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:: Well Increasing Trends Decreasing Trends
<br /> Number
<br /> AMW-1 Barium,Bicarbonate,Specific Nitrate-N,pH, Sulfate
<br /> Conductance, 1,1-DCA,cis-1,2-DCE,
<br /> Vinyl Chloride
<br /> AMW-3 None Apparent None Apparent
<br /> AMW-4 None Apparent Chloride,Barium,Bicarbonate,
<br /> Calcium,Magnesium,Potassium,
<br /> Strontium,TDS
<br /> AMW-5/5R Barium,Bicarbonate,Chloride,Nitrate-N, None Apparent
<br /> pH, Specific Conductance,Sulfate,TDS
<br /> AMW-10 Sulfate,cis-1,2-DCE Calcium,Magnesium,Nitrate-N,
<br /> Strontium, 1,1-DCA
<br /> AMW-11 Sodium Calcium,Chloride,Magnesium,
<br /> Strontium,Specific Conductance TDS,
<br /> cis-1,2-DCE,PCE,TCE
<br /> AMW-18 Barium,Bicarbonate Arsenic,Sulfate,Sodium
<br /> AMW-19 PCE Sodium,Sulfate
<br /> The presence of cis-1,2-DCE suggests reductive dechlorination is occurring in the
<br /> vicinity of wells AMW-1 and AMW-10 where increasing trends were calculated. As
<br /> summarized in the Annual Corrective Action Evaluation prepared by Herst & Associates
<br /> (2007), the overall groundwater quality at the site is generally improving.
<br /> 3.1.6 Domestic Well Monitoring
<br /> Two domestic wells (7898-A and 8106-A) were sampled on November 5, 2007. Table 3-
<br /> 3 summarizes the current analytical results for the domestic well samples collected. As
<br /> shown on Table 3-3, three VOCs were measured above the PQL in the sample from
<br /> domestic well 7898-A,while five VOCs were detected in the sample from domestic well
<br /> 8106-A with four VOCs measured above the PQL.
<br /> 3.1.7 Surface Water Monitoring
<br /> Surface-water sampling was conducted at surface-water monitoring stations ASW-1 and
<br /> ASW-2 on November 5, 2007. Table 3-4 summarizes the-current analytical results for
<br /> surface water samples collected at the Austin Unit and compares the results with the
<br /> WQPS (concentration limits). No CLs were exceeded during the first quarter 2007
<br /> monitoring period at downgradient surface-water monitoring station ASW-2. There were
<br /> no VOCs detected at surface water monitoring stations during the fourth quarter 2007
<br /> monitoring period. A comparison of upgradient(ASW-1) to downgradient (ASW-2)
<br /> surface water samples indicates generally similar concentrations.
<br /> 3.1.8 Leachate Monitoring
<br /> According to the Operations Manager, no leachate was taken off site during the fourth
<br /> quarter 2007. The leachate collection system, which collects leachate from the north face
<br /> of the landfill, has been operational since November 1996. WQPS (concentration limits)
<br /> D:\2007-0043\FonvardAustin_4QO7.doc
<br /> 12 Geologic Associates
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