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. � , <br /> southwest comcr of thc lot. It is our opinion that thc exploration pits rcpresent ihe subsurface <br /> conditions acn�ss thc cntire lot. <br /> Explorauon pit (EP) logs of the completed explorations are attached to this report. The subsurface <br /> conditions consisted of a minor emount of fill soil or previously dishubed earth o�erlying Vashon <br /> aged advance outwash sand sedimen�s. <br /> S'.raNgraphy <br /> The upper soils in all thrce explorations were comprised of topsoil or fill soil. The fill soil was <br /> comprisod of the silt and send sediments from the leveli�g of the adjaccnt lot to the south. 7'hcre: <br /> was an excavation adjacent to ihe s6op building on the adjacent south lot with the same sediment <br /> conditions as describcd below for the subject lot. The fill generally consisted of inedium dcnse, dry <br /> to damp, light grey-brown, silty sand with some small gravels and organic fiagments. Thc fill soils <br /> were found to be between 2 to •1 feet thick in the threc cxploradon pits. <br /> Underlying the fill soils wete sediments consisting of inedium dense to dense with increasing dcpth, <br /> dry to damp, light g�ey-brown, silty with somc fine sand in thc upper 1 to 2 fcet grading to finc to <br /> medium sand with trace gravel extending beyond thc termination depth of the pits. 'I'hesc sediments <br /> cxtended below ttie tertnination depths of our cxplorallon pits at 6 to 7 feet below ground surfacc. <br /> This material was interpreted to be Vashon advancc outwash sand that was depositcd as an outwash <br /> alluvium in front of the advancing ice sheet during the last glacial advancc into the Pugct Sound <br /> reyon. Thc sill layer in the upper portion of the deposit represcnts un ovcr-bank floodplain type <br /> deposit. 11�e outwash sr.diments were subsequendy ovcr-run by scvcrul thousand fect of glacial icc <br /> resulting in a dense sediment with good strength and moderatc permcability characteristics. <br /> Ground Water <br /> There was no ground watcr seepage encountered in thc exploration pits at thc timc of our ficld <br /> cxplorations. We do not anticipate cncountcring any subsurfaa,gound water conditions during lhc <br /> development of this project. Surface runoff water appcars to infiltrate through thc sitc scdiments <br /> with excess runofTt]owing as shcct wash down slope. The shcct wa�sh has not caused rilling or any <br /> other erosional fcatures onsite. <br /> Grnlogic HazardQ <br /> The following discussion of potential gcoiogic ha�ards is bascd on the visual reconnaissance of thc <br /> sitc, thc subsurfacc cxplorations, und n rcview of �crial photographs and n:gional topographic maps <br /> of thc arca. <br /> Stccp Slope smd I.andslidc Ha�ards <br /> Thc sitc was locatcd ncar ihc top of a historic drninagc frum an upland arca dowc� to thc Pugct <br /> Sound. The moderate slopc of the top of this historic drainage channel was created by erosion <br /> through previous dcposition rathcr than mass wasting cvcnts. 'fhc slopc was comprised of dcnsc, � <br /> moderatcly frce draining scdiments with no cvidence of patil slope instabiliry. It is our opinion that <br /> thc clopc is considcrcd to bc stablc basud on current gcotechnical engincering practice and thc risk of <br /> slopc instability is low. 7'hc development oCa single Camily residence onsite will not nfTcct thc <br /> BGC, pllc 14267 209°i Avenue NE Woodlnvflle, WA 98077 (425) 273-506?. <br /> � �`� ' '' <br />