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Limited Geotechnical Engineering Study <br /> View Ridge Elementary School Portable Classroom Installation <br /> Everett, Washington and Downspout Infiltration Feasibility <br /> Published Geologic Map <br /> Review of the regional geologic map titled "Geologic Map of the Everett 7.5-Minute Quadrangle, <br /> Snohomish County, Washington" by J.P. Minard (1985) indicates that the subject property is <br /> underlain at shallow depths by lodgement till,with advance outwash mapped at lower elevations <br /> to the east and west. Our interpretation of subsurface conditions differs from the published <br /> mapping in that our exploration borings encountered advance outwash sediments. <br /> Published Soils Map <br /> Review of the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service <br /> (NRCS) Web Soil Survey indicates that the subject site is underlain by Alderwood-Urban land <br /> complex, 2 to 8 percent slopes. Alderwood-Urban land soils are generally formed from the <br /> weathering of lodgement till. Our interpretation of the soils encountered in our explorations is <br /> not in agreement with the regional soils map. The advance outwash sediments observed below <br /> existing fill in our exploration borings are generally consistent with Indianola series sediments in <br /> the NRCS naming system. <br /> Stratigraphy <br /> As shown on the field logs,our explorations in the area of planned portable classroom installation <br /> generally encountered fill soils extending to 3 to 4 feet below the ground surface underlain by <br /> native,glacially consolidated Vashon advance outwash sediments.The following section presents <br /> more detailed subsurface information organized from the youngest (shallowest) to the oldest <br /> (deepest) sediment types. A copy of our exploration logs is included in Appendix A. <br /> Sod and Topsoil <br /> All three of our exploration borings in the current project area, EB-8, EB-9, and EB-10, <br /> encountered approximately 3 inches of sod and topsoil; the sod and topsoil are not suitable for <br /> structural support and should be stripped from structural areas. <br /> Fill <br /> Existing fill was encountered in all of the explorations completed in the area where new portable <br /> classrooms will be installed immediately below the sod and topsoil. The existing fill generally <br /> consisted of dry ranging to moist, brown with occasional minor oxidation staining,silty fine sand <br /> with occasional gravels and organics (rootlets) to fine sand with inclusions of silt with occasional <br /> July 12,2023 ASSOCIATED EARTH SCIENCES, INC. <br /> BCY/Id-20100255E004-002 Page 4 <br />