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® MW-4(Down gradient): Concentrations of all the parameters analyzed were within established concentration limits this quarter(Table 1). A"significantly decreasing"trend is reported by the Sanitas program for sulfate and TDS this quarter(Table 3). However,the variation in concentrations are slight, so the reports of "significant trend" appears to be an artifact of the Sanitas statistical calculations. This slight trend seems to be the result of improving the drainage ditch in 2003. This indicates the continuation of a relatively long trend of improving general water quality conditions at this well. It is likely that the improvements to the drainage ditch in 2003 resulted in these improvements in general water quality at MW-4. No VOCs were reported at this well this quarter. Other than compounds also reported in quality control blanks, VOCs have not been reported in this well since third quarter 2001. MW-5(Impacted): Concentrations of all the parameters analyzed were within established concentration limits this quarter(Table 1). Based on output from the Sanitas statistical software, an increasing trend is reported in TDS, whereas a decreasing trend is reported in and Sulfate (Table 3). Four VOCs were reported above the PQL this quarter, five at"trace" (Table 1). These data are consistent with previous monitoring results. Trend analysis of VOC concentrations indicates increasing trends for 1,1-Dichloroethane, Cis- 1,2-Dichloroethene, and PCE, and a decreasing trend for Dichlorodifluoromethane (Freon 12), 1,2-Dichloropropane, Trichloroethene (TCE), and Vinyl Chloride. Trend analysis will continue quarterly to evaluate concentrations of VOCs in MW-5. MW-8(Impacted): Concentrations of all parameters were within established concentration limits where the limits could be determined(Table 1). Based on output from the Sanitas statistical software, a decreasing trend is reported in the concentration of Chloride,Nitrate as Nitrogen, and Sulfate (Table 3). These data are consistent with previous monitoring results. Four VOCs were reported above the PQL this quarter,two at"trace" concentrations (Table 1). All VOCs detected in this well are among the VOCs found in MW-5, generally at lower concentrations. It is our opinion that MW-5 is closer to the source of the VOCs and thus has more VOCs. Trend analysis of VOC concentrations indicates increasing trends for 1,1-Dichloroethane, Dichlorodifluoromethane, PCE and Freon 11. Trend analysis also indicated a decreasing trend in Corral Hollow Sanitary Landfill Department of Public Works/Solid Waste 4" Quarter and Annual 2012 Groundwater Monitoring County of San Joaquin—January 15,2013