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CvvATC A S S O C I A T E S I N C data were used to develop the groundwater elevation contour map (Figure 2). Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer beneath the site flowed in a northerly direction. The average hydraulic gradient on June 5, 2002 was calculated to be 0.003 ft/ft or about 13 feet/mile. The data indicates a groundwater gradient that is generally consistent with previous groundwater gradients observed at the site. A summary of groundwater monitoring data is presented in Table 1. Groundwater elevations are referenced to feet above mean sea level. Groundwater samples were collected from monitoring wells MW-1 through MW-6. Prior to collection of groundwater samples a minimum of three well casing volumes were purged. The pH, electrical conductivity, and temperature were measured and allowed to stabilize before groundwater samples were collected. Samples were then collected from each well using disposable bailers. Purge water was contained in 55-gallon DOT approved drums. Purge water from monitoring wells MW-1 and MW-6 from the previous sampling event did not contain detectable concentrations of petroleum hydrocarbons and was discharged to the ground surface. Groundwater well purge and sample logs are provided in Appendix A. The groundwater samples collected from each well were submitted with Chain of Custody Record to State-certified Argon Laboratories Inc. (ELAP Cert. No. 2359). The samples were analyzed for TPHg by EPA method 8015; BTEX by EPA method 8020, and MTBE and other fuel oxygenates by EPA method 8260. Groundwater analytical results are summarized in Table 2. The laboratory analytical reports are included in Appendix B. RESULTS OF LABORATORY ANALYSES Results of the laboratory analysis of groundwater samples from the monitoring wells indicate the presence of petroleum hydrocarbons in groundwater samples from monitoring wells MW-2 and MW-3. No petroleum hydrocarbons were detected in monitoring wells MW-1, MW-4, MW-5, and MW-6. No fuel oxygenates including MTBE were detected in any of the wells. The analytical results are summarized in Table 2. CONCLUSIONS AND RECOMMENDATIONS Results of the most recent monitoring event indicate that the concentrations of petroleum hydrocarbons in the groundwater have generally remained nondetect or decreased since the last monitoring event. The groundwater gradient direction has remained the same. Based on the results ATC recommends no further action. w:\17861\reports\2gmr2002.doc 3