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to 11 June 2001 AGE-NC Project No. 97-0327 Page 3 of 4 ' or less, or approximately I 1 feet per mile (Figure 3). 3.2. LABORATORY RESULTS OF GROUND WATER SAMPLES A total of three ground water samples were submitted to a DHS-certified laboratory for analysis of TPH-g, TPH-d,BTEX and fuel oxygenated compounds. TPH-g was not detected in water samples collected from MW-1, MW-2 or MW-3; however, TPH-d was detected in all three samples at concentrations as high as 180 ,ugll. BTEX compounds were not detected in ground water samples collected from MW-1, MW-2 or MW-3. MTBE was detected(EPA Method 8260)in ground water samples collected from wells MW-1 and ' MW-2 at concentrations of 1.7 and 15/.cg/l respectively; TAME was detected in the sample collected from well MW-2 at a concentration of 40µg/1; 1,2-DCA was detected in samples from wells MW-1 and MW-2 at concentrations of 4.1 and 2.7µg/l.No other fuel oxygenated compounds were detected ' by laboratory analysis. Analytical results of the ground water samples are summarized in Tables 2 and 3. The laboratory reports (Castle Analytical Laboratory Reference No. 3539 and McCampbell Analytical Inc. Lab I.D. 60546 through 60548) and chain-of-custody forms are presented in Appendix B. ' 4.0. DISCUSSION AND CONCLUSIONS The implications of the findings from the February 2001 ground water monitoring event are as follows: • Ground water flow direction at the site was inferred to be toward the south at a gradient of 0.002 ft/ft or less; due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly ' modify ground water flow direction. • The decrease of ground water elevation of approximately 1.87 feet between August 2000 and February 2001 is probably due to seasonal fluctuation. ' • Dissolved TPH-d was detected in samples collected from wells MW-1, MW-2 and MW-3; the greatest TPH-d concentrations have been detected from wells MW-2 and MW-3 while low concentrations have been detected from well MW-1. Low concentrations of dissolved MTBE and 1,2-DCA were detected in samples from wells MW-1 and MW-2 indicating a minor impact to ground water in the area assessed. • Minor concentrations of dissolved TAME were detected in the sample collected from well MW-2; TAME had not been detected from previous ground water monitoring events. • TBA had previously been detected in wells MW-1, MW-2 and MW-3, but was not detected ' Advanced CeoEnvironmental,Inc.