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13 May 2002 AGE-NC Project No 98-0511 Page 3 of 4 ' MW-1 at concentrations of 330µg/1 benzene,270µg11 toluene,540µg/1 ethylbenzene and 4,200µg/1 total xylenes ' MTBE was detected in the ground water samples collected from MW-1, MW-3 and MW-5 at concentrations of 110 µg11, 10 µg/1 and 110µg11,respectively No other fuel oxygenated compounds were detected above laboratory reporting limits ' Analytical results of ground water samples are summarized on Tables 2 and 3 The Inferred lateral distribution of TPH-g,benzene and MTBE Is Illustrated on Figure 4 Copies of the laboratory report ' (Cal Tech Laboratory IDs 0203-061-1 through 0203-061-8) and chain-of-custody forms are in Appendix B ' 4,0. SUMMARY AND CONCLUSIONS ' Based upon data collected from the site, AGE concludes the following • On 13 March 2002 the ground water elevation in the monitored area averaged 4 96 feet tabove mean sea level, ground water has risen approximately 1 7 feet since the previous quarter The ground water flow direction was Inferred to be generally westward under a ' gradient ranging from 0 003 ft/ft to 0 006 fl/ft • TPH g was detected at concentrations as high as 8,200 µg/1 in monitoring wells MW-1 and MW-5 Benzene, toluene, ethylbenezene and xylenes were detected in the sample collected ' from MW-1 at concentrations of 330 µg/l, 270 µg/l, 540 µg11 and 4,200 µg/l, respectively BTEX constituents were not detected in samples collected from the other seven monitoring wells • The MTBE concentrations in the ground water samples collected from MW-1 (110 µg/1), MW-3 (10 µg/1) and MW-5 (110 µg/1) are above the DHS Secondary Maximum ' Contaminant Level (5 µg/1) for MTBE • Hydrocarbon-impacted ground water is not defined vertically and laterally along the east side ' of the site ' 5.0. RECOMMENDATIONS Based upon data collected from the site, AGE recommends Continued quarterly ground water monitoring IAdvanced GeoEnvironmental,Inc I