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1 ' 22 August 2002 AGE-NC Project No 99-0657 ' Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the water samples collected from wells MW-1, MW-2 and MW-4 at a ' maximum concentration of 7,300 micrograms/liter (µg/1), in the sample from MW-1 TPH-d was detected in the sample collected from MW-1 at a concentration of 820 µg/1 ' One or more BTEX compound was detected in water samples collected from wells MW-1, MW-2 and MW-4 The maximum benzene (1300 µg/1), toluene (1100 µg/1) and xylenes (780 µg/1) concentrations were detected In water sample MW-1,the maximum ethylbenzene concentration(60 ' µg/1) was detected in sample MW-4 The following fuel additives were detected by EPA Method 8260 MTBE was detected in all of the I water samples at concentrations of 1,300 gg/l(MW-1), 1,100 µg/1 (MW-2) , 350 gg/1(MW-4), and 5 0 µg/l(MW-3) 1,2-DCA was detected in water samples collected from MW-1,MW-3 and MW-4 at a maximum concentration of 35 µg/1(MW-1) TAME was detected in the water sample collected ' from MW-2 at a concentration of 8 0 µg/1 TBA was detected in the water sample collected from MW-1 at a concentration of 27 gg/1 EDB was detected in the water sample collected from MW-1 • at a concentration of 7 0 gg/1 No other fuel additives were detected in the ground water samples The analytical results of water samples collected in u1 2 yt p July 002 are summarized on Table 2 The laboratory report(CTEL Lab I D No 0207-041-1 through 0207-041-4),QA/QC report and chain-of- custody form are included in Appendix B I4.0. SUMMARY AND CONCLUSIONS The following conclusions were drawn from the results of this investigation • The ground water elevations ranged from 6 01 to 6 35 feet above MSL Ground water is inferred to be flowing toward the southwest at an average gradient of 0 005 feet/feet The relative ground water elevation at the site decreased an average 1 73 feet between the April 2002 and July 2002 monitoring events • Concentrations of dissolved TPH-g and MTBE have remained relatively stable, TPH-d and 1,2-DCA have decreased slightly, while BTEX concentrations increased slightly since the last monitoring event in April 2002 • The highest concentrations of dissolved hydrocarbons occurred in monitoring wells MW-1 and MW-4, which are located down-gradient of the UST area Iso concentration maps depicting the approximate distribution of dissolved TPH-g,benzene and MTBE are presented . In Figures 4, 5 and 6 Advanced Geo Enviro n mental,Inc