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3.0 SOIL EXCAVATION <br /> 3.1 Extent of Excavation <br /> Remedial soil excavation took place on December 9-11, 1991 A total of 1100 loose <br /> cubic yards of soil were removed during the excavation Figure 3 shows the extent ` <br /> of the excavation and the location of all samples <br /> ' 3.2 Soil g <br /> Sam lin Methods <br /> Sampling <br /> ' Confirmation soil samples were obtained by driving a brass tube into soils in the <br /> excavator bucket. Samples were sealed with aluminum foil, capped, labeled and <br /> placed in cooler containing ice prior to analysis A chain of custody was completed <br /> ' listing the samples and the analytical testing All water samples and soil sample SW- <br /> 13 were transported under chain of custody in a ice-filled cooler to BACE Analytical, <br /> Field Services (BAFS) for testing. Appropriate sample packaging and labeling was <br /> ' maintained. Copies of the analytical data sheets and chain of custodies are included <br /> in Appendix B. <br /> 3.3 Analytical Testing <br /> g <br /> A total of 21 confirmation soil samples were analyzed from the excavation Soil <br /> samples were analyzed for TPH as diesel and BTEX by a California certified mobile <br /> analytical lab operating on-site by BAFS Table 1 summarizes the analytical results. <br /> 1 <br /> 3.4 Removal of Contaminated Soils <br /> ' The excavation initially proceeded to the depth of the water table at zine feet below <br /> surface grade where eight soil samples were collected ( 1A to 8A) Based on the <br /> analytical results of these samples, DPC removed additional soils below the water <br /> table to a depth of 12-14 feet below surface grade which corresponds to or extends <br /> beneath the original UST excavation subgrade In addition, the excavation was <br /> extended in all directions laterally Soil staining was visible immediately above the <br /> ' water level and was used to guide the extent of excavation prior to analytical testing. <br /> The grey stained soils also possessed a pungent petroleum hydrocarbon odor <br /> ' During excavation, the petroleum hydrocarbons were found to exist past the <br /> location of piezometer P-1 on the east side of the excavation The piezometer was <br /> destroyed by excavating to a depth of 12-13 feet below surface grade. The entire 16 <br /> ' feet of casing and screen were removed from the excavation. Well destruction <br /> permit for the piezometer was completed and subxnitted to the SJCPHS on January <br /> 24, 1992. A copy of the permit has been included in this report as Appendix A. The <br /> ' permit application was signed under authorization of the licenced C-57 drilling <br /> 3 <br /> BRUNSING ASSOCIATES, INC <br />