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I <br /> GRANITE CONSTRUCTION <br /> WKA No 2088 07 <br /> April 7, 1995 <br /> Page 4 <br /> I <br />' Four soil borings (133 through B6) ranging in depth from 24 to 29 feet were drilled in the vicinity <br /> of the former dispenser island located approximately 80 feet east of the former gasoline and <br />' diesel USTs Laboratory analyses of sample B4-21, obtained at a depth of 6 5 feet in boring B4, <br /> revealed TPH as gasoline and TPH as diesel concentrations of 2,000 mg/kg and 7,800 mg/kg, <br /> respectively, BTEX constituents also were detected Analysis of the samples obtained from soil <br /> borings B3, B5, and B6 revealed no detectable concentrations of TPH or BTEX Additional <br /> analysis of the soil samples obtained from borings B3 through B6 revealed total lead <br />' concentrations ranging from 1 8 mg/kg to 6 5 mg/kg <br />' Eleven borings (137 through B17) were drilled in the vicinity of the former gasoline and diesel <br /> USTs Laboratory analysis of samples obtained from borings B7 through B17 revealed detectable <br /> concentrations of either TPH as gasoline or BTEX in each boring Analysis of soil samples <br /> obtained from borings B7, B8, B10, BI 1, and B13 at depths of 16 to 21 5 feet below site grade <br /> revealed the most significant TPH as gasoline concentrations ranging from 250 mg/kg to 930 <br /> mg/kg Analysis of soil samples obtained from the remaining soil borings in this area revealed <br /> TPH as gasoline concentrations ranging from non-detectable to 6 0 mg/kg Additional analysis of <br />' the samples obtained from borings B7 through B17 revealed total Iead concentrations ranging <br /> from <1 0 mg/kg to 7 8 mg/kg <br />' Three monitoring wells (MWI through MW3) were drilled and constructed to depths ranging <br /> g <br />' from 39 to 40 feet below surface grade at the locations shown on Plate 3 Analysis of the soil <br /> samples obtained during the construction of MWI through MW3 revealed trace concentrations of <br />' TPH as gasoline and benzene in each monitoring well boring Additionally, TPH as diesel <br /> concentrations of 12 mg/kg were revealed in laboratory analysis of soils obtained from boring <br /> MW3 Analysis of the soil samples obtained from MW 1 through MW3 revealed total lead <br />' concentrations ranging from 2 3 mg/kg to 6 6 mg/kg <br />' Ground water measurements on September 28, 1993, revealed a ground water flow direction to <br /> the northeast Analytical results of the initial ground water samples collected from MW 1 and <br /> MW2 generally revealed non-detectable concentrations of TPH as gasoline, however, monitoring <br /> well MW3 revealed a TPH as gasoline concentration of 1,100 micrograms per liter (µg/f) <br />' <br /> WALLACE <br /> Recycled paper &ASSOCIATES INC <br />