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1 <br />' 30 March 2005 <br /> AGE-NC Project No 95-0130 <br />' Page 11 of 13 <br />' • The greatest concentrations of Top Filling Station dissolved MTBE were detected at <br /> concentrations as high as 3,100 µg/1 in the samples collected from wells VW-3A(screened <br /> 43 to 63 feet) and MW-6B (screened 50 to 55 feet), the approximate extent of dissolved <br />' MTBE is depicted in Figures 6 and 8 <br /> • TBA was not detected in any of the analyzed water samples, however, TBA was previously <br /> I detected in wells MW-1, MW-2, MW-3, MW-5, VW-1C, VW-2A, VW-2B and VW-3A, <br /> suggesting a minor TBA-impact to ground water at the site <br /> • Significant concentrations of 1,2-DCA were detected or have consistently been detected from <br />' wells MW-3, MW-8, MW-6B, MW-6C, VW-1B, VW-1C, VW-2A, VW-2B and VW-3A <br /> indicating a significant 1,2-DCA-impact to ground water at the site <br /> • EDB has previously been detected from wells MW-7B, VW-1B, VW-1C and VW-2A at <br /> concentrations significantly above the DHS's Maximum Contaminant Level (MCL) in <br /> drinking water <br /> I • TAME was detected in ground water samples collected from wells MW-3,MW-6B,MW-7 <br /> (B-C),VW-1C, VW-2A and VW-3A at concentrations as high as 100 µg/l (MW-7B) This <br /> is the third consecutive occurrence that TAME has been detected in ground water samples <br /> collected from the site,with the exception of one detection of TAME in December 2003 and <br /> March 2003 in wells VW-2A and VW-3A, respectively <br /> • The high concentrations of petroleum hydrocarbons detected in samples collected from wells <br /> MW-6(B and C),MW-7(A and B),VW-1 C,VW-2A and VW-3A indicated that these wells <br /> are within or near the dissolved petroleum hydrocarbon"core area"of the plume (Figures 5 <br /> Ithrough 8) <br /> • The lateral and vertical extent of the dissolved petroleum hydrocarbon plume is not known <br /> toward the northwest,north,northeast, east and southeast of the area bound by wells MW-1 <br /> through MW-7 (Figures 5 through 8) <br /> Based on SVE remediation data collected between 01 October and 22 December 2004, AGE <br /> concludes <br /> • Analytical results of SVE inlet vapor concentrations ranged between 5,100 µg/l and 43,000 <br /> pg/I, the average SVE inlet vapor concentration was approximately 24,660 µg/l <br /> • A significant decline in hydrocarbon vapor concentrations was evident between the 18 <br /> October 2004 and the 23 November 2004 monitoring events, a plot of the influent TPH-g <br /> concentrations versus time is included in Appendix G <br /> . • The average SVE inlet flow rate was approximately 39 cubic feet per minute, the average <br /> differential pressure measurements were recorded at 0 48 inches of water (Table 6) <br /> IAdvanced GeaEnvironment$I,Inc <br />