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i - x i17 December 2004 • AGE-NC Project No 95-0130 iPage 3 of 6 i3.0. FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected I onl l May 2004 The contaminant impact to ground water was quantified by laboratory analysis of water samples I3 1 GROUND WATER ELEVATION AND GRADIENT The depths to ground water from the purged wells were measured between 42 22 and 43 43 feet below the top of the well casings Ground water elevations were calculated to be between 26 46 (MW-8) feet and 27 21 (MW-6A) feet below mean sea level (MSL) Generally, ground water I elevation at the site increased an average 0 79 feet between the February 2004 and the May 2004 ground water monitoring events First zone (between 35 and 55 feet) ground water flow direction at the Top Filling Station was inferred to be towards the northeast at an approximate gradient of I0 006 ft/ft, and at the Knowles-Roek site ground water was inferred to be towards the east at an approximate gradient of 0 002 ft/ft Second zone (between 55 and 85 feet bsg) ground water flow • direction at the Top Filling Station was inferred to be towards the east at a gradient of 0 003 ft/ft or less, and at the Knowles-Roek site ground water in the second zone was inferred to be towards the east to northeast at an approximate gradient of 0 002 ft/ft The ground water elevation data collected during the May 2004 ground water monitoring event is depicted on Figures 3 and 4 I3 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES On 11 May 2004, a total of fifteen ground water samples were submitted to Cal Tech Environmental Laboratories (CTEL), a DHS-certified laboratory, for analysis referenced in Section 2 3 TPH-g was detected in water samples collected from wells MW-2, MW-3, MW-5, MW-6(B-E), MW-7(B-D),MW-8,VW-1 C,VW-2A and VW-3A at concentrations as high as 180,000 micrograms per liter (µg/l) in the sample collected from VW-2A Benzene was detected in the above monitoring well samples at a maximum concentration of 60,000 µg/1 (VW-2A) Other BTEX compounds were detected in the above monitoring well samples at concentrations as high as 43,000 µg/l (toluene from VW-1C) IMTBE was detected in ground water samples collected from wells MW-3, MW-6(B-E), MW-7B, VW-1C, VW-2A and VW-3A at concentrations as high as 2,300 µg/l (VW-3A), 1,2-DCA was Idetected in ground water samples collected from wells MW-3, VW-IC, V W-2A, MW-6B and MW-7B at concentrations as high as 44 µg11 (MW-6B), TAME was detected in ground water IAdvanced GeoEnveronmental,Inc I