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1.0 Surface Water Monitoring During the first quarter 2011 monitoring event, surface water sampling was performed at the French Camp Landfill by Del-Tech Geotechnical Support Services, Inc. (Del-Tech). Surface water samples were collected from monitoring points SW-I, SW-2, and SW-3. Upstream surface water monitoring points SW-1 in Walker Slough and SW-2 in French Camp Slough are sampled to provide background monitoring data. Surface water monitoring point SW-3 is downstream at the confluence of the sloughs. The Waste Discharge Requirements(WDRs) stipulate semi-annual sampling of the surface water monitoring points for field parameters (pH, specific conductance, temperature, and turbidity) and monitoring parameters (bicarbonate alkalinity, calcium, carbonate alkalinity, chloride, magnesium,nitrate, potassium, sodium, sulfate,total dissolved solids [TDS], and volatile organic compounds [VOCs]). The field results provided by Del-Tech and the laboratory results provided by TestAmerica Laboratories, Inc. (TestAmerica) for the first quarter 2011 surface water monitoring event are summarized on Table 2.1. The historical surface water data are presented in Appendix A. Time series concentration plots of historical surface water data are presented in Appendix B. The concentration limits presented on Table 2.1 were calculated from upstream data collected through the third quarter 2010 monitoring event. The statistical analysis calculations for surface water monitoring points are presented in Appendix B. Information on the development of the concentration limits can be found in the Fourth Quarter/Annual 1999 Monitoring Report, French Camp Landfill prepared by CH2M HILL in January 2000. A copy of the statistical analysis methodology is presented in Appendix C. Potassium was the only constituent that exceeded its concentration limit at SW-3 during the first quarter 2011 monitoring event. There were no VOCs detected at surface water monitoring points during the first quarter 2011 monitoring event. Historical data from the surface water monitoring points were evaluated for temporal trend using Mann-Kendall / Sen's Slope trend analysis. Graphs and summary tables of the Mann-Kendall / Sen's Slope analyses are presented in Appendix B. Only carbonate alkalinity at SW-1 and SW-3 and field turbidity at SW-1, SW-2, and SW-3 exhibited significant increasing statistical trends according to the Mann-Kendall/ Sen's Slope evaluation. Given that carbonate alkalinity exhibits a significant increasing statistical trend at upstream monitoring point SW-1 and turbidity at upstream points SW-1 and SW-2, the increasing trends for carbonate alkalinity and turbidity at downstream point SW-3 are likely due to ongoing changes in the natural surface water geochemistry at the site. Bicarbonate alkalinity at SW-I, nitrate at SW-I, sulfate at SW-I, and TDS at SW-1 exhibited significant decreasing statistical trends according to the Mann-Kendall Sen's Slope evaluation. The first quarter 2011 concentration of potassium at SW-3 (6.4 mg/L) is consistent with the concentrations observed at upstream monitoring points SW-1 (6.1 mg/L) and SW-2 (6.3 mg/L). The first quarter 2011 monitoring event represents the highest potassium concentration observed at both upstream (SW-1 and SW-2) and downstream (SW-3) monitoring points since the beginning of backgound in May 2005. Prior to the first quarter 2011, upstream potassium concentrations ranged from 1.3 mg/L to 4.8 mg/L and downstream concentrations ranged from 1.9 mg/L to 4.9 mg/L. As discussed above, potassium does not exhibit a significant upward statistical trend at SW-I, SW-2, or SW-3. The presence of elevated potassium concentrations during the first quarter 2011 monitoring event at both upstream and downstream monitoring locations indicates that the concentration limit exceedance for potassium at SW-3 may be due to a recent change in the natural surface water geochemistry at the site. It is recommended that the