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