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The data indicated that surface soil in the work area contained concentrations of copper above <br /> the TTLC. Levels detected in the surface samples ranged from 7,600 to 41,000 ppm. <br /> However, samples from the work area at depths of 3-inches and 6-inches only contained <br /> concentrations of copper between 38 and 64 ppm. These levels are consistent with the <br /> background levels for San Joaquin County soils reported in Elements in North American Soils <br /> (Dragun and Chiasson, 1991). The samples collected from the levee bank and from the area <br /> ' west of the work area also contained background levels of copper. The surface sample <br /> collected 21 feet east of the work area contained an elevated concentration of copper (870 ppm) <br /> indicating that some impact may not be associated with the Marina West Marine Services <br /> operation. <br /> 3.3 Workplan Preparation and Approval <br /> GZA prepared the Workplan for Contaminated Soil Abatement and Additional Investigation dated <br /> October 2, 2003. The Workplan was approved with conditions by DTSC in a memorandum <br /> dated October 30, 2003. Copies of the Workplan (including laboratory reports) and the approval <br /> memorandum are included in Appendix B. <br /> 4.0 SOIL EXCAVATION AND SAMIPLING <br /> In accordance with the Workplan, contaminated soil was excavated and disposed of and <br /> additional soil samples were collected and analyzed. <br /> 4.1 Soil Excavation and Disposal <br /> ' On November 12, 2003, under the direction of GZA geologist Sean Garvey, Thorpe Oil Inc. <br /> personnel used a backhoe to excavate the upper 3 inches of soil from the work area and from <br /> suspected impacted soil to the east of the work area. To prevent inadvertent movement of <br /> contaminated soil down the levee face, Thorpe erected a silt fence prior to excavation. The <br /> completed excavation extended a distance of approximately 240 feet in an east-west direction and <br /> ranged from approximately 8 to 10 feet in width. A total of approximately 20 cubic yards of soil <br /> ' was excavated. The excavated area was lined with plastic sheeting pending backfilling. The <br /> excavated area is depicted on Figure 3. Field notes and photographs are included in Appendix C. <br /> The excavated soil was placed in covered rolloff bins pending disposal. On November 24, 2003 <br /> the 26.7 tons of contaminated soil were transported under hazardous waste manifest to <br /> Chem.Waste Management's Class I landfill in Kettleman City, California. Copies of the <br /> hazardous waste manifests are included in Appendix C. <br /> 4 <br /> i <br /> i <br />