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As summarized in the Annual Corrective Action Evaluation prepared by Herst & is Associates (2005),no CAP wells have exceeded the site's threshold limits. 3.1.6 Domestic Well Monitoring Two domestic wells (7898-A and 8106-A)were sampled on February 2, 2006. Table 3-3 summarizes the current analytical results for the domestic well samples collected. As shown on Table 3-3,three VOCs (DCDFM,PCE, and TCE)were measured above the .PQL in the sample from domestic wells 7898-A and 8106-A. In addition,two VOCs (1,1-DCA and cis-1,2-DCE)were measured at estimated trace levels in the sample from domestic well 8106-A. 3.1.7 Surface-Water Monitoring Surface-water sampling locations was conducted on February 2, 2006, at upstream 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. 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 first quarter 2006. 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 leachate monitoring and collection system operated effectively during the first quarter 2006. Leachate samples were collected on a monthly basis and analyzed in the field for pH and specific conductance. In addition to monthly monitoring, the leachate is sampled annually during the fourth quarter monitoring period for the parameters listed in Table 2-1. Results of monthly field monitoring measurements for the first quarter 2006 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 1,773 hours between December 29, 2005, and March 30, 2006, at 81 percent uptime and treated 8.829 million gallons of groundwater at an average flow rate of 83 gallons per minute or 0.119 million gallons per day. During this period, the D:\2003_021\ForwardAustin_w06.d ocW/20/2006 13 Geologic Associates