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Fr, 26April 2003 r AGE-NC Project No. 96-0254 Page 3 of 4' FOctober 2002 and March 2003 sampling events;the ground water elevation in well MW-7 decreased 0.66 feet between-the October 2002 and March 2003 'sampling events. , The ground water,flow direction for the 12 March 2003 sampling event was infezred to be toward the north to northwest at an average hydraulic gradient of 0.006 feet/feet. Data-from the deeper- screened wells MW-IA,MW-2A and MW-7 was not used to determine the ground water gradient. F Figure 3 illustrates the contoured ground water elevations. 3.2. LABORATORY RESULTS OF GROUND WATER SAMPLES , TPH-g was•deiected in the samples collected from wells MW-1B and MW-4 at concentrations of - 1,200 micrograms per liter(µg/1) and 820 res ective µ�1, p ly(Figure 4). TPH-d was detected in the water.samples collected from wells MW-1B,MW-4 and MW-7 at concentrations of 150 µg/l, 110 µ/1 and 93 µg%1, respectively. TPH-g and TPH-d were not detected in the remaining samples. BTE&X Was detected in the ground water samples collected from monitoring wells MW-1B and MW-4 at concentrations as high as 350 Ag/l benzene{MW-1B), 31 µg/1 toluene(MW-1B), 50µg/1 ethylbenezene (MW-4) and 37 µg/1 total xylcnes (MW4B). MTBE was detected in the samples collected from MW-.1B, MW2B and MW-4 at concentrations of 23 µg/1, 0.58:µi 1 and 2.9 µ�l, respectively (Figure 6). No other fuel additives were detected in the ground water samples. The analytical results are summarized in Tables_2 and 3. Copies of the-laboratory reports.(MAI Laboratory IDs.03 03 190-001 through 0343190-010); QA/QC reports and chain-of-custody forms are in Appendix B. '-4.0. SUMMARY AND CONCLUSIONS Based on the data collected during this monitoring period, AGE concludes: The depth to ground water at the site was between 7.12,feet and 7.95 feet below the well casing tops: The prevailing ground water flow direction at the site was generallytoward the north, consistent with the'previously determined flow directions. Petroleum hydrocarbon-impacted ground water was encounteredin samples fioin monitoring wells MW-1B,MW-2B,MW-4..Benzene concentrations exceeded the State ofCalifornia's F maximum contaminant level(MCL)of 1 µg/1 in samples collected from wells MW-1B and �,.. MW-4. Advanced GeoEnvironmental Inc.