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DMP - 'Trend Analyses In order to evaluate changes in water quality in DMP wells at the Austin Unit, historical trends in groundwater were evaluated beginning in 1994 when the groundwater treatment facility began operation. The observed groundwater quality constituent trends were evaluated using Mann-Kendall / Sen's Slope trend analyses to determine if significant increasing or decreasing trends were evident in the data. Trend analyses, performed by Herst & Associates, are presented in Appendix D and summarized below. Wells and analytes not discussed below either do not show significant trends (rising or falling) or have too few data points to establish meaningful trends. Well Number Increasing Trends Decreasing Trends AMW-2 Bicarbonate,Nitrate-N,Specific None Apparent Conductance AMW-6 Barium,Chloride, Magnesium,Nitrate-N, None Apparent Specific Conductance,Strontium,Total Dissolved Solids(TDS) AMW-7 Bicarbonate,Calcium, Chloride, Potassium Magnesium,Nitrate-N, Specific Conductance, Sulfate,TDS AMW-12 None Apparent Calcium, Chloride,Magnesium, Strontium AMW-13 Bicarbonate Nitrate-N AMW-14 Barium,Calcium, Hexavalent Chromium, DCDFM, PCE,TCE Magnesium,Nitrate-N,Potassium, Sodium, Strontium, Sulfate With the exception of barium concentrations measured in well AMW-14, no constituents that exhibited a statistically significant increasing trend during the second quarter 2011 monitoring event also exceeded their concentration limits. The second quarter 2011 barium concentration measured in the sample collected from well AMW-14 (0.260 mg/L) is within the historical range of values observed at this well, and is well below the state primary drinking water standard (I mg/L). 3.1.5 Corrective Action Program Field and laboratory results for CAP wells for the second quarter 2011 monitoring period are summarized in Table 3-2. As shown in Table 3-2, 12 VOCs were detected in CAP wells during the current monitoring period. Well AMW-I had the greatest number of VOCs (11), including eight measured above the PQL. In order to evaluate the effectiveness of corrective action measures,particularly with the groundwater treatment facility(GTF), trend analyses were performed for CAP wells at the Austin Unit, beginning in 1994 when the GTF began operation. The observed groundwater quality constituent trends were evaluated using Mann-Kendall / Sen's Slope trend analyses to determine if significant increasing or decreasing trends were evident in the data. Trend analyses, performed by Herst & Associates, are presented in Appendix D and are summarized below. Wells and analytes not discussed below either do not show D:\201 1_0050\FA-2QI Ldoex 10 Geologic Associates