ARCHIVED REPORTS_XR0007371 CASE 2

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• OBSERVATIONS AND RESULTS OF ANALYSES No free-phase liquid hydrocarbon layer or sheen was seen on the water tape during the measurement of the five groundwater-monitoring wells In addition, all purged and sampled water appeared to be clear and lacked any odor (Appendix B) The depth-to water measurements indicate that the standing height of water in each monitoring well had fallen by approximately eight feet as compared to the March samplings The drop in the water table has also changed its gradient, it now slopes toward the south-southwest at approximately one foot per one hundred seventy feet (Figure 2) The laboratory results are non-detect for BTEX (<0 5 micrograms per liter - µg/L), non- detect for MTBE (<5 0 micrograms per liter - µg/L), and non-detect for TPH-diesel (<50 µg/L) in all of the groundwater samples extracted from the wells The results of the laboratory analyses are presented in Table 1 A copy of the laboratory analytical report and the chain-of-custody record is included in Appendix A DISCUSSION Sampling of the groundwater monitor wells has been ongoing since the middle of 2003 In thirty-one of the thirty-six samples analyzed for TPH-diesel to date, the laboratory results have reported analyte concentrations below the laboratory detection limit In the five remaining samples, predominantly from the same two wells (MW-06 & MW-08), the concentrations were found to be just slightly above the detection limit CONCLUSION The results of analyses appear to confirm that the petrochemical contamination found in the upper soil layers has not adversely affected the local groundwater table In the few samples that had detection in the past, it is not clear if they were due to actual groundwater issues or possible sample contamination in the field RMC will continue to evaluate its sampling techniques during monitor the future groundwater sample results Quarter 2 Sampling Report-2005 Page 2 of 2