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I ' 30 April 2005 AGE-NC Project No 95-0141 Page 9 of 10 I ' 0 The lateral extent of soil contamination is defined in the east by boring MW-8, marginally in the north by boring MW-4,in the southeast by boring MW-7 and MW-13,in the northwest and southwest by MW-10 and MW-12 and marginally in the west by boring MW-2 ' (Figure 12) • At the time of the December 2004 ground water monitoring event, ground water elevations at the site ranged from 1193 feet to 12 98 feet below MSL The shallow ground water was ' inferred to flow generally toward the southeast, at a gradient of 0 002 ft/ft while the deeper ground water zone was inferred to flow generally toward the southwest and southeast, at ' gradients of 0 002 to 0 004 ft/ft • TPH-g was detected in ground water samples collected from seven of the sixteen wells at the site at concentrations as high as 140,000 µg/1 TPH-g-impacted shallow ground water has ' been defined (Figure 7) However, the TPH-g-impact to the deeper ground water zone has not been defined toward the east and to a lesser degree south and north (Figure 7) ' 0 Various BTEX constituents were detected in ten of the sixteen ground water wells The detected benzene concentrations in the wells exceeded the DHS' Maximum Contaminant Level(MCL)for benzene in drinking water and the concentrations of toluene,ethylbenzene ' . and total xylenes in well EX-1 were significantly above their respective MCLS However,the use of the shallow and deeper ground water in the region does not immediately appear to be for domestic use, due to extreme salinity ' 0 1,2-DCA was detected in ground water samples collected from nine of the sixteen wells at the site at concentrations as high as 370 pg/1 (EX-1) The detected concentrations of ' 1,2-DCA were above the MCL 1,2-DCA-impacted shallow ground water has not been defined toward the east, and 1,2-DCA-impacted deeper ground water zone has not been defined toward the south, east and north Again, the use of the shallow and deeper ground ' water in the region does not immediately appear to be for domestic use A map illustrating the approximate extent of 1,2-DCA in shallow and deep ground water is presented on Figure 8 ' a EDB was detected in ground water sample EX-1 at a concentration of 230 µg/1 EDB has been detected intermittently in well EX-1, located near the former UST location 6.0. RECOMMENDATIONS ' Based on the results of this and previous investigations, AGE recommends ' Continued quarterly monitoring of the ground water monitoring network 1 Advanced GeoEnvironmental,Inc I