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GEOMATRIX <br /> 3.0 FIELD INVESTIGATION <br /> Geomatrix contracted with Precision Sampling,Inc.(Precision),of Richmond,California to advance <br /> seven soil borings(GMX-9 through GMX-12 and GMX-20 through GN UC-22)at the site on <br /> September 23 and 24, 1999. Prior to boring activities,Geomatrix obtained a soil boring permit from <br /> the SJCPHS; Cruz Brothers Sub-Surface Locators,Inc.,of Milpitas,California,performed an <br /> underground utility clearance at each boring location;and Underground Service Alert(USA)was <br /> notified. All drilling and soil sampling equipment was steam cleaned prior to use and between each <br /> boring. <br /> Soil borings were advanced by Precision using a 2-inch-diameter,hydraulically driven direct push <br /> core barrel and drive sampler. A continuous soil core was collected from each boring and logged <br /> according to Unified Soil Classification System(USCS)as presented in the American Society of <br /> Testing and Materials(ASTM) Standard D2488-90. Borings with visible petroleum hydrocarbon- <br /> affected soil were advanced until affected soil was no longer observed in the recovered soil core to <br /> assess the vertical extent of the residual petroleum. Petroleum hydrocarbon-stained soil was <br /> observed in three borings(GMX-9, 10,and 12)between depths of 7 and 14 feet bgs. A soil sample <br /> was collected from these borings from the most visibly affected portion of the soil core. An <br /> additional four step-out borings(GMX-11,20,21,and 22)were advanced to assess the lateral extent <br /> of petroleum-affected soil on the property. A confirmation soil sample was collected directly above <br /> the water table(approximately 11 to 12.5 feet bgs)from borings advanced outside of the area of <br /> visibly affected soil. Soil samples were collected in clean stainless steel sleeves,sealed with Teflon <br /> sheets,plastic end caps,and tape. Samples were labeled,sealed in plastic bags,and stored in an ice- <br /> cooled chest. Boring logs are presented in Appendix A. <br /> A b groundwater sample was collected from just beneath the affected soil in boring GMX-12. <br /> � �' P J <br /> The sample was collected by advancing drive casing through the affected soil and continuing for <br /> approximately 6 feet thereafter. A temporary polyvinyl chloride(PVC)blank casing and 5 feet of <br /> well screen were placed within the cased borehole and the drive casing was pulled back to the bottom <br /> of the affected soil to avoid cross-contamination of the groundwater sample by the affected soil. The <br /> grab groundwater samples was collected using a disposable PVC bailer and was decanted into 40 <br /> milliliter(ml)acidified volatile organic analysis(VOA)vials and 1-liter amber bottles. Sample <br /> containers were labeled, sealed in plastic bags,and stored in an ice-cooled chest. <br /> The soil and groundwater samples were submitted to Friedman and Bruya, Inc.,of Seattle, <br /> Washington,a California-certified analytical laboratory,under Geomatrix chain-of-custody <br /> procedures. Soil samples were submitted for analysis for TPH quantified as gasoline(TPHg;C6-C12 <br /> \\SF3\DEPTDATA\DOC_SAFE15000S\5650\13URNS\BURNS SOILGW RPT.DOC 2 <br />