ARCHIVED REPORTS_XR0006879- CASE 2

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1 ' 31 July 2003 AGE-NC Project No 97-0351 Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF WATER SAMPLES The results of laboratory analysis of ground water samples collected at the site on 21 May 2003 are ' as follows • TPH-g was detected 1n the samples from ground water monitoring wells MW-1 and MW-UST at concentrations of 4,000 micrograms per liter(µg11)and 3,200µg11,respectively ' • BTEX compounds were detected in the sample from monitoring well MW-1 at concentrations of 180 µg11 of benzene, 15 µg/1 of toluene, 32 µg/l of ethylbenzene and 12 µg/1 of total xylenes Benzene was detected In the sample collected from well MW-UST at a concentration of 27 µg11 ' • MTBE was not detected In the samples collected from wells MW-1 through MW-5 and MW- UST DIPE was detected In the sample collected from well MW-3 at a concentration of 36 µg11 Laboratory results of samples analyzed for petroleum hydrocarbons are summarized in Table 2 and Table 3 The laboratory report(CTEL Project No CT214-0305135) and chain-of-custody form are included In Appendix C ' 4 0. SUMMARY AND CONCLUSIONS ' Based upon the results of this quarterly monitoring event, AGE concludes • The ground water flow direction was inferred to be northeast at a gradient of approximately 0 003 ft/ft which is consistent with previously determined flow directions and gradients ' • The highest concentrations of dissolved petroleum hydrocarbons were detected in the sample collected from well MW-1,near the former UST location,TPH-g increased significantly in ' wells MW-1 and MW-UST compared to the previous quarterly monitoring event 4 The benzene concentrations In wells MW-1 and MW-UST were significantly above the ' DHS's Maximum Contaminant Level of 10 µg/1 In drinking water At the present time,neither the vertical extent nor the western lateral extent of the dissolved hydrocarbons have been defined Advanced GeoEnvironmental,Inc