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RS_ Preliminary Geotech Report_190426_v1
e a r t h w a t e r+ppeecc tt C O N S U L T I N G PRELIMINARY GEOTECHNICAL EVALUATION King County Parks and Recreation Division – Renton Shop 3005 4th Street NE Renton, Washington Prepared for: Mr. Christopher Walling, Project Manager HDR Architecture, Inc. Project No. 170383 - Task 200 March 20, 2018 earth +water Aspect Consulting, LLC 401 2nd Avenue S. Suite 201 Seattle, WA 98104 206.328.7443 www.aspectconsulting.com ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 i i Contents 1 Introduction ................................................................................................. 1 1.1 General ...................................................................................................... 1 1.2 Scope of Services ..................................................................................... 1 1.3 Project Description ................................................................................... 2 2 Site Conditions ............................................................................................ 3 2.1 Site Description ........................................................................................ 3 2.2 Critical Areas ............................................................................................. 4 2.3 Geologic Setting ....................................................................................... 4 2.3.1 Geology ............................................................................................... 4 2.3.2 Faults and Seismicity ......................................................................... 4 2.3.3 Geologic and Seismic Hazards .......................................................... 5 2.4 Site Reconnaissance ................................................................................ 6 2.5 Subsurface Conditions ............................................................................. 7 2.5.1 Previous Subsurface Explorations ..................................................... 7 2.5.2 Aspect Consulting Environmental Subsurface Explorations ........... 7 2.5.3 Groundwater ....................................................................................... 8 2.5.4 Stormwater Infiltration ...................................................................... 8 3 Conclusions and Recommendations ......................................................... 9 3.1 General ...................................................................................................... 9 3.2 Seismic Design Criteria .......................................................................... 10 3.3 Foundation Design ................................................................................. 11 3.3.1 Shallow Foundations ....................................................................... 11 3.4 Floor Slabs and Modulus of Subgrade Reaction .................................. 12 3.5 Pavement Design .................................................................................... 12 4 Construction Considerations .................................................................... 13 4.1 General .................................................................................................... 13 4.2 Site Preparation ...................................................................................... 13 4.3 Proofrolling and Subgrade Verification ................................................ 13 4.4 Wet Weather Conditions ........................................................................ 13 4.5 Excavation ............................................................................................... 14 4.5.1 General .............................................................................................. 14 4.5.2 Trenches ............................................................................................ 14 4.5.3 Temporary and Permanent Slopes .................................................. 15 4.6 Structural Fill Material and Compaction............................................... 15 4.7 Ground Moisture .................................................................................... 16 4.7.1 General .............................................................................................. 16 ASPECT CONSULTING ii PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 4.7.2 Perimeter Footing Drains ................................................................. 16 5 Project Design and Construction Monitoring .......................................... 18 6 References .................................................................................................. 19 7 Limitations ................................................................................................. 20 List of Tables Table 1. Summary of Site Conditions ................................................................3 Table 2. Geologic and Seismic Hazards Potentially Affecting the Site ..........6 Table 3. 2018 IBC Seismic Design Parameters ................................................ 10 Table 4. NEHRP Description of Category III-Type Buildings .......................... 11 Table 5. Spread Footing Foundation Design Recommendations1 ................ 11 Table 6. Preliminary Pavement Section .......................................................... 12 Table 7. Fill Type and Compaction Requirements .......................................... 16 List of Figures 1 Site Location Map 2 Site Exploration Map List of Appendices A Soil Exploration Logs B Analytical Laboratory Test Results C King County May 22, 2017 Preliminary Geotechnical Design Report – Subsurface Explorations D Report Limitations and Guidance for Use ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 1 1 1 Introduction 1.1 General This report summarizes Aspect Consulting, LLC’s (Aspect) preliminary geotechnical engineering evaluation for the King County (County) Parks and Recreation Division’s (Parks’) Renton Shop located at 3005 4th Street NE in Renton, Washington (Site). We performed our services in accordance with our agreed-upon scope of work and signed contract dated January 18, 2018. The Site location is shown on Figure 1, Site Location Map. 1.2 Scope of Services Our scope of services included a literature review, Site reconnaissance, environmental subsurface explorations, laboratory testing, critical areas assessments and preliminary geotechnical engineering assessment of the Site. This report includes: Site and preliminary project descriptions. A discussion of the data review findings, including opinions regarding the effects of relevant geologic and seismic hazards and possible past Site activities on future development. Distribution and characteristics of the shallow subsurface soils and groundwater surrounding two onsite decommissioned Underground Storage Tanks (USTs) based on four geoprobes. Exploration logs and a Site plan showing approximate exploration locations. Environmental laboratory test results. An assessment of relevant critical area (geohazard and aquifer protection) considerations, and preliminary recommendations for seismic design, earthwork, shoring, foundation support, slabs-on-grade support, retaining walls, stormwater infiltration, pavement design, and related geotechnical construction recommendations. Review of the alternatives and the geotechnical feasibility, risk factor and cost input. Review of the King County Historic Preservation Program Project Screening completed for the project to determine if future boring locations will require additional screening prior to drilling. Additional scope items in Task 200, including soil thermal conductivity testing and reviewing alternatives, conceptual and preliminary designs with geotechnical input support, will be provided in a subsequent task when more plan details are known. Geotechnical explorations will be completed under Task 400 to provide foundation designs. ASPECT CONSULTING 2 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 1.3 Project Description The Renton Shop Facility Design (Project) is located at 3005 NE 4 th Street in Renton, Washington. The facility plays a critical role in Parks’ ability to adequately and efficiently serve the regional trails, back country trails and parks throughout the County. This facility functions as the headquarters for Parks Operations & Maintenance (O&M) Section, and acts as the dispatch center for Parks’ centralized work crews which support the entire system. It also provides space for O&M staff, warehousing/inventory, and is Parks’ emergency operations center. The Site consists of several small facilities, parking areas, and yard storage areas. The Project will design and construct facilities large enough to accommodate future growth of the Parks O&M Section. Preliminary designs, feasibility analyses and preliminary permit application processes were completed with the City of Renton based upon previous anticipated needs from 2009 to 2014. Site redevelopment, new utilities, and new facilities are necessary to accommodate current and future planned operations and spaces for employees to work for the next 25 to 30 years. The in-development Project will create a functionally efficient Site with a combined total of 40,000 to 60,000 square feet (sq2) of enclosed facilities. The main building will contain crew work spaces, locker rooms, restrooms, workshop areas, offices, storage, training/conference rooms, and accessory support spaces. The Project also includes yard materials storage, covered and uncovered storage, a sawmill shelter, emergency back-up power, fleet and equipment parking, utilities, staff and visitor parking, pedestrian and vehicular circulation, and landscaping. Site development alternatives are currently being evaluated by the County an d the preferred configuration will be selected in the near future. Per King County’s 2015 Strategic Climate Action Plan1 and the most current adopted Green Building and Sustainable Development Ordinance #17709, the Project must be designed and constructed to meet the requirements of LEED™ Platinum certification by the United States Green Building Council (USGBC) as a base requirement. The Project may additionally achieve design to achieve Net Zero certification or Petal certification by the International Living Future Institute – if the County decides to pursue this certification. 