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Water Quality Monitoring Report French Camp Landfill generally similar to those observed in previous years. During one or both semiannual monitoring periods in 2015, inorganic CLs were exceeded for chloride in the samples from wells MW-913 and MW-10A; for pH value in wells MW-9A and MW-10A; and for specific conductance and TDS in samples 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. With the exception of TCFM at well WM-9A and chloroform at well MW-6A, no VOCs were measured at quantifiable concentrations in groundwater samples during the 2015 monitoring year. Both TCFM and chloroform have been previously confirmed in retest samples, however, neither of these VOCs exhibit an increasing trend. Given the distance of well MW-6A from the landfill, the chloroform concentrations 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. 6.3 Surface Water Surface water elevations at stream gauging locations varied by about one to two feet during the 2015 monitoring year. These changes reflect tidal and seasonal precipitation patterns. Surface water generally flows west toward the San Francisco Bay. The results of water quality analyses completed during the 2015 monitoring year from the surface water monitoring stations are generally consistent with previous results. During the first semiannual 2015 monitoring period, dibromochloromethane and bromodichloromethane were measured at quantifiable concentrations, and chloroform was measured at a trace concentration in the sample from SW-3. Additionally, all three VOCs were measured at trace concentrations in the sample from 5W-2. However, no VOCs were detected in retest samples collected at surface water stations SW-2 and SW-3. Additionally, no VOCs were detected during the second semiannual 2015 monitoring period. A comparison of upstream (SW-1 and SW-2)to downstream (SW-3) surface water samples during the 2015 monitoring year indicates generally similar inorganic constituent concentrations. 6.4 Soil-Pore Gas Field screening results from soil-pore gas monitoring probes indicate that methane was not measured at concentrations exceeded 0.1 percent by volume in soil-pore gas monitoring probes during the 2015 monitoring year. Project No.2015.0014 6