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Mr. Becker (DTSC) and Lt. Vielhauer (DFG) <br /> Page 3 of 5 <br /> BASELINE SOIL SAMPLING <br /> In order to obtain baseline information on the magnitude and the lateral and vertical extent of soil <br /> contamination, Ground Zero personnel inspected the site and collected thirteen soil samples on <br /> September 26, 2003. <br /> Paint chips were visually observed along a narrow strip of bare soil on the south side of the boat <br /> repair area. This suspected area of impact or"work area"is approximately 200 feet in length and 6- <br /> 8 feet in width. This area is bounded on the south by the levee bank, which is densely overgrown <br /> with blackberry bushes, on the north by asphalt paved parking, and on the east and west by <br /> untrammeled soil with a sparse cover of brush and blackberry bushes. Soil samples were collected <br /> from the surface and from depths of 3-inches and 6-inches below grade at three locations in the <br /> work area. The samples were identified by X, Y&Z coordinates: distance in feet east or west (E or <br /> W) of the zero point marked on the ground, distance in feet south of the asphalt border (S) and by <br /> depth in inches. In addition, surface soil samples were collected at points approximately 20 feet <br /> east and 20 feet west of the edge of the work area. Samples were also collected from the levee face <br /> at two points south of the work area. Sampling locations are identified on Figure 2. Field notes are <br /> included in Attachment B. <br /> The soil samples were submitted to GeoAnalytical Laboratories for analysis of total copper using <br /> EPA Method 6010B. Laboratory reports and chain of custody documentation are included in <br /> Attachment B. <br /> DISTRIBUTION OF COPPER IN SOIL <br /> The data indicate that surface soil in the work area contains concentrations of copper above the <br /> TTLC. Levels detected in the surface samples ranged from 7,600 to 41,000 ppm. However, <br /> ' samples from the work area at depths of 3-inches and 6-inches only contained concentrations of <br /> copper between 38 and 64 ppm. These levels are consistent with the background levels for San <br /> Joaquin County soils reported in Elements in North American Soils (Dragun and Chiasson, 1991). <br /> The samples collected from the levee bank and from the area west of the work area also contained <br /> background levels of copper. The surface sample collected 21 feet east of the work area contained <br /> an elevated concentration of copper (870 ppm) which, however, is below the TTLC hazardous <br /> waste criterion and below the US EPA Preliminary Remediation Goal for residential property use <br /> (3,100 ppm). <br /> WORKPLAN <br /> We are proposing a phased approach to investigation and cleanup of contamination at the site. In <br /> order to minimize or eliminate the immediate threat to waters of the state posed by the surficial <br /> \\GZA_FS\VOL_I\DATA\GROUNDZE\MARINA\REPORTS\Workplan.doc <br />