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MW-1 OA was performed (Herst, 2005) in response to CL exceedances of chloride and TDS. The NRD concluded that French Camp Landfill, located within the central Stockton area,has been impacted by saltwater intrusion and the elevated chloride and TDS concentrations measured in well MW-I OA are believed to be the result of this condition and not the result of landfill-related impacts. 4.5 LEACHATE MONITORING The laboratory results for leachate monitoring well MW-2 are summarized in Table 3 and time-series concentration plots are presented in Appendix D. As shown on Table 3, no VOCs were detected in leachate monitoring well MW-2 during the monitoring period. 4.6 SURFACE-WATER MONITORING Field and laboratory results for surface-water monitoring stations (SW-1, SW-2, and SW-3) for the current monitoring period are summarized in Table 4. Stations SW-1 and SW-2 are located upstream of the landfill within the Walker and French Camp Sloughs, respectively, and are used as background sampling points,while station SW-3 is located downstream of the landfill at the confluence of the two sloughs. Water quality data from surface-water sampling stations were graphed on time-series concentration plots and are presented in Appendix D. For the surface water monitoring stations at the French Camp Landfill, CLs are used for the WQPS. The CLs shown in Table 4 were calculated by Herst& Associates using Sanitas®, a state-approved statistical software program using historical data from background surface water stations SW-1 and SW-2, and are presented in Appendix D. As shown in Table 4, no CLs were exceeded and no VOCs were detected in the samples collected from the surface water stations during the monitoring period. A comparison of upgradient(SW-1 and SW-2)to downgradient(SW- 3) surface water samples indicates generally similar inorganic constituent concentrations in the upgradient and downgradient surface water stations, suggesting that the landfill is not impacting surface water quality. As has been the case historically, statistically significant increasing trends for turbidity were calculated at surface water stations SW-1, SW-2, and SW-3 (Appendix D). Since turbidity exhibits a statistically significant increasing trend at background surface water stations SW-1 and SW-2, the increasing trend in turbidity at SW-3 is unlikely to be indicative of an impact from the landfill. Stream gauging was performed on August 18, and December 29, 2009 at monitoring points SG-1 and SG-2 and the data are summarized in Table 5. As shown in Figure 1, monitoring point SG-1 is located upgradient in the Walker Slough and monitoring point SG-2 is located upgradient in the French Camp Slough. 4.7 CONSTITUENTS OF CONCERN In addition to the routine quarterly monitoring parameters, groundwater, leachate, and surface water samples were also analyzed for the full suite of COCs. Table 1 summarizes D:\2008-0012\FC_2SA09.doc 5 Geologic Associates