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data points to establish meaningful trends. As shown in the following table, increasing
<br /> trends were noted for three VOCs in DMP well AMW-13,while decreasing VOC trends
<br /> were noted in well AMW-14. Of the increasing inorganic constituent trends identified
<br /> during the first quarter 2006 monitoring period,only the barium concentration in well
<br /> AMW-12 exceeded a concentrations limit.
<br /> Well Number Increasing Trends Decreasing Trends
<br /> AMW-2 Nitrate-N,Magnesium,Specific Conductance None Apparent
<br /> AMW-6 Bicarbonate,Chloride,Nitrate-N Arsenic,Sulfate
<br /> A AW-7 Barium,Bicarbonate,Chloride,Nitrate-N, Arsenic
<br /> Specific Conductance,TDS
<br /> AMW-12 Barium,Bicarbonate,Hexavalent Chromium Chloride
<br /> AMW-13 Bicarbonate,cis-1,2-DCE,PCE,TCE Nitrate-N,Sulfate
<br /> AMM-14 Sodium,Strontium Chloride,Specific Conductance,
<br /> Sulfate,TDS,PCE,TCE
<br /> 3.1.5 Corrective Action Program
<br /> Field and laboratory results for CAP wells for the first quarter 2006 are summarized in
<br /> Table 3-2. Data were graphed on time-series concentration plots by Herst&Associates
<br /> from data collected through the first quarter 2006, and are presented in Appendix D. As
<br /> shown in Table 3-2, 17 VOCs were measured in CAP wells during the current monitoring
<br /> period,with the greatest number of VOCs(seven)measured above the PQL in the sample
<br /> from well AMW-1.
<br /> In order to evaluate the effectiveness of corrective action measures,particularly with the i
<br /> GTF,trend analyses were performed for CAP wells at the Austin Unit,beginning in 1994
<br /> when the GTF began operation. The observed groundwater quality constituent trends
<br /> were evaluated using Sen's Slope trend analyses to determine if significant increasing or
<br /> decreasing trends were evident in the data. Trend analyses,performed by Herst&
<br /> Associates, are presented in Appendix D and are summarized below. Wells and analytes
<br /> not discussed below either do not show significant trends(rising or falling) or have too
<br /> few data points to establish meaningful trends. As shown in the following table
<br /> statistically significant increasing trends were noted for VOC constituents in CAP wells
<br /> AMW- and AMW-10, while decreasing trends were noted for several VOCs in CAP
<br /> well AMW-11.
<br /> Well Number Increasing Trends Decreasing Trends
<br /> AMW-I Bicarbonate,Specific Conductance, 1,2-DCA, Chloride,Nitrate-N,pH,
<br /> cis-1,2-DCE,Vinyl Chloride Sulfate,DCDFM
<br /> AMW-3 Chloride,Nitrate-N,Specific Conductance pH,Arsenic
<br /> AMW-4 None Apparent Chloride,Strontium
<br /> AMW-5 Chloride,Nitrate-N,pH,Specific Conductance, None Apparent
<br /> Sulfate,TDS
<br /> AMW-10 Specific Conductance,Sulfate,cis-1,2-DCE,TCE TCFM
<br /> AMW-11 None Apparent Chloride,Calcium,Magnesium,
<br /> TDS,cis-1,2-DCE,DCDFM,
<br /> PCE,TCFM
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<br /> 12 Geologic Associates
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