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31 Jul 2002 <br /> 1 y <br /> • AGE-NC Project No. 98-0520 <br /> Page 3 of 4 <br /> • I <br /> 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> t <br /> TPH-g was detected in the water samples collected from wells MW-1 through MW-5, MW-8 and <br /> ' MW-9 at concentrations ranging from 190 micrograms per liter (gg/l) in MW-4 to 5,500 µg11 in <br /> MW-5 (Figure 4). <br /> Various BTEX compounds except benzene were detected in wells MW-2, MW-3, MW-5 and <br /> MW-9; the maximum concentrations were detected in sample MW-5 at concentrations of 5.0 pgll <br /> toluene, 280 pg/l ethylbenzene and 290 µg/l xylenes. <br /> MTBE was detected utilizing EPA Method 8260B in wells MW-1, MW-2 and MW-6 at <br /> concentrations of 4.0 pg/l, 3.5 p,g/1 and 5.0 pg/l, respectively. <br /> ' TBA, EDB and 1,2-DCA were not detected at or above laboratory reporting limits in the ground' <br /> water samples collected. <br /> ' <br /> Analytical results of ground water samples are summarized on Table 2.The laboratory report(CTEL <br /> • Lab I.D.No.0206-090-1 through 0206-090-03 and 0206-045-4 through 0206-045-10)and'chain-of- <br /> ' custody forms are included in Appendix B., <br /> ' 4.0. SUMMARY AND CONCLUSIONS <br /> Based upon data collected from the site, AGE concludes: <br /> • Depth to ground water at the site averaged approximately 21.65 feet bsg on 18 June 2002. <br /> ' On 18 June 2002 the ground water elevation at the site averaged approximately 14.90 feet <br /> above mean sea level,with a net flow towards the north-northwest under an average gradient <br /> of 0.001 ft/ft. - <br /> ' TPH-g concentrations remained relatively stable in ground water samples collected from <br /> MW-1 through MW-10 compared with the previous quarterly monitoring event. <br /> ' Various BTEX compounds were detected in five of the ten ground water monitoring wells. <br /> The concentrations of the BTEX compounds were below the DHS Maximum Contaminant <br /> ' Levels (MCLS) for drinking water. <br /> • MTBE was detected for the first time in the deep-screened well MW-6 at a concentration of <br /> 5.0 µg/l, which equals the DHS Secondary.MCL for drinking water. MTBE was also. <br /> ' detected for the first time in samples MW-1 and MW-2 at concentrations below the <br /> • Secondary MCL. <br /> Advanced GeoEnvironmental,Inc. <br />