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' 20 December 2001 AGE-NC Project No 99-0624 ' Page 3 of 4 ' direction varied slightly from south-southwest to south-southeast Figure 2 illustrates the contoured ground water elevations as measured on 28 September 2001 ' 32 LABORATORY RESULTS OF GROUND WATER SAMPLES ' Petroleum hydrocarbons quantified as TPH-g and MTBE were detected in ground water samples collected from monitoring wells MW-1, MW-2 and MW-3 The highest concentrations of TPH-g I (140 micrograms per liter- µg11) and MTBE (880 4g/1) were detected in the sample from MW-2 The highest concentrations of BTEX compounds(28 µg/1 benzene,0 96 µg/l toluene,2 1 µg/1 ethyl- benzene and 5 2 µg/l xylenes) were detected from the sample collected from MW-2 Analytical results of the ground water samples for the third quarter - 2001 monitoring event are summarized on Table 2 The laboratory report (MAI Laboratory ID 79939-79941), QA/QC and chain-of-custody are included in Appendix B lie 4.0. SUMMARY/CONCLUSIONS The following conclusions were drawn from the results of the site investigation • The average depth to ground water and ground water elevation on 28 September 2001 in Imonitoring wells on-site was approximately 55 feet below surface grade and 16 feet below MSL, respectively • The inferred ground water gradient on 28 September 2001 was calculated to be 0 003 11/ft towards the south • TPH-g was detected in ground water samples from all three monitoring wells, the highest concentration was detected in the sample collected from MW-2 at 140 µg/l, a significant decline from the high of 8,900 µg/1 detected in.May 2000 • Various BTEX compounds were detected in the water samples collected from the three monitoring wells, the MW-2 sample had the highest concentrations • Utilizing EPA Method 8260M,MTBE was detected at concentrations of 880µg/1 and 20 µg/l in ground water samples from MW-2 and MW-3, respectively 0 Advanced GeoEnv:ronmental,Inc. r