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30 October 2002 <br /> . AGE-NC Project No 96-0254 <br /> IPage 3 of 4 <br /> I 29 13 feet above mean sea level (MSL) in well MW-7 and 30 30 feet above MSL in well MW-6 <br /> Ground water elevations in wells MW-1 through MW-6 at the site increased an average 0 04 feet <br /> between the April 2002 and July 2002 sampling events, the ground water elevation in well MW-7 <br /> IIncreased 0 97 feet between the April 2002 and July 2002 sampling events <br /> The ground water flow direction for the 23 July 2002 sampling event was inferred to be toward the <br /> north at an average hydraulic gradient of 0 005 feet/feet, data from the deeper-screened wells <br /> MW-IA, MW-2A and MW-7 was not used to determine the ground water gradient Figure 3 <br /> illustrates the contoured ground water elevations <br /> 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES <br /> ITPH-g was detected in the samples collected from wells MW-1B and MW-4 at concentrations of <br /> 30,000 micrograms per liter(µg/1) and 12,000 µg/l,respectively(Figure 4) TPH-d was detected in <br />' the water samples collected from wells MW-1B and MW-4 at concentrations of 1,900 µg/1 and <br /> 1,100 µg/1 TPH-g and TPH-d were not detected in the remaining samples <br /> i . BTEX compounds were detected in the ground water samples collected from monitoring wells <br /> MW-lB, MW-4 and MW-7 (with the exception of ethylbenzene in well MW-7) at concentrations <br /> I as high as 7,700 µg/1 benzene, 1,900 µg/1 toluene, 1,200 µg/1 ethylbenzene and 2,000 µg/l total <br /> xylenes (MW-1B) <br /> MTBE was detected in the samples collected from MW-1B, MW2B and MW-4 at concentrations <br /> of 260 µg11, 0 89 µg/l and 22 µg/1, respectively(Figure 6) No other fuel additives were detected in <br /> the ground water samples <br /> IThe analytical results are summarized in Table 2 Copies of the laboratory reports(MAI Laboratory <br /> ID 0207356-001 to 0207356-009), QA/QC reports and chain-of-custody forms are in Appendix B <br /> 4.0. SUMMARY AND CONCLUSIONS <br />' Based on the data collected during this monitoring period, AGE concludes <br /> I • The depth to ground water at the site was between 6 96 to 7 79 feet below the well casing <br /> tops The prevailing ground water flow direction at the site was generally toward the north, <br /> consistent with the previously determined flow directions <br /> • Petroleum hydrocarbon-impacted ground water was encountered in samples from monitoring <br /> • wells MW-IB, MW-2B, MW-4 and MW-7, benzene concentrations exceeded the State of <br /> IAdvanced GcoEnvironmental Inc <br /> I <br />