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A zone of wcathercd till typically ovcrlies thc dcnse glacial till to depths of 2 to 10 feet. This weathercd <br /> zone is somewhat drained, whereas the unweathered till is a bartier ro vertical drainage. Water <br /> Fx.rcolating into the weathaed till will usually pond and migrate laterally between the weathered and <br /> unweathered mnes. <br /> Subsudacc soil conditions encountered in our borings are fairly consistent with the geologic mapping. In <br /> gencral, wc obscrved fill overlaying a thin laycr of owwash ovcrlaying glacial till. Glacial till was <br /> obscrved to the depths cxplored. Detailed descriptions arc provided in[hc following section. <br /> SITE CONDITIONS <br /> SURFACE CONDITIONS <br /> Thc ground surface is relatively 11at with an overall increase in elevation of about 4 fect from the centnl <br /> portion of Ihe allcy to thc south bordcr of thc property. As prcviously discussed,existing develo�ment on <br /> thc site includes asphalt paved parking lots on thc wcst, a ccntral asphalt concrete alley, and a one-story <br /> timber building (Good Guys Car Store). The Snohomish }iealth District Building is a 3-story shucture <br /> with one Ievcl of below-grade parking. Adjacent property on the northwest portion of the site includes <br /> additional asphalt parking arcac and a one-story cinder block structurc. Wc understand that a 20-inch <br /> diametcr sewer oipe is locatcd approximately 20 feet bclow the existing ground surface, cztrnding <br /> north-south bcncath Ihc allcy. Gxisting sitc fcatures arc prescntcd in thc Sitc Plan,Figurc 2. <br /> SUBSURFACE CONDITIONS <br /> General <br /> Subsurface conditiais al thc projec� sitc werc c��aluatcd by drilling tcn hollow-stcm auger borings to <br /> depths ranging Gom 10 to 29 fect bclow thc existing ground surface. The approximate locations of the <br /> borings are shown in Figure 2. A gcneralizcd profile showing the subsurface soils and thc estimated <br /> botlom of cxcavation are prescnted as }�igurc 3. A dcscriptirni of thc ficld exploration procedures,logs of <br /> borings,and laboratory Icst results arc prescntcd in Appcndix A. <br /> Soil Conditlons <br /> Genenl. Subsurfacc soils cncountered in the borings consist of fill o��crlying dense to very dense <br /> outwash o��cdying glacial till. Parcmeni scctions consisting of asphall and/or concrcte were obscrved in <br /> thc borings ovcrlying vcry loose to mcdium dense fill. Specific descriptions of Ihc conditions <br /> encoumercd in our borings arc provided bclow. <br /> Pavement Section. Our explorations encauntercd a pavement section consisting of 2%: to 4 inches of <br /> asphalt concrcte pavcmcnt and�or 4 to 10 inches of cemcnt concrelc pavement. The parking lot situated <br /> bchvccn tlic Good Guys Car Storc and thc Snohomish Hcalth District IIuilding consists of 7 to 10 inches <br /> of concrete o�•crlying loosc to mcdium dcnse sand fill. Doring II-3 was abandoned in this area at a depth <br /> of 10 fect whcn a concrcte obstn�ction was encountcrcd (possible old foundation remnant). Doring 3a <br /> was drilled approzimately R fcet to the southwest and did not encountcr this obstruction and was <br /> tcrminatcd at a depth of 29 fcct. <br /> Borings l3-8 and 13-9 w�ere located along Pacific Avenuc, north of the sidewalk, and cncuuntered a <br /> one-inch-thick asphalt concrctc ovcday over 4 to 7 inchcs of concrctc. The remaining borings <br /> cncountered 2'/: to 4 iuches of asphalt concrctc surfacing. Two to four inches of gravel baze course was <br /> ����.�� mi��nni-on PaKr1 GEoEMen�e[�� <br /> J�����n.lnnx <br /> � <br />