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Well Number Increasing Trends Decreasing Trends
<br /> AMW-2 Barium,Nitrate-N,Specific Conductance None Apparent
<br /> AMW-6 Barium,Bicarbonate,Chloride,Nitrate-N Sulfate
<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,Potassium
<br /> AMW-14 Calcium,Magnesium,Potassium, Chloride,Specific Conductance,TDS,
<br /> Sodium,Strontium PCE,TCE
<br /> 3.1.5 Corrective Action Program
<br /> Field and laboratory results for CAP wells for the first quarter 2007 monitoring period are
<br /> summarized in Table 3-2. Data were graphed on time-series concentration plots by Herst
<br /> &Associates from data collected through the first quarter 2007, and are presented in
<br /> Appendix D. As shown in Table 3-2, excluding a suspected laboratory contaminant, 14
<br /> VOCs were measured in CAP wells during the current monitoring period with the
<br /> greatest number of VOCs measured above the PQL(six)in the sample from well
<br /> 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 /> AMIL 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 VOC constituents in CAP wells AMW-1 and
<br /> AMW-11.
<br /> Well Increasing Trends Decreasing Trends
<br /> Number
<br /> AMW-1 Barium,Bicarbonate,Specific Chloride,Nitrate-N,Sulfate,DCDFM
<br /> Conductance,cis-1,2-DCE,Vinyl Chloride
<br /> AMW-3 None Apparent None Apparent
<br /> AMW-4 None Apparent Chloride,Barium,Bicarbonate,
<br /> Calcium,Magnesium,Strontium,TDS
<br /> AMW-5 None Apparent None Apparent
<br /> AMW-10 Sulfate,cis-1,2-DCE None Apparent
<br /> AMW-11 pH Calcium,Chloride,Magnesium,
<br /> Specific Conductance TDS,cis-1,2-
<br /> DCE,DCDFM,PCE,TCE
<br /> AMW-18 Barium Arsenic,Sulfate,Sodium
<br /> AMW-19 PCE Sulfate
<br /> D:\2007_0043\ForwnrdAustin_wo7.doc
<br /> 11 Geologic Associates
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