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all LEW3MILL•MERKEMMOFF. INC. for depths of 16.5 to 36.5 feet. SB3 contained high concentrations of TPH as gasoline ranging from 160 to 5, 100 mg/kg at all depths except 21 .5 feet. The highest concentration level of I00 mg/k from boring SB3 occurred at 31 .5 feet, within 5 feet of where grounawater was encountered during dril ing /,operations. The deepest sample analyzed within the excavation was from boring SB4 at 36.5 feet, which contained 1 mg/kg TPH as gasoline. This indicates that there was probably a significant release of gasoline in the vicinity of soil boring SB3 and S84 and that this petroleum hydrocarbon contamination migrated vertically down to at least 36.5 feet and probably impacted the groundwater beneath the excavation. The low concentrations of gasoline constituents found in SB2 indicate that the contamination is located primarily in the eastern half of the former UST excavation. Low or non-detectable concentrations of BTX&E and TPH found in MW1 and SBI indicate that the contamination has not migrated to the south of the former excavation. However, the high concentrations of BTX&E and TPH found in MW2 indicates that the contamination from the excavation has migrated laterally to the north and possibly off-site at a depth of approximately 16.5 feet. The contaminated soil appears to be limited to those soils within an area approximately 30 feet wide beneath the center to eastern end of the former UST excavation to a depth of at least 36.5 feet below the surface. It appears as though little, if any, of the contamination as migrated to the south of the former excavation. However, with the high concentrations of soil contaminants found during the boring for MW2, at a depth of 15 feet, lateral definition of the contamination to the north of the excavation cannot be made. Since the shallowest soil samples that were analyzed from borings SB3 and SB4 were retrieved from a depth of 11 .5 feet within the contaminated area, and contained high concentration levels of TPH as gasoline, it is unknown whether the overburden soils from the surface to a depth less than 11 .5 feet are contaminated. Because of this, these overburden soils should be segregated during subsequent remediation activities and/or analyzed prior to remediation to determine proper handling and disposal . I l ' '5 ( V n IC ✓1 o Soil Boring, Adjacent to the Waste Oil Tank Analysis of soil samples from SB6 adjacent to the waste oil tank indicate non- detectable concentrations of BTXBE and TPH as gasoline and diesel at all depths sampled. This indicates that even though the waste oil tank failed the precision tank test, it may not be leaking. It is possible that contamination from the waste oil tank could be present on the northeast side of the tank; however, the presence of the building precluded access for sampli oil tank. ng on this side of the waste i �~ i 1 16 l i j