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The second quarter 2006 detection of 1,2-dichloropropane at AMW-12 (0.54 ug/L) is the first detection of 1,2-dichloropropane at that well, but the concentration is well below the National Primary Drinking Water Standard (5 ug/L). The second quarter 2006 dichlorodifluoromethane concentration at AMW-12 (0.66 ug/L) is higher than concentrations previously observed at that well. The second quarter 2006 tetrachloroethene concentration at AMW-12 (11 ug/L) is the highest concentration observed at that well since April 1995. The second quarter 2006 trichloroethene concentration at AMW-12 (1.3 ug/L) is higher than concentrations previously observed at that well. The second quarter 2006 concentration of cis-1,2-dichloroethene at AMW-13 (8.2 ug/L) is higher than concentrations previously observed at that well, but is well below the National Primary Drinking Water Standard (70 ug/L). The second quarter 2006 concentration of dichlorodifluoromethane at AMW-13 (0.78 ug/L) is comparable to concentrations observed at that well intermittently since September 1996. The second quarter 2006 concentration of tetrachlorothene at AMW-13 (18 ug/L) is comparable to concentrations observed at that well intermittently since January 1998. The second quarter 2006 concentration of trichloroethene at AMW-13 (5.0 ug/L) is comparable to concentrations observed at that well intermittently since January 2002. The second quarter 2006 concentration of 1,2-dichloropropane at AMW-14 (0.52 ug/L) is comparable to concentrations observed at that well intermittently since December 1996, and is well below the National Primary Drinking Water Standard (5 ug/L). The second quarter 2006 concentration of dichlorodifluoromethane at AMW-14 (0.62 ug/L) is comparable to concentrations observed at that well intermittently since May 1996. The second quarter 2006 concentration of tetrachlorothene at AMW-13 (11 ug/L) is comparable to concentrations observed at that well intermittently since March 1996. The second quarter 2006 concentration of trichloroethene at AMW-14 (1.3 ug/L) is comparable to concentrations observed at that well intermittently since March 1996, and is well below the National Primary Drinking Water Standard (5 ug/L). Historical data from the detection monitoring wells were analyzed for temporal trend using Sen's Slope trend analysis. Graphs of the Sen's Slope analyses for detection monitoring wells are included in Appendix E. The following inorganic constituents exhibited an increasing trend according to the Sen's Slope analysis: barium at AMW-7 and AMW-12, bicarbonate at AMW-6, AMW-12, and AMW-13, calcium at AMW-14, chloride at AMW-6 and AMW-7, hexavalent chromium at AMW-12, magnesium at AMW-2 and AMW-14, nitrate at AMW-2, AMW-6, and AMW-7, potassium at AMW-14, sodium at AMW-14, field specific conductance at AMW-2 and AMW-7, strontium at AMW-14, and total dissolved solids (TDS) at AMW-7. Of the constituents that exhibited a statistically significant increasing trend during the second quarter 2006, only bicarbonate at AMW-13 exceeded its concentration limit. Although there were increasing trends for magnesium at AMW-14, nitrate at AMW-6 and AMW-7, and field specific conductance at AMW-7, background well AMW-2 also exhibited increasing trends for magnesium, nitrate, and field specific conductance during the second quarter 2006 monitoring event. Sen's Slope analysis identified decreasing trends in the following inorganic parameters: arsenic at AMW-2, AMW-7, AMW-12, chloride at AMW-12 and AMW-14, nitrate at AMW-13, potassium at AMW-13, field specific conductance at AMW-14, sulfate at AMW-6, and AMW-14, total dissolved solids (TDS) at AMW-14, and field turbidity at AMW-2. Of the organic parameters that were detected in detection monitoring wells during the second isquarter 2006 monitoring event, cis-l,2-dichloroethene, tetrachloroethene and trichloroethene at