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I ' 02 June 2005 AGE-NC Project No 95-0130 IPage 11 of 13 ' of dissolved TPH-g is depicted in Figures 5 and 7 'r 'r The greatest concentrations of Top Filling Station dissolved MTBE were detected at concentrations as high as 5,400 µg/1 in the samples collected from well MW-6B (screened 50 to 55 feet), the approximate extent of dissolved MTBE is depicted in Figures 6 and 8 • TBA was not detected in any of the analyzed water samples,however, TBA was previously ' detected in wells MW-1, MW-2, MW-3, MW-5, VW-1C, VW-2A, VW-2B and VW-3A, suggesting a minor TBA-impact to ground water at the site I • Significant concentrations of 1,2-DCA were detected or have consistently been detected from wells MW-3, MW-8, MW-6B, MW-6C, VW-1B, VW-1C, VW-2A, VW-2B and VW-3A indicating a significant 1,2-DCA-impact to ground water at the site ' • EDB has previously been detected from wells MW-713, VW-1B, VW-1C and VW-2A at concentrations significantly above the DHS's Maximum Contaminant Level (MCL) in drinking water • TAME was detected in ground water samples collected from wells MW-1, MW-2, MW-3, MW-6 (B-E), MW-7 (B-D), VW-1C, VW-2A and VW-3A at concentrations as high as 49 �ig/l (MW-7B) This is the fourth consecutive occurrence that TAME has been detected in ground water samples collected from the site, with the exception of one detection of TAME in December 2003 and March 2003 in wells VW-2A and VW-3A, respectively ' Y The high concentrations ofpetroleum hydrocarbons detected in samples collected from wells MW-6(B and C),MW-7(A and B),VW-1C,VW-2A and VW-3A indicated that these wells are within or near the dissolved petroleum hydrocarbon"core area"of the plume(Figures 5 through 8) • The lateral and vertical extent of the dissolved petroleum hydrocarbon plume is not known toward the northwest,north,northeast, east and southeast of the area bound by wells MW-1 through MW-7 (Figures 5 through 8) Based on SVE remediation data collected between 22 December 2004 and 08 March 2005, AGE concludes • Analytical results of SVE inlet vapor concentrations ranged between 3,100 µg/1 and 12,000 lig/l, the average SVE inlet vapor concentration was approximately 6,675 [ig/l • A significant decline in hydrocarbon vapor concentrations was evident between the fourth quarter 2004 and the first quarter 2005 monitoring events, a plot of the influent TPH-g Iconcentrations versus time is included in Appendix G . • The average SVE inlet flow rate was approximately 59 cubic feet per minute, the average IAdvanced GeoEnvironmental,Inc I