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Well Number Increasin Trends Decreasing Trends
<br /> Is AMW-2 Nitrate-N,Specific Conductance Arsenic
<br /> AMW-6 Barium,Bicarbonate,Chloride,Nitrate-N Arsenic
<br /> AMW-7 Bicarbonate,Chloride,Nitrate-N, None Apparent
<br /> Specific Conductance,TDS
<br /> AMW-12 Bicarbonate Calcium,Chloride,Magnesium,Strontium
<br /> AMW-13 Bicarbonate Nitrate-N
<br /> AMW-14 Barium,Calcium,Magnesium, Specific Conductance,TDS,PCE,TCE
<br /> Potassium,Sodium,Strontium
<br /> 3.1.5 Corrective Action Program
<br /> Field and laboratory results for CAP wells for the third quarter 2007 monitoring period
<br /> are summarized in Table 3-2. Data were graphed on time-series concentration plots by
<br /> Herst&Associates from data collected through the third quarter 2007, and are presented
<br /> in Appendix D. As shown in Table 3-2, excluding trace values of methylene chloride, a
<br /> suspected laboratory contaminant, 17 VOCs were measured in CAP wells during the
<br /> current monitoring period. The greatest number of VOCs, including 10 measured above
<br /> the PQL,were measured in the sample from well AMW-1.
<br /> In order to evaluate the effectiveness of corrective action measures,particularly with the
<br /> groundwater treatment facility(GTF), trend analyses were performed for CAP wells at
<br /> the Austin Unit,beginning in 1994 when the GTF began operation. The observed
<br /> groundwater quality constituent trends were evaluated using Sen's Slope trend analyses
<br /> to determine if significant increasing or decreasing trends were evident in the data. Trend
<br /> analyses,performed by Herst&Associates, are presented in Appendix D and are
<br /> summarized below. Wells and analytes not discussed below either do not show
<br /> significant trends(rising or falling)or have too few data points to establish meaningful
<br /> trends. As shown in the following table, significant increasing trends were calculated for
<br /> one or more VOC constituents in CAP wells AMW-1, AMW-10, and AMW-19,while
<br /> decreasing trends were calculated for one or more VOC constituents in CAP wells
<br /> AMW-1, AMW-4, AMW-10,AMW-11, and AMW-18.
<br /> Well Increasing Trends Decreasing Trends
<br /> Number
<br /> AMW-1 Barium,Bicarbonate,Specific Nitrate-N,pH,Sulfate,DCDFM
<br /> Conductance,cis-1,2-DCE,Vinyl Chloride
<br /> AMW-3 None Apparent None Apparent
<br /> AMW4LBarnium,
<br /> None Apparent Chloride,Barium,Bicarbonate,
<br /> Calcium,Magnesium,Potassium,
<br /> Strontium,TDS,DCDFM
<br /> AMW-5/5Bicarbonate,Chloride,Nitrate-N, None Apparent
<br /> Specific Conductance,Sulfate,TDS
<br /> AMW-10 Sulfate,cis-1,2-DCE Strontium,DCDFM
<br /> AMW-11 pH Calcium,Chloride,Magnesium,
<br /> Strontium,Specific Conductance TDS,
<br /> cis-1,2-DCE,DCDFM,PCE,TCE
<br /> AMW-18 Barium,Bicarbonate Arsenic,Sulfate,Sodium, 1,2-DCP
<br /> AMW-19 PCE Sodium,Sulfate
<br /> D:UO07_0043XFomardAustin SUm07.doc
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<br /> GeoLogic Associates
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