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' 19 April 1999 • AGE-NC Project No 95-0104 Page 3 of 5 water elevation at the site increased an average 1 72 feet between the September 1998 and the January 1999 ground water monitoring events The ground water elevation data for MW-1 through MW-6 and VW-1 during the January 1999 ground water monitoring event is depicted in Figure 3 IGround water monitoring data collected In the area of wells MW-1, MW-2, MW-4 and MW-6 indicated that the ground water flow direction was generally toward the northeast at a gradient of I 0 002 ft/ft, or approximately 11 feet per mile, ground water monitoring data collected In the area VW-1,MW-3 and MW-5 inferred a southeast ground water flow direction at a gradient of 0 002 ft/ft, (Figure 3) Ground water was approximately 22 feet above the screen intervals at MW-2, MW-3 and ' MW4 Therefore these wells are "drowned", and yield samples more representative of deeper ground water than of shallow ground water, which is commonly the more intensely impacted by petroleum hydrocarbons I3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES A total of four ground water samples were submitted to a DHS-certified laboratory in January 1999 ' . TPH-g was detected in water samples collected from wells MW-1, MW-5, MW-6 and VW-1 at concentrations ranging up to 4,300 micrograms per liter (/Ig/1) BTEX compounds were detected in ground water samples collected from wells MW-1,MW-5,MW- 6 and VW-I at concentrations ranging as high as 520 gg/l (xylenes, VW-1) The greatest benzene concentration was detected In the sample from well MW-6 at a concentration of 20,ug/l MTBE was confirmed in samples collected from wells MW-1 and VW-1 utilizing EPA Method 8260 P g at concentrations as high as 16µg/l, MTBE was not detected above laboratory reporting limits for any of the analyzed samples utilizing EPA Method 8020, TBA was detected from wells MW-1 and VW-1 at concentrations ranging as high as 6 9 yg/l No other fuel oxygenated additives were detected above Iaboratory reporting limits from the analyzed samples Analytical results of the ground water samples are summarized in Table 2 The laboratory reports (Alpha Analytical Laboratories Inc Batch 99-0112-010) and chain-of-custody forms are presented in Appendix B 4.0. DISCUSSION AND CONCLUSIONS Based upon data collected during the January 1999 monitoring event, AGE concludes Groundwater monitoring data collected in the area of wells MW-1, MW-2, MW-4 and MW- Advanced GeoEnvironmenta[,Inc I