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GROUNDWATER ELEVATIONS AND GRADIENT Contour maps of groundwater elevations for March 22, June 20, September 30, and December 22, 2005 are shown in Figures 3, 4, 5, and 6 respectively Current and historical water level elevation data for all wells are included in Table 2 The shallowest water levels were measured in June, when the depth to water ranged from 43 to 44 feet below ground surface, or approximately-26 feet with reference to mean sea level datum (MSLD) The deepest water levels were measured in September, when the water level elevation in the central portion of the site was approximately -31 feet MSLD A hydrograph of groundwater level elevations in DMW-1 (Figure 7) shows that water levels rose about 30 feet during the 1990's to a high of-18 feet MSLD in May 2000, and have since declined by approximately 13 feet The direction of the groundwater gradient remained relatively consistently to the north-northeast during 2005, and ranged in magnitude from 0 001 to 0 004,with the highest measured gradient occurring in September GROUNDWATER ANALYTICAL RESULTS A historical summary of analytical results for groundwater samples collected through December 2005 is included in Table 3 Results for tetrachloroethene (PCE) and 1,2-dichloroethane (1,2-DCA) for samples collected during 2005 are presented on Figure 8 Time versus concentration plots of 1,2-DCA in monitoring well samples are presented in Figures 9 and 10 TPH-diesel Neither total petroleum hydrocarbon (TPH) reported as diesel or unknown hydrocarbon (UH) were identified in groundwater samples collected during 2005 Volatiles and Oxygenates by EPA Method 8260B 1,2-Dichloroethane was reported in samples collected from DMW-2, DMW-5, DMW-6, and DMW-9, with the higher concentrations reported in DMW-6 and DMW-9 Concentrations of 1,2-dichlorroethane in DMW-6 ranged from 20 micrograms per liter (µg/L) in December to 23 pg/]L in March and September Concentrations of 1,2-dichlon oethane in DMW-9 ranged from 20 }ig/L in September to 36 pg/L in June Tetrachloroethene (PCE) was reported only in DMW-9, at concentrations ranging from 1 3 4g/L in December to 4 2 µg/L in September Chloroform was reported in samples collected from DMW-1, DMW4, DMW-5, and DMW-8 The highest concentrations of chloroform were observed for DMW-4, where concentrations ranged from 1 8 }ig/L in March to 2 9 µg/L in December Plots of 1,2-DCA concentrations versus time were prepared for the four monitoring wells in which that constituent has been consistently reported These plots are presented as Figure 9 (DMW-2 and DMW-3), and Figure 10 (DMW-6 and DMW-9) Trend lines, based on a linear regression analysis, are shown on these plots, together with their equation in the form of y = nix +b, where m is the slope of the line A negative slope to the trendline is statistically indicative of declining concentrations The regression analysis shows a declining trend for DMW-2, DMW-3, and DMW-6 The data for DMW-9 show a rising trend However,the period of record is short and the data are relatively variable D1Q4051REVIEW PACKAG"005 GROUNDWATFR.MONITORING REPORT-TEXT DOC