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Water Quality Monitoring Report French Camp Landfill two sloughs. A comparison of upgradient (SW-1 and SW-2) to downgradient (SW-3) surface water samples indicates generally similar inorganic constituent concentrations. No VOCs were detected in surface water samples during the monitoring period. Stream gauging was performed on August 3 and November 25, 2016, at monitoring points SG-1 and SG-2 and the data are summarized in Table 5. As shown in Figures 1 and 2, 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 In accordance with WDR Order No. R5-2007-0046; perimeter soil-pore gas probes are monitored using a field screening protocol, and soil-pore gas samples are only collected if field screening indicates methane concentrations greater than 2.5 percent. During the monitoring period, field screening of soil-pore gas probes was conducted on September 30 and December 28, 2016. As shown on Table 6, methane was only detected in two of the soil-pore gas probes (SGP-2A and SGP-7A) at concentrations of 0.1 percent by volume during the third quarter 2016. As a result, no samples were collected. 6.0 ANNUAL SUMMARY .1 General During the 2016 monitoring year, groundwater elevation measurements were performed quarterly and water quality sampling and soil-pore gas monitoring were performed semiannually in accordance with WDR Order No. 115-2007-0046. All of the monitoring points were sampled for the monitoring parameters summarized in Table 1. A tabular summary of the historical monitoring data is presented in Appendix C and time-series plots depicting groundwater and surface water constituent concentrations are presented in Appendix D. Stiff diagrams of the semiannual data obtained in 2016, hydrographs illustrating the historical groundwater elevations of the detection monitoring wells, and information relative to well screen elevations and pump intake elevations are also included in Appendix D. 6.2 Groundwater Over the 2016 monitoring year, groundwater elevations varied by about one to four feet with hydraulic gradients ranging between 0.001 ft/ft to 0.002 ft/ft to the east-southeast. Groundwater quality conditions beneath the French Camp Landfill during the 2016 monitoring year are generally similar to those observed in previous years. During one or both semiannual monitoring periods in 2016, inorganic CLs were exceeded for chloride in the samples from wells MW-913 and MW-10A. However, trend analyses for these chloride concentrations do not exhibited statistically significant increasing trends. 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 Project No.2016.0007 5