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I 03 March 2004 AGE-NC Project No 95-0143 ' Page 3 of 4 ' 32 ANALYTICAL RESULTS OF WATER SAMPLES During the August 2003 monitoring event, TPH-g was detected in samples collected from monitoring wells MW-3,MW-6,MW-9,MW-10 and MW-22 at concentrations ranging from 62 gg/1 (MW-6) to 200,000 µg/1 (MW-3) Various BTEX compounds were detected in the same wells at concentrations as high as 5,000 gg/l of benzene,49,000 gg/l of toluene,4,400 µg/l of ethylbenzene and 23,000 gg/l of xylenes, in sample MW-3 Figure 4 illustrates the approximate extent of TPH-g and benzene contamination in ground water Target analytes were not detected in the ground water sample collected from monitoring well MW-10 Analytical results of ground water samples collected during the August 2003 monitoring event are summarized on Table 2 Analytical results of historical ground water samples are summarized on r Tables 3 and 4 The Iaboratory report(MAI Lab Report ID 0308123)and chain-of-custody forms are ■ included in Appendix B 4.0 SUMMARY/CONCLUSIONS lie Based upon data collected from the site, AGE concludes • The average ground water elevation was 8 5 feet below mean sea level(MSL), a decrease of 1 foot since the May 2003 monitoring event The inferred ground water flow direction was northeast at a gradient of approximately 0 003 foot/foot • Ground water was within the screened intervals of MW-10, MW-14, MW-15, MW-16, MW-17,MW-22,MW-23 and MW-24,but ranged from 1 feet to 4 5 feet above the screened interval in the other monitoring wells • TPH-g and BTEX compounds were detected in MW-3,MW-6,MW-9,MW-10 and MW-22 The highest concentration of TPH-g and BTEX compounds were detected in samples collected from monitoring well MW-3 and were well above the above the DHS's Maximum Contaminant Levels for BTEX in drinking water However,the use ofthe shallow and deeper ground water in the region does not immediately appear to be for domestic use • The concentrations of TPH-g and BTEX constituents in the sample collected from MW-22 was near the highest detected to date in samples collected from the respective wells An apparent explanation for the significant increase in concentrations is not known to AGE at this time However,desorption of contaminates from deeper impacted soil,due to the process of in-situ oxidation, may have temporarily increased the dissolved concentrations • During the August 2003 sampling event, target analytes were not detected in the sample collected from well MW-10 Advanced GeoEnvironmental,Inc I