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1 a20052 d Quarter Groundwater Report ' Frontier Transportation, Inc. August 5, 2005 Page 5 ' of TPH-g, excluding March and June of 2004 that were non-detect No other wells identified TPH-g concentrations (<8 µg/L) See Figure 7 See Table 1 FV'na � IA4 ' Historically no detectable to trace concentrations (<5-8-pgfL' of dissolved BTEX were identified in monitoring wells MW-4, MW-5, MW-6, MW-7, MW-8, MW-9, MW-10, MW-11, ' MW-12 and MW-14 since initial groundwater testing began in each well 'Monrtoring wells MW-1 and MW-2 have remained at non-detect to trace levels since at least July of 1999 J Monitoring well MW-13 contained 62 µg/L dissolved total BTEX in June 2002 but has remained ' non-detect since then Newly installed monitoring wells MW-15 through MW-18 idelbtified no detectable concentrations of dissolmd Val BTEX during the 2004 first and second�g3itarter groundwater monitoring events�`My monitoring wells MW-3 and its replacement MW-3R contained dissolved BTEX from almost every groundwater sampling episode Detectable concentrations of dissolved BTEX were identified exclusively in monitoring ' well MW-3R for the groundwater samples collected in June 2005 'Groundwater sample results from MW-1 identified no dissolved BTEX above the laboratory reporting limit (<0 5 µg/L) See Figure 8 for dissolved benzene in MW-1 over time Analytical results from MW-3R demonstrated a significant decrease in total dissolved BTEX from 221 6 µg/L in December 2003 to <11 9 µg/L in June 2005 Dissolved benzene was detected above the MCL at 5 6 µg2 from ' MW-3R in June 2005, a decrease from the maximum of 494 µg/L identified in October 2002 See Figure 9 for dissolved benzene over time in MW-3R , dtsso ve re i i to groundw`a isatifi e�� d� ' -rer img-seven ^ermg-wel�See Figure 10 for the recent dissolved BTEX lsoconcentration Map ' MTBE was identified above MCL in four groundwater wells (MW-1, MW-3R, MW-9 and MW-17) using EPA method 8260 from the second quarter 2005 sampling episode The current California Department of Health Services (CDHS) primary Maximum Contaminant ' Level (MCL) for MTBE in groundwater is 13 pg/L Monitoring well,,MW-1 identified dissolved MTBE concentrations at 2,100 pg/L in June 2005, which is a decrease from the maximum concentration of 8,100 µg/L in September 2004'/(See Figure 11 for MTBE in MW-1 over time) ' Monitoring well MW-3 identified a maximum dissolved MTBE concentration of 29,400 µg/L in March 1998 This well was abandoned in May 2002 Groundwater analysis for replacement well ' MW-3R identified a maximum dissolved MTBE concentration of 6,000 µg/L in December 2003 Dissolved MTBE for June 2005 was identified at 1,000 µg/L, a decrease from the previous level at 3,600 }ig/L (See Figure 12 for MTBE in MW-3R over time) The second quarter 2005 ' groundwater sampling also identified dissolved MTBE in MW-9 at 1,600 µg/L and in MW-17 at 330 µg/L Dissolved MTBE was detected at 12 µg/L in MW-18, which is a deeper well and has i