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Mann-Kendall / Sen's Slope analysis identified significant decreasing statistical trends for the following inorganic constituents: calcium at AMW-12, chloride at AMW-12, hexavalent chromium at AMW-7, magnesium at AMW-12, nitrate at AMW-13, potassium at AMW-7, strontium at AMW-12, and field turbidity at AMW-2. Carbonate at AMW-12 exhibited an apparent decreasing trend according to the Mann-Kendall / Sen's Slope analysis, but this trend is due to a historical decrease in the laboratory RL. Mann-Kendall / Sen's Slope analysis did not identify any significant increasing statistical trends for VOCs. Mann-Kendall / Sen's Slope analysis identified significant decreasing statistical trends for trichlorofluoromethane at AMW-13 and 1,1-dichloroethane, cis-1,2-dichloroethene, dichlorodifluoromethane, tetrachloroethene,and trichloroethene at AMW-14. The first quarter 2012 barium concentration at AMW-13 (0.27 mg/L) is within the range of concentrations observed at that well since the beginning of monitoring in May 1995 (0.24 to 0.34 mg/L). As discussed above, barium at AMW-13 does not exhibit a significant increasing statistical trend. A Wilcoxon rank-sum test comparing the barium data at upgradient well AMW- 2 to the data at AMW-13 (a = 0.05) indicates that the barium data at AMW-13 are statistically distinct from those at the upgradient well. The Wilcoxon rank sum plot is presented in Appendix E. The presence of stable barium concentrations at AMW-13 that are statistically distinct from upgradient concentrations indicates that the concentration limit exceedance for barium at AMW- 13 in the first quarter 2012 is likely due to spatial variation in the natural groundwater geochemistry at the site. The first quarter 2012 barium concentration at AMW-14 (0.26 mg/L) is within the range of concentrations observed at that well since the beginning of monitoring in July 1995 (0.093 to 0.3 mg/L). As discussed above, barium at AMW-14 exhibits a significant increasing statistical trend. The increasing trend is not observed when the data are limited to the period of February 2009 to February 2012. A Wilcoxon rank-sum test comparing the July 1995 to November 2008 barium data at AMW-14 to the February 2009 to February 2012 data (a = 0.05) indicates that these periods are statistically distinct. The Wilcoxon rank sum plot is presented in Appendix E. This indicates that the significant increasing statistical trend in barium at AMW-14 may be due to a localized change in the site's natural geochemistry near AMW-14 in 2008-2009. This change was signified by a shift in barium at AMW-14 to higher but stable concentrations. The first quarter 2012 chloride concentration at AMW-14 (86 mg/L) is within the range of concentrations observed at that well since the beginning of monitoring in July 1995 (3 to 168 mg/L). As discussed above, chloride at AMW-14 exhibits a significant increasing statistical trend. The increasing trend is not observed when the data are limited to the period of March 2010 to February 2012. A Wilcoxon rank-sum test comparing the July 1995 to November 2009 chloride data at AMW-14 to the March 2010 to February 2012 data data (a= 0.05) indicates that these periods are statistically distinct. The Wilcoxon rank sum plot is presented in Appendix E. This indicates that the significant increasing statistical trend in chloride at AMW-14 may be due to a localized change in the site's natural geochemistry near AMW-14 in 2009-2010. This change was signified by a shift in chloride at AMW-14 to higher but stable concentrations. The first quarter 2012 hexavalent chromium at AMW-6 (0.0052 mg/L) is within the range of concentrations observed at that well since the beginning of monitoring in July 1995 (<0.002 to 0.0068 mg/L). As discussed above, hexavalent chromium at AMW-6 does not exhibit a significant increasing statistical trend. A Wilcoxon rank-sum test comparing the hexavalent chromium data at upgradient well AMW-2 to the data at AMW-6 (a = 0.05) indicates that the hexavalent chromium data at AMW-6 are statistically distinct from those at the upgradient well. 3