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1 <br />' GRANITE CONSTRUCTION FACILITY <br /> WKA No 2088 08 <br /> August 18, 1999 <br /> f Page 4 <br /> revealed no detectable concentrations of TPH as gasoline, diesel, or BTEX However, water <br /> samples collected from MW 1 through MW3 now revealed detectable concentrations of TPH as <br /> gasoline ranging from 590 µg/l to 3,200 pg/l, BTEX constituents were also detected Results of <br /> laboratory analysis of soil samples obtained from wells MW4 and MW6 are summarized in <br />' Table 3 <br /> On September 28, 1993, the diesel and gasoline UST excavations were lined with plastic and <br /> backfilled with clean fill upon authorization from SJCPHS <br />' Also on September 28, 1993, approximately 700 cubic yards of diesel contaminated soil were <br />' excavated from the vicinity of the former dispenser island Thirteen soil samples (EX1 through <br /> EX13) were obtained from the bottom and sidewalls of the excavation(Plate No 2) Analytical <br /> results of the excavation soil samples generally revealed low but detectable concentrations of <br />' TPH as diesel Based on the analytical results of the excavation samples, it was our opinion that <br /> additional excavation beneath the former dispenser location was not necessary and we <br /> recommended backfilling the excavation The excavation was backfilled by Granite <br /> Construction Company using clean fill, following authorization from SJCPHS Results of <br /> laboratory analysis of soil samples obtained from the bottom and sidewalls of the former UST <br /> excavation are summarized in Table 4 <br /> In accordance with our October 12, 1994 Soil and Ground Water Investigation Workplan, soil <br /> boring (B 18) and monitoring wells (MW7 and MW8) were drilled on January 17, 1995 (Plate 2) <br /> The borings were drilled by B & F Drilling using a Mobile B-61 drill ng equipped with 6-inch <br /> and 8-inch diameter hollow stem augers Soil boring B18 was advanced to a depth of <br />' approximately 20 feet below site grade, monitoring wells MW7 and MWS were advanced to <br /> depths of approximately 40 feet below site grade Wells MW7 and MW8 were installed with <br />' two-inch diameter schedule 40 PVC casing <br /> A total of 12 soil samples and 8 ground water samples were collected from the soil boring, two <br /> newly constructed wells, and the six existing wells Selected samples were analyzed for Total <br /> Petroleum Hydrocarbons(TPH) as gasoline and diesel using EPA method 8015 Modified, <br /> Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX) using EPA method 8020 and for Total <br /> Lead using EPA method 6010 <br /> `�W <br /> WALLACE KUHL <br /> Recycledpgp Er ASSOCIATES INC <br />