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0 NRD concluded that French Camp Landfill, located within the central Stockton area,has <br /> been impacted by saltwater intrusion and the elevated chloride and TDS concentrations <br /> measured in well MW-l0A are believed to be the result of this condition and not the <br /> result of landfill-related impacts. <br /> .5 LEACHATE MONITORING <br /> The laboratory results for leachate monitoring well MW-2 are summarized in Table 3 and <br /> time-series concentration plots are presented in Appendix D. As shown on Table 3, one <br /> VOCs (dibromochloromethane) was measured at a trace concentration in leachate <br /> monitoring well MW-2 during the monitoring period. <br /> .6 SURFACE-WATER MONITORING <br /> Field and laboratory results for surface-water monitoring stations (SW-1, SW-2, and <br /> SW-3) for the current monitoring period are summarized in Table 4. Locations SW-1 <br /> and SW-2 are located upstream of the landfill within the Walker and French Camp <br /> Sloughs, respectively, and are used as background sampling points, while SW-3 is <br /> located downstream of the landfill at the confluence of the two sloughs. Water quality <br /> data from surface-water sampling stations were graphed on time-series concentration <br /> plots and are presented in Appendix D. For the surface water monitoring stations at the <br /> French Camp Landfill, CLs are used for the WQPS. The CLs shown in Table 4 were <br /> calculated by Herst&Associates using Sanitas®, a state-approved statistical software <br /> program using historical data from background surface water stations SW-1 and SW-2, <br /> and are presented in Appendix D. As shown in Table 4,no CLs were exceeded during <br /> the monitoring period. <br /> As has been the case historically, statistically significant increasing trends for turbidity <br /> were calculated at surface water stations SW-1, SW-2, and SW-3 (Appendix D). Since <br /> turbidity exhibits a statistically significant increasing trend at background surface water <br /> stations SW-1 and SW-2,the increasing trend in turbidity at SW-3 is unlikely to be <br /> indicative of an impact from the landfill. <br /> Stream gauging was performed on August 18 and December 5, 2008 at monitoring points <br /> SG-1 and SG-2 and the data are summarized in Table 5. As shown in Figure 1, <br /> monitoring point SG-1 is located upgradient in the Walker Slough and monitoring point <br /> SG-2 is located upgradient in the French Camp Slough. <br /> .7 CONSTITUENTS OF CONCERN <br /> In addition to the routine quarterly monitoring parameters, groundwater,leachate, and <br /> surface water samples were also analyzed for the full suite of COCs stipulated in <br /> RWQCB Order No. R5-2007-0046 and performed every five years. Table 1 summarizes <br /> the CDCs included for the French Camp Landfill and Tables 2 through 4 summarize the <br /> results. Excluding the metals which may be naturally occurring,the only COC detected <br /> in samples collected from the French Camp Landfill was trace level concentrations of <br /> D:\2008-0012\FC_2SA08.doc 5 GeoLoglc Associates <br /> L <br />