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11 May 2004 AGE-NC Project No 95-0141 Page 3 of 5 3 1 GROUND WATER ELEVATION AND GRADIENT At the tune of the March 2004 monitoring event, depths to ground water ranged from 19 40 feet to 20 90 feet below the tops of the well casings (btoc) Ground water elevations at the site ranged from 12 17 feet below mean sea level (MSL) in well MW-1 IA to 13 51 feet below MSL in well MW-12A (Table 1) The tops of the well screens in MW-3 and MW-5 were drowned by approximately 9 4 to 8 1 feet, respectively Wells MW-5, MW-7, MW-SA through MW-IOA and EX-1 were used to determine ground water flow direction and gradient for shallow ground water The shallow ground water was inferred to flow generally toward the southeast, at a gradient of 0 005 foot/foot Figure 3 illustrates the contoured shallow ground water elevations as measured on 30 March 2004 Ground water elevation data from wells MW-3, MW-1 1A and MW-12A were not used to determine ground water gradient and flow direction, the data appears to be anomalous Wells MW-6 and MW-813 through MW-12B were used to determine ground water flow direction and gradient for the deep ground water zone The deep ground water was inferred to flow generally toward the east-southeast, at a gradient of 0 002 foot/foot Figure 4 illustrates the • contoured deep ground water elevations as measured on 30 March 2004 3 2 ANALYTICAL RESULTS FROM GROUND WATER SAMPLES The analytical results of the ground water samples were as follows • TPH-g was detected in ground water samples collected from wells MW-3, MW-5, MW-6, MW-813, MWA 1B and EX-1 at concentrations ranging from 110 µg/1 in MW-5 to 110,000 µg/1 in EX-1 • Various BTEX compounds were detected in samples MW-3,MW-6,MW-813,MW-I I B and EX-1 at concentrations as high as 13,000 µg/1 of benzene,27,000 µg/l of toluene, 2,700}Lg/1 of ethylbenzene and 15,000 µg/1 of xylenes These high concentrations were all from well EX-1 • 1,2-DCA was detected in ground water samples collected from all wells except MW-3, MW-S, MW-6, MW-7, MW-8A, MW-9B, MW-11B and EX-1 1,2-DCA was detected at concentrations ranging from 2 4 gg/l (MW-6) to 190 µg/1 (EX-1) The areal extent of TPH-g- and 1,2-DCA-impacted shallow and deep ground water is illustrated on Figures 5 and 6, respectively Laboratory results of water samples analyzed are summarized in Tables 2 through 5 The laboratory reports for the quarterly monitoring event (CTEL Laboratory • IDs 0403-243-1 through 0403-243-15), QA/QC reports and chain-of-custody form are included in Appendix B Advanced GeoEnvironmental,Inc