1 https://www.kingcounty.gov/services/environment/climate/strategies/strategic-climate-action- plan.aspx ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 3 3 2 Site Conditions 2.1 Site Description Site details are provided in Table 1 below. Table 1. Summary of Site Conditions Detail Description Location Parcel 143400-0012 with a legal Site address listed as 3003 4th Street NE, Renton, Washington Existing conditions The roughly rectangular 5.71-acre Site is currently the County’s active Central Maintenance Facility. Three buildings consisting of offices and maintenance garages are situated in the western portion of the property and the eastern portion is primarily open lots paved with asphalt or gravel. A driveway traverses east-west through the middle of the Site and a small building is on the located on the south side of it, near the center of the property. Current ground cover The Site is primarily open, paved and unpaved lots. Limited landscaping is planted near the front of one of the Site buildings and consists of a few deciduous trees, plants, and small shrubs. The perimeter of the Site on the north, west, and south sides consists of larger deciduous type trees, weeds, and shrubs. Site topography The ground surface is relatively flat with elevation (EL, NAVD88) between approximately EL 325 feet and EL 330 feet, sloping gradually down to the west. Steeper slopes are along the western and north-western property boundaries. Adjacent Properties The Site is bounded, for a distance of 150 feet beyond the Site’s perimeter and proposed easement, by: North Side: Renton Housing Authority Residential Property (Parcel 1623059120), AM PM Convenience Store and Gas Station (Parcel 1623059115) and the currently vacant King County Public Health Offices (Parcel 1623059130). East Side: An asphalt paved access road (Parcel 1434000010) for other King County facilities in the area is directly adjacent to the planned DNRP Maintenance Facility. In addition, there is an approximate 50-foot-deep depression that was previously used to mine sand and gravel (Parcel 1623059059). South Side: County property (Parcel 1434000020) that includes a gravel surfaced equipment storage area and other undeveloped property with natural vegetation. West Side: Commercial properties (Parcels 1623059144 and 1623059143) that include office and storage facilities. The City of Renton has issued a preliminary building permit for Parcel 1623059144 to remove an existing building and add a new three- story building totaling approximately 58,350 square feet. ASPECT CONSULTING 4 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 2.2 Critical Areas The City of Renton's Maps (COR), an online GIS portal, was reviewed for potential Critical Areas at the Site that consider wellhead protection area zones, coalmines, erosion hazards, flood zones, landslides, regulated slopes and shorelines, wetlands, and seismic hazards. Specific geologic hazards identified in the Renton Municipal Code (RMC) Section 4-3-050 include Steep Slopes, Landslides, Erosion, Seismic and Coal Mines. Based on the COR, the Critical Areas shown are: • The Site and surrounding area is within the Wellhead Protection Area and designated within Zone 2. According to the Washington State Wellhead Protection Program Guidance Document (Washington Department of Health, 2010), the relevant zones in the Project area include: o Zone 1 and Zone 1 - Modified: The 1-year horizontal time-of-travel boundary for groundwater. Zone 1 is managed to protect the drinking water supply from viral, microbial, and direct chemical contamination. Zone 1 includes a 6-month time-of-travel boundary. The modification is intended to protect a high-priority well, well-field or spring withdrawing from a confined aquifer with some degree of leakage into overlying or underlying confining layers. o Zone 2: The 5-year time-of-travel boundary for groundwater. Zone 2 is managed to control potential chemical contaminants. All potential contaminant sources must be addressed with emphasis on pollution prevention and risk reduction. Zone 2 provides information local planners use to site future "high risk" and "medium risk" potential contaminant sources. • Portions of the northwest and western property boundary are within the Regulated Slopes. Most of the Site is shown as >15 percent to <25 percent, with a small, narrow strip shown as >25 percent to <40 percent (Sensitive Slope) at the slope’s toe. 2.3 Geologic Setting 2.3.1 Geology Based on our review of the geologic map (Mullineaux, 1965), the Site is underlain by Pleistocene Vashon Stade recessional stratified drift, glaciofluvial deposits (Qpa). The glaciofluvial deposits consist chiefly of well-sorted sand and gravel. The unit is subdivided according to origin and topographic form with outwash along the Cedar River valley, sandy gravels containing cobbles in the easternmost terraces that grades to interbedded sand and gravel in Renton and to sand near the north edge of quadrangle. 2.3.2 Faults and Seismicity The Site is located within the Puget Lowland physiographic province, an area of active seismicity that is subject to earthquakes on shallow crustal faults and deeper subduction zone earthquakes. The Site area lies about 2.2 miles southwest of the southern boundary of a concealed trace of the Seattle fault zone, which consists of shallow crustal tectonic ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 5 5 structures that are considered active (evidence for movement within the Holocene [since about 15,000 years ago]) and is believed to be capable of producing earthquakes of magnitude 7.3 or greater. The recurrence interval of earthquakes on this fault zone is believed to be on the order of 1,000 years or more. The most recent large earthquake on the Seattle fault occurred about 1,100 years ago (Pratt et al., 2015). There are also several other shallow crustal faults in the region capable of producing earthquakes and strong ground shaking. The Site area also lies within the zone of strong ground shaking from earthquakes associated with the Cascadia Subduction Zone (CSZ). Subduction zone earthquakes occur due to rupture between the subducting oceanic plate and the overlying continental plate. The CSZ can produce earthquakes up to magnitude 9.3, and the recurrence interval is thought to be on the order of about 500 years. A recent study estimates the most recent subduction zone earthquake occurred on January 26, 1700 (Atwater et al., 2015). Deep intra-slab earthquakes, which occur from tensional rupture of the sinking oceanic plate, are also associated with the CSZ. An example of this type of seismicity is the 2001 Nisqually earthquake. Deep intra-slab earthquakes typically are magnitude 7.5 or less and occur approximately every 10 to 30 years. 2.3.3 Geologic and Seismic Hazards Geologic and seismic hazards are defined as those conditions associated with the geologic and seismic environment that could influence existing and/or proposed improvements. In general, the geologic and seismic hazards most commonly associated with the physical and chemical characteristics of near surface soil, rock, and groundwater include the following. Those shown in bold are the geologic and seismic hazards that could affect the Project area’s development and should be considered during the planning process. Geologic Hazards • Slope stability • Adverse soils • Hydrogeology and groundwater • Subsurface voids • Hydrology and drainage • Hazardous minerals and gases • Volcanic hazards • Land subsidence • Erosion and sedimentation Seismic Hazards • Liquefaction • Lateral spreading • Fault ground rupture • Ground shaking • Tsunamis • Earthquake-induced landslides • Seiches Specific hazards identified above in bold are presented in Table 2 below. The “Level of Concern” is a qualitative assessment based on our engineering geology and geotechnical engineering judgment. Where noted with footnotes, the terminology is taken from a specific source (e.g., DNR webviewer). ASPECT CONSULTING 6 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 Table 2. Geologic and Seismic Hazards Potentially Affecting the Site Geologic and Seismic Hazard Examples Level of Concern Adverse Soils Artificial Fill Expansive Soil, Compressible Soil, Organic-Rich Soil, Sensitive Clay Low to Moderate, Site was graded and filled in areas and is an active maintenance facility with possible buried debris and USTs None to Low Hydrology and Drainage Floodinga Seiches or Standing Water Not in FEMA 100-year flood plain None to Low Slope Stability Landslides and Existing Slope Movements Low, exception along west property boundary Hydrogeology and Groundwater Shallow or artesian groundwater Seepage Permeability or percolation Low None to Low Low Seismic Hazards Cascadia M9.0 scenarioa Crustal – Seattle FZ M7.2 scenarioa Local Fault Rupture Liquefactiona MMIb 7 MMIb 9 None to Low Very Low Notes: a – DNR webviewer: https://geologyportal.dnr.wa.gov/ b – MMI = Modified Mercalli Intensity Scale: http://resilience.abag.ca.gov/shaking/mmi/ The primary geologic hazards that may require further evaluation during engineering design are related to potential fill and debris. The primary seismic hazard that could impact the Site is ground shaking from a Cascadia earthquake or Seattle fault zone earthquake. 