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TPHg was detected in the soil samples collected from borings SBI through SB7 Elevated <br /> concentrations of TPHg were detected above and below the groundwater interface at <br /> ' approximately 30 feet bgs in soil borings SB2, SB3, and SB6 The highest of these <br /> concentrations were in soil samples SB3-20 5 at 7,800 parts per million (ppm) and SB3-35 5 at <br /> 1,100 ppm The highest concentrations of TPHg appear to be limited to depths between 15 feet <br /> bgs and 35 feet bgs near the center of the former tank locations (SB3) and to between 20 feet bgs <br /> and 30 feet bgs in the remaining soil borings <br /> Benzene was detected in the soil samples collected from borings SB 1 through SB7 Elevated <br /> 1 concentrations of benzene were detected above and below the groundwater interface at <br /> approximately 30 feet bgs in soil borings SB2, SB3, and SB6 The highest of these <br /> concentrations were in soil samples SB3-20 5 at 35 ppm and SB3-35 5 at 7 5 ppm <br /> MTBE was only detected in sample SB7-28 5 at 0 015 ppm, but several samples had elevated <br /> 1 detection limits due to dilution factors VOCs were not detected in any soil samples collected <br /> from borings SBI through SB7, but several samples had elevated detection limits due to dilution <br /> factors PCBs were not detected in any soil samples collected from borings SBI through SB7 <br /> Lead was detected in all samples collected from borings SBI through SB7 The lead <br /> concentrations were consistent with background concentrations of lead for the San Joaquin Valley <br /> (less than 15 ppm) with the exception of sample SB3-15 5 which contained lead at 52 ppm <br /> These data indicate residual soil contamination from the former waste oil tank and the former <br /> unleaded gasoline tanks exists in shallow soils near the former tank pit and within the capillary <br /> fringe Since contaminants associated with waste oil tanks (TPHd, VOCs, and PCBs) were not <br /> ' detected in any borings except SB3, the residual soil contamination from the former waste oil tank <br /> appears to be limited to the vicinity of the former waste oil tank <br /> These data also indicate that residual soil contamination from the former unleaded gasoline tanks <br /> exists in shallow soils and within the capillary fringe The horizontal extent of residual soil <br /> ' contamination from the unleaded gasoline tanks can not be determined based upon present <br /> available data <br /> Four samples were collected from a depth of 45 5 feet bgs, SB2-45 5, SB3-45 5, SB4-45 5, and <br /> SB5-45 5 The soil samples collected from borings SB2, SB3, and SB5 contained very low <br /> ' concentrations of TPHg and BTEX The soil samples collected from boring SB4 did not contain <br /> detectable concentrations of TPHg or BTEX Concentrations of TPHg and BTEX were high at <br /> shallower depths and decreased to very low at 45 5 feet bgs These data indicate the vertical <br /> extent of residual soil contamination appears to be limited to approximately 45 5 feet bgs <br /> w 197731Veporislpsi doc 5 <br /> • <br /> SMTN <br />