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data points to establish meaningful trends. There were no constituents that exhibited a
<br />statistically significant increasing trend during the second quarter 2008 monitoring event
<br />and also exceeded their concentration limits.
<br />Well Number
<br />Increasing Trends
<br />Decreasing Trends
<br />AMW-2
<br />Nitrate -N
<br />None Apparent
<br />AMW-6
<br />Barium, Bicarbonate, Chloride, Nitrate -N,
<br />Strontium
<br />Strontium
<br />AMW-7
<br />Bicarbonate, Chloride, Magnesium,
<br />Nitrate -N, Specific Conductance, Sulfate,
<br />TDS
<br />None Apparent
<br />AMW-12
<br />Bicarbonate
<br />Calcium, Chloride, Magnesium, Strontium
<br />AMW-13
<br />Bicarbonate, cis-1,2-DCE
<br />Nitrate -N
<br />AMW-14
<br />Barium, Calcium, Magnesium,
<br />Potassium, Sodium, Strontium
<br />Specific Conductance, TDS, TCE
<br />3.1.5 Corrective Action Program
<br />Field and laboratory results for CAP wells for the second quarter 2008 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 second quarter 2008, and are
<br />presented in Appendix D. As shown in Table 3-2, 12 VOCs were detected in CAP wells
<br />during the current monitoring period. The greatest number of VOCs, including five
<br />measured above the PQL, were detected in the sample from well AMW-) .
<br />In order to evaluate the effectiveness of corrective action measures,articular) with the
<br />p Y
<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 VOC trends were noted in CAP wells AMW-1, AMW-4, AMW-10, and
<br />AMW-11.
<br />Well
<br />Increasing Trends
<br />Decreasing Trends
<br />Number
<br />AMW-1
<br />Barium, Bicarbonate, Specific Conductance,
<br />Nitrate -N, pH, Sulfate, Benzene
<br />1,1 -DCA, cis-1,2-DCE, Vinyl Chloride
<br />AMW-3
<br />None Apparent
<br />None Apparent
<br />AMW4
<br />None Apparent
<br />Chloride, Barium, Bicarbonate, Calcium,
<br />Magnesium, Potassium, Strontium,
<br />Specific Conductance, TDS, 1,1 -DCA,
<br />Vinyl Chloride
<br />AMW-5/5R
<br />Barium, Bicarbonate, Chloride, Nitrate -N,
<br />None Apparent
<br />H, Specific Conductance, Sulfate, TDS
<br />MUoos_om OTA-2Qo8.a o0
<br />m
<br />Geologic Associates
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