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The presence of cis-1,2-DCE suggests reductive dechlorination is occurring in the vicinity of wells AMW-1,AMW-4,AMW-10, and AMW-19 and in particular in the vicinity of wells AMW-I and AMW-10 where an increasing trend was calculated. As summarized in the Annual Corrective Action Evaluation prepared by Herst&Associates (2007), the overall groundwater quality at the site is generally improving. 3.1.6 Domestic Well Monitoring Two domestic wells(7898-A and 8106-A)were sampled on August 14,2007. Table 3-3 summarizes the current analytical results for the domestic well samples collected. As shown on Table 3-3, three VOCs were measured above the PQL in the sample from domestic well 7898-A, while five VOCs were measured in the sample from domestic well 8106-A with three VOCs measured above the PQL. 3.1.7 Surface Water Monitoring Surface-water sampling locations was conducted on August 14,2007, at surface-water monitoring stations ASW-1 and ASW-2. Table 3-4 summarizes the current analytical results for surface water samples collected at the Austin Unit and compares the results with the WQPS (concentration limits). No CLs were exceeded during the first quarter 2006 monitoring period at downgradient surface-water monitoring station ASW-2. A comparison of upgradient(ASW-1)to downgradient(ASW-2) surface water samples indicates generally similar concentrations. 3.1.8 Leachate Monitoring According to the Operations Manager,no leachate was taken off site during the third quarter 2007. 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 2007. Leachate samples were collected from the pond on a monthly basis and analyzed in the field for pH and specific conductance. Results of monthly field monitoring measurements and analytical results for the third quarter 2007 are presented in Table 3-6. 3.1.9 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 1,947 hours between July 1 and September 30, 2007, at 88.2 percent uptime, and treated 24.158 million gallons of groundwater at an average flow rate D:\2007_00431ForwardAus6n—s=o7.doc 12 Geologic Associates