Laserfiche WebLink
1 <br /> Background Soil. Two background soil samples were analyzed for <br /> 1 As, Cr, Cu, Hg and Pb. Sample BG-1 was collected on-site while <br /> sample BG-2 was collected off-site. Analytical results are <br /> 1 summarized in Table 8. <br /> 1 Quality Assurance Samples. Table 9 summarizes the results of the <br /> quality assurance samples. <br /> 1 <br /> DISCUSSION OF INVESTIGATION RESULTS <br /> 1 The following discussion is a preliminary assessment of subsurface <br /> 1 materials and site contamination at the Stockton facility. The <br /> descriptions of subsurface materials are based on a visual <br /> examination of materials excavated from the pits. No physical <br /> 1 testing of the Phase 1 soil samples was performed. <br /> 1 Truck Parking and Lumber Storage Areas. Pits excavated in the truck <br /> parking and lumber storage areas indicate that the upper 6 inches of <br /> 1 material consists of a coarse gravel fill. The surface soils were <br /> visibly oily at locations P1, P2, P3 and P4. The fill is underlain <br /> by a dark brown silty clay to a depth of approximately 2 feet. <br /> Underlying the silty clay was a brown clayey silt. <br /> 1 Maintenance Shop Ditch. Pits excavated in the maintenance shop <br /> ditch indicate that the soils are a brown silty clay. <br /> 1 A preliminary assessment of site contamination at the Stockton <br /> 1 facility is based on a comparison of contaminant concentrations with <br /> background concentrations obtained from BG-1 and BG-2 and regulatory <br /> values of Total Threshold Limit Concentration (TTLC) for metals <br /> 1 (listed in Title 22, Division 4, Chapter 30, Article 11 of the <br /> California Administrative Code) . <br /> 1 <br /> i <br /> 1 _ 5 _ <br /> 2611F <br />