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. A S S O C I A T E S I N C flowed towards the east-northeast. The average hydraulic gradient on January 24, 2003 was calculated to be 0.0002 or approximately 1.2 ft/mile. A summary of groundwater monitoring data is presented in Table 1. SAMPLING ACTIVITIES On January 24, 2003, 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 TPHg utilizing EPA method 8015 modified, and BTEX and oxygenate fuel additives including MTBE utilizing EPA method 8260. Groundwater well purge and sample logs are contained in Attachment 1. ANALYTICAL RESULTS . The groundwater analytical results measured at monitoring wells MW1, MW2, and MW3 showed detectable concentrations of TPHg, BTEX, MTBE, TBA, and 1,2-DCA. The Maximum Contaminant Level (MCL) for benzene, 1 µg/ , was exceeded at monitoring wells MW1 and MW2 which had detected concentrations of 2.2 µg/L and 8.2 µg/L, respectively. The MCL for MTBE, 13 µg/L, was exceeded at MW1, MW2, and MW3, which had detected concentrations of 20 µg/L, 82 gg/L, and 150 ug/L, respectively. The MCL for 1,2-DCA, 0.5 µg/L, was exceeded at monitoring wells MW1, MW2 and MW3, which had detected concentrations of 29 µg/L, 45 [g/L, and 58 µg/L. An Action Level for TBA, 12 µg/L, was exceeded at wells MW 1, MW2, and MW3 that had detected concentrations of 30 µg/L, 47 pg/L, and 45 µg/L, respectively. CONCLUSIONS Groundwater flow direction and gradient is consistent with previous sampling events. Water table elevations have increased since the October 2002 monitoring event. Groundwater analytical results show a general increase in concentrations, though most remained within historical parameters as set by previous groundwater analytical results. RECOMMENDATIONS Based on the results of the first quarter 2003 monitoring event, we recommend continued • quarterly groundwater monitoring with analysis of samples for TPHg, BTEX, and fuel oxygenates. w:lwordpro122493aeportsl I QR-03.doc 3