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nitrate at AMW-2, AMW-6, AMW-7, and AMW-14; potassium at AMW-14; sodium at AMW- 14; field specific conductance at AMW-2, AMW-6, and AMW-7; strontium at AMW-6 and AMW-14; sulfate at AMW-7, AMW-13,AMW-14; and TDS at AMW-6 and AMW-7. Given that bicarbonate alkalinity, nitrate, and field specific conductance exhibit significant increasing trends at upgradient well AMW-2, the increasing trends for these constituents at downgradient wells are likely due to ongoing changes in the natural groundwater geochemistry at the site. 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-l,2-dichloroethene, dichlorodifluoromethane,tetrachloroethene,and trichloroethene at AMW-14. The second quarter 2012 barium concentration at AMW-13 (0.28 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 second quarter 2012 is likely due to spatial variation in the natural groundwater geochemistry at the site. The second quarter 2012 barium concentration at AMW-14 (0.28 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 August 2009 to May 2012. A Wilcoxon rank-sum test comparing the July 1995 to May 2009 barium data at AMW-14 to the August 2009 to May 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 2009. This change was signified by a shift in barium at AMW-14 to higher but stable concentrations. The second quarter 2012 chloride concentration at AMW-14 (95 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 May 2012. A Wilcoxon rank-sum test comparing the July 1995 to November 2009 chloride data at AMW-14 to the March 2010 to May 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 3