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16 October 2003 AGE-NC Project No 01-0827 ' Page 3 of 4 I (btoc), the water table was approximately 10 feet above the screened intervals of wells VW-2d and VW-5d and 35 feet above the screened interval of well MW-6 (Table 1) ' The ground water elevations and gradient were calculated and determined from depths to ground water data from monitoring wells MW-1 through MW-6 The ground water elevations at the site ranged from 12 13 feet (MW-5) to 13 15 feet (MW-2) below mean sea level (MSL) The ground ' water flow direction was inferred to be east at a gradient of approximately 0 01 ft/ft west of the site and 0 004 on-site (Figure 3) ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the ground water samples from wells MW-6 and VW-2d at concentrations of 1, 000 micrograms per liter (µg/1) and 2,700 µg/1 Various BTEX compounds were detected in samples MW-6 and VW-2d at maximum concentrations of 640µg/1 benzene,21 µg/1 toluene,31 µg/l ethylbenzene and 60 µg/1 xylenes, mostly in sample VW-2d The fuel additive MTBE was only detected in ground water sample VW-2d at a concentration of 91 µg/1 The analytical results are summarized in Tables 2 and 3 A copy of the laboratory report (CTEL Project No 214-0307046) and chain-of-custody form are included in Appendix B 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the site, AGE finds • On 08 July 2003,ground water was encountered at a depth of approximately 23 feet btoc At the former UST area, ground water flow was inferred to be towards the east under a gradient of 0 004 ft/ft Except for wells VW-1 and VW-3, all site wells are"drowned"and analytical data from these wells may not be representative of shallow-water conditions, analytical data from monitoring well MW-6, screened from 60 to 65 feet bsg, may be representative of deeper ground water conditions I I • The maximum concentrations of petroleum hydrocarbon and BTEX compounds in ground water were detected in the ground water sample collected from on-site vapor well VW-2d However, the current distribution of contaminates is limited 1,2-DCA was not detected in the ground water samples this quarter • The concentrations of benzene in samples MW-6 and VW-2d and MTBE in sample VW-2d I were above the DHS's Primary Maximum Contaminant Levels (MCL) for these chemicals in drinking water Advanced GeoEnvironmental,Inc