2.4 Site Reconnaissance We performed our geotechnical site reconnaissance of the Site on February 15, 2018. The weather was cool and windy with no measurable precipitation, though about 0.25 inch of rain had fallen on the Site during the two prior days. Much of the Site is unpaved gravel lot with and the impervious surfaces including the four buildings and the driveway that leads west from Jefferson Avenue NE into the Site. Topographically, the ground surface at the Site is relatively flat, with only about 5 feet of elevation difference from the west boundary of the parcel to the east boundary, a distance of approximately 600 feet, and no apparent elevation change across the 400 feet from the north to the south. A few shallow depressions (<1 inch) with standing water were observed.in low spots on the concrete slabs and mud pits in two shallow, unpaved low spots. We did not observe ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 7 7 indications of concentrated surface flows across the Site, areas of groundwater seepage from the western slopes, or of recent or ongoing soil erosion. 2.5 Subsurface Conditions 2.5.1 Previous Subsurface Explorations King County performed six geotechnical borings on April 13, 2017 as part of their preliminary geotechnical evaluation of the Site (Appendix C). Borings B-1 through B-5 were drilled to 26.5 feet below ground surface (bgs) at the Site (Parcel No. 1434000012) and boring B-6 to 16.5 feet bgs for a proposed utility easement located along the west side of the adjacent property to the north (Parcel No. 1623059130) (Figure 2, Site Exploration map). The soils encountered were generally consistent throughout the Site and consisted of: • GROUD SURFACE: Ground Surface to up to 0.5 bgs feet, crushed gravel surfacing mixed with sand and silt was encountered in borings B-1 through B-5. Boring B-6 encountered a few inches of topsoil and organic matter. • FILL: From between 1.5 and 5 feet bgs, silty sand and mixtures of sand and gravel were encountered in the borings with the exception of B-2, where no fill was observed. The fill material was medium dense to dense immediately beneath the crushed gravel surface and graded to loose with depth. • OUTWASH DEPOSITS (Qpa): Outwash deposits were encountered in the borings to the total exploration depths. The soils typically consisted of interbedded mixtures of medium dense poorly-graded mixtures of sand and gravel, including some cobbles and boulders. The previous report (Appendix C) also noted potential over-sized materials may be present and it is difficult to determine the percentage of cobbles and, potentially boulders, in the underlying soil deposits. However, cobbles were observed and will likely be encountered during construction, potentially with occasional small boulders. In addition, their report also identified two test pits were excavated to between 4.5 to 5.5 feet bgs during previous [no date stated] exploration of the DNRP Maintenance Complex property. These test pits encountered approximately 2 to 2.5 feet of medium dense to dense gravelly sand fill overlying medium dense to dense native sand and gravel outwash deposits, to the total excavated depths. 2.5.2 Aspect Consulting Environmental Subsurface Explorations Subsurface conditions were explored by advancing four 15- to 20-foot deep direct push borings (designated AB-01 through AB-4) on February 16, 2018 around the perimeter of the two decommissioned USTs (refer to Figure 2). The explorations were logged and soil samples collected by a licensed geologist on the Aspect staff. Exploration logs summarizing the subsurface conditions are presented in Appendix A. Observations and tests were performed in general accordance with ASTM International (ASTM) D 2488, Standard Practice for Description and Identification of ASPECT CONSULTING 8 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 Soils (Visual-Manual Procedure). The terminology used in the soil classifications and other modifiers are defined and presented on the attached Figure A-1 included in Appendix A. 2.5.2.1 Soils The summary of the subsurface units below the existing ground surface encountered in the borings are as follows: FILL Between 7 and 10 feet of fill was encountered in the probes that consisted of brown, silty GRAVEL (GM) with sand and cobbles. The upper fill layer contained some construction debris and the soil color transitioned to gray and tan with depth. OUTWASH DEPOSITS (Qpa) Glacial outwash deposits were encountered underlying the fill to 20 feet bgs. The soils consisted of gray, well-graded and poorly-graded SAND (SW or SP) with variable gravel content. 2.5.2.2 Sampling and Analysis During the direct-push exploration, soil samples were subjected to field screening for hydrocarbon contamination. Field screening consisted of visual and olfactory screening and screening the samples with a photoionization detector (PID). No visual, olfactory, or PID field indications of contamination were observed. One soil sample from each of the four borings was submitted to an accredited analytical laboratory for detection and quantification of contamination. The selected samples were collected at a depth at or below the presumed depth of the bottom of the USTs. Samples were collected in general conformance with EPA Method 5030 and with applicable industry practices. The laboratory analyzed each sample for gasoline-range organics (by method NWTPH- G) and diesel- and oil-range organics (method NWTPH-Dx). The laboratory report is in Appendix B. None of the analytes were detected at the reporting detection limits. 2.5.3 Groundwater Groundwater was not observed in our direct-push borings (maximum depth of 20 feet) or King County’s previous borings (maximum depth 26.5 feet) during field exploration. Groundwater depths will fluctuate due to variations in rainfall, irrigation, and the season. Local well logs reviewed from the Department of Ecology’s well database show Renton Highlands Landfill (Well Log 328114) groundwater at 11 feet bgs and another record for Nickelson Development (Well Log 328143) at 17 feet bgs. Groundwater depths identified by these two well logs are likely perched and regional groundwater depths are nearer to 40 feet bgs. 2.5.4 Stormwater Infiltration The Site is underlain by medium dense sand and gravel deposits outwash sands and gravels to at least 26 feet bgs and groundwater is anticipated to be deeper than about 35 feet or more. These soil and groundwater condition are typically conducive to stormwater infiltration and management. ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 9 9 3 Conclusions and Recommendations 3.1 General Based on our geotechnical evaluation of the Site, including data review, Site reconnaissance, subsurface explorations, and laboratory testing, the following key preliminary findings and conclusions should be included in further evaluating the Site: The Site is within the Zone 2 Wellhead Protection Area and the City may require a permit applicant to submit a hydrogeologic study if the proposed project has the potential to significantly impact groundwater quantity or quality, and sufficient information is not readily available. Generally medium dense sands and gravels with variable amounts of silt have been encountered in the explorations. The Qpa deposits contain cobbles and boulders that may be encountered during earthwork. The area surrounding the decommissioned USTs did not have indications of contaminated soil. Although no field or laboratory indications of product release from the USTs were measured or observed, the steel USTs could have leaked while these were in service. Because the soils around and below the USTs are coarse-grained and permeable, any release from the USTs would have migrated vertically. If the tanks will be removed as part of the construction, we recommend field-screening the soil directly under the tanks for indications of contamination and, if detected, completing additional analytical laboratory tests. Shallow spread footings are an appropriate foundation type. Groundwater is not anticipated within these excavation depths. Existing structure, overhead utilities, paved areas, and piles of debris will require demolition and removal. Outwash sands and gravels are generally well suited for stormwater infiltration. The Site’s designation as a Wellhead Protection Area Zone 2 should be considered. From a geotechnical perspective, typical activities associated with site development such as clearing and grading, utility placement, and building construction will have no adverse impacts on surrounding properties provided City of Renton and/or other regulatory requirements for design and construction are implemented. Although plans had not been completed at the time of this report, we anticipate cuts and fills will generally be less than 2 feet over most of the Site. From a geotechnical perspective, earthwork excavation using conventional equipment will be feasible during construction. ASPECT CONSULTING 10 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 3.2 Seismic Design Criteria Inertial seismic forces are expected to affect the Site and structures. Appropriate design of structures in accordance with the current version of the International Building Code (IBC) with State of Washington amendments will mitigate seismic hazards. The IBC requires design for a “Maximum Considered Earthquake (MCE)” with a 2 percent probability of exceedance (PE) in 50 years (2,475-year return period; IBC, 2015). The U.S. Geological Survey (USGS) has completed probabilistic ground motion studies and maps for Washington (USGS, 2014). Current IBC design methodologies express the effects of site-specific subsurface conditions on the ground motion response in terms of the “site class.” The site class can be correlated to the average standard penetration resistance (SPT) in the upper 100 feet of the soil profile. Based on the results of the previous subsurface exploration program and using the 2015 IBC criteria, we recommend the Site be characterized by a Seismic Site Class D. Based on the Site’s latitude and longitude (47.488°N, 122.178°W), the code-based seismic design criteria, in accordance with the 2015 IBC, are summarized in Table 3. Table 3. 