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C A 5 S O C I A T E 5 I N C On February 18, 1999, a geologist from ATC Associates supervised the installation of three groundwater-monitoring wells from 39 to 41 feet bgs Soil borings MW 1, MW2, and MW3 were completed as two-inch monitoring wells One soil sample from each boring was collected and after the groundwater monitoring wells were developed on groundwater sample was collected from each well Soil and groundwater samples contained detectable concentrations of petroleum hydrocarbons Results are summarized in ATC's Summary Report of Additional Subsurface Investigation, dated June 1, 1999 SAMPLING ACTIVITIES On March 21, 2001, ATC personnel collected groundwater samples from monitoring wells MW1, MW2, and MW3 The locations of the monitoring wells are shown on Figure 2 Prior to collection of groundwater samples, the depth to water, pH, electrical conductivity, and temperature were measured in the monitoring wells and recorded A minimum volume of three well casings was purged from each well prior to sampling The wells were allowed to recover and samples were collected from each well using disposable bailers The groundwater matrix samples collected from each well were submitted to State-certified Argon Laboratories (FLAP Cert No 2359) for chemical analysis of total petroleum hydrocarbons as gasoline (TPH-g) utilizing EPA method 8015 modified, and benzene, toluene, • ethylbenzene, xylenes (BTEX) and methyl tertiary butyl ether (MTBE) utilizing EPA method 8020 Groundwater well purge and sample logs are contained in Attachment 1 ANALYTICAL RESULTS The groundwater matrix analytical results measured at monitoring well MW 1 showed detectable concentrations of TPHg and BTEX The measured concentration of TPHg at MW was 4,000 pg/L Benzene was detected at 14 gg/L, toluene was detected at 7 4 pg/L, ethylbenzene was detected at 74 gg/L, and xylenes were detected at 8 1 pg/L The groundwater matrix analytical results measured at monitoring well MW2 showed detectable concentrations of TPHg and benzene at 200 pg/L and 2 4 pg/L respectively The groundwater matrix analytical results measured at monitoring well MW3 showed detectable concentrations of TPHg and BTEX TPHg was detected at a concentration of 1,300 gg/L, benzene was detected at 0 6 pg/L,toluene was detected at 0 9 pg/L, ethylbenzene was detected at 8 3 pg/L, and xylenes were detected at 14 pg/L The Maximum Contaminant Level (MCL) for benzene, 1 pg/L, was exceeded at monitoring wells MW 1 and MW2 which had detected concentrations of 14 pg/L and 2 4 gg/L respectively w Iwordpro11498111QR-01 doc 2