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Water Quality Monitoring Report French Camp Landfill May 9, 2013. As shown on Table 6, methane was not detected in any of the soil-pore gas probes,and as a result, no samples were collected. 6.0 SUMMARY During the monitoring period,groundwater quality conditions beneath the French Camp Landfill are generally similar to those observed in previous monitoring periods. Inorganic CLs were exceeded for chloride in the samples from wells MW-9B and MW- 10A; and for pH value, specific conductance, and TDS in the sample from well MW-10A. However, none of the constituents that exceeded a CL exhibited a statistically significant increasing trend. In January 2005 a No Release Demonstration (NRD) for groundwater monitoring well MW-10A 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-10A are believed to be the result of this condition and not the result of landfill-related impacts. During the monitoring period, chloroform and TCFM were measured above the PQL in the samples collected from background well MW-6A and compliance well MW-9A, respectively. Confirmation sampling was not performed since chloroform and TCFM have already been confirmed in these wells. However, given the distance of well MW- 6A from the landfill, the chloroform concentrations recently measured in well MW-6A are not believed to be the result of a release from the landfill. The TCFM concentrations measured in well MW-9A are well below risk-based concentrations and have been attributed to LFG. Results of trend analysis performed on these constituents indicate no statistically significant increasing trends. In addition, trace-level concentrations of 1,2- .dichloroethane and toluene were measured in the sample from well MW-913. In response, the RWQCB was notified of the non-statistical exceedance in well MW-913 in a letter dated June 23, 2014 and confirmation samples were collected in June 2014. The results of water quality analyses completed from the surface water monitoring stations are generally consistent with previous results. With the exception of VOCs related to drinking water disinfection (trihalomethanes) measured at both upgradient and downgradient surface water monitoring stations, no VOCs were detected during the monitoring period. However, since VOCs were measured at quantifiable concentrations in the sample from SW-3, the RWQCB was notified of the non-statistical exceedance at SW-3 and conformation samples were collected in June 2014. A comparison of upstream (SW-1 and SW-2) to downstream (SW-3) surface water samples indicates generally similar inorganic constituent concentrations between upstream and downstream surface water monitoring locations, suggesting that the landfill is not impacting surface water quality. Field screening results from soil-pore gas monitoring probes indicate that no methane was measured in soil-pore gas monitoring probes during the monitoring period. M:\2014.0012\FC 1SA14.doc 6 7/10/2014,Rev.0