2018 IBC Seismic Design Parameters Parameter Short Period 1 Second Maximum Credible Earthquake Spectral Acceleration Ss = 1.42 g S1 = 0.53 g Site Class D Site Coefficient Fa = 1.00 Fv = 1.56 Adjusted Spectral Acceleration SMS = 1.42 g SM1 = 0.80 g Design Spectral Response Acceleration Parameters SDS = 0.94 g SD1 = 0.53 g Design Spectral Peak Ground Acceleration 0.58 g Notes: g = acceleration due to gravity The NEHRP Recommended Seismic Provisions recognizes that, independent of the quality of their design and construction, not all buildings pose the same seismic risk. Factors that affect a structure’s seismic risk include: • The intensity of ground shaking and other earthquake effects the structure is likely to experience and • The structure’s use including consideration of the number of people who would be affected by the structure’s failure and the need to use the structure for its intended purpose after an earthquake. Based on the anticipated occupancy type and building uses, ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 11 11 Table 4. NEHRP Description of Category III-Type Buildings Category Representative Buildings Acceptable Risk III Buildings and structures that: • Have large numbers of occupants (e.g., high-rise office buildings, sports arenas, and large theaters), • Shelter persons with limited mobility (e.g., jails, schools, and some healthcare facilities); • Support lifelines and utilities important to a community’s welfare; or • Contain materials that pose some risk to the public if released. Reduced risk of earthquake- induced collapse relative to Occupancy Category II structures. Reduced risk of shaking-imposed damage to nonstructural components relative to Occupancy Category II structures. Low risk of release of hazardous materials or loss of function of critical lifelines and utilities. 3.3 Foundation Design 3.3.1 Shallow Foundations Based on our observations of the subsurface conditions at the Site, shallow foundations on spread footings may be used for building supports if placed on the Qpa deposits. Spread footings should be established in firm, undisturbed soil or compacted structural fill. The exposed subgrade surface of all footings should be evaluated by a qualified geotechnical engineer or engineering geologist. Table 5. Spread Footing Foundation Design Recommendations1 Design Item Design Information Structures Renton Shop Buildings Bearing Material Qpa deposits and compacted structural fill Allowable Bearing Pressure1 2,500 psf Minimum Embedment Depth2,3 18 inches Total Estimated Settlement Differential Settlement Less than 1 inch Less than ½-inch between adjacent footings Notes: 1 Designs are based on the subsurface conditions encountered in the explorations and assumes the recommendations in the Construction Considerations Section will be adhered to. 2 For preliminary information related to minimum depth of footing for frost action. Does not infer or indicate depth to bearing strata. Will be updated at final design. 3 The recommended allowable bearing pressure applies to the total of dead plus long-term-live loads. Allowable bearing pressures may be increased by one-third (⅓) for seismic and wind loads. For use in design, an ultimate coefficient of friction of 0.45 may be assumed along the interface between the base of a cast-in-place concrete footing and the subgrade soils. An ultimate passive earth pressure of 450 pounds per cubic foot (pcf) may be assumed for ASPECT CONSULTING 12 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 structural fill replacement or gravel soils adjacent to below-grade elements. The upper 1 foot of passive resistance should be neglected in design. The recommended coefficient of friction and passive pressure values are ultimate values that do not include a safety factor. We recommend applying a factor of safety of at least 1.5 in design for determining allowable values for coefficient of friction and passive pressure. 3.4 Floor Slabs and Modulus of Subgrade Reaction Concrete slabs-on-grade should be designed in accordance with the American Concrete Institute (ACI) Committee’s 360R-10 Guide to Design of Slabs-on-Ground (ACI, 2010). For slabs that are designed as beam-on-elastic foundation, a modulus of vertical subgrade reaction of 150 pounds per cubic inch (pci) may be utilized. Satisfactory support for building floor slabs can be obtained from the native silt, clay, or gravel subgrades prepared in accordance with our recommendations presented in the Site Preparation and/or Wet-Weather/Wet-Soil Conditions sections of this report (Sections 4.2 and 4.4, respectively). A minimum 6-inch-thick layer of imported granular material should be placed and compacted over the prepared subgrade. Imported granular material should be composed of crushed rock or crushed gravel that is relatively well-graded between coarse and fine, contains no deleterious materials, has a maximum particle size of 1 inch, and has less than 5 percent by dry weight passing the US Standard No. 200 Sieve. 3.5 Pavement Design Traffic volume estimates and loading patterns were not provided at the time of this report. We anticipate that parking and ancillary access drives will primarily be paved with hot mix asphalt (HMA) pavement. Without traffic volume information to complete a pavement design, the general pavement section recommendation in accordance with the King County Roads Standards (King County, 2016). The main drive lanes entering and leaving the Site and areas of the buildings where maintenance vehicles will frequently be using, including loading ramps, should consider more robust HMA pavement sections or using portland cement concrete (PCC). For planning purposes pavement sections are shown in Table 6 below. Table 6. Preliminary Pavement Section Parking areas and ancillary drive lanes Loading ramps and main drive lanes HMA HMA PCC HMA CLASS ½” (wearing course) 2 2 in HMA CLASS ½” (leveling course) 2 3.5 PCC 8 CSBC 8.5 12 6 ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 13 13 4 Construction Considerations 4.1 General Earthwork is typically most economical when performed under dry weather conditions. Appropriate erosion control measures should be implemented prior to beginning earthwork activities in accordance with the local regulations. In our opinion, excavation can generally be accomplished using standard excavation equipment. While not directly observed in Aspect’s subsurface explorations, the presence of potential obstructions, such as small boulders, buried logs, or other debris, in the fill or other deposits should be anticipated. 4.2 Site Preparation Site preparation within the proposed construction footprint should include removal of fill and soils containing roots, organics, debris, and any other deleterious materials. The contractor must use care during Site preparation and excavation operations, so that any bearing surfaces are not disturbed. If disturbance does occur, the disturbed material should be removed to expose undisturbed material or be compacted in place to acceptable criteria as determined by the geotechnical engineer. All footing excavations should be trimmed neat and the bottom of the excavation should be carefully prepared. All loose or softened soil should be removed from the footing excavation or compacted in place prior to placing reinforcing steel bars. We recommend that footing excavations be observed by the geotechnical engineer prior to placing steel and concrete to verify the recommendations in this report have been followed. The subgrade under the HMA pavement section areas should be prepared by scarifying, moisture conditioning, and recompacting a minimum of 12 inches below the bottom of the base course. Materials generated during earthwork should be transported off-site or stockpiled in areas designated by the owner’s representative. 4.3 Proofrolling and Subgrade Verification Following Site preparation, and prior to placing an aggregate base for the pavement sections, the exposed subgrade should be evaluated either by proofrolling or another method of subgrade verification. The subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify unsuitable areas. If evaluation of the subgrades occurs during wet conditions, or if proofrolling the subgrades will result in disturbance, they should be evaluated by Aspect using a steel foundation probe. We recommend that Aspect be retained to observe the proofrolling and perform the subgrade verifications. Unsuitable areas identified during the field evaluation should be compacted to a firm condition or be excavated and replaced with structural fill. 4.4 Wet Weather Conditions If earthwork is to be performed or fill is to be placed in wet weather or under wet conditions, when soil moisture content is above optimum and difficult to control, the following recommendations apply: ASPECT CONSULTING 14 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 Earthwork should be performed in small areas to minimize exposure. Structural fill placed during wet weather should consist of material meeting the criteria for Gravel Borrow as specified in Section 9-03.14(1) of the WSDOT Standard Specifications (WSDOT, 2016). Excavation or the removal of unsuitable soils should be followed promptly by the placement and compaction of the specified structural fill. The size, type, and access of construction equipment used may have to be limited to prevent soil disturbance. The ground surface within the construction area should be graded to promote runoff of surface water away from the slopes and to prevent water ponding. The ground surface within the construction area should be properly covered and under no circumstances should be left uncompacted and/or exposed to moisture. Soils that become too wet for compaction should be removed and replaced with specified structural fill. Excavation and placement of fill should be observed by the geotechnical engineer to verify that all unsuitable materials are removed prior to placement, compaction requirements are met, and site drainage is appropriate. Erosion and sedimentation control should be implemented in accordance with best management practices (BMPs). 