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V 28 February 1997 AGE-NC Project No 95-0111 , Page 2 of 4 " MTBE detected by EPA Method 602 were analyzed by EPA Method 8260 to confirm the MTBE ' presence I3.0. FINDINGS ' 3 1 GROUND WATER FLOW DIRECTION AND GRADIENT The relative elevation of ground water in each well was calculated by subtracting the ground water ' depth from the surveyed casing elevation The depths to ground water and relative ground water elevations are tabulated in Table 1 - Relative Ground Water Elevations All wells were surveyed relative to casing of monitoring well MW-1, which had been assigned an arbitiary casing elevation ' of 20 feet The relative ground water elevation ranged from 10 75 feet in MW-1 to 9 59 feet in MW-6 Ground water elevation increased an average of 0 91 feet at the site between September and December 1996 A sheen of free product was observed in MW-4 and MW-5, however, thickness of the free product was not measurable in the field Ground water flow direction at the site was toward the north and northeast Gi ound water gradient ' at the south end of the site was approximately 0 0045 ft/ft The gradient steepens towards the north end of the site was approximately 0 005 ft/ft Ground water surface elevation is depicted in Figure 3 -Relative Ground Water Elevation y J 3 2 ANALYTICAL RESULTS OF GROUNDWATER SAMPLES TPH-g was detected in samples collected from monitoring wells MW-1, N4W-2 and MW-5 at concentrations of 330, 130 and 200 yg/l (micrograms per liter or part's per billion ppb),respectively TPH-d was detected in samples from wells MW-1, MW-4 and MW-5 at concentrations of 92 ppb, 2,300 ppb and 16,000 ppb,respectively Laboratory notations for samples collected from'wells MW- 4 and MW-5 indicated the presence of free product Benzene was detected in samples collected from wells MW-1, MW-2, MW-4 and MW-5 at concentrations as high as 97 ppb, ethyl benzene, toluene and xylenes were detected in samples from MW-1, MW-2, MW-4 and'MW-5 at concentrations as high as 1 I ppb I MTBE was detected by EPA method 8020/602 in samples collected from wells MW-1, MW-4 and MW-5 at concentrations of 330, 110 and 9 ppb,respectively The detection of MTBE was confirmed using EPA method 8260 in wells MW-1, MW-4 and MW-5 at concentrations of 600, 170 and 16