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i 07 March 2003 ' AGE-NC Project No 95-0141 Page 8of10 ' Wells MW-3,MW-.-;,MW-7,MW-8A through MW-12A and EX-1 were used to determine grould 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 0 004 foot/foot Figure 5 illustrates the contoured shallow ground water elevations as measured on 28 October 2002 ' Wells MW-6 and MW-8B through MW-12B were used to determine ground water flow direction and gradient for deep ground water The deep ground water was inferred to flow generally toward the southeast, at a gradient of 0 007 foot/foot Figure 6 illustrates the contoured deep ground water ' elevations as measured on 28 October 2002 3 6 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-6, MW-813, MW-9B, MW-11B and EX-1 TPH-g concentrations ranged from 80 µg/1 in MW-11B to 150,000 µg/1 in EX-I One or more BTEX compound were detected in samples MW-3,MW 6,MW-8B, MW-9B, MW-11B and EX-I at concentrations as high as 11,000 µg/1 benzene, 36,000 pg/1 toluene, I4,000 µg/1 ethylbenzene and 20,000 gg/1 xylenes (EX-1) Fael oxygenates were not detected in the ground water samples collet, :d from `he site ® 1,2-DCA was detected in ground water samples collected from all wells except MW-I OA/B ' and MW-12A/B Concentrations ranged from 0 50 µg/1 (MW-11A) to 410 µg/1 (EX-1) In addition, EDB was detected in the ground water sample collected from well EX-1 at a Iconcentration of 65 gg/1 The areal extent of TPH-g and 1,2-DCA impacted shallow and deep ground water is illustrated on Figures 7 and 8,respectively Laboratory results ofwater samples analyzed are summarized in Tables 3 and 4 The Iaboratory reports for the quarterly monitoring event(MAI Laboratory IDs 0210536-001 through 0210536-015) QA/QC reports and chain-of-custody form are included in Appendix G I 4.0. SUMMARY AND CONCLUSIONS I The findings of the fourthuarter site investigation events include the following q g g • Generally, sand, silty sand and gravelly sand were encountered at depths between 20 and 31 . feet bsg, 48 and 74 feet bsg and 113 and 117 feet bsg Fine grained, silt, silty clay, clayey silt,sandy silt and clay were observed at all other depths The computer generated boring log for CPT-01 is included in Appendix B Advanced GeoEnvironmental,Inc I