Laserfiche WebLink
CONSTITUENT Concentration I DMP MONITORING WELL <br /> I Limit AMW-23 AMW-6 AMW-7 FA-MW-13 AMW-IT <br /> MONITORING PARAMETERS(m /1) <br /> Barium 0.224 0.260 0.270 <br /> Chloride 74.53 92 <br /> Chromium(hexavalent) 1 0.005012 0.0054 <br /> [VOLATILE ORGANIC COMPOUNDS(pg/l) <br /> �etrachloroethene 0.5 6.2 0;76 <br /> �rrichloroethene 0.5 1.8 <br /> NOTES: (B)-Background Well. <br /> DMP -Trend Analyses <br /> In order to evaluate changes in water quality in DMP wells at the Austin Unit, historical <br /> trends in groundwater were evaluated beginning in 1994 when the groundwater treatment <br /> facility began operation. The observed groundwater quality constituent trends were <br /> evaluated using Mann-Kendall/ Sen's Slope trend analyses to determine if significant <br /> increasing or decreasing trends were evident in the data. Trend analyses, performed by <br /> Herst& Associates, are presented in Appendix D and summarized below. Wells and <br /> analytes not discussed below either do not show significant trends (rising or falling) or <br /> have too few data points to establish meaningful trends. <br /> Well Number Increasing Trends Decreasing Trends <br /> AMW-2 Bicarbonate,Nitrate-N, Specific None Apparent <br /> Conductance <br /> AMW-6 Barium,Chloride, Magnesium,Nitrate-N, None Apparent <br /> Strontium, Specific Conductance,TDS <br /> AMW-7 Bicarbonate,Calcium, Chloride, Hexavalent Chromium, Potassium <br /> Magnesium,Nitrate-N, Specific <br /> Conductance,Sulfate,TDS <br /> AMW-12 None Apparent Calcium,Chloride,Magnesium, Strontium <br /> AMW-13 Bicarbonate Nitrate-N <br /> AMW-14 Barium,Calcium, Hexavalent Chromium, PCE,TCE <br /> Magnesium,Nitrate-N, Potassium, <br /> Sodium, Strontium, Sulfate <br /> With the exception of barium concentrations measured in well AMW-14, no constituents <br /> that exhibited a statistically significant increasing trend during the fourth quarter 2011 <br /> monitoring event and also exceeded their concentration limits. It should be noted, <br /> however, that the barium concentration measured in the sample collected from well <br /> AMW-14 (0.270 mg/L) during the current monitoring period is within the historical <br /> range of values observed at this well, and is well below the state primary drinking water <br /> standard(I mg/L). <br /> C:\2ou-oo5o\FA_4Qu.doc 10 Geo-Logic Associates <br />