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Trend analysis of VOC concentrations indicate increasing trends for 1, 1 -Dichloroethane, <br />Dichlorodifluoromethane, PCE and Freon 11. Trend analysis also indicated a decreasing trend in <br />TCE is quarter. Trend analysis will continue to be used quarterly to evaluate concentrations of <br />VOCs in MW -8. <br />Two compounds previously repeatedly reported at this well are no longer detecdted. Cis-1,2- <br />Dichloroethene has not been detected in two two quarters. Methylene Chloride has not been <br />detected since May 2012. This indicates improving groundwater quality at this well. <br />MW -9A (Newly -installed): <br />This is the seventh quarter in which MW -9A and the other off-site wells were monitored. <br />Concentrations of all parameters were within established concentration limits where the limits <br />could be determined (Table 1). <br />No VOCs were reported in MW -9A this quarter (Table 1). <br />Data is not sufficient to establish a trend in this well. <br />MW -IDA (Newly -installed, Impacted): <br />Concentrations of all parameters were within established concentration limits where the limits <br />could be determined (Table 1). <br />Three VOCs were reported this quarter, one above PQL and two below the PQL at "trace" <br />concentration (Table 1). This is a slight improvement over previous quarters. <br />All VOCs detected in this well are among the VOCs found in MW -5 and MW -8, but at lower <br />concentrations. These data support the conclusion that MW -5 is closer to the source of the VOCs. <br />Data is not sufficient to establish a trend in this well. <br />1 MW -11A (Newly -installed, Impacted): <br />Concentrations of all parameters were within established concentration limits where the limits <br />could be determined (Table 1). <br />Three VOCs were reported above the PQL this quarter (Table 1). Two VOCs were reported in <br />this well during the 3`d Quarter and 5 VOCs were reported during the 2nd Quarter. Note that five <br />VOCs were detected at this well when it was first monitored in May 2012. <br />All VOCs detected in this well are among the VOCs found in MW -5 and MW -8, generally at <br />lower concentrations. These data support the conclusion that MW -5 is closer to the source of the <br />VOCs.Data is not sufficient to establish a trend in this well. <br />Corral Hollow Sanitary Landfill 14 Department of Public Works/Solid Waste <br />1 4l" Quarter and Annual 2013 Groundwater Monitoring County of San Joaquin — January 15, 2014 <br />