ......... ....... ......... ....... .........-- .. ...... ......... ....,.... ........ . , .,,,,,,,,,. ..20 75 ._ .... ......... _,25 70, ...... ........ .......... ......... ........... .... ......... ......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... ........... -" 30 65 ,...... ..... ..... ... .. ........ "" 35 to..... co 60 ........ ._.... ..... -.. (p 40 2 CD 55 . ... ... .... ... ... .... ... - ..48 n c80, .. ........ ....... .. ........... ............ ... ............... .. .... ... ...... ..... ........ ... ......... ........ ..,....... ....... .. _. .,, 50 N IL N G 45 ... ... �� ..... ... N40 .......... ...... .. .. ....., .. ..... ............................. .................... .......... ... ......... .. ........--- .. ......... .... 60 � 25 _.. 75 20 ......... ..... ..... ........... . .. .. ................ ... ... ...... ........ ......... ......... ... ...... , <......., . ... ... 80 15 ..... ..... ......... ._ .. ..._ ..... ..... _ 85 10 .. .... -. ... .. _ 90 5 .. _.. 95 0 N O O O O O N <p h b ^b R. o b M ry ^ a 1 0 0 o 0 b M N 0 0 0 0 0'` o b 0 0 0 o Oo Oo Oo Oo 0o Oo 100 ^o• o� o� � o• o' o� o� o Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (ft) Symbol Group Name % % % % % % By By Std. 0 B-4, S-2' 5.0 SM Silty Sand 8 64 29 15 4 10.2 AKV JFL D422 rn ■ B-4, S-4' 10.0 SM Silty Sand 10 50 40 9.7 AKV JFL C136 Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project BORING B-5 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV �b ti �ro o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory Q ^� qvM M O' O' O' O' O' 100 0 90 ........ .... .. ........... ......... .. .......... .... ....... ........ ... ........ .. ......... .......... .. 10 85 .. ..... .... .... ..... ... .... , ...... ._ 15 80 ,....... .. ..... ...... ..... .. ....... ....................... ...... ....................... ........ , ., ..,,,,,,,,. ,20 75 .-. .-. ... -_ . ... -25 70, ........ , ....... ...... ............ ........... .......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... ........... -. 30 65 ... ... .. ... ,. ... .. , .... " "" 35 co 60 _ .. -. N ' 40 CD Z3 55 . ... ... ... ._ .... .... ... - ..48 n = 80, .. ........ ......... .... .. .. .. ..... ...... ..... ........ ... ..,...... _. .,, 50 N IL N G 45 �� ... �. ... ... ... ... """55 (D 40 .......... ...... .. .. ....., .. .. ......... ........... .. ........--- .. ......... .... 60 � 35 . ..... ..... _ . _ . . _ _ 65 N 25 _.. 75 20 ......... ..... ..... ........... . .. .. ................ ... .. ..... ...... ...,....... ,... ..... ... ...... , <......., . ... ... 80 15 ..... ..._ ...... ..... ......... .... .._ .-. •... .... ..... ....... ..... ..... ........ -85 10, 5 - - 95 p N O O O O O N <p h b ^b R. 1 0 0 o b M ry ^ a o 0 b M N 0 0 0 0 0'` o N 0 0 0 o Oo Oo Oo Oo 0o Oo 100 ^o• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. 0 B-5, S-3' 7.5 SM Silty Sand 14 54 32 22 8 15.0 AKV JFL D422 rn ■ B-5, S-6' 15.0 SM Silty Sand with Gravel 15 52 33 10.0 AKV JFL C136 Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project BORING B-11 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV �a ti �ro o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory Q M O' O' O' 100 0 90 ......... .... .... ........... ......... .. .......... .... ....... ........ ... ........ .. ......... ............10 85 -. ... --15 80,,...... ..... ..... ......... .,,,., ....... ....................... ...... ......... ......... ........ ., .......... ..20 75 ...... ......... _ , 25 70 ....... ..... .. ............ ............ .. ............ .. „ ......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... .. . -" 30 ... 35 U co 60- ......... ... ��, ... -.. N '40 CD 55 .... ... .... ... ... .... ... -..48 IL N G 45 • .... .... .... ... ... N U `G N40 ......... .. ... ...... ........................ ......... ... ..... ..... .............. .. ......... .... 60 N ....... ......... . .. ........ ........ ...._ ........................ .. e. .:.... ......... .. ......... .... 25 ...... _.. 75 20 .... ..... ..... ..... .......... ..........., .. .. ................ ... .. ..... .... ,.... "... ....... .. ......... ... ......, <.......,. ... . .. 80 15 ..... ...._ ...... ..... ......... .... .... ..._ ...... ....... ..... 10 .. .... -. ._. ..... .. 90 ry o 0 0 0 o ro <o h a M N �° �` M ry p v co a M ry O Q, O O O O y 11 ". o a M ry ro o a ry 0 0 0 o O- O- o- o- * 100 ^0• o o o o Z)o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. B-11, S-11' 5.0 SM Silty Sand 13 53 34 8.1 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project TEST PIT PITA Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV M� \11,MO W ro ' ' '. O O O O O O O O� 100 0 90 85,„ ..... . .A�S�.. ........... ......... .. ......... .... ....... ........ ... ......... .. ......... .......... ... --15 .. 10 80„ ........ ..... ..... ...... ..., ........................... ....... ....................... ...... ....................... ........ . , ..,,,,,,,, 75 ....... .... ..._ ......... 25 65 .... .. .. ..... ...... .. ........ "" 35 co 60 ........ ... -.. N ' 40 CD Z3 55 . ... ... ... ... .... ... -..48 . ` p IL N G 45 ��............�. ... .. ... ... 55 (D 40 .......... ...... .. .. ....., .. ........... ....................... ...... ..,,,,,,. .. ------ .. ......... .... 60 � 35 . .._ . ... _ . _. . _'65 N 25 75 20 ......... ..... ..... ........... . .. .. ................ ... ... .... ...... ........ ,.... .......... .......... ... ...... , <......... ... ... 80 15 ..... ..._ ...... .. ..... ......... ..._ ........ ----. ......_. tl.. .... ...._ ...... ....... _ . ..... ........ -85 10 .. .... -. ........ .. _ 90 5 _.. 95 0 ry o 0 0 0 o ro 1. h a M N 1 v <o a M ry �° �` M ry p O O O O O O y ¢i O^ o a M ry ro o a ry 0 0 0 0 100 ^0• o o o o Z)o• o' Grain Size (mm) Sample Depth USCSp USCS Cobbles Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % % By By Std. PIT-1, S-1' 3.0 SM Silty Sand with Gravel 15 56 29 5.7 AKV JFL C136 rn ■ PIT-1, S-6' 7.0 SM Silty Sand with Gravel and Cobbles 13 28 51 21 13.9 AKV JFL C136 Test specimen did not meet minimum mass recommendations. 2 Cobble percentages are calculated using the pre -removal, oven -dried mass of the total specimen. USCS Group Symbol, Soil Classification Group Name, Gravel %, Sand %, Fines %, <0.02mm %, <2um%, Cu, and Cc values are calculated from particles smaller than 76.2mm (3 inches) only, per ASTM D248T Z a x a N O O N N N Z < U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project TEST PIT PIT-2 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV �a ti �ro o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory Q M O' O' O' O' O' O' O' 100 0 90 ........ ....... ........ .. ........... ......... .. .......... .... ....... ........ ... ........ .. ......... .......... .. 10 85 ,...... .... .... ..... ... ...., ...... ._.15 80 .. .... ........... , ........... ........... ....... ....................... ...... ......... ......... ........ . , .......... ..20 75 ....... ..... ......... _ , 25 70 ........... .... ..... .... ............ ............ ,,,,,,,,,,,,,,,,, ......... .......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... .. . -" 30 65 �.. .. ... ... ,. ... .. , .... " "" 35 co 60 ' 40 2 CD 55 . ... ... .... ... ... .... ... - ..48 = 80 ........ ....... .. ........... ............ ... ............... .. .. ..... ....... ..... ........ ... ......... ........ ..,....... ....... .. _. ..50 � IL N G 45 �� . ... .... .. .. ... ... " "" 55 (D 40 , .. ... ...... .. .. ...., .. ..... ............................. ................ ............... .... . ..... .............. ......... .... 60 � d y 35 . ... _ ...._. . .. _._65 N 25 _.. 75 20 .... ..... ..... ..... ............ .. .. ................ ... .. ..... .... ,.... "... ....... .. ......... ... ......, <.......,. ... . .. 80 15 ..... ..._ ...... ..... ......... .... .... ..._ ...... ....... ..... 10 .. .... -. ._. ..... .. _ 90 5 _.. 95 0 ry o 0 0 0 o ro <o h a M N �° �` M ry p 1 v co a M ry O O O O O O y 11 O^ o a M ry ro o a ry 0 0 0 0 100 ^0• o? o o o Z)o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. PIT-2, S-2' 3.5 SM Silty Sand 12 55 33 8.7 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project TEST PIT PIT-3 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV \\O O O O O 00 W ro D M 00 00 Ob O� Ory O 00 00 00 00 00 Q qvM M O' O' O' O' 100 0 90 ..... .... ......... ........... ......... .. .......... .... ....... ........ ... ........ .. ......... .......... .. 10 85 -... ..... ..... .... .... ..... ... ...., ...... ._.15 80„ ,...... .... .,...... ........... ........... ............................... ....... ....................... ...... ......... ........ ........ . , ..,,,,,,,, 75 ..._ ......... _,25 65 .. .. .... ........ .. ........ "" 35 co 60 ' 40 0 Z3 55 . ... ... ... ... ... .... ... - ..48 n = 80, .. ........ ........ .......... ......... ........ ........ ... ... ..... .... ....... ..... ........ ....... .......... ........ ... ..,...... _. .,, 50 N IL N G 45 �� . ... .. ... .. ... ... " "" 55 N40 .......... ...... .. .. ....., .. ........... .. ,,,,,,.,,, ............ ........................ ........--- .. ......... .... 60 � 35 . ..... .... ..... _ . _ . . _ _ 65 (n 30 .. ... ........ .. _,. 70 25 _.. 75 20 ......... ..... ..... ............ . .. ... .......... ......... ........... ....... ...... ....;. .......... ......... ... ...... , <......., . ... ... 80 15 ..... .... .._ ............................... ..._ ..... ..... _ 85 10 .. ... ......... -- ... ..... .. _ 90 5 _.. 95 0 _ N O O O O O N <o h b ^b o b M ry ^ a R. 10 0 o 0 b M N 0 0 0 0 0 <o 0'` o b M 0 0 0 o Oo Oo Oo Oo 0o Oo 100 ^o• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (ft) Symbol Group Name % % % % % % By By Std. PIT-3, S-2' 3.0 SM Silty Sand with Gravel 26 47 27 5.9 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project TEST PIT TP-1 F Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV �a ti �ro o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory Q M O' O' O' O' O' 100 0 90 ......... .......... .... ........... ......... .. .......... .... ....... ........ ... ........ .. ......... .......... .. 10 85 .... ..... .... .... ..... ... .... , ...... ._ 15 80 ...... ... ... ...... ................ ....... ....................... ...... ......... ......... ........ . , .......... ..20 75 ... . . .... ... .... ... -_ . ... -25 70, ........ .... ......... ............ ........... .. ,. ......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... ........... -" 30 65 ,...... .. .... .... .. .. ........ "" 35 to.. co 60 .._ ... -.._ ... -.. fD -40 2 CD 55 . ... ... .... ... .... .... ... - ..48 IL N G 45 �� . .. .. ... ... ... ... " "" 55 N40 .. ... ...... .. .. ...., .. .. .. ........................ ...... .. ........--- ......... .... 60 � d y 35 . .. _ ...._. . .. _._65 (n 25 _.. 75 20 ......... ..... ..... ............ . .. ._ ,. .. ..... ........ .......... .......... ... ...... , <......., . ... ... 80 15 .. .. _ . ........ -85 10 ..... ... ..... ... """""""" ." 90 5 _.. 95 0100 ry o 0 0 0 o ro <o h a M N �° �` M ry p v co a O Q, O O O O O^ o M ry ro o a ry 0 0 ^0• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. DTP-1F,S-1' 7.0 SM Silty Sand 13 55 31 7.5 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Preliminary Hydrogeologic Report New Madrona K-8 Project TEST PIT TP-2F Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters ^ M� \11,MO 0 W ro D M � O O O O O O O O ^� 0� ^O ry0 p0 00 O� O� O� 100 0 90 .... .... ,. ......... ........... ......... .. .......... .... ....... ........ ... ........ .. ......... .......... .. 10 85 ..... ..... .... .... ..... ... .... , ...... ._ 15 80 ...... ..... .... ... ..... ........... ........... ............................... ....... ....................... ...... ......... ........ ........ . , ..,,,,,,,, 75 ...... ..._ ......... _,25 65 .. ... .. ... ,. ... .. , .... " "" 35 to 0 60 .. .._. -. fD 40 2 CD CD 55 .... ... .. .... .... ... -.. 45 c80 .. ........ ... ..... .... ............ ......... .......... .... ............. ..... ...... ..... ........ ... ......... ........ ..,....... .... _. .,, 50 N IL N 45 .. ... ... ... ... ... " ""55 N40, ......... ... ...... ........... ............ ..... .... ...... .......... .. ........--- .. ......... .... 60 � ....... ......... . .. ........ ........ ......... ......... .._ .......... .. .,... ......... .. ......... .... 20 .... ..... ..... ..... .......... ..........., .. .. ......... ......... .......... .... ............ ....... .. .......... ... ......, <.......,. ... . .. 80 15 ..... ...._ ...... ......._ ....................... ----. _ .... :_ .... ...._ ...... ....... _ . ..... ........ -85 10 .. _ -. .... ........ .. _ 90 0 _ N O O O O O N <o h b ^b o b M ry ^ a R. 10 0 o 0 b M N 0 0 0 0 o 0 0 0 o Oo Oo Oo Oo 0o Oo 100 ^o• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (11) Symbol Group Name % % % % % % By By Std. TP-2F, S-1' 6.0 SM Silty Sand with Gravel 29 58 13 7.3 AKV JFL C136 N Test specimen did not meet minimum mass recommendations. 0 ca >J_ Z a N O O N N N Z <1 U) M O O N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 ANALYTICAL LABORATORY TEST RESULTS 21-1-22082-004 EN wk,51-hs 26276 Twelve Trees Lane, Suite C - Poulsbo,WA98370 ® (360)779-5141 - Fax (360)779-5150 I � M M. . = � "r Inv —r;—. , Pit Seattle, WA 98125 1 1 74 11�11 jlll Sample Date: 7/29/16 pH 1:2 soil to wt Phosphonis &W PPFn Potassium NH40Ac ppm Calcium NH4OAc nieqt100 g KAagneSiUM NH4OAc nW100 g Sodium NH4QAc nW1 00 g SMP Buffer Index* Organic KAafter 1-01 Nitrate -Nitrogen Ka pprn Sol Saft 1:2 soil iAoter dS/m Soil Fertility Levels ................ 4 PH Phosphorus (P) Potassium (K) Calcium Magnesium Neutral High Low Low Medium Low Salinity Negligible a www.spectra-lab.com W1 PAPLACUMdRed 2014 b=- ram= illag go P SPECTRA Laboratories-- Kitsap ...Where experience matters 26276 Twelve Trees Lane, Suite C - Poulsbo,WA98370 - (360)779-5141 - Fax (360)779-5150 - wwwspectra-lab.com i ► Sample F. 7129/16 PH 1.2 soil to M Phosphorus Bray pprn Potassium NH4GAc ppTr, Calcium NH4QAc nvW100 g Magnesium NH4OAc mecVl 00 g Sodium NF14QAc rraW100 g SMP Buffer Index* Organic Matter Lol % by w� Nitrate -Nitrogen Ka pprr Sul, saii 1:2 scirwater 6ij . ar 11 NA- Not analyzed 11-111 44,11, J I "I'll, --- . "I'll I'll, i . 