4.5 Excavation 4.5.1 General The near-surface soils at the Site can be excavated with conventional earthwork equipment. Sloughing and caving should be anticipated in loose, noncohesive materials. Aspect should be retained to review the grading and utility plans when they become available for comparison with encountered field conditions; additional work may be required to better define the impact on the Project. Maintenance of safe working conditions, including temporary excavation stability, is the sole responsibility of the contractor. All temporary cuts in excess of 4 feet in height that are not protected by trench boxes, or otherwise shored, should be sloped in accordance with Part N of Washington Administrative Code (WAC) 296-155 (WAC, 2009). 4.5.2 Trenches Trench cuts should stand relatively vertical to a depth of approximately 4 feet bgs, provided no groundwater seepage is present in the trench walls. Open excavation techniques may be used in the clay, silt, silty sand, and sandy silt, provided the excavation is configured in accordance with the U.S. Occupational Safety and Health Administration (OSHA) requirements, groundwater seepage is not present, and with the understanding that some sloughing may occur. The trenches should be flattened if sloughing occurs or seepage is present. If shallow groundwater is observed during construction, use of a trench shield or other approved temporary shoring is recommended for cuts that extend below groundwater seepage, or if vertical walls are desired for cuts deeper than 4 feet bgs. If dewatering is used, we recommend that the type and design of ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 15 15 the dewatering system be the responsibility of the contractor, who is in the best position to choose systems that fit the overall plan of operation. 4.5.3 Temporary and Permanent Slopes With time and the presence of seepage and/or precipitation, the stability of temporary unsupported cut slopes can be significantly reduced. We recommend planning the construction schedule to have excavation occur during the summer months and to minimize the amount of time that the temporary slopes will be unsupported during construction. The contractor should monitor the stability of the temporary cut slopes and adjust the construction schedule and slope inclination accordingly. Vibrations created by traffic and construction equipment may cause caving and raveling of the face of the temporary slopes. At no time should soil stockpiles, equipment, and other loads be placed immediately adjacent to an excavation. In general, shallow surface soils, such as topsoil and unconsolidated soils that will be subject to excavation and sloping on the Site classify OSHA Soil Classification Type C. These soils are expected to fail at steep angles. Temporary excavation side slopes (cut slopes) are anticipated to stand as steep as 1.5H:1V within the topsoil and unconsolidated soils. The cut slope inclinations estimated above are for planning purposes only and are applicable to excavations without inflowing perched groundwater or runoff. Permanent slopes for the project should have a maximum inclination of 2H:1V. Access roads and pavements should be located at least 5 feet from the top of temporary slopes. Surface water runoff should be collected and directed away from slopes to prevent water from running down the face. 4.6 Structural Fill Material and Compaction Structural fill, including base rock, should be placed over subgrades that have been prepared in conformance with the Site Preparation and Wet-Weather/Wet-Soil Conditions sections of this report. Source material may be derived from on-site sources, or imported. The on-Site soils will likely contain over-sized materials with fine contents above optimum moisture but may be suitable for re-use on the Project, provided the soil meets the material requirements described below and can be sufficiently screened. Soil derived from saturated excavations should be anticipated to be less suitable for use as fill due to elevated moisture contents. General fill specifics are provided in Table 7. ASPECT CONSULTING 16 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 Table 7. Fill Type and Compaction Requirements Fill Type WSDOT Specification Details Lift Thickness1 and Compaction Requirements2 Onsite Soil N/A 8 to 12 inches Dependent on Application Imported Granular Materials WSDOT SS 9-03.14(2) – Select Borrow3 9 inches 95 percent Crushed Aggregate Base WSDOT SS 9-03.9(3) – Crushed Surfacing Top Course or Base Course 9 inches 95 percent Foundation Base Aggregate WSDOT SS 9-03.12(1)A – Gravel Backfill for Foundations (Class A) 9 inches 95 percent Trench Backfill WSDOT SS 9-03.12(3) – Gravel Backfill for Pipe Zone Bedding4 WSDOT SS 9-03.19– Bank Run Gravel for Trench Backfill5 WSDOT SS 9-03.14 – Borrow and WSDOT SS 9-03.15 – Native Material for Trench Backfill6 9 inches 90 percent7 9 inches 92 percent7 9 inches 95 percent8 9 inches 90 percent7 Notes: 1. Maximum uncompacted thickness 2. Maximum dry density, as determined by ASTM D1557 3. Fraction passing the US Standard No. 4 Sieve, less than 5 percent by dry weight should pass the US Standard No. 200 Sieve. 4. Trench backfill placed beneath, adjacent to, and for at least 2 feet above utility lines (i.e., the pipe zone) 5. Within pavement areas or beneath building pads 6. Outside of structural improvement areas (e.g., roadway alignments or building pads), trench backfill placed above the pipe zone 7. Or per manufacturer / local building department 8. Within 2 feet below pavement 4.7 Ground Moisture 4.7.1 General The perimeter ground surface and hard-scaping should be sloped to drain away from all structures and away from adjacent slopes. Gutters should be tight -lined to a suitable discharge and maintained as free-flowing. Any crawl spaces should be adequately ventilated and sloped to drain to a suitable, exterior discharge. 4.7.2 Perimeter Footing Drains Due to the potential for perched groundwater, we recommend perimeter foundation drains be installed around all proposed structures. The foundation subdrainage system should include a minimum 4-inch-diameter perforated pipe in a drain rock envelope. A nonwoven geotextile filter fabric, such as Mirafi 140N or equivalent, should be used to completely wrap the drain rock envelope, separating it from the native soil and footing backfill materials. The invert of the ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 17 17 perimeter drain lines should be placed approximately at the bottom of footing elevation. Also, the subdrainage system should be sealed at the ground surface. The perforated subdrainage pipe should be laid to drain by gravity into a non-perforated, solid pipe and finally connected to the Site drainage stem at a suitable location. Water from downspouts and surface water should be independently collected and routed to a storm sewer or other outlet. This water must not be allowed to enter the bearing soils. ASPECT CONSULTING 18 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 5 Project Design and Construction Monitoring At the time of this report, site plans, site grading, structural plans, and construction methods have not been finalized, and the recommendations presented herein are based on preliminary project information. Additional work including geotechnical explorations and infiltration tests, engineering analyses, and geotechnical design recommendations wil l be needed for the selected, preferred alternative development. This report is issued with the understanding that the information and recommendations contained herein will be brought to the attention of the appropriate design team personnel and incorporated into the project plans and specifications, and that the necessary steps will be taken to verify that the contractor and subcontractors carry out such recommendations in the field. We do not direct the contractor’s operations, and we cannot be responsible for the safety of personnel other than our own on the Site; the safety of others is the responsibility of the contractor. The contractor should notify the property owner if he considers any of the recommended actions presented herein unsafe. We are available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundation depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 19 19 6 References American Concrete Institute (ACI), 2010, Guide to Design of Slabs-on-Ground, Reported by ACI Committee 360, April 2010. ASTM International (ASTM), 2017, 2017 Annual Book of ASTM Standards, West Conshohocken, Pennsylvania. Atwater, B.F., Musumi-Rokkaku, S., Satake, K., Tsuji, Y., Ueda, K., and Yamaguchi, D.K., 2015, The orphan tsunami of 1700—Japanese clues to a parent earthquake in North America, 2nd ed.: Seattle, University of Washington Press, U.S. Geological Survey Professional Paper 1707, 135 p. City of Renton, 2018, Maps of Your Community online portal , Website, http://rp.rentonwa.gov/HTML5Public/Index.HTML?viewer=CORMaps, Accessed March 1, 2018 International Building Code (IBC), 2015, International Building Code. Prepared by International Code Council, January. King County, 2016, Road Design and Construction Standards, Department of Transportation, Road Services Division, 18420 Attachment A, revised November 28, 2016. King County, King County Interactive Mapping Program (iMap) Web Portal, website https://gismaps.kingcounty.gov/iMap/, Accessed March 1, 2018. Mullineaux, D. R., 1965, Geologic map of the Renton quadrangle, King County, Washington, U.S. Geological Survey, Geologic Quadrangle Map GQ-405, 1 sheet, scale 1:24,000. Pratt, T.L., K.G. Troost, J.K. Odum, and W.J. Stephenson, 2015, Kinematics of shallow backthrusts in the Seattle fault zone, Washington State, Geosphere, v. 11, no. 6, p. 1–27, doi:10.1130/GES01179.1. U.S. Geological Survey (USGS), 2014, U.S. Seismic Design Maps, Page Last Modified: January 30, 2017 18:07:40 UTC, Website, http://earthquake.usgs.gov/designmaps/us/application.php, Accessed March 1, 2018. Washington Department