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A S S 0 C I A T E S I N C The groundwater matrix samples collected from each well were submitted to State-certified Argon Laboratories (ELAP 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 MWI, MW2, and MW3 showed detectable concentrations of TPHg, BTEX, MTBE, TBA, and 1,2-DCA. The measured concentration of TPHg at MWI was 750 pg/L. Benzene was detected at 2.3 pg/L, toluene was detected at 1.0 µg/L, ethylbenzene was detected at 9.8 pg/L, and xylenes were detected at 26 pg/L. MTBE was detected at 13 pg/L, TBA at 35 µg/L., and 1,2-DCA at 18 µg/L. The measured concentration of TPHg at MW2 was 2,500 µg/L. Benzene was detected at 11 pg/L, toluene was detected at 49 pg/L, ethylbenzene was detected at 32 pg/L, and xylenes were detected at 56 gg/L. MTBE was detected at 110 pg/L, TBA at 130 µg/L, and 1,2-DCA at 92 Ag/L. The measured concentration of TPHg at MW I was 920 pg/L. Benzene was detected at 0.7 pg/L, • toluene was detected at 2.1 gg/L., ethylbenzene was detected at 5.2 gg/L, and xylenes were detected at 13 pg/L. MTBE was detected at 170 gg/L, TBA at 61 µg/L, and 1,2-DCA at 87 ply• The Maximum Contaminant Level (MCL) for benzene, 1 µg/L, was exceeded at monitoring wells MWI and MW2 which had detected concentrations of 2.3 Pg/L and 11 gg/L,. The MCL for MTBE, 13 pg/L, was exceeded at MWI, MW2, and MW3, which had detected concentrations of 13 pg/L, 110 gg/L, and 170 pg/L, respectively. GROUNDWATER FLOW DIRECTION Water level measurements were collected from monitoring wells MWI, MW2, and MW3 on July 23, 2002. Water level elevations ranged from —24.05 to —24.16, representing an average increase in water table elevation of approximately 2.66 feet since April 2002. The water level data were used to develop the groundwater elevation contour map (Figure 3). Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer beneath the site flowed towards the northeast. The average hydraulic gradient on July 23, 2002 was calculated to be 0.002 or approximately 9.4 ft/mile. A summary of groundwater monitoring data is presented in Table 1. CONCLUSIONS • Groundwater flow direction and gradient is consistent with previous sampling events. Water table elevations have increased since the April 2002 monitoring event. Groundwater analytical w:lwordpro1224931Reports\3QR-02.doc 3