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the composited soil samples collected at a depth of five feet bgs, and were detected at 21mg/kg <br /> and 62 mg/kg in the other two composited soil samples from five feet bgs. Composited soil <br /> samples from five feet bgs did not contain concentrations of metals associated with waste motor <br /> oil. Composited surface samples contained motor oil-weight petroleum hydrocarbon <br /> concentrations ranging from 76 mg/kg to 475 mg/kg, and concentrations of zinc ranging from <br /> 218 mg/kg to 912 mg/kg. One composited sample contained a lead concentration of 175 mg/kg. <br /> 4.1.3 OMS <br /> Eight borings, B-20 through B-27, were advanced to investigate potential impacts in the area of <br /> OMS operations, including a former vehicle fueling station containing gasoline and diesel fuel. <br /> As shown on Figure 4, boring B-20 was advanced to assess potential impacts from a vehicle <br /> inspection rack. Jet fuel-weight petroleum hydrocarbon was detected at a concentration of <br /> 10,500 mg/kg, and gasoline, diesel fuel, and motor oil-weight petroleum hydrocarbons were <br /> detected at concentrations of 9.2 mg/kg, 14.3 mg/kg, and 153 mg/kg, respectively, in soil at a <br /> depth of ten feet bgs; VOCs were not detected in soil vapor at the same depth. <br /> Borings B-21 and B-22 were advanced at the locations of a washpad and clarifier, and a waste-oil <br /> tank which may still exist on the south side of the OMS building. CDCs, such as petroleum <br /> hydrocarbons, SVOCs, VOCs, and heavy metals, were not detected in soil and soil vapor <br /> samples collected at a depth of ten feet bgs at either boring location. Borings B-23 and B-24 <br /> were advanced in an unpaved area used for truck parking and temporary storage of hazardous <br /> materials. Petroleum hydrocarbons were not detected in soil at a depth of five feet bgs at either <br /> location; VOCs were not detected in soil gas from five feet bgs at either location. <br /> Boring B-25 was hand augured in the battery storage,filling, and maintenance room located in <br /> the northeast corner of the OMS building. A core was cut through the coated concrete floor slab, <br /> and a soil sample collected from the hand auger at a depth of 2.5 feet bgs. Evidence of lead or <br /> pH impact to soil was not detected in the soil sample. <br /> Borings B-26 and B-27 were advanced at the former location of two underground petroleum <br /> storage tanks at a fill island, as shown on Figure 4. Each boring was advanced to 25 feet in depth <br /> and sampled at 10, 15, and 20 feet bgs for petroleum hydrocarbons as gasoline and diesel fuel. <br /> TPH-g and TPH-d were detected in each boring at a depth of 25 feet. Boring B-26 contained <br /> concentrations in soil of TPH-g and TPH-d of 25.4 mg/kg and 209 mg/kg, respectively. Boring <br /> B-27 contained concentrations of TPH-g and TPH-d of 5.9 mg/kg and 8.13 mg/kg, respectively. <br /> 4.2 Groundwater Evaluation <br /> Versar collected one groundwater sample from each of the three groundwater monitoring wells <br /> located around the former jet fuel USTs at the AASF. The location of the monitoring wells is <br /> shown in Figure 3. The groundwater samples were collected in accordance with the procedures <br /> • specified in Versar's 1999 revised work plan. Physio-chemical parameter measurements made <br /> 2187-01/3134-100/MAY26'00 12 <br />