of Health, 2010, Washington State Wellhead Protection Program Guidance Document, June 2010. Washington Department of Natural Resources (DNR), 2017, Interactive Geologic Map, Website: https://geologyportal.dnr.wa.gov/, Division of Geology and Earth Resources, Accessed March 1, 2018. Washington State Department of Transportation (WSDOT), 2016, Standard Specifications for Road, Bridge and Municipal Construction, Document M 41-10. ASPECT CONSULTING 20 PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 7 Limitations Work for this project was performed for HDR Architecture, Inc. (Client), and this report was prepared consistent with recognized standards of professionals in the same locality and involving similar conditions, at the time the work was performed. No other warranty, expressed or implied, is made by Aspect Consulting, LLC (Aspect). Recommendations presented herein are based on our interpretation of site conditions, geotechnical engineering calculations, and judgment in accordance with our mutually agreed-upon scope of work. Our recommendations are unique and specific to the project, site, and Client. Application of this report for any purpose other than the project should be done only after consultation with Aspect. Variations may exist between the soil and groundwater conditions reported and those actually underlying the site. The nature and extent of such soil variations may change over time and may not be evident before construction begins. If any soil conditions are encountered at the site that are different from those described in this report, Aspect should be notified immediately to review the applicability of our recommendations. It is the Client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, and agents, are made aware of this report in its entirety. At the time of this report, design plans and construction methods have not been finalized, and the recommendations presented herein are based on preliminary project information. If project developments result in changes from the preliminary project information, Aspect should be contacted to determine if our recommendations contained in this report should be revised and/or expanded upon. The scope of work does not include services related to construction safety precautions. Site safety is typically the responsibility of the contractor, and our recommendations are not intended to direct the contractor’s site safety methods, techniques, sequences, or procedures. The scope of our work also does not include the assessment of environmental characteristics, particularly those involving potentially hazardous substances in soil or groundwater. All reports prepared by Aspect for the Client apply only to the services described in the Agreement(s) with the Client. Any use or reuse by any party other than the Client is at the sole risk of that party, and without liability to Aspect. Aspect’s original files/reports shall govern in the event of any dispute regarding the content of electronic documents furnished to others. Please refer to Appendix D titled “Report Limitations and Guidelines for Use” for additional information governing the use of this report. i FIGURES ^GIS Path: T:\projects_8\KingCountyParksMaintenanceFacility_170383\Delivered\01 Site Location Map.mxd || Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet || Date Saved: 3/13/2018 || User: kschrup || Print Date: 3/13/2018Site Location MapPreliminary Geotechnical ReportRenton Shop3005 NE 4th StreetRenton, Washington C O N SU LT I N G FIGURE NO .1MAR-2018 PROJECT NO.170292 BY:MWS / KES REVISED BY:- - - 0 2,000 4,000 Feet ! ! ! #! ! ! ! !( W A S H I N G T O N Bellingham Olympia Port Angeles Seattle Spokane Tacoma Wenatchee Yakima ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! # ! ! !( PugetSound LakeWashin gtonElliottBay Auburn Bellevue Burien Covington Des Moines Factoria Federal Way Issaquah Kent Maple Valley Mercer Island Newcastle Renton SammamishSeattle Tukwila White Center Basemap Layer Credits || Sources: Esri, HERE, DeLorme, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo,MapmyIndia, © OpenStreetMap contributors, and the GIS User CommunityCopyright:© 2014 Esri SITE LOCATION SITELOCATION SITELOCATION !<!<!<!<"/ "/ "/ "/ "/JEFFERSON AVE NEAB-01 AB-02 AB-04 AB-03 B-1 B-2 B-3 B-4B-5 C O N SU LT I N G FIGURE NO .2MAR-2018 PROJECT NO.170292 BY:MWS / KES REVISED BY:- - - Site Exploration MapPreliminary Geotechnical ReportRenton Shop3005 NE 4th StreetRenton, Washington Basemap Layer Credits || Pictometry International Corp. 2015 GIS Path: T:\projects_8\KingCountyParksMaintenanceFacility_170383\Delivered\02 Site Exploration Plan.mxd || Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet || Date Saved: 3/13/2018 || User: kschrup || Print Date: 3/13/20180 80 160 Feet "/King County Department of Transpor tation Borings Drilled April 2017 !<Aspect Consulting LLC Geoprobes Drilled February 2018 Subject Proper ty Tax Parcel i APPENDIX A Subsurface Explorations ASPECT CONSULTING PROJECT NO. 170383 - TASK 200 MARCH 20, 2018 A-1 1 A. Subsurface Exploration Program Environmental geoprobes (designated AB-01 through AB-4) were pushed on February 16, 2018 in the vicinity of two decommissioned USTs. The probes were advanced to between 15 and 20 feet below existing ground surface (bgs) by Holt Services, Inc. with a Geoprobe 7822D. The geoprobe locations are shown on Figure 2 and were estimated in the field by measuring from existing Site features. The explorations were backfilled with the bentonite in accordance with Washington State Department of Ecology guidelines. Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual-manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. Terms Describing Relative Density and Consistency Estimated Percentage Symbols Moisture Content Percentage by Weight Coarse-Grained Modifier Fine-Grained Modifier Sampler Type Sampler Type Description Blows/6" or portion of 6" Component Definitions Size Range and Sieve Number Larger than 12" Descriptive Term Smaller than No. 200 (0.075 mm) 3" to 12" Coarse- Grained Soils Fine- Grained Soils Density Very Loose Loose Medium Dense Dense Very Dense SPT blows/foot 0 to 4 4 to 10 10 to 30 30 to 50 >50 (2) 0 to 2 2 to 4 4 to 8 8 to 15 15 to 30 >30 Consistency Very Soft Soft Medium Stiff Stiff Very Stiff Hard SPT blows/foot(2) 2.0" OD Split-Spoon Sampler (SPT)Continuous Push Non-Standard Sampler Bulk sample 3.0" OD Thin-Wall Tube Sampler (including Shelby tube) Grab Sample Portion not recovered(1)ATD = At time of drilling Static water level (date) Percentage by dry weight (SPT) Standard Penetration Test (ASTM D-1586) In General Accordance with Standard Practice for Description and Identification of Soils (ASTM D-2488) Test Symbols Depth of groundwater(4) (1) (2) (3) Cement grout surface seal Groutseal End cap Filter pack with blank casing section Boulders Silt and Clay Gravel Coarse Gravel Fine Gravel Cobbles Sand Coarse Sand Medium Sand Fine Sand Dry - Absence of moisture, dusty, dry to the touch Slightly Moist - Perceptible moisture Moist - Damp but no visible water Very Moist - Water visible but not free draining Wet - Visible free water, usually from below water table HighlyOrganicSoilsFine-Grained Soils - 50% or More Passes No. 200 Sieve(1)Coarse-Grained Soils - More than 50% Retained on No. 200 SieveGravels - More than 50% of Coarse Fraction Retained on No. 4 Sieve15% Fines5% FinesSands - 50% or More of Coarse Fraction Passes No. 4 SieveSilts and ClaysLiquid Limit Less than 50Silts and ClaysLiquid Limit 50 or More(5)Combined USCS symbols used for fines between 5% and 15% as estimated in General Accordance with Standard Practice for Description and Identification of Soils (ASTM D-2488)(1)(1)15% Fines5% Fines(5)(5)(5)(5)FC = Fines Content G = Grain Size M = Moisture Content A = Atterberg Limits C = Consolidation DD = Dry Density K = Permeability Str = Shear Strength Env = Environmental PiD = Photoionization No. 4 (4.75 mm) to No. 10 (2.00 mm) No. 10 (2.00 mm) to No. 40 (0.425 mm) No. 40 (0.425 mm) to No. 200 (0.075 mm) 3" to No. 4 (4.75 mm) 3" to 3/4" 3/4" to No. 4 (4.75 mm) No. 4 (4.75 mm) to No. 200 (0.075 mm) Well-graded gravel and gravel with sand, little to no fines Poorly-graded gravel and gravel with sand, little to no fines Silty gravel and silty gravel with sand Clayey gravel and clayey gravel with sand Well-graded sand and sand with gravel, little to no fines Poorly-graded sand and sand with gravel, little to no fines Silty sand and silty sand with gravel Clayey sand and clayey sand with gravel Silt, sandy silt, gravelly silt, silt with sand or gravel Clay of low to medium plasticity; silty, sandy, or gravelly clay, lean clay Organic clay or silt of low plasticity Elastic silt, clayey silt, silt with micaceous or diato- maceous fine sand or silt Clay of high plasticity, sandy or gravelly clay, fat clay with sand or gravel Organic clay or silt of medium to high plasticity Peat, muck and other highly organic soils GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT Trace Trace With silt or clay Silty or Clayey <5 5 to 15 16 to 49 16 to 30 With sand or gravel Sandy or Gravelly31 to 49 Screened casing or Hydrotip with filter pack Bentonitechips FIGURE NO. PROJECT NO.DATE: REVISED BY: DRAWN BY: DESIGNED BY: www.aspectconsulting.com earth + water Exploration Log Key A-1 Q:\_ACAD Standards\Standard Details\Exploration Log Key A1.dwgDetector Grouted Transducer BGS = below ground surface Vacuum excavated to 5 ft bgs Borehole backfilled with bentonite chips AB-01-12 NWTPH-Dx, NWTPH-G FILL SILTY GRAVEL WITH SAND (GM); wet to moist, brown; fine to coarse sand Abundant cobbles Becomes slightly moist; becomes gray, tan, and brown GLACIAL OUTWASH SAND WITH GRAVEL (SW); moist, gray; fine to coarse sand, fine to coarse gravel, few percent silt Bottom of exploration at 20 ft. bgs. PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None Depth (feet) Material Type Ground Surface (GS) Elev. (NAVD88) Mike No Soil Sample Recovery WaterLevelAB-01 Sheet 1 of 1 Depth (ft) Sampling Method 2/16/2018 