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Sen's Slope analysis identified decreasing trends in the following inorganic parameters: arsenic at AMW-18, barium at AMW4, bicarbonate at AMW4, calcium at AMW-4, AMW-10, and AMW-11, chloride at AMW-4 and AMW-11, magnesium at AMW4, AMW-10, and AMW-11, nitrate at AMW-1 and AMW-10, field pH at AMW-1,potassium at AMW4, sodium at AMW-18 and AMW-19, strontium at AMW4, AMW-10 and AMW-11, field specific conductance at AMW-11, sulfate at AMW-1, AMW-18, and AMW-19,TDS at AMW4 and AMW-11, and field turbidity at AMW4. The field pH value observed at AMW-1 during the fourth quarter 2007 (6.24 s.u.) is comparable to pH values observed at that well intermittently since May 2005, but is outside the National Secondary Drinking Water Standard range(6.5 -8.5 s.u.). The following organic parameters exhibited an increasing trend according to the Sen's Slope analysis: 1,1-dichloroethane at AMW-1, cis-1,2-dichloroethene at AMW-1 and AMW-10, tetrachloroethene at AMW-19,and vinyl chloride at AMW-1. The fourth quarter 2007 concentration of 1,1-dichloroethane at AMW-1 (7.5 ug/L) is comparable to concentrations observed at that well intermittently since November 2005. The fourth quarter 2007 concentration of cis-1,2-dichloroethene at AMW-1 (3.6 ug/L) is comparable to concentrations observed at that well intermittently since October 2001. The fourth quarter 2007 concentration of cis-1,2-dichloroethene at AMW-10 (0.52 ug/L) is is the lowest concentration observed at that well since November 1999. The concentration of cis-1,2-dichloroethene at both AMW-1 and AMW-10 is below the National Primary Drinking Water Standard (70 ug/L). The fourth quarter 2007 concentration of tetrachloroethene at AMW-19 (2.5 ug/L) is comparable to the concentrations observed during the previous four monitoring events at that well, and is below the National Primary Drinking Water Standard (5 ug/L). The fourth quarter 2007 concentration of vinyl chloride at AMW-1 (0.79 ug/L) is comparable to concentrations observed at that well intermittently since October 2001, and is below the National Primary Drinking Water Standard(2 ug/L). Sen's Slope analysis identified decreasing trends in the following organic parameters: 1,1- dichlorochloroethane and AMW-10, cis-1,2-dichloroethene at AMW-11, tetrachloroethene at AMW-11, and trichloroethene at AMW-11. Piper diagrams of the first through fourth quarter 2007 results for the corrective action monitoring wells are included in Appendix H. Hydrographs of the corrective action monitoring wells, illustrating historic groundwater elevations, well screen elevations, and pump intake elevations, are included in Appendix I. 5