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' 31 October 2001 . AGE-NC Project No 95-0144 Page 3 of 4 ' screened interval in monitoring wells MW-I, MW-2, MW-4, MW-5, MW-8, MW-11, MW-12 and MW-13 Groundwater was within the screened intervals of MW-19A, MW-20A and MW-21A Ground water elevations in nested wells MW-19, MW-20 and MW-21 were between 174 and 1 99 feet lower in deeper screened intervals beneath a clay layer than in the shallower screened intervals Data fromwells with the upper screened intervals,established in first-encountered groundwater,was ' utilized for gradient determination ' 3 2 ANALYTICAL RESULTS OF WATER SAMPLES ' During the August 2001 monitoring event, TFH-g was detected m samples from monitoring wells MW-21A, MW-21B and MW-13 at concentrations of 3,300 micrograms per hter (µg/1), 680 gg/1 and 130 [g/1,respectively Various BTEX compounds were detected in samples fromwells MW-13, ' MW-2 i A and MW-21 B at concentrations as high as 160 gg/1 (benzene, MW-21A) TPH-d was detected in samples collected from MW-13, MW-19A, MW-20A, MW-21A and MW-21B at concentrations of 68 gg/l, 71 gg/l, 200 µg/1, 8,800 µg/1 and 1,100 gg/l, respectively TPH-mo was ,. detected in monitoring well sample MW-21A and MW-21B at concentrations of 740 gg/1 and 250 gg/l, respectively The extent of hypdrocarbon-unpacted ground water is illustrated in Figure 4 ' MTBE was detected in ground water samples from MW-19A, MW-19B and MW-21B at concentrations of 1 3 gg/l, 1 1 [g/1 and 1 0 µg/1, respectively Historically, only low concentrations of MTBE and TBA have been detected intermittently at the site Analytical results for the third quarter 2001 monitoring event are summarized on Table 2 Analytical yt results of recent and historical ground water samples are surra arized on Tables 3 and 4 The ' laboratory report(MAI Lab IDs 74970 through 74979) and chain-of-custody forms are included in Appendix B 1 , 4.0. SUMMARY/CONCLUSIONS ' Based upon data collected during the ground water monitoring event, AGE concludes ' a Ground water elevation decreased approximately 0 61 feet at the site since the previous ground water monitoring event Ground water remained above the screened interval in nme of the shallow wells sampled during the third quarter of 2001 Ground water elevations in ' wells completed beneath the clay layer (approximately 35-45 feet bsg) were lower than in . wells completed within first ground water 1 Advanced GeoEnvsronmeata4 The