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f' 1 v Direction of Groundwater Flow East-Northeast Groundwater Gradient 0 0040 to 0 0045 ft/ft DISCUSSION Concentrations of TPHG (38,000 µg/1) and benzene (2,200 µg11) detected in the sample collected from monitoring well MW-1 are the highest since groundwater monitoring was initiated While TPHG and benzene concentrations in well MW-1 have fluctuated, historical data from the past four quarters show an increasing trend TPHG was also detected in samples collected from wells MW-4 (150 µg/1) and VW-213 (250 µg/1) MTBE was detected 1n the samples collected from wells MW-1 (4500 µg/1), MW-4 (7600 4g/1), VW-1B (1100 µg/1), VW-2B (2400 µg/1), and VW-38 (90 µg/1) MTBE concentrations in wells MW-4, VW-1 B, and VW-2B show increasing trends over the last four quarters Petroleum hydrocarbons and fuel oxygenates were not detected in samples collected from offsite monitoring wells MW-5 through MW-7 Groundwater flow during the third quarter 2001 was calculated to be towards the east-northeast at gradients ranging from 0 0040 to 0 0045 ft/ft East, northeast, and southeast groundwater flow directions have been reported since groundwater monitoring was initiated in 1995 At the time of the quarterly sampling event (September 13, 2001), groundwater elevations had decreased approximately 6 feet since the previous sampling event (.lune 21, 2001) ATTACHMENTS • Table 1 Groundwater Monitoring Data • Table 2 Groundwater Analytical Results for Oxygenates • Table 3 Groundwater Elevation Data • Figure 1 Site Location Map • Figure 2,3,4 Groundwater Elevation Contours (3rd Quarter 2001) • Figure 5 Groundwater Analytical Summary (3`d Quarter 2001) • Appendix A Field Data Sheets • Appendix B Sampling and Analysis Procedures • Appendix C Certified Analytical Reports and Chain-of-Custody Records • P WRC0121861QTRLY120011Arco_2186_3Q0]Repon doe Delta