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1 ~ <br /> GRANITE CONSTRUCTION, FRENCH CAMP <br /> WKA No 2088 03 <br /> April 29, 1993 <br /> Page 5 <br /> these concentrations are well below the Soluble Threshold Limit Concentrations in Title 22, <br /> ICalifornia Code of Regulations, Article 3, Section 66261 24 <br /> Former Dispenser Island <br /> Four borings (B3 through B6) ranging in depth from 24 to 29 feet were drilled in the vicinity of <br /> the former dispenser island located approximately 80 feet east of the tank farm (Plate 3) The <br /> soils in this area consisted primarily of sandy silts interbedded with silty clays to a depth of <br /> approximately 22 feet, fine to coarse grain sands were encountered in each boring at a depth of <br /> approximately 22 feet Gray/green soils exhibiting strong petroleum hydrocarbon odors were <br /> observed in boring B4 to a depth of approximately 11 5 feet <br /> Laboratory analyses of sample B4-2I, obtained from a depth of 6 5 feet in boring B4, revealed <br /> TPH-gasoline and TPH-diesel concentrations of 2,000 mg/kg, and 7,800 mg/kg, respectively, <br /> BTEX constituents also were detected Analysis of the samples obtained from borings B3, B5, <br /> and B6 revealed no detectable concentrations of TPH or BTEX Additional analysis of the <br />' samples obtained from borings B3 through B6 revealed total lead concentrations ranging from 1 8 <br /> mg/kg to 6 5 mg/kg <br /> Former Tank Farm <br /> Eleven borings (B7 through B17) were drilled in the vicinity of the four underground gasoline <br /> and diesel storage tanks (Plate 3) The borings ranged in depth from 24 to 31 feet below site <br /> grade The soils encountered in these borings consisted primarily of sandy silts interbedded with <br /> fine to medium grained sands Moderate to strong petroleum hydrocarbon odors were <br /> encountered in soil samples obtained from borings B7 through B13 while slight or trace odors <br /> were noted in soil samples obtained from borings B14 through B17 <br /> Laboratory analysis of samples obtained from borings B7 through B17 revealed detectable <br /> concentrations of either TPH-gasoline or BTEX in each boring Analysis of samples obtained <br /> 6 from borings B7, B8, B10, B11, and B13 at depths of 16 to 21 5 feet below site grade revealed <br /> 6 the most significant TPH-gasoline concentrations, ranging from 250 mg/kg to 930 mg/kg <br /> " �W <br /> WALLACE•KUHL <br /> Recycledpafvr &ASSOCIATES INC <br />