ARCHIVED REPORTS_QUARTERLY REPORT - THIRD QUARTER 2003

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26 September 2003 • AGE-NC Project No. 98-0500 Page 4of5 • Ethylbenzene and xylenes were detected in ground water samples MW-10 and OW-2 at a ' concentration of 4.1 µg/1 and 200 µg/1,respectively.Xylenes were detected in ground water samples MW-10 and OW-2 at a concentrations of 5.7 µg/1 and 1,100 µg/l, respectively. Toluene was also detected in ground water sample OW-2 at a concentration of 120 µg/1. ' • 1,2-DCA was detected in ground water samples MW-5, MW-6, MW-10, and MW-12, MW-13 and MW-14 through MW-16 and OW-1 at concentrations ranging from 2.1 µg/1 r (OW-1) to 27 µg/1 (MW-5). • TBA was detected in sample MW-14 at a concentration of 9.3 4g/l.MTBE was detected in intermediate-screened sample MW-13 at 2.2 µg/l. • The highest detections of VOCs were detected as follows: 1,2-dichlorobenzene at 18 µg/1 (OW-1), chlorobenzene at 9.1 4g/1(OW-1), naphthalene at 200 4g/1(OW-2), ' sec-butylbenzene in sample OW-2 at a concentration of 120 µg/l, isopropylbenzene at 140µg/1 and n-propylbenzene at 380 gg/1(OW-2),1,3,5-trimethylbenzene at 740 4g/1(OW-2) and 1,2,4-trimethylbenzene at 3,100 µg/1 in sample OW-2. Analytical results of the monitoring well ground water samples are summarized in Table 2. The ' • laboratory report (MAI I.D. 0305181), quality assurance and quality control and chain-of-custody forms are presented in Appendix C. 4.0. CONCLUSIONS The findings from the July 2003 ground water monitoring event are as follows: • The ground water elevation at the site has decreased an average of 7.5 feet since the second ' quarter 2003 monitoring event. • The ground water flow direction in the First Water Zone was toward the northeast and 1 towards the southeast in the Second and Fourth Water Zones. The ground water gradients ranged between 0.004 feet/feet and 0.013 feet/feet. The flow directions and gradients are similar to previously monitoring events. ' • TPH-g and TPH-ss were detected in ground water samples MW-5,MW 10 and OW-2(near the former dry well locations).Toluene and xylenes were detected in the same ground water ' samples and ethylbenzene was detected in sample MW-10 at low concentrations.Well OW-2 has not been sampled prior to this event,however,the concentrations detected this well were significantly greater than previous chemical data. ' TBA and MTBE were only detected in samples at low concentrations, below maximum • concentration limits. Advanced GeoEnvironmental,Inc.