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During the third quarter 2006 monitoring event, no VOCs were detected above the laboratory PQL in samples collected from detection monitoring wells AMW-12. Bromoform and dibromochloromethane were detected above the PQL at AMW-2 during the third quarter 2006. Bromoform was detected above the PQL at AMW-6 during the third quarter 2006. Bromoform and dibromochloroemethane were detected above the PQL at AMW-7 during the third quarter 2006. Tetrachloroethene was detected above the PQL at AMW-13 during the thrid quarter 2006. Bromoform, tetrachloroethene, and trichloroethene were detected above the PQL at -14 during the third quarter 2006. The third quarter 2006 detections of bromoform at AMW-2 (1.9 ug/L), AMW-6 (1.6 ug/L), AMW-7 (1.8 ug/L), AMW-14 (1.1 ug/L) are the first detections of bromoform at these wells. The third quarter 2006 detections of dibromochloromethane at AMW-2 (0.73 ug/L) and AMW-7 (0.68 ug/L)are the first detections of dibromochloromethane at these wells. The third quarter 2006 concentration of tetrachlorothene at AMW-13 (1.6 ug/L) is comparable to concentrations observed at that well intermittently since March 1994, and is below the National Primary Drinking Water Standard (5 ug/L). The third quarter 2006 concentration of tetrachloroethene at AMW-14 (7.6 ug/L) is comparable to concentrations observed at that well intermittently since March 1996. The third quarter 2006 concentration of trichloroethene at AMW-14 (1 ug/L) is comparable to concentrations observed at that well intermittently since March 1996, and is 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-6 and AMW-7, bicarbonate at AMW-6, AMW-12, and AMW-13, calcium at AMW-14, chloride at AMW-6 and AMW-7, magnesium at 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. None of the constituents that exhibited a statistically significant increasing trend during the third quarter 2006 exceeded their concentration limits. Although there were increasing trends for nitrate at AMW-6 and AMW-7 and field specific conductance at AMW-7,background well AMW-2 also exhibited increasing trends for nitrate and field specific conductance during the third quarter 2006 monitoring event. Sen's Slope analysis identified decreasing trends in the following inorganic parameters: arsenic at AMW-2, AMW-6, 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 third quarter 2006 monitoring event, tetrachloroethene and trichloroethene at AMW-13 exhibited an increasing trend according to the Sen's Slope analysis. The third quarter 2006 tetrachloroethene concentration at AMW-13 (1.6 ug/L) is comparable to concentrations observed at that well intermittently since March 1994, and is the lowest concentration observed since May 2005. The third quarter 2006 trichloroethene concentration at AMW-13 (0.28 ug/L) is comparable to concentrations observed at that well intermittently since March 1994, and is the lowest concentration observed since May 2005. Both the tetrachloroethene and trichloroethene concentrations at AMW-13 are below the National Primary Drinking Water Standard (5 ug/L for both constituents). Tetrachloroethene and trichloroethene at AMW-14 exhibited a statistically significant decreasing trend according to the Sen's Slope analysis. 3