10105 19TH AVE SE Geotech Report 2018-01-02 MF Import

� . � , , � � . Geotechnical 8ngineerin�Gvaluation Everett Veterinary Clinic February 21,2002 � NGA�le No. 342902 Page 3 at the time of our field reconnaissance on February 7,2002. The site slopes very gently 6uwn to the wes4 I Surface water was not observed at the time of our field reconnaissance. ( During our field reconnaissance, the backhce perfortning the subsurface explorations broke a portion of a concrete vault lid. This lid was le,ss than one foot below grede, and the vault was nearly full of water. IWe do not know the depth oc• size of the vault, but we suspact that the vault is an old septic tank. The vault was located approximately 90 feet east of the westem property line and 55 feet noRh of the southem � property line. We covered the opening with a piece of plywood and a few inches of soil. I I Subsurface Cond[tiona Geoiogy: Most of the Puget Sound region was affected by past intrusion of continental glaciation. The last period of glaciution, the Vashon Stade, ended approximately 10,000 to 11,000 years ego. Many of Ithe geomorphic features seen today are a result of scouring and overriding by glacial ice. During the Vashon St�de, the Puget Sound region was overridden by ovcr 3,W0 feet of ice. Soil layers overridden ' by the ice sheet were compacted to a much greater extent than those that were not. A typical glacial sequence includes recessional outwash sand, ovedying glacial till or drift, and underla�n by advance � outwash. The Geoloyic Map of the Everett 7.5-Minute Ouadrangle, Snohamish County. Washin¢ton, by James P. I- Minard(U.S. Geological Survey, 1985) was referenced for the ge�logic conditions at Ihe site. The site is I mapped as glacial till. Glacial till in this area consists of an unsorted mixture of sand, silt, and gravel that was deposited at the base of the glacier. Our explorations encountered glacial till. IExploretions:The subsurface conditions were explored at the site on February 7, 2002 by excavating six test pit� to depths of 4.0 to 6.5 feet below the existing ground surfuce using a backhce. The explorat�ons were Icxated in the field by an NGA engineer who also examined the soils and geologic conditions encountered and maintained logs of the test pits. , The approximate locations of our explorations are shown on the Site Plan in Figure 2. The soils were visually classified in general accordance with the Unified Soil Classiruation System, presented as Figure 3. The logs of our explorations are presented in Figures 4 and 5. We present a brief surtunary of the , ,i subsurface conditions in the following paragraphs. For a more detailed description of the site soils, the NELSON GEOTECHN/CAL ASSOClATES, INC. 4U