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a lr <br /> . 18 January 2001 <br /> I AGE-NC Project No 95-0111 <br /> Page 3 of 4 <br /> is approximately 0 006 feet/feet The relative ground water elevation contours are depicted in Figure <br /> 3 <br /> I3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> I TPH-g was detected in ground water samples collected from MW-4 and MW-7 at 76 micrograms <br /> per liter (/,sg/1) and 250 µg/1 TPH-d was detected in samples MW-4, MW-5 and MW-7 at <br /> concentrations of 2,600 µg/1, 2,500 ,ug/1 and 98 ,ug/l, respectively <br /> BTEX compounds were detected in water samples collected from MW-1,MW-4,MW-6,MW-7 and <br /> MW-8 at concentrations up to 3 4 4g/1, 37 ,ug/l, 12 ,ug/l and 50 mg/1, respectively <br /> IMTBE was detected by EPA Method 8020 in samples from MW-1 and MW-7 at concentrations of <br /> 100 ,ug/1 and 9 4 /,tg/l, respectively MTBE was confirmed in MW-1 and MW-7 and detected in <br /> MW-4 by EPA method 8260-modified at concentrations of 120 yg/l, 9 4 ug/l and 3 2 ,ug/l, <br /> respectively No other fuel oxygenated compound was detected above laboratory reporting limits in <br /> Ithe ground water samples analyzed <br /> Analytical results of the ground water samples are summarized in Tables 2 and 3 The laboratory <br /> reports (MAI Laboratory Sample Nos 56616 through 56623), quality assurance and quality control <br /> report and chain-of-custody forms are included in Appendix B <br /> I4.0. SUMMARY AND CONCLUSIONS <br /> IBased on the findings from this investigation, AGE concludes <br /> • The northerly ground water flow direction inferred from data collected during this <br /> monitoring event is consistent with ground water flow directions determined during past <br /> monitoring events at the site <br /> I • The concentrations of TPH-g, TPH-d and BTEX detected in the ground water samples from <br /> MW-1, MW-4 and MW-5 remain near the low end of the range of concentrations previously <br /> detected The hydrocarbons are located primarily in the down-gradient direction from the <br />! UST facility TPH-g concentrations in well MW-7 were unusually high this quarter, <br /> f increasing from non-detectable concentrations to 250,ug/l MW-7 is cross-gradient to former <br /> UST pit <br /> • MTBE was only detected in three wells (MW-1, MW-4 and MW-7) with the highest <br /> . concentration (120 4g/1) occurring immediately down-gradient of the UST facility(MW-1) <br /> Only trace concentrations of MTBE were detected in MW-4 and MW-7 <br /> Advanced GeoEnvironmental Inc <br />