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1 dispenser island was defined by analysis of soil samples collected at 14 and 23 feet bgs from the angled soil boring D-2 The soil sample collected at 14 feet from D-2 only contained 0 0054 mg/kg of MTBE, and no gasoline compounds were detected in the soil sample collected at 23 ' feet Impacted soil in the area of the former western dispenser and piping was subsequently excavated to depths ranging between 7 and 12 feet bgs Although no confirmation soil samples were collected following excavation, the existing soil sample analytical results suggest that any ' remaining impacted soil in the vicinity of the western dispenser island appears minimal and probably does not pose a threat to groundwater beneath the site ' Beneath the northern end of the former UST (Tank 2), the soil sample collected at 14 feet bgs contained 7,000 mg/kg of TPH-as-gasoline, 3 5 mg/kg of benzene, 90 mg/kg of ethylbenzene, 590 mg/kg of xylenes, and 0 024 mg/kg of MTBE The lateral extent of impacted soil at the base of the former tank basin is defined to non-detectable concentrations to the west, east, and south by samples T1-N-15, T3-N-14, and T2-S-14 The estimated lateral extent of hydrocarbons remaining in soil associated with the former USTs is shown on Figure 4 ' Based on the analytical results from soil samples collected from sod boring SB-1, drilled adjacent to the northern end of former UST (Tank 2), the vertical extent of impacted soil and most of the gasoline hydrocarbon mass appears to be defined to a depth of between 15 and 25 feet bgs The soil sample collected at 15 feet from SBA contained 1,200 mg/kg of TPH-as-gasoline, 1 7 mg/kg of benzene, 34 mg/kg of toluene, 29 mg/kg of ethylbenzene, 150 mg/kg of xylenes, and 0 62 mg/kg of MTBE The soil samples collected at 25 feet and deeper from SB-1 did not contain detectable concentrations of TPH-as-gasoline, benzene or MTBE Toluene, ethylbenzene and/or ' xylenes were detected in soil samples collected at 25 feet or deeper from SBA, but the concentrations were low Vertically, the soil sample collected at 80 feet from SBA did not contain any detectable concentrations of gasoline compounds Hydrocarbons in Groundwater ' The groundwater sample collected from a temporary well installed in SB-1 contained 130 µg11 of 1 TPH-as-gasoline, 1 9 µg/l of toluene, 1 4 µg11 of ethylbenzene, and 9 5 µg11 of xylenes Although groundwater samples collected from temporary wells are considered more representative than samples collected from open boreholes, it is possible that a portion of the initial groundwater impact may be attributed to the drilling process itself, which may have mobilized hydrocarbons from a higher position in the borehole r 13 1