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The results of the annual leachate sample indicate that of the constituents detected, only <br /> benzoic acid is a potential new COC. Verification samples will be collected from the <br /> Forward leachate sample point in May 2008 for analysis of SVOCs and reported with the <br /> second quarter 2008 monitoring report. <br /> The results of the LCRS gas test conducted in August 2007 at the Forward Unit indicated <br /> that an open-air conduit is present across the LCRS unit, allowing sufficient leachate <br /> evaporation. Based on freeboard logs, LCRS gas testing, and observations from Forward <br /> personnel, the leachate control facilities were operating effectively during the 2007 <br /> monitoring year. <br /> 4.5 AUSTIN UNIT <br /> 4.5.1 Groundwater <br /> With the exception of the third quarter 2007 monitoring period, measured groundwater <br /> elevations during 2007 generally reflect seasonal precipitation patterns. Hydrographs <br /> depicting groundwater elevations over the past seven years are presented in Appendix D. <br /> Overall groundwater flow direction during the 2007 monitoring year were generally <br /> consistent with past monitoring periods with flow directed to the north-northwest at a <br /> gradient of 0.002 ft/ft. During the third quarter 2007 monitoring period, lower <br /> groundwater levels associated with observed pumping from adjacent agricultural wells <br /> resulted in groundwater flow directed to the east-southeast in the vicinity of wells <br /> AMWA and AMW-2. <br /> Groundwater quality conditions beneath the Austin Unit during the 2007 monitoring year <br /> are generally similar to those observed in the previous monitoring year. For DMP wells, <br /> CLs were consistently exceeded in wells AMW-13 and AMW-14 as a result of detected <br /> VOCs. However, only well AMW-13 consistently contained VOCs at concentrations <br /> greater than the PQL with one or more statistically significant increasing trends. In the <br /> CAP wells, VOCs were consistently detected in wells AMW-1, AMW-4, AMW-10, and <br /> AMW-19A at concentrations exceeding the PQL. Trend analyses indicate increasing <br /> trends were consistently noted for VOCs in wells AMW-1 and AMW-10, and AMW- <br /> 19A. However, as summarized in the Annual Corrective Action Evaluation prepared by <br /> Herst& Associates (2007), the overall groundwater quality at the site is generally <br /> improving and the presence of cis-1,2-DCE suggests natural dechlorination is occurring <br /> in the vicinity of wells AMW-1 and AMW-10. <br /> D:UO07_0043Toma rdAustin_4Q07.doc <br /> 16 Geologic Associates <br />