Project Address & Site Specific Location Environmental Exploration Log Logged by: Mv Approved by: MWS 03/12/18 330' NA 3005 NE 4th St, Renton, Washington, SW corner of canopy King County Parks Renton Shop - 170383 ExplorationLog NEW STANDARD LOG FORM P:\GINTW\PROJECTS\KCP CFD 170383.GPJ March 13, 2018Sample Type/ID Elev. (feet) No Water Encountered Operator Work Start/Completion Dates Top of Casing Elev. (NAVD88) 5 10 15 20 Continuous core 1.5" ID Grab sample Field Tests Percussion hammerGeoprobe 7822D Direct push Holt Svcs Exploration Method(s) See Exploration Log Key for explanation of symbols Exploration Completion and Notes No Water Encountered Depth to Water (Below GS) Exploration Number SampleMethodDescription Equipment Legend Contractor 325 320 315 310 AB-01 Coordinates (Lat,Lon WGS84) Analytical Sample Number & Lab Test(s) 5 10 15 20 47.48615, -122.17895 (est) Vacuum excavated to 5 ft bgs Borehole backfilled with bentonite chips AB-02-7 NWTPH-Dx, NWTPH-G FILL SILTY GRAVEL WITH SAND (GM); moist to wet, brown; fine to coarse gravel, fine to coarse sand Abundant cobbles Becomes slightly moist; becomes gray, tan, and brown GLACIAL OUTWASH SAND (SW); moist, gray; fine to coarse sand, few percent gravel, few percent silt SAND (SP); moist, gray; fine to medium sand, few percent gravel, few percent silt Bottom of exploration at 20 ft. bgs. PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Depth (feet) Material Type Ground Surface (GS) Elev. (NAVD88) Mike No Soil Sample Recovery WaterLevelAB-02 Sheet 1 of 1 Depth (ft) Sampling Method 2/16/2018 Project Address & Site Specific Location Environmental Exploration Log Logged by: Mv Approved by: MWS 03/12/18 330' NA 3005 NE 4th St, Renton, Washington, NW corner of canopy King County Parks Renton Shop - 170383 ExplorationLog NEW STANDARD LOG FORM P:\GINTW\PROJECTS\KCP CFD 170383.GPJ March 13, 2018Sample Type/ID Elev. (feet) No Water Encountered Operator Work Start/Completion Dates Top of Casing Elev. (NAVD88) 5 10 15 20 Continuous core 1.5" ID Grab sample Field Tests Percussion hammerGeoprobe 7822D Direct push Holt Svcs Exploration Method(s) See Exploration Log Key for explanation of symbols Exploration Completion and Notes No Water Encountered Depth to Water (Below GS) Exploration Number SampleMethodDescription Equipment Legend Contractor 325 320 315 310 AB-02 Coordinates (Lat,Lon WGS84) Analytical Sample Number & Lab Test(s) 5 10 15 20 47.48621, -122.17898 (est) Vacuum excavated to 5 ft bgs Borehole backfilled with bentonite chips AB-03-12 NWTPH-Dx, NWTPH-G FILL SILTY GRAVEL WITH SAND (GM); wet to moist, brown; fine to coarse gravel, fine to coarse sand GLACIAL OUTWASH SAND (SW); moist, gray; fine to coarse sand, few percent gravel, few percent silt Bottom of exploration at 15 ft. bgs. PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Depth (feet) Material Type Ground Surface (GS) Elev. (NAVD88) Mike No Soil Sample Recovery WaterLevelAB-03 Sheet 1 of 1 Depth (ft) Sampling Method 2/16/2018 Project Address & Site Specific Location Environmental Exploration Log Logged by: Mv Approved by: MWS 03/12/18 330' NA 3005 NE 4th St, Renton, Washington, NE corner of canopy King County Parks Renton Shop - 170383 ExplorationLog NEW STANDARD LOG FORM P:\GINTW\PROJECTS\KCP CFD 170383.GPJ March 13, 2018Sample Type/ID Elev. (feet) No Water Encountered Operator Work Start/Completion Dates Top of Casing Elev. (NAVD88) 5 10 15 20 Continuous core 1.5" ID Grab sample Field Tests Percussion hammerGeoprobe 7822D Direct push Holt Svcs Exploration Method(s) See Exploration Log Key for explanation of symbols Exploration Completion and Notes No Water Encountered Depth to Water (Below GS) Exploration Number SampleMethodDescription Equipment Legend Contractor 325 320 315 310 AB-03 Coordinates (Lat,Lon WGS84) Analytical Sample Number & Lab Test(s) 5 10 15 20 47.48620, -122.17884 (est) Vacuum excavated to 5 ft bgs Borehole backfilled with bentonite chips AB-04-12 NWTPH-Dx, NWTPH-G FILL SILTY GRAVEL WITH SAND (GM); wet to moist, brown; fine to coarse sand, fine to coarse gravel; few percent construction debris Becomes slighlty moist; becomes gray, tan, brown GLACIAL OUTWASH SAND (SW); moist, gray; fine to coarse sand, few percent gravel, few percent silt Bottom of exploration at 15 ft. bgs. PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None PID= 0 Sheen= None Depth (feet) Material Type Ground Surface (GS) Elev. (NAVD88) Mike No Soil Sample Recovery WaterLevelAB-04 Sheet 1 of 1 Depth (ft) Sampling Method 2/16/2018 Project Address & Site Specific Location Environmental Exploration Log Logged by: Mv Approved by: MWS 03/12/18 330' NA 3005 NE 4th St, Renton, Washington, SE corner of canopy King County Parks Renton Shop - 170383 ExplorationLog NEW STANDARD LOG FORM P:\GINTW\PROJECTS\KCP CFD 170383.GPJ March 13, 2018Sample Type/ID Elev. (feet) No Water Encountered Operator Work Start/Completion Dates Top of Casing Elev. (NAVD88) 5 10 15 20 Continuous core 1.5" ID Grab sample Field Tests Percussion hammerGeoprobe 7822D Direct push Holt Svcs Exploration Method(s) See Exploration Log Key for explanation of symbols Exploration Completion and Notes No Water Encountered Depth to Water (Below GS) Exploration Number SampleMethodDescription Equipment Legend Contractor 325 320 315 310 AB-04 Coordinates (Lat,Lon WGS84) Analytical Sample Number & Lab Test(s) 5 10 15 20 47.48618, -122.17884 (est) 1 APPENDIX B Analytical Laboratory Test Results FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS James E. Bruya, Ph.D. 3012 16th Avenue West Yelena Aravkina, M.S. Seattle, WA 98119-2029 Michael Erdahl, B.S. (206)285-8282 Arina Podnozova, B.S. fbi@isomedia.com Eric Young, B.S. www.friedmanandbruya.com February 22, 2018 Matthew Vonder-Ahe, Project Manager Aspect Consulting, LLC 350 Madison Ave. N. Bainbridge Island, WA 98110-1810 Dear Mr Vonder-Ahe: Included are the results from the testing of material submitted on February 16, 2018 from the KCPCFM 170383, F&BI 802285 project. There are 6 pages included in this report. Any samples that may remain are currently scheduled for disposal in 30 days. If you would like us to return your samples or arrange for long term storage at our offices, please contact us as soon as possible. We appreciate this opportunity to be of service to you and hope you will call if you have any questions. Sincerely, FRIEDMAN & BRUYA, INC. Michael Erdahl Project Manager Enclosu res c: data@aspectconsulting.com ASP0222R.DOC FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 1 CASE NARRATIVE This case narrative encompasses samples received on February 16, 2018 by Friedman & Bruya, Inc. from the Aspect Consulting, LLC KCPCFM 170383, F&BI 802285 project. Samples were logged in under the laboratory ID’s listed below. Laboratory ID Aspect Consulting, LLC 802285 -01 AB-02-7 802285 -02 AB-01-12 802285 -03 AB-03-12 802285 -04 AB-04-12 802285 -05 Trip Blank All quality control requirements were acceptable. FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 2 Date of Report: 02/22/18 Date Received: 02/16/18 Project: KCPCFM 170383, F&BI 802285 Date Extracted: 02/20/18 Date Analyzed: 02/20/18 RESULTS FROM THE ANALYSIS OF SOIL SAMPLES FOR TOTAL PETROLEUM HYDROCARBONS AS GASOLINE USING METHOD NWTPH-Gx Results Reported on a Dry Weight Basis Results Reported as mg/kg (ppm) Surrogate Sample ID Gasoline Range (% Recovery ) Laboratory ID (Limit 58-139) AB-02-7 <5 99 802285-01 AB-01-12 <5 97 802285-02 AB-03-12 <5 98 802285-03 AB-04-12 <5 95 802285-04 Method Blank <5 95 08-340 MB2 FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 3 Date of Report: 02/22/18 Date Received: 02/16/18 Project: KCPCFM 170383, F&BI 802285 Date Extracted: 02/19/18 Date Analyzed: 02/19/18 RESULTS FROM THE ANALYSIS OF SOIL SAMPLES FOR TOTAL PETROLEUM HYDROCARBONS AS DIESEL AND MOTOR OIL USING METHOD NWTPH-Dx Results Reported on a Dry Weight Basis Results Reported as mg/kg (ppm) Surrogate Sample ID Diesel Range Motor Oil Range (% Recovery) Laboratory ID (C10-C25) (C25-C36) (Limit 48-168) AB-02-7 <50 <250 101 802285-01 AB-01-12 <50 <250 97 802285-02 AB-03-12 <50 <250 108 802285-03 AB-04-12 <50 <250 109 802285-04 Method Blank <50 <250 101 08-375 MB FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 4 Date of Report: 02/22/18 Date Received: 02/16/18 Project: KCPCFM 170383, F&BI 802285 QUALITY ASSURANCE RESULTS FOR THE ANALYSIS OF SOIL SAMPLES FOR TPH AS GASOLINE USING METHOD NWTPH-Gx Laboratory Code: 802300-01 (Duplicate) Analyte Reporting Units Sample Result (Wet Wt) Duplicate Result (Wet Wt) RPD (Limit 20) Gasoline mg/kg (ppm) <5 <5 nm Laboratory Code: Laboratory Control Sample Analyte Reporting Units Spike Level Percent Recovery LCS Acceptance Criteria Gasoline mg/kg (ppm) 20 95 71-131 FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 5 Date of Report: 02/22/18 Date Received: 02/16/18 Project: KCPCFM 170383, F&BI 802285 QUALITY ASSURANCE RESULTS FROM THE ANALYSIS OF SOIL SAMPLES FOR TOTAL PETROLEUM HYDROCARBONS AS DIESEL EXTENDED USING METHOD NWTPH-Dx Laboratory Code: 802289-01 (Matrix Spike) Analyte Reporting Units Spike Level Sample Result (Wet Wt) Percent Recovery MS Percent Recovery MSD Acceptance Criteria RPD (Limit 20) Diesel Extended mg/kg (ppm) 5,000 <50 90 94 73-135 4 Laboratory Code: Laboratory Control Sample Analyte Reporting Units Spike Level Percent Recovery LCS Acceptance Criteria Diesel Extended mg/kg (ppm) 5,000 80 74-139 FRIEDMAN & BRUYA, INC. _________________________________________________ ENVIRONMENTAL CHEMISTS 6 Data Qualifiers & Definitions a - The analyte was detected at a level less than five times the reporting limit. The RPD results may not provide reliable information on the variability of the analysis. b - The analyte was spiked at a level that was less than five times that present in the sample. Matrix spike recoveries may not be meaningful. ca - The calibration results for the analyte were outside of acceptance criteria. The value reported is an estimate. c - The presence of the analyte may be due to carryover from previous sample injections. cf - The