Laserfiche WebLink
i <br /> iFobruary 19, 1991 <br /> Iwakwioll of Soil .led (.)roned Winer •GS 38032-3 <br /> Unocal Station No. 6981, Stockton, Galifarnia _ f <br /> { I <br /> :1}lpendiz :�. Rcsultti of tl,c oil-vapor Survey indicated that low levels of gasolirle <br /> were In cserlt in vapors c\tracted from soil in test probe dole number VP. <br /> hydrocarbon vapors <br /> 7, near the southwest cothe silo. 1-lowever, the soil-vapor survey provided no <br /> rner of <br /> conclusive data on hydrocarbons below 13 feet. Based ori tilese results, Unocal requested <br /> \pplicd GeoSystcnls In perforru ail rove sliLation of the soil and ground .vater beneath the <br /> site. <br /> Iql-'l.j) WORK AND N11"THODS <br /> w DLII.1r1Q Ill's nlyCSlrgatinrl, Applied Gvoststcrtls monitored the drilling of live soil borings and <br /> the installation of five nu0nitorillg«�Ils it,the borings, he borings were drilled to collect soil <br /> nalysis and to conStruct (11 -water monitoring wells to allow <br /> samples for laboratory a <br /> evaluation of the ground-water gradient Unci L}utility beneath the site. Based on the ILleyation <br /> of Water in wells for S)ring 1986 Map. for the Sac•rUlnento Valley and Redline iiasin <br /> (California Department of Water Resources. 1986), the direction of groundwater flow was <br /> initially inferred to be towarcts the southwest. <br /> ucted field work at the site in accordance with Applied GeoSystems' <br /> Applied GeoSystems condi <br /> Site Safety Plan No. 3S032-3S (Applied GeoSystems• December 4, 1989). Ficld site safety, i <br /> " drilling methods, equipment, sampling techniques, and decontamination procedures are <br /> described in Appendix C. <br /> Soil Borings and Soil Sam lint! <br /> Dn January 31, 1990, February 1 and 2. 1990, and February 5 through 7, 1990, an Applied <br /> GeoSystems geologist monitored the drilling of five soil borings at the site by Spectrum <br /> ---- -— <br /> ,4pp/ied GeasySA9177S — <br />