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1 10 11 January 2006 AGE-NC Project No 95-0130 ' Page 4 of 14 2 4 1 GROUND WATER ELEVATION AND GRADIENT The measured depths to ground water from the purged wells were between 42 44 and 44 49 feet ' below the top of the well casings Ground water elevations were calculated to be between 26 89 feet (MW-1) and 28 33 feet(MW-7B)below mean sea level (MSL) Generally, ground water elevation at the site decreased an average of 0 38 feet between the June 2005 and the September 2005 ground water monitoring events First zone (HUI - 40 to 55 feet) ground water flow direction at the Top Filling Station was inferred to be towards the northeast at an approximate gradient of 0 01 ft/ft, Second zone (HU2 and HU3 - 55 to 85 feet bsg) ground water flow direction at the Top Filling ' Station was inferred to be east-southeast at a gradient of 0 01 ft/ft or less The First and Second zone ground water elevation data collected during the September 2005 ground water monitoring event is depicted on Figures 3 and 4, respectively I 2 4 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES On 22 September 2005, a total of fifteen ground water samples were submitted to CTEL, a DHS- certified HS- certifed laboratory, for the analysis referenced in Section 2 3 ' • TPH-g was detected from wells MW-6(B-E), MW-7(B-D), VW-1C VW-2A and VW-3A at concentrations as high as 160,000 micrograms per liter(µg11)in the sample collected from MW-7B ' The estimated extent of First Zone (between 35 and 55 feet bsg)and Second Zone (between 55 and 80 feet bsg) dissolved TPH-g are depicted in Figures 5 and 7, respectively Benzene was detected in the above monitoring well samples and well MW-3 at a maximum concentration of 20,000 gg/l (MW-7B) Other BTEX compounds were detected in the above monitoring well samples at concentrations as high as 23,000 gg/1 toluene from MW-7B, and 3,100 gg/1 ethylbenzene and 19,500 µg/l total xylenes from VW-2A MTBE was detected in ground water samples collected from wells MW-6(B-D),MW-7B,VW-1C, VW-2A and VW-3A at concentrations as high as 2,600 gg/l(MW-6B) The estimated extent of First Zone and Second Zone dissolved MTBE are depicted in Figures 6 and 8, respectively 1,2-DCA was detected in ground water samples collected from wells MW-6 (B-D),MW-7 (B-D), MW-8,VW-1C,VW-2A and VW-3A at concentrations as high as 190 gg/I (MW-7B), TAME was detected in ground water samples collected from wells MW-6 (B-E), MW-7 (B-D), VW-1C and VW-2A at concentrations as high as 57 µg/1 (VW-1C) No other fuel components were detected in the groundwater samples Previous and current analytical • results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory Advanced GeoEnvironmental,Inc