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4.4.3 Leachate Monitoring Leachate sumps are inspected for the presence of leachate and observations are recorded at least weekly by Forward Landfill personnel. If leachate is detected in the sump it is pumped into the surface impoundment (WMU F) for evaporation. During the 2006 monitoring year, leachate was only observed at holding areas WMU-D93/94, WMW- DOl, WMU-D02, WMW-FU03, WMW-FU04, and WMU-FU05. The other holding areas were reported to be dry by Forward Landfill personnel. Freeboard at WMU F ranged from approximately 5.25 feet to 12.00 feet during the 2006 monitoring year. Leachate monitoring is performed annually during the fourth quarter monitoring period for analysis of the parameters listed in Table 2-1. The results of the annual leachate sample indicates that of the constituents detected, only sulfide and 3-&-4-methylphenol are potential new COCs. Verification samples will be collected from the Forward leachate sample point in February 2007 and reported with the first quarter 2007 monitoring report. The results of the LCRS gas test conducted in August 2006 at the Forward Unit indicated that an open-air conduit is present across the LCRS unit, allowing sufficient leachate evaporation. Based on freeboard logs, LCRS gas testing, and observations from Forward personnel, the leachate control facilities were operating effectively during the 2006 monitoring year. 4.5 AUSTIN UNIT 4.5.1 Groundwater With the exception of the second quarter 2006 monitoring period, measured groundwater elevations during 2006 generally reflect seasonal precipitation patterns. Hydrographs depicting groundwater elevations over the past six years are presented in Appendix D. Overall groundwater flow direction during the 2006 monitoring year were generally consistent with past monitoring periods with flow directed to the north-northwest at a gradient ranging from 0.001 to 0.003 ft/ft. During the second quarter 2006 monitoring period, significant increases in groundwater elevations were noted in the EMP wells resulting in groundwater flow directed to the south-southwest in the vicinity of the EMP wells. It is believed that this anomalous condition was the result of heavy rains during the winter, since the water level measurements taken in August 2006 reflected historical flow directions to the north-northwest. Groundwater quality conditions beneath the Austin Unit during the 2006 monitoring year are generally similar to those observed in the previous monitoring year. For DMP wells, CLs were consistently exceeded in wells AMW-13 and AMW-14 as a result of detected VOCs. However, only well AMW-13 consistently contained VOCs at concentrations greater than the PQL with statistically significant increasing trends. In the CAP wells, VOCs were consistently detected in wells AMW-1, AMW-4, AMW-10, AMW-11, and D:\2003_021\ForwardAnstin W6.doc\ 16 Geologic Associates