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1.0 Surface Water Monitoring Surface water samples were collected by Bryan A. Stirrat and Associates during the second quarter 2006 monitoring event from surface water monitoring points SW-1, 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 quarterly analysis for field parameters(pH, specific conductance, temperature, and turbidity) and monitoring parameters (barium, bicarbonate, calcium, carbonate, chloride, magnesium, nitrate, potassium, sodium, sulfate, and total dissolved solids [TDS]). Second quarter 2006 field and laboratory sampling results from surface water monitoring points are summarized on Table 2.1,along with the concentration limits determined from upstream data. The historical surface water data are presented in Appendix A. The data are graphed on time series concentration plots in Appendix B. The concentration limits were calculated from data collected through the second quarter 2006. Information on the development of the concentration limits can be found in the Fourth Quarter/Annual 1999 Monitoring Report, French Camp Landfall prepared by CH2M HILL in January 2000. The statistical analysis calculations are presented in Appendix B. A copy of the statistical analysis methodology is presented in Appendix C. During the second quarter 2006 monitoring event, no constituents exceeded their concentration limits at SW-3. Historical data from the surface water sampling points were evaluated for temporal trend using Sen's Slope trend analysis. Graphs of the Sen's Slope analyses are included in Appendix B. Only turbidity at SW-1, SW-2, and SW-3 exhibited an increasing trend according to the Sen's Slope analysis. As noted above, