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V iW .fa GROUNDWATER ELEVATIONS AND GRADIENT A contour map of groundwater elevations is shown in Figure 3. Current and historical water level elevation data for all wells are included in Table 2. Water levels measured in the second quarter of 2003 were 44 to 46 feet below ground surface, or approximately —30 feet with reference to mean sea level datum(MSLD). Although historical data indicate a rise in water levels subsequent to 1990, data collected since December 1999 suggest that this trend may have stabilized or reversed. The water level elevations measured in the second quarter of 2003 were the lowest measured since January 1998. Second quarter 2003 water level data indicate a groundwater gradient of 0.11 to the south. This is the reverse of the north to north-northeast gradient that has been observed historically. GROUNDWATER ANALYTICAL RESULTS A historical summary of analytical results for groundwater samples collected through June 2003 is included in Table 3. Results for tetrachloroethene (PCE) and 1,2-dichloroethatne (1,2-DCA) are also presented on Figure 4. TPH-Diesel No detections of TPH-diesel or unknown hydrocarbon (Table 3) were reported for any of the samples collected during the second quarter 2003 groundwater monitoring round. This is consistent with results obtained during the previous groundwater monitoring round in December 2001. 1 Volatiles and Oxygenates by EPA Method 82605 1,2-Dichloroethane was reported in samples collected from DMW-5 (13 micrograms per liter)( �tg/L), and - DMW-6 (26 gg/L). These results are equal to or lower than previously reported results. Chloroform was -=' reported in samples collected from two wells, DMW-1 (1.9 µg2), and DMW-4 (1.4 gg/L). No PCE or other volatile constituents were detected. SUMMARY The following summarizes the results of June 2003 groundwater monitoring. • Groundwater elevations measured during June 2003 were approximately —30 feet MSLD, the lowest observed since January 1998. • The groundwater gradient direction was to the south, the reverse of the more typical northerly direction. <' • Analytical results for TPH were below reporting limits for all wells, which is consistent with the previous monitoring round conducted in December 2001. • 1,2-DCA was reported for only two wells, DMW-5 and DMW-6, at concentrations within or -! below previously reported ranges of concentrations for those wells. • PCE was not reported in any of the samples. K 3 W PROCESS 1227 3 612 Q O3 AFP_RE V O l.D O C