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I ' 23 April 2003 S AGE-NC Project No 95-0130 ' Page 4 of 6 ' EDB was detected in water samples collected from VW-1 C and VW-2A at concentrations of49,ug/l and 12,ug/l, respectively ' No other fuel components were detected In the ground water samples Previous and current analytical results ofground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports (Castle Analytical Laboratory Reference No 5290)and chain-of-custody forms are presented in Appendix ' B i i I4.0. SUMMARY AND CONCLUSIONS IThe Implications from the December 2002 ground water monitoring event are as follows • Ground water flow direction was Inferred to be towards the northeast at a gradient of 0 005 fl/ft in the area bound by wells MW-1 through MW-5 Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge ofthe local ground water could greatly modify the Inferred ground water flow direction � . • The decrease of ground water elevation of approximately 124 feet between the September 2002 and the December 2002 monitoring events maybe due to seasonal ground water fluctuation or a ' longer-term drought cycle,decreasing ground water elevations have generallybeen reported at the site since the May 2001 monitoring event • Ground water at the site is above the screen Intervals of wells MW-i through MW-5,MW-6 (B-E), MW-7 (B-E), VW-1C, VW-2A and VW-3A (I a screened below ground water elevation),and may not yield samples fully representative of shallowest ground water conditions The ground water table appeared to be within the screen interval ofwells MW-6A and MW-7A and should be representative of shallowest ground water conditions • The greatest concentrations of dissolved TPH-g and BTEX were detected in samples collected from wells VW- C,VW-2A and MW-7B(Figure 4)which is consistent with previous monitoring results, TPH-g concentrations were detected as high as 200,000 fcg/l I0 The greatest concentrations of dissolved MTBE was detected in the sample collected from well MW-6A(Figure 5)which is located immediately east of the former UST pit No 1 Reported I concentrations of MTBE have not demonstrated an increasing or decreasing trend during the ground water monitoring program, ranging between 14,000 yg/l and 55,000,ug/1 • Significant concentrations of 1,2-DCA were detected or have consistently been detected from wells MW-2, MW-3, MW-6B, MW-6C, MW-7A, MW-7B, VW-lB, VW-lC, VW-2A, . VW-2B and VW-3A suggesting a significant 1,2-DCA-impact to ground water at the site Advanced GeoEnviron mental,Inc