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I& <br />AMW-19A at concentrations exceeding the PQL. Trend analyses indicate increasing <br />trends were consistently noted for VOCs in wells AMW-1 and AMW-10. However, as <br />summarized in the Annual Corrective Action Evaluation prepared by Herst & Associates <br />(2006), the overall groundwater quality at the site is improving and the presence of cis- <br />1,2-DCE suggests natural dechlorination is occurring in the vicinity of wells AMW-1 and <br />AMW-10. <br />4.5.2 Surface Water <br />Surface water samples were collected from surface water stations ASW -1 and ASW -2 <br />during the 2006 monitoring year. During the year, CLs were only exceeded for specific <br />conductance during the second quarter 2006 monitoring period, and pH during the second <br />quarter 2006 monitoring period. However, a comparison of the upgradient (ASW -1) to <br />downgradient (ASW -2) surface water samples indicates generally similar concentrations. <br />4.5.3 Leachate Monitoring <br />According to the Operations Manager, no leachate was taken off site during the 2006 <br />monitoring year. The leachate collection system, which collects leachate from the north <br />face of the landfill, has been operational since November 1996. WQPS (concentration <br />limits) are not required for leachate because it is collected and removed for disposal, <br />rather than discharged. According to the Operations Manager, the leachate monitoring <br />and collection system operated effectively during the 2006 monitoring year. <br />Leachate samples were collected on a monthly basis and analyzed in the field for pH and <br />specific conductance. In addition to monthly monitoring, the leachate is sampled <br />annually during the fourth quarter monitoring period for the parameters listed in Table <br />2-1. The annual leachate sample results indicates that of the constituents detected, <br />mercury and the pesticides dicholorvos and naled are potential new COCs. Therefore, in <br />accordance with WDR No. R5-2003-0049, verification samples will be collected from <br />the Austin leachate sample point in February 2007 and reported with the first quarter <br />2007 monitoring report. <br />D:12003 021WorwardAusdn 106.doc% <br />17 Geologic Associates <br />