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l� In July 1989, at the recommendation of E. James of the Central Valley Region of the California Regional Water Quality Control Board, EA supervised the drilling of three additional soil borings (SB5, SB6, SB7, Figure 2 ) . The borings were used to investigate the extent of petroleum contamination. remaining in the soil in the areas of the former product tank field (SB6 and SB7) and the former waste oil tank pit (SB5) . Barings were drilled to the top of the saturated zone, which was at 57-58 feet below grade on 10 July 1989. As the soil borings were drilled, undisturbed soil samples were collected at five-foot intervals following standard sampling protocol, in accordance with SJCEHD and RWQCB regulations. . i Selected soil samples from SB6 and SB7 (within the gasoline tank �' field excavation) were analyzed for total . y petroleum hydrocarbons (TPH), benzene, toluene,. xylenes, and ethylbenzene (BTXE) by DHS- ` modified EPA Method. 8015. Selected soil samples from SB5, in the rea of the waste oil tank excavation, were ,analyzed for the 1 waste oil compounds listed in Table 2 of the Tri=Regional Board guidelines. These include the metals Cd, Cr, Pb, Zn; TPH•.as gasoline and as diesel (assessed using DHS-modified EPA Method ; € 8015 ) ; oil .and grease. EPA (Method 503 D&E); volatile organic'$ (EPA Method 8249); and. PCB, PCD, creosote, and PMA (EPA Method i 8270). After:..the' soil 'borings had been drilled to 55 feet and the. final samples collected at 55-60.5 feet, the holes were grouted to the . _.surface_with-neat_cemenfi -grout. The results of the soil analysis indicate that only minor concen= tratlons of fuel constituentsare present in the soil . section below the' backfilled_ product and waste oil' tank pits .(Table 6) . Borings SB6 and SB7 encountered soils which contained 0.311 to M 0 E ; ;. 0.034 mg/kg toluene and xylenes at depths of 30 to 45 feet. TPH T� e35/71050/2-90/tx. 21 . v10 r. -