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On August 17, 1994, FEA drilled one soil boring (designated B-1), near the center of the former UST excavation (Figure 2), to a total depth of 60 feet below ground surface (bgs) Soil samples collected at 30 and 40 feet bgs contained detectable concentrations of TPH-as-gasoline, toluene, ethylbenzene and xylenes Soil samples collected at 55 and 60 feet bgs only contained trace concentrations of xylenes of up to 0 018 mg/kg These sod sample results are summarized in Table 1 A groundwater-grab sample collected from B-1 contained 76,000 micrograms per liter (µg11) of TPH-as-gasoline, 38 µg11 of benzene, 310 p.g/l of toluene, 4 8 of µg11 ethylbenzene and 6,800 µg/l of xylenes 1 2 2 Prelimina Investigation and Evaluation On January 5 and 6, 1999, Ramage Environmental conducted a preliminary investigation and evaluation, which included the drilling of five on-site soil borings for soil sampling and analysis Three of the soil borings were converted to groundwater monitoring wells The on-site soil boring and monitoring well locations are shown on Figure 2 N A metal detection survey conducted at the site, on January 13, 1999, discovered strong metallic signals in the vicinity of the former UST excavation The metal may be drums of waste not accounted for from earlier site investigation activities and other material used to backfill the former UST excavation In soil, the highest concentrations of gasoline hydrocarbons were detected in the sample collected at 30 feet bgs from the soil boring for MW-2 This sample, collected directly beneath the former UST excavation, contained 2,400 mg/kg of TPH-as-gasoline and detectable concentrations of toluene, ethylbenzene and xylenes Laterally, the extent of impacted soil appeared to be limited to the footprint of the former UST excavation The soil sample analytical results are summarized in Table 1 The depth to groundwater beneath the site ranged from 39 31 to 40 34 feet bgs Groundwater flow was to the south-southeast at a gradient of 0 05 foot/foot The well construction details and groundwater monitoring data are summarized in Table 2 Concentrations of TPH-as-gasoline and BTEX compounds were detected in the groundwater samples collected from MW-2 and MW-3 The groundwater sample collected from MW-1 did not contain detectable concentrations of any gasoline compounds As such, the lateral extent of impacted groundwater was undefined to the north (upgradient), west and south (downgradjent) of the former UST excavation However, the lateral extent was defined to the northeast by MW-1 The groundwater analytical data are summarized in Table 3 6 r