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I10 June 1999 AGE-NC ProjectNo 98-0450 Page 3 of 5 feet below the tops of the well casings Between February and May 1999, ground water elevation ' has increase an average 0 7 feet at the site The ground water elevation data for the four wells during the latest ground water monitoring event is depicted in Figure 3 ' Table 1 shows the screen intervals for monitoring wells BMW-3, BMW-4 and BMW-5 and the assumed screen intervals for monitoring wells BMW-1 and BMW-2 Well MW-5 may be screened approximately 4 feet below the ground water table The results obtained are believed to be representative of the dissolved hydrocarbon concentrations in the shallow ground water at the site ' Ground water monitoring data collected at the site indicated a southerly to a south-southwesterly ground water flow direction. Based on a southerly flow direction within the area contained by six monitoring wells, well MW-5 is in the most down-gradient position from the former dispenser system and well BMW-2 is down gradient from the former UST area In August 1998, the gradient was calculated to be approximately 0 003 on the site or 17 6 feet mile (Figure 3) 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g and BTEX were detected in all of the ground water samples collected and analyzed ' Benzene was detected at concentrations up to 840 micrograms per liter (µg/1) in the sample from well BMW-4 TPH-g concentrations in the samples ranged from 95µg/1 from well BMW-2 to 67,000µg/I from well BMW-4 ' MTBE was detected by EPA Method 8020 at concentration ranging from 8 0µg/1 (BMW-5) to 470 µg/1 (BMW-4) and by EPA Method 8260 Modified at concentrations ranging from 2 0 µg11 in the ' sample from well BMW-1 to 290µg/1 in the sample from well BMW-4 TBA was detected by EPA Method 8260 Modified in three samples from wells at concentrations up to 25 µg/1 TAME, DIPE ' and ETBE were not detected by laboratory analyses of any of the ground water samples The Iaboratory report (McCampbell Analytical Inc Laboratory I D No 11643 to 11648), Quality ' Assurance and Quality Control Data (QA/QC) and chain-of-custody forms are presented in Appendix B The results of the analyses are contained in Table 2 and Table 3 ' 4.0. DISCUSSION AND CONCLUSIONS ' Based upon data collected during the May 1999 quarterly monitoring event, AGE concludes • Ground water on the site was flowing toward the south to the southwest from the former Advanced GeoEnt tronmental,Inc