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® 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 fourth quarter 2006. Leachate samples were collected from the pond 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 and analytical results for the fourth quarter 2006 are presented in Table 3-6. As shown on Table 3-6, 10 dissolved metal constituents were measured with six measured above the PQL; two VOCs were measured with one above the PQL; one SVOCs (bis[2-ethylhexyl] phthalate), a confirmed laboratory contaminant was measured; two pesticides were measured above the PQL; and one herbicide was measured above the PQL in the leachate sample collected during the fourth quarter 2006 monitoring period. Review of the November 2006 leachate sample data indicates that of the constituents detected, mercury and the pesticides dicholorvos and naled are potential new COCs. Therefore, in accordance with WDR No. R5-2003-0049, verification samples will be collected from the Austin leachate sample point in February 2007 and reported with the first quarter 2007 monitoring report. 3.1.9 Groundwater Treatment Facility Operations gft 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 1,635 hours between October 1 and December 27, 2006, at 78 percent uptime and treated 21.555 million gallons of groundwater at an average flow rate of 220 gallons per minute, or 0.316 million gallon per day (mgd). During this period, the GTF removed approximately 2.3 pounds of volatile organic compounds (CH2M Hill, 2007). 3.2 SUMMARY Groundwater quality conditions beneath the Austin Unit during the fourth quarter 2006 monitoring period are generally similar to historical results. Excluding suspected laboratory contaminants, CLs were exceeded in DMP wells AMW-6, AMW-7, AMW-12, AMW-13, and AMW-14. Of the CL exceedances, a statistically significant increasing trend was noted for hexavalent chromium in well AMW-12, and for several VOC constituents in well AMW-13. Statistically significant decreasing VOC trends were calculated in well AMW-14. In the CAP wells, trend analyses are performed instead of comparison to CLs. During the current monitoring period, statistically significant increasing trends were noted for VOCs in wells AMW-1 and AMW-10, while decreasing VOC trends were noted in CAP wells AMW-1, AMW-4, and AMW-11. The annual leachate sample results indicates that of the constituents detected, mercury and the pesticides dicholorvos and naled are potential new COCs. Therefore, in D:X2003_021 Tomar"ustin_ft.doc1 13 Geologic Associates