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� u <br /> Woodward-Clyde <br /> V <br /> 4 Ms. Linda Turkatte <br /> San Joaquin County Environmental Health Division <br /> August 5, 1996 <br /> Page 5 <br /> V <br /> Approximately 12 cubic yards of diesel-contaminated soil were excavated from below the <br /> former north end of the UST from approximately 16 to 22 feet bgs. The excavation extended <br /> 6d approximately two feet east from the former east excavation edge, three feet north-northwest <br /> from the former north edge of the excavation, and approximately 2 feet west from the former <br /> west edge of the excavation (Figure 3). The diesel-contaminated soil was temporarily <br /> �- stockpiled on polyethylene sheeting southwest of the new excavation. <br /> WCFS collected four soil samples (KRST-1, KRST-2, KRST-3, and KRST-4) from the bottom <br /> of the excavation to confirm the absence of diesel contaminated soil in the excavation. The soil <br /> samples were collected from the backhoe bucket into clean brass liners by scraping away 4 to 6 <br /> inches in the area of the backhoe teeth, at a chosen "most representative" sample area, filling <br /> the liner by pushing it into the sample area, then placing Teflon sheeting and plastic end-caps on <br /> the ends of the liners, labeling the samples with sample number, time and date, and placing <br /> them on ice in an ice chest. One blind duplicate sample (KRST-4) was collected for sampling <br /> point KRST-3. The samples were transported under chain of custody procedures to Inchcape <br /> Testing Services of San Jose, California, a California certified analytical laboratory. The <br /> ,r samples were analyzed on a 24-hour turnaround priority for TPH as diesel using modified EPA <br /> Method 8015 and BTEX using EPA Method 8020. <br /> �. Soil sample KRST-1 was collected from the north-central floor beneath the former UST (Figure <br /> 3) at a depth of 21.5 feet bgs and consisted of a dry, brown silty clay material. Petro FLAG <br /> screening analysis of KRST-1 indicated a 52 mg/Kg relative concentration of TPH as diesel. <br /> Soil sample KRST-2 was collected from the northeast floor-wall interface at a depth of 21 feet <br /> bgs approximately 3 feet northeast of the former excavation edge. It consisted of a light <br /> yellowish brown silty clay material and exhibited a Petro FLAG relative concentration of 79 <br /> mg/Kg TPH as diesel. <br /> Soil sample KRST-3 was collected from the northwest floor-wall interface at a depth of 20.5 <br /> feet bgs approximately 4 feet northeast of the former excavation edge. It consisted of a brown <br /> silty clay material that exhibited a Petro FLAG relative concentration of 27 mg/Kg TPH as <br /> diesel. One blind duplicate soil sample (KRST-4) was collected from the same sample area as <br /> sample KRST-3 and was not field screened. <br /> Ir <br /> V <br /> V <br />