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In addition to PCE, TCE, and 1,1,1-TCA, 11 other VOCs were detected at trace <br /> concentrations in monitoring well samples during 1999 and 2000. The trace level VOCs <br /> that were detected include: <br /> • <br /> 1,1,2-trichloro-1,2,2-trifluoroethane <br /> • 1,1-DCA <br /> • <br /> 1,1-dichloroethene (1,1-DCE) <br /> • benzene <br /> • ethylbenzene <br /> 1 • chloromethane <br /> • cis-1,2-DCE <br /> • toluene <br /> • xylene <br /> • trichlorotrifluoromethane <br /> • trichlorofluoromethane <br /> 1 Detection of VOCs in samples from wells W-13 and MW-14 is not unusual. The <br /> following table summarizes the VOC detections (above and below PQLs) at these wells <br /> since 1990. <br /> VOC Detections <br /> Monitoring Wells -13 and MW-14 <br /> 1990 to 2000 Quarterly Monitoring Events <br /> Year No. Detections Range Detections (µg/1) No. Detections <br /> Above PQL Below PQL <br /> 1990 3 0.5 - 1.3 - <br /> 1991 11 0.55 -7.8 - <br /> 1992 39 0.51 - 11 - <br /> 1993 7 0.58 -0.75 - <br /> 1994 9 0.5 -0.6 - <br /> 1995 0 4 <br /> 1996 0 - 20 <br /> 1997 0 - 12 <br /> 1998 12 0.58 - 13 14 <br /> 1999 7 0.11 -2.8 13 <br /> 2000 6 0.081 -2.8 14 <br /> 2.2 VADOSE ZONE <br /> Four VOCs were detected above laboratory PQLs in lysimeter samples in 1999. <br /> However, 2 of these constituents (methylene chloride and acetone) are common <br /> laboratory contaminants and were not considered indicative of actual water quality <br /> conditions. No VOCs were detected above PQLs in lysimeter samples during 2000. <br /> 5 <br /> Geologic Associates <br />