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22 July 2003 - • AGE-NC Project No 00-0764 Page 3 of 4 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES The results of laboratory analysis of ground water samples collected at the site on 25 April 2003 are as follows • TPH-g was detected in the samples from ground water monitoring well MW-3 at a concentration of 310 micrograms per liter(µg11) • Benzene was detected in the samples from monitoring well MW-3 at a concentration of 16 [tg/1 benzene • 1,2-DCA was detected in the samples collected from well MW-4 at a concentration of 5 4 µg/1 1,1-DCA was detected in the samples collected from well MW-4 at a concentration of 11 µg/I No additional target analytes were detected in the samples analyzed Laboratory results of samples analyzed for petroleum hydrocarbons are summarized in Table 2 and Table 3 The laboratory reports (CTEL Laboratory ID CT214-0304158),quality assurance and quality controI(QA/QC)reports and chain-of-custody form is included in Appendix C 4.0. SUMMARY AND CONCLUSIONS Based upon the results of this quarterly monitoring event, AGE concludes • Ground water flow direction was inferred to be towards the east from the former UST location, at a gradient of approximately 0 005 ft/ft • The highest concentrations of dissolved petroleum hydrocarbons were detected in the sample collected from well MW-3, near the former UST location • The benzene concentration in well MW-3 and the 1,1-DCA concentration in well MW-4 are above the DHS's Maximum Contaminant Level of 10 pg/1 and 5 0 µg11, respectively, in drinking water • At the present time, the vertical extent of the dissolved hydrocarbons have been defined by bonngs B1 and well MW-5 The lateral extent of the dissolved hydrocarbons have been defined by shallow wells 5.0. RECOMMENDATIONS Based on the results of this investigation, AGE recommends Advanced GeoEovironmental,Inc