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monitoring period for each of these COCs measured above the PQL. As shown in Table 3-2, none of the COCs were confirmed in the retest samples,indicating these primary COC results were false positives. 3.1.9 Leachate Monitoring According to the Operations Manager,no leachate was taken off site during the third quarter 2008. The leachate collection system,which collects leachate from the north face of the landfill,has been operational since November 1996. WQPS (concentration limits) are not required for leachate because it is collected and removed for disposal, rather than discharged. According to the Operations Manager, the LCRS operated effectively during the third quarter 2008. Leachate samples were collected from the holding pond on a monthly basis and analyzed in the field for pH and specific conductance. Results of monthly field monitoring measurements for the third quarter 2008 are presented in Table 3-6. 3.1.10 Groundwater Treatment Facility Operations The Groundwater Treatment Facility(GTF) at the Austin Unit has been operational since 1994 to mitigate impacts from landfill releases. At the GTF, contaminated groundwater is extracted by two wells(EW-1 and EW-2), treated, and discharged to an infiltration pond. The GTF operated for 1,553 hours between July 1 and September 30, 2008, at 70.3 percent uptime, and treated 16.920 million gallons of groundwater at an average flow rate of 182 gallons per minute, or 0.261 million gallons per day. During this period, the GTF removed approximately 1.5 pounds of VOCs. (CH2M Hill, 2008). 3.2 SUMMARY Groundwater quality conditions beneath the Austin Unit during the third quarter 2008 monitoring period were generally similar to historical results. Excluding suspected field/laboratory contaminants, CLs were exceeded in DMP wells AMW-6, AMW-7, AMW-13, and AMW-14. However, none of the CL exceedances exhibited statistically significant increasing trends. In the CAP wells, trend analyses are performed instead of comparison to CLs. During the current monitoring period, one or more statistically significant increasing trends were noted for VOC constituents in CAP wells AMW-1, AMW-10, and AMW-19,while decreasing VOC trends were noted in CAP wells AMW- 1,AMW-4, AMW-10, and AMW-11. The increasing vinyl chloride and/or cis-1,2-DCE trends in wells AMW-1 and AMW-10 suggest that active reductive dechlorination is occurring in the vicinity of this well. The retest results for the 5-year COC sampling conducted during the second quarter 2008 monitoring period indicates that none of the COCs were confirmed in the retest samples, suggesting that the primary results were false positives. D:\2008_0010WA_3Q0&doc 14 Geologic Associates