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0 <br /> M � <br /> Mr. Jerry Lile (DTSC) <br /> Page 2 of 7 <br /> side of the boat repair area. The area of visual impact coincided with a"work area" approximately <br /> 200 feet in length and 10 feet or less in width. Soil samples were collected from the surface and <br /> from depths of 3-inches and 6-inches below grade at three locations in the work area. Four <br /> additional samples were collected from surface soil outside the work area. Sample locations and <br /> depths were identified by X, Y and Z coordinates: X= distance in feet east or west(E or W) of the <br /> arbitrary zero point marked on the ground with white paint, Y = distance in feet south (S) of the <br /> asphalt pavement and Z equals depth in inches below surface grade. <br /> The data indicated that surface soil in the work area contained concentrations of copper above the <br /> TTLC. Levels detected in the surface samples ranged from 7,600 to 41,000 mg/kg soil [parts per <br /> million (ppm)]. However, samples from the work area at depths of 3-inches and 6-inches only <br /> contained 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 /> (Dragon and Chiasson, 1991). The samples collected from the levee bank and from the area west <br /> of the work area also contained background levels of copper. The surface sample collected 21 <br /> feet east of the work area contained an elevated concentration of copper (870 ppm) indicating <br /> that some impact may not be associated with the Marina West Marine Services operation, but <br /> may have resulted from boat storage or other non-operational sources. The location of the "work <br /> area" and soil samples are shown on Figure 2. Analytical results for pre-excavation soil samples <br /> are summarized in Table 1. <br /> Excavation and Post-Excavation Soil Sampling <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. The completed excavation extended a distance <br /> of approximately 240 feet in an east-west direction and ranged from approximately 8 to 10 feet in <br /> width. A total of approximately 20 cubic yards of soil was excavated. The excavated area is <br /> depicted on Figure 3. <br /> Following the completion of excavation, confirmation soil samples were collected from the floor of <br /> the excavation. At the request of DTSC, additional delineation samples were also collected east of <br /> the excavated area and one additional delineation sample was collected from the face of the levee. <br /> Sampling locations are shown on Figure 3. In keeping with the previous work, the samples were <br /> identified by X & Y coordinates: X = distance in feet east or west (E or W) of an arbitrary zero <br /> point marked on the ground with white paint, and Y = distance in feet south (S) of the asphalt <br /> pavement. Confirmation samples are indicated by the letter"C"in the first part of the identification <br /> and by "SURF" at the end. These were collected from the floor of the excavated area, or <br /> approximately 3 inches beneath the original ground surface. The additional delineation samples <br /> were collected from the current ground surface. <br /> G:\GROUNDZE\MARINA\VillageWest\Aquatoxrpt.doc <br />