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COBALT Cobalt Geosciences,LLC <br /> GEOSCIENCEs P.O.Box 82243 <br /> Kenmore,Washington 98028 <br /> September 23,2022 <br /> Sherman Perry <br /> shermansperry(a7gmail.corn <br /> RE: Geotechnical Evaluation <br /> Proposed Residence <br /> 417 Tamarack Avenue <br /> Everett,Washington <br /> In accordance with your authorization, Cobalt Geosciences, LLC has prepared this letter to <br /> discuss the results of our geotechnical evaluation at the referenced site. The purpose of our <br /> evaluation was to provide recommendations for foundation design,grading,and earthwork. <br /> Site Description <br /> The site is located at 417 Tamarack Avenue in Everett, Washington. The site consists of one <br /> nearly rectangular shaped parcel(No.00393400006400)with a total area of 0.21 acres. <br /> The site is developed with a residence,driveway and detached accessory building. The remainder <br /> of the property is vegetated with grasses,bushes,and sparse trees. The site is nearly level to very <br /> slightly sloping in multiple directions. <br /> The site is bordered to the north, east, and west by residences, and to the south by Tamarack <br /> Avenue. <br /> The proposed development includes a new residence and driveway. Stormwater will include <br /> infiltration or other systems depending on feasibility. Site grading may include cuts and fills of 3 <br /> feet or less for foundation placement and structural loads are expected to be light. <br /> We should be provided with the final plans to verify that our recommendations remain valid and <br /> do not require updating. <br /> Area Geology <br /> The Geologic Map of Everett Quadrangles, indicates that the site is underlain by Vashon Glacial <br /> Till. <br /> Vashon Glacial Till includes mixtures of silt, sand, gravel, and clay in a nonsorted matrix or <br /> diamict. These deposits are nearly impermeable and become denser with depth. <br /> Soil & Groundwater Conditions <br /> As part of our evaluation,we observed excavation of three test pits where accessible. <br /> The explorations encountered approximately 6 inches of grass and topsoil underlain by <br /> approximately 1.5 to 2.5 feet of loose to medium dense, silty-fine to medium grained sand trace <br /> gravel (Fill). These materials were underlain by approximately 1.5 to 2 feet of loose to medium <br /> dense, silty-fine to medium grained sand with gravel (Weathered Glacial Till). These materials <br /> were underlain by dense to very dense, silty-fine to medium grained sand trace to with gravel <br /> (Glacial Till),which continued to the termination depths of the explorations. <br /> www.cobaltgeo.com (206)331-1097 <br />