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COBALT <br /> GEOTECHNICAL INVESTIGATION it G E o s C I E N C E s <br /> EVERETT, WASHINGTON <br /> November 16,2018 <br /> 4.o Field Investigation <br /> 4.1.1 Site Investigation Program <br /> The geoteclmieal field investigation program was completed on October 16, 2018 and included excavating <br /> and sampling three hand borings within the property for subsurface analysis. <br /> The soils encountered were logged in the field and are described in accordance with the Unified Soil <br /> Classification System(USCS). <br /> A Cobalt Geosciences field representative conducted the explorations, collected disturbed soil samples, <br /> classified the encountered soils, kept detailed logs of the explorations, and observed and recorded <br /> pertinent site features. <br /> The results of the explorations are present on the hand boring logs enclosed in Appendix C. <br /> 5.0 Soil and Groundwater Conditions <br /> 5.1.1 Area Geology <br /> The site lies within the Puget Lowland. The lowland is part of a regional north-south trending trough that <br /> extends from southwestern British Columbia to near Eugene, Oregon. North of Olympia, Washington, <br /> this lowland is glacially carved, with a depositional and erosional history including at least four separate <br /> glacial advances/retreats. The Puget Lowland is bounded to the west by the Olympic Mountains and to <br /> the east by the Cascade Range. The lowland is filled with glacial and non-glacial sediments consisting of <br /> interbedded gravel,sand,silt,till,and peat lenses. <br /> The Geologic Map of Washington — Northwest Quadrant, indicates that the site is underlain by Vashon <br /> Glacial Till. <br /> Vashon Glacial Till consists of dense mixtures of silt, sand and gravel. These materials are nearly <br /> impermeable in their unweathered state. <br /> Hand Borings <br /> All of the hand borings encountered approximately 6 to 10 inches of topsoil and vegetation underlain by <br /> 3.5 to 4.5 feet of loose to medium dense,silty-fine to medium grained sand with gravel(Weathered Glacial <br /> Till). This layer was underlain by dense, silty-fine to medium grained sand with gravel (Glacial Till), <br /> which continued to the termination depths of the hand borings. <br /> There is evidence of fill within the property. There is a mound in the central portion of the property that <br /> is likely comprised of undocumented fill. Additional fill should be expected in any site excavations. <br /> 2 <br /> PO Box 82243 <br /> Kenmore,WA 98028 <br /> cobaltaeo(iibgmail.com <br /> 2o6-331-1097 <br />