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1 . 03 March 1999 AGE-NC Project No 95-0111 Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES ' TPH-g was detected in samples collected from monitoring wells MW-1;MW-4 and MW-5 at concentrations of 57 micrograms per later (,ug/1), 190 µg11 and 160 ug/l, respectively These concentrations are near the low end of the range of TPH-g concentrations previously detected in ' ground water samples collected from these wells The sample collected from monitoring well MW-2 did not contain a detectable concentration of TPH-g this 4uarter,but has periodically during previous monitoring events ' TPH-d was detected in samples from wells MW-1, MW-4 and MW-5 at concentrations of 83 µg11, 290,000µg/1 and 11,000µg/l,respectively The concentration from well MW-4 are at the high end Iof the range of TPH-d concentrations detected in ground water samples collected from this well during previous ground water monitoring events Laboratory notations for the ground water sample collected from wells MW-4 and MW-5 indicated the presence of an immiscible sheen ' Benzene was detected int samples collected from wells MW-1, MW-2 and MW-4 a concentrations t • of 37µg/l, 10µg/I and 4 9µg/l, respectively Ethylbenzene was detected in MW-1, MW-2 MW-4 and MW-5 at concentrations as high as 2 3 µg/1 Xylenes were detected in samples from MW-1 and MW-2 at concentrations as high as 2 9 µg11 ' MTBE was detected by EPA Method 8260 Modified in samples collected from wells MW-1,MW-4 and MW-5 at concentrations of 370 µg11, 45 µg/l and 29 µg/1, respectively ' Analytical results of ground water samples are summarized in Table 2 and Table 3 The laboratory report(MAI Laboratory Sample No 00755 to 00760), quality assurance and quality control report ' and chain-of-custody are included in Appendix B '+ 4.0. SUMMARY AND CONCLUSIONS A t Based upon data collected from the site during the current and preceding ground water monitoring events, AGE concludes ' During the December 1998 monitoring event,the inferred ground water flow direction at the site was generally toward the northeast, consistent with the inferred ground water flow direction determined from the previous ground water monitoring events The gradient was ' approximately 0 005 ft/ft or 28 feet per mile . In general,the concentrations of TPH-g and BTEX detected in the ground water samples are ' at the low end of the range of concentrations previously detected, indicating that the mass Advanced GeoEnviron mental Inc.