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30 January 2004 AGE-NC Prod ect No 01-0865 Page 6 of 7 concentrations In EW-1,while showing some decline In wells MW-6 and a slight increase in MW-2 Graphs depicting these trends are provided in Figures 8A, 8B, 9A, 9B and 10 4 2 3 Analytical Results of Surface Water Samples MTBE, TPH-g and TAME were detected in the surface water samples at the following maximum concentrations over the past year 1,100 gg/l MTBE (DDS, March 2003), 540 µg11 TPH-g (DDS, March 2003), and 7 6gg/l total xylenes (DDS, March 2003) No other analytes were detected at or above laboratory detection levels 5.0. SUMMARY AND CONCLUSIONS Based on the findings from this Investigation, AGE concludes • Ground water elevations at the site ranged from 3 17 feet above mean sea level (MSL) in well MW-12 to 16 45 feet below MSL In well EW-1, relative to the September 2003 monitoring event,ground water elevation increased in all first water and deep-screened wells The average ground water elevation at the site was 13 32 feet below MSL,which represents an overall elevation increase of approximately 1 54 feet between the September 2003 and December 2003 sampling events • The ground water flow direction of first ground water on 31 December 2003 was inferred to be towards the southeast under an average ground water gradient of approximately 0 25 foot/foot in the central portion of the levee while rotating more easterly and decreasing to 0 085 foot/foot toward the northern part of the site, the flow direction rotates to a more southerly direction at the eastern portion of the site and the gradient decreases to approximately 0 027 foot/foot(Figure 3) The dominate gradient direction remains southeast, while the central component of the gradient at the levee Is very steep, dropping one foot of elevation for every four lateral feet The ground water flow inferred from deep-screened (50 feet to 60 feet bsg) wells MW-6 through MW-8 and MW-11 atop the levee (70 feet to 80 feet bsg) was east, but under a much shallower average gradient of 0 005 foot/foot (Figure 4) • TPH-g was detected in the ground water samples collected from MW-2 through MW-6 and EW-1 Compared to data from the previous quarter,TPH-g concentrations decreased overall with exception to MW-2 • One or more BTEX compounds were detected in the samples from wells MW-2 through MW-6 Benzene and toluene were detected at concentrations above their respective MCLs • Advanced GeoEnviron mental,Inc