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GEOMATRIX <br /> the subsurface; the Dividend property was granted closure in 1996 because the residual <br /> petroleum did not pose a risk to human health or groundwater quality. Groundwater at the <br /> ' Dividend property occurs at about 7 feet below ground surface (bgs) and the gradient is <br /> north/northeasterly. <br /> ' 3.0 FIELD ACTIVITIES <br /> ' To assess the site in accordance with the Technical Approach, Geomatrix advanced borings <br /> ' GB-1 through GB-8 (Figure 2) to evaluate the lateral and vertical extent of petroleum-affected <br /> soil; collected grab groundwater samples in GB-1, GB-4, and GB-5 to evaluate whether <br /> ' groundwater is affected by dissolved petroleum hydrocarbons; and analyzed groundwater and <br /> soil samples collected in accordance with the analytical suite presented in the Technical <br /> tApproach. These activities are described below. <br /> ' 3.1 SOIL BORINGS <br /> Eight soil borings (GB-1 through GB-8)were advanced at the site by Precision Sampling, Inc. <br /> ' (Precision), of San Rafael, California on 8 July 1998. Prior to boring activities, Geomatrix <br /> obtained a soil boring permit from the SJCPHS; Cruz Brothers Sub-Surface Locators,Inc., of <br /> Milpitas, California,performed an underground utility clearance to identify potential subsurface <br /> utilities at each boring location; and Geomatrix notified Underground Service Alert. All <br /> ' drilling and soil sampling equipment was steam cleaned prior to use. <br /> 1 Petroleum hydrocarbon-stained soil was observed in borings GB-1, GB-2, and GB-3 during <br /> field operations. The vertical extent of petroleum hydrocarbon-stained soil was assessed in <br /> GB-1. Based on observation of the soil core,petroleum hydrocarbon-stained soil extended <br /> from depths of 4.5 to 13.5 feet bgs. Borings GB-4 through GB-6 were subsequently advanced <br /> ' in the assumed downgradient direction from borings GB-1 through GB-3 to evaluate the lateral <br /> extent of petroleum-affected soil and to assess groundwater quality. Borings GB-7 and GB-8 <br /> ' were advanced to the northwest and southeast of the borings GB-1 through GB-3 to assess the <br /> lateral extent of petroleum affected soil. Boring logs are presented in Appendix A. <br /> ' \\s@\deptdata\Doc_Safe\47Wsw1dtpt.dx 2 <br />