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• 10 February 2003 <br /> ' AGE-NC Project No 95-0167 <br /> Page 3 of 4 <br /> BTEX compounds were detected in the water samples collected from monitoring wells MW-I and <br /> MW-2, the highest concentrations were detected in the sample from MW-1 at 4,500 µg/1 benzene, <br /> 5,000 µg11 toluene, 780 µg/1 ethylbenzene and 4,200 µg11 xylenes <br /> MTBE was detected by EPA Method 8260B in samples MW-I and MW-2 at concentrations of 54 <br /> pg/l and 4 2 µg11,respectively No other fuel additives were detected in the ground water samples <br /> Analytical results of water samples collected during the December 2002 monitoring event are <br /> ' summarized on Tables 2 and 3 The Iaboratory report (MAI Lab IDs 0212215-001 through <br /> 0212215-006), QA/QC report and chain-of-custody form are included in Appendix B Figure 4 <br /> depicts the estimated areal distributions of impacted ground water containing TPH-g and benzene <br /> ' for I 1 December 2002 <br /> 4.0. SUMMARY AND CONCLUSIONS <br /> Data collected at the site indicates that <br /> h ' o <br /> The ground water flow direction during this monitoring event was toward the northwest at <br /> t <br /> an average gradient of 0 03 ft/ft Ground water flow at the site has historically been towards <br /> the northwest Ground water flow direction is not well defined south of the former UST pit <br /> • Relatively high concentrations of TPH-g and BTEX occur in ground water in the area of <br /> monitoring wells MW-I and MW-2; the TPR-g. and BTEX concentrations in well MW-1 <br /> were the highest detected since November 2000 <br /> • MTBE was present in monitoring wells MW-1 and MW-2 at concentrations of 54 }tg/l and <br /> 4 2 ug/l, respectively <br /> • The contaminant plume appeared to be confined to the general area of the former UST <br /> ' location and MW-1 and MW-2 Petroleum hydrocarbons were not detected in perimeter <br /> wells MW-3, MW-4, MW-5 and MW-6 In addition, petroleum hydrocarbons were not <br /> detected in a grab ground water sample collected and analyzed in April 1997 from soil <br /> boring P4, south of the fortifier UST location <br /> ' 5.0. RECOMMENDATIONS- <br /> Based <br /> ECOMMENDATIONS-Based on present site conditions, AGE recommends <br /> . Continued quarterly ground water monitoring at the site The next monitoring event should <br /> be scheduled for February 2002 <br /> b <br /> Advanced GmEnviranmental,Inc <br /> °1 <br /> h <br /> 6 - - - - - - - <br />