sample was centrifuged prior to analysis. d - The sample was diluted. Detection limits were raised and surrogate recoveries may not be meaningful. dv - Insufficient sample volume was available to achieve normal reporting limits. f - The sample was laboratory filtered prior to analysis. fb - The analyte was detected in the method blank. fc - The compound is a common laboratory and field contaminant. hr - The sample and duplicate were reextracted and reanalyzed. RPD results were still outside of control limits. Variability is attributed to sample inhomogeneity. hs - Headspace was present in the container used for analysis. ht – The analysis was performed outside the method or client-specified holding time requirement. ip - Recovery fell outside of control limits. Compounds in the sample matrix interfered with the quantitation of the analyte. j - The analyte concentration is reported below the lowest calibration standard. The value reported is an estimate. J - The internal standard associated with the analyte is out of control limits. The reported concentration is an estimate. jl - The laboratory control sample(s) percent recovery and/or RPD were out of control limits. The reported concentration should be considered an estimate. js - The surrogate associated with the analyte is out of control limits. The reported concentration should be considered an estimate. lc - The presence of the analyte is likely due to laboratory contamination. L - The reported concentration was generated from a library search. nm - The analyte was not detected in one or more of the duplicate analyses. Therefore, calculation of the RPD is not applicable. pc - The sample was received with incorrect preservation or in a container not approved by the method. The value reported should be considered an estimate. ve - The analyte response exceeded the valid instrument calibration range. The value reported is an estimate. vo - The value reported fell outside the control limits established for this analyte. x - The sample chromatographic pattern does not resemble the fuel standard used for quantitation. 1 APPENDIX C King County May 22, 2017 Preliminary Geotechnical Design Report – Subsurface Explorations LOG OF BORING BORING B-1 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan DATE: 4/13/2017 START: 1115 BORING METHOD: Hollow Stem Auger FINISH: 1215 LOGGER: Tim Hyden DRILLER: Holocene Drilling DEPTH TO -Water: N/A Caving: Yes DATE CHECKED: 4/13/2017 ELEVATION/ SOIL SYMBOLS SAMPLER SYMBOLS uses Description Moist -200 (%) (%) Remarks DEPTH AND FIELD TEST DATA 0 10,8,18 6,8,10 4 8,11,8 8 8,10,11 5,13,9 12 16 8,9,12 20 7,8,10 24 6,8,8 28 sw ··· •.3f1Gravel Surfacing. 12" Recove1y Reddish Brown, Medium Dense, Well sM ··· · .-9!.~4.~4 §~!14 v.Ytt.h Qr~ry~L M2i~t.'. (fiH?} Tan/Gray, Medium Dense, Silty Sand with 4.1 18.2 12" Recovery SP GP SP Gravel, Moist. Tan, Medium Dense, Gravelly Poorly . Graded Sand, Moist. Tan, Medium Dense, Poorly Graded Sandy Gravel, Moist. Tan/Reddish Brown, Medium Dense, Fine to Medium Grain Poorly Graded Sand with Some Gravel, Moist. 7" Recovery 10" Recovery 9" Recovery 17" Recovery 18" Recovery 18" Recovery FIGURE A-1 LOG OF BORING BORING 8-2 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan BORING METHOD: Hollow Stem Auger DRILLER: Holocene Drilling DATE: 4/13/2017 START: 1245 DEPTH TO -Water: N/A Caving: Yes FINISH: 1315 LOGGER: Tim Hyden DATE CHECKED: 4/13/2017 ELEVATION/ SOIL SYMBOLS SAMPLER SYMBOLS uses Description DEPTH AND FIELD TEST DATA 0 4 8 12 16 20 10,17,16 24 8,10,12 28 P~GM -_§'' Qrc:1:Y~L§~rf.8:<;Ji:ig: SP Light Brown, Medium Dense to Dense, Poorly Graded Gravel with Silt and Sand, Moist. Tan, Medium Dense to Dense, Fine to Medium Grained Poorly Graded Sand, Moist. Moist -200 (%) (%) Remarks 14" Recovery 1 O" Recovery 2.3 52 11" Recovery 12" Recovery 12" Recovery 12" Recovery 18" Recove1y 18" Recovery FIGURE A-2 LOG OF BORING BORING B-3 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan DATE: 4-13-17 START: 1000 BORING METHOD: Hollow Stem Auger DRILLER: Holocene Drilling DEPTH TO -Water: N/A Caving: Yes FINISH: 1100 LOGGER: Tim Hyden DATE CHECKED: 4/13/2017 ELEVATION/ SOIL SYMBOLS SAMPLER SYMBOLS uses Description DEPTH AND FIELD TEST DATA 0 4 8 12 16 13,14,14 20 8,14,19 24 9,11,12 28 GP ···· \.3f1Gravel Surfacing. Reddish Brown, Very Dense, Poorly Graded Sandy Gravel, Moist. (Fill?) ..................................... ..... .................................... . ...... . P-GM Reddish Brown, Loose to Medium Dense, Poorly Graded Gravel with Silt and Sand, ··· ·Moist. (Fill?) GM ·· ....................................................... . GP SP Reddish Brown, Medium Dense, Silty Gravel with Sand, Moist. Tan, Medium Dense, Sandy Poorly Graded Gravel, Moist. Tan, Medium Dense, Gravelly Poorly Graded Dand, Moist. Moist -200 (%) (%) Remarks 17" Recovery 5.1 5.6 8" Recovery 9.3 9.3 4" Recovery 3" Recovery 15" Recovery 15" Recovery 12" Recovery 16" Recovery FIGURE A-3 LOG OF BORING BORING B-4 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan DATE: 4/13/2017 START: 0845 BORING METHOD: Hollow Stem Auger DRILLER: Holocene Drilling DEPTH TO -Water: N/A Caving: Yes FINISH: 0945 LOGGER: Tim Hyden DATE CHECKED: 4/13/2017 ELEVATION/ SOIL SYMBOLS SAMPLER SYMBOLS uses Description DEPTH AND FIELD TEST DATA 0 6,4,4 7,14,15 4 8,11,14 8 8,14,21 7,12,13 12 16 20,21,35 20 8,13,14 24 6,10,12 28 SM ··· \. 31!Grave1Surfacing. . . Reddish Brown, Loose, Silty Sand with SP .... .\ Gt~Y~J, N211.:P.J<.1.~!i~1M2t~!: (fiU?.) GW SW SP Tan, Medium Dense, Poorly Graded Sand with Gravel, Moist. Tan, Medium Dense to Very Dense, Well Graded Gravel with Sand, Moist. Tan, Medium Dense, Gravelly Well Graded Sand, Moist., Tan, Medium Dense, Gravelly Poorly Graded Sand, Moist. Moist -200 (%) (%) 3.2 3.1 2.1 2.5 Remarks 14 11 Recovery 12 11 Recovery 12 11 Recovery 14 11 Recovery 12 11 Recovery 12" Recovery 15 11 Recovery FIGURE A-4 LOG OF BORING BORING 8-5 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan DATE: 4/13/2017 START: 1345 BORING METHOD: Hollow Stem Auger FINISH: 1500 LOGGER: Tim Hyden DRILLER: Holocene Drilling DEPTH TO -Water: N/A Caving: Yes DATE CHECKED: 4/13/2017 ELEVATION/ SOIL SYMBOLS SAMPLER SYMBOLS uses Description DEPTH AND FIELD TEST DATA 0 27,18,12 5,5,5 4 8,10,12 8 6,8,10 5,7,9 12 16 7,13,16 20 19,31,33 24 9,13,17 28 -. 6" Gravel Surfacing. SM · ········· GW GP GW SP Reddish Brown, Loose to Medium Dense, Silty Sand with Gravel, Moist. (Fill?) Tan, Medium Dense, Well Graded Gravel with Sand, Moist. Tan/Reddish Brown, Medium Dense, Sandy Poorly Graded Gravel, Moist. Tan, Very Dense, Well Graded Sandy Gravel, Moist. Tan, Medium Dense, Fine to Medium Grained Poorly Graded Sand, Moist. Moist -200 (%) (%) Remarks 4" Recovery 7.7 14.6 6" Recovery No Recovery 2.9 4.1 12" Recovery 5" Recovery 9" Recovery 13" Recovery 18" Recovery FIGURE A-5 LOG OF BORING BORING B-6 PROJECT: DNRP Maintenance Facility -Renton BORING LOCATION: See Attached Site Plan BORING METHOD: Hollow Stem Auger DRILLER: Holocene Drilling DATE: 4/13/2017 START: 0740 DEPTH TO -Water: N/A Caving: Yes FINISH: 0830 LOGGER: Tim Hyden DATE CHECKED: 4/13/2017 I ELEVATION/ I SOIL SYMBOLS SAMPLER SYMBOLS DEPTH AND FIELD TEST DATA -o -4 -a ::'::'::'':it : :::: ::.Ll12,16,15 >-12 -16 ;;;;;;;;;;;; ~121519 ............ 'I .. 'I -20 -24 -28 uses Description -.. SM \\211 Topsoil .. andOrganics. Light Brown, Loose, Silty Sand with -······················· ·\ Gravel, Non-Plastic, Moist. (Fill?) SP-SM , ............................................................................................................................................. . -... SP SW Tan, Loose, Fine to Medium Grain Poorly Graded Sand with Silt and Gravel, Moist. Tan, Medium Dense, Poorly Graded Sand with Silt and Gravel, Moist. Tan, Dense, Gravelly. Poorly Graded Sand, Moist. Tan, Dense, Well Graded Sand with Gravel, Moist. Moist -200 (%) (%) Remarks 3 11 Recovery 15 11 Recovery 17 11 Recovery 6, 1 5A 14 11 Recovery 14 11 Recovery 13 11 Recovery FIGURE A-6 - - - - i APPENDIX D Report Limitations and Guidelines for Use ASPECT CONSULTING 1 REPORT LIMITATIONS AND GUIDELINES FOR USE Geoscience is Not Exact The geoscience practices (geotechnical engineering, geology, and environmental science) are far less exact than other engineering and natural science disciplines . It is important to recognize this limitation in evaluating the content of the report. If you are unclear how these "Report Limitations and Guidelines for Use" apply to your project or property, you should contact Aspect Consulting, LLC (Aspect). This Report and Project-Specific Factors Aspect’s services are designed to meet the specific needs of our clients. Aspect has performed the services in general accordance with our agreement (the Agreement) with the Client (defined under the Limitations section of this project’s work product). This report has been prepared for the exclusive use of the Client. This report should not be applied for any purpose or project except the purpose described in the Agreement. Aspect considered many unique, project-specific factors when establishing the Scope of Work for this project and report. 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Within the limitations of scope, schedule, and budget, our services have been executed in accordance with our Agreement with the Client and recognized geoscience practices in the same locality and involving similar conditions at the time this report was prepared Property Conditions Change Over Time This report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by events such as a change in property use or occupancy, or by natural events, such as floods, ASPECT CONSULTING earthquakes, slope instability, or groundwater fluctuations. If any of the described events may have occurred following the issuance of the report, you should contact Aspect so that we may evaluate whether changed conditions affect the continued reliability or applicability of our conclusions and recommendations. 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