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P Ll 11, C I variation in concentrations are slight, so the reports of "significant trend" appears to be an artifact of the Sanitas statistical calculations. No VOCs were reported at SB -1 this quarter. A trace concentration of one VOC was reported in this well in the 4th Quarter 2011 which can be attributed to laboratory contamination. Preventing such contamination becomes increasingly difficult as the detection limits for VOCs continue to decrease. With this one exception, VOCs have not been reported in this well since second quarter 2004 when trace concentrations of one VOC was reported. 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 chloride, sulfate and TDS this quarter (Table 3). A significant reduction in these parameters were observed after fourth quarter 2004. 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 within the shallow aquifer 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. -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 Turbidity and Sulfate (Table 3). Seven VOCs were reported this quarter, four above the laboratory's practical quantification limit (PQL) and three below the PQL at "trace" concentrations (Table 1). These data are consistent with previous monitoring results. Trend analysis of VOC concentrations indicate increasing trends for 1,1-Dichloroethane, Cis-1,2- Dichloroethene, and PCE, and decreasing trends for Dichlorodifluoromethane (Freon 12), Trichloroethene (TCE), and Vinyl Chloride. Trend analysis will continue quarterly to evaluate concentrations of VOCs in MW -5. 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. Five VOCs were reported above the PQL this quarter (Table 1). All VOCs detected in this well are among the VOCs found in MW -5. Corral Hollow Sanitary Landfill 13 Department of Public Works/Solid Waste 3'" Quarter 2013 Groundwater Monitoring County of San Joaquin — October 15, 2013