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Mann -Kendall / Sen's Slope analysis identified significant decreasing statistical trends in the following inorganic constituents: calcium at AMW-12, chloride at AMW-12, magnesium at AMW-12, nitrate at W-13, potassium at AMW-7, strontium at AMW-12, and field turbidity at AMW-2. 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 dichlorodifluoromethane, tetrachloroethene, and trichloroethene at AMW-14. The second quarter 2011 barium concentration at AMW-12 (0.26 mg/L) is within the range of concentrations observed at that well since the beginning of monitoring in May 1995 (0.14 to 0.28. mg/L). As discussed above, barium at AMW-12 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-12 (a = 0.05) indicates that the barium data at AMW-12 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-12 that are statistically distinct from upgradient concentrations indicates that the concentration limit exceedance for barium at AMW- 12 in the second quarter 2011 is likely due to spatial variation in the natural groundwater geochemistry at the site. The second quarter 2011 barium concentration at AMW-13 (0.26 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 2011 is likely due to spatial variation in the natural groundwater geochemistry at the site. The second quarter 2011 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 August 2006 to May 2011. A Wilcoxon rank -sum test comparing the July 1995 to May 2006 barium data at AMW-14 to the August 2006 to May 2011 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 2006. This change was signified by a shift in barium at AMW-14 to higher but stable concentrations. The second quarter 2011 chloride concentration at AMW-14 (85 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 does not exhibit a significant increasing statistical trend. A Wilcoxon rank -sum test comparing the chloride data at upgradient well AMW-2 to the data at AMW-14 (a = 0.05) indicates that the chloride data at AMW-14 are statistically distinct from those at the upgradient well. The Wilcoxon rank sum plot is presented in Appendix E. The presence of stable chloride concentrations at AMW-14 that are statistically indistinct from upgradient concentrations indicates that the concentration limit exceedance for