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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 measured in leachate monitoring well MW-2 during the third quarter 2007 monitoring period. 4.6 SURFACE-WATER MONITORING Thirduarter 2007 field ld and laboratory results for surface-water monitoring stations (SW-1, SW-2, and SW-3) are summarized in Table 4. Locations 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 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 foz the WQPS. The CLs shown in Table 4 were calculated by Herst &Associates using Sanitase, 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, toluene was detected at a trace concentration in the sample collected from background station SW-1. Trend analyses indicate that turbidity at surface water stations SW-1, SW-2, and SW-3 depict statistically significant increasing trends. 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 facility. Stream gauging was performed on August 20,2007 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. 5.0 SOIL-PORE GAS MONITORING During the current monitoring period, soil-pore gas samples were collected from probes SGP-IA, SGP-2A, SGP-3, SGP-4A, SGP-5A, SGP-6A, SGP-7A, and SGP-8A on August 20, 2007. Table 6 summarizes the results for the soil-pore gas samples collected during current event at the French Camp Landfill. Methane was not detected in any of soil-pore gas probes. However, 17 VOCs were detected in the samples from soil-pore gas monitoring probes during the current monitoring period, with the sample from probe SGP-2A containing the highest total concentration of VOCs. W2007-00"TC mm07.doc 5 Geologic Associates