0r .► 291T, 9X- e LDW Medium High Sofl Ferfifity Levels 9 Uff I Y -* 42 1 Xd L40d& k-M PH Moderately Acid 5.2-6.0 Phosphorus (P) Medium 2040 ppm Potassium (K) Low <150 ppm Calcium Low <5 meq/1 OOg Magnesium Low <0.5 meq/100g Nitrate -Nitrogen Low <10 ppm EC (Sol Salts) Salinity Negligible <0.4 dS/m W 'aot E SPECTRA Laboratories - Kits ...Where experience inarters 26276Twelve beesLane,Suite C a Poulsbo,WA98370 @ (360)779-5141 * Fax(360)779-5150 - www.specLra-lab.com. Project: Madrona K-8 Lab Work Order #: 161057 Sample Date: 7/29/16 Sample Received: 8/1/16 Recommendation: SF 1: The pH of this area is best suited for turf, vegetable gardens and bedding plants (>6.0). The use of sulfatearti-f-iTti futili7f,-r-, I r, * - il - * �W 1�i� # sir I ��� - 4-11 wo 074-4,6JI-01lik to our native plants, orlde pA can tie adjusted downward by broadcasting 2 lbs of finely ground elemental sulfur or 6 lbs of iron sulfate per 1000 sq ft, soil for every 1/2to I pH unit decrease desired. Repeat this application every 3 months until the desired amount of sulfur has been added. (Iron sulfate works faster.) A pH requirement sheet has been included to help you decide if the pH needs to be adjusted to meet yourneeds. The calcium and magnesium levels are low, but in an acceptable ratio to one another. Increase both by incorporating 50 lbs of gypsum and 20 lbs of Epsom salts per 1000 sq ft of soil. The macromitrient levels of nitrogen, phosphorus and potassium are all low. Incorporate a complete fertilizer such as 10 lbs of 10-20-20 plus 12 lbs of 0-0-60 per 1000 sq ft. The goal should be approximately 1 lbs of actual nitrogen, 2 lbs Of P205 and 9 lbs of K20 per 1000 sq ft. SF 2: The pH of this soil is closer to that needed for native plants, but still acceptable for turf. The pH can be lowered further as stated above for natives. The buffer pH indicates that timing is not needed, but the calcium and magnesium levels are low. Increase as stated above. The macronutrient levels are low. Incorporate a complete fertilizer such as 10 lbs of 10-20-20 plus 7 lbs of 0-0-60 per 1000 sq ft. The goal should be approximately I lbs of actual nitrogen, 2 lbs Of P205 and 6 lbs of K,20 per 1000 sq Both areas: The soluble salts. and sodium content are low indicating that excess salts have not built up to a level that will harm plants. The organic matter is low in SF- I and borderline in SF-2. Adding 2-4 inches of compost or other top -dressing will be of benefit. More nitrogen may need to be added periodically during the growing season (April, July and late October -November) at the rate of one lb actual nitrogen per 1000 sq ft of soil (for example, 5 lbs of 21 -0-0) if a rapid growth is desired. The reuse of grass iCund, s-Lixoduced fmm a mubkfu Ift take the place of one of the nitrogen applications for turf during the growing season or a good grade of compost or manure can be substituted for one of the fertilizer applications. Spread 1/4 inch deep over the soil, compost will supply nutrients and increase the organic matter content of any soil, which in turn will boost nutrient and water -holding capacity. For turf maintenance, Washington State University studies have shown that grass uses N:P:K in the ratio of 3:1:2 and it is helpful to use a fertilizer with that ratio of N:P:K in future applications. For ongoing maintenance of woody ornamentals, once a year in the spring they can be fertilized lightly (5 lbs per 1000 sq ft) with a complete fertilizer such as 10-20-20. Thank you for the opportunity to help you prepare healthy landscape. Nancy Parrott Laboratory Supervisor WDOE Accreditation #C594 This report is issued solely for the person or company to whom it is addressed. This laboratory accepts responsibility only for the due performance of analysis according to industry accepted practice. Spectra Laboratones - KitsaD or its enmlovees 9.re -rot reanif 4x 4 -Fir Isik -f -rm- 0 SPECTRA Laboratories — Kitsap, LL 26276 Twelve Trees Lane, Suite C Poulsbo, WA 9337 (360) 77 -5141 FAX (60) 7 9- 150 www,Wsslabs.com Wa a� a -to � i o o cif. ¢ #ix a I 3F to g g_ss� y RrOje�i anagerlRepori T` < ) € M U) ! fCif �Ct m C3 C7 ante 4 Telephone - d� Earl ECL a* �' CO l� Z a Lab ID a eAJ f I F� g=, tea, �- rt rl S 6 s 10 11 12 0 Routine Disposal 0 Hazardous sample disposal Special Instructions ❑ Return to Client (Coat or disposal VWII be billed to client) TOtal of �rltairrers ,,�° gh ' r.a CtC Bela eeaeat? irtta�t? Relinquished by: Cent an t 1 a !7 p Y Dale . r * Time _. Tertt at re i ? l� (PH ►d (Signal gam les irtta�t? Received by: LAVJ Received Via Company r Date Time (prin) (Signature) T. ui tandard (10 Business days) Relinquished by: Company Date Time 13 Rush (specify date needed) (print) (Signature) Ft, ther (specify) Received by: Company Date Time �t of c v *,Yg,, ruay apply (Prino (Signature) — Samples ceived after 12 noon will be considered as reddtudd the following Wetness day SATernplateASample Manager enfiSPECTRA Cf1C 092515 Rev. 1.1 11104114 Page of • 1 1 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT 21-1-22082-004 SHANNON & WILSON, INC. Attachment to and part of Report 21-1-22082-004 Geotechnical and Environmental Consultants Date: October 31, 2016 To: Ms. Taine Wilton Edmonds School District #15 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS. Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant. THE CONSULTANT'S REPORT IS BASED ON PROJECT -SPECIFIC FACTORS. A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project -specific factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as access roads, parking lots, and underground utilities; and the additional risk created by scope -of -service limitations imposed by the client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed. SUBSURFACE CONDITIONS CAN CHANGE. Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example, groundwater conditions commonly vary seasonally. Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary. f ll [��' l i 7 �rZ�7 i�� 1 ��� I � ►17_� � [il �"�_I7 �;1:%7. � �'? E;'� [�1 i [LR�11LIr] �r� I � � � �� Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect. Page 1 of 2 1/2016 A REPORT'S CONCLUSIONS ARE PRELIMINARY. The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction. THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION. Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of their plans and specifications relative to these issues. BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT. Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale. ZAPt;�l3I>AkVLqW-[1M� *X6-TA:WA Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. The preceding paragraphs are based on information provided by the ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland Page 2 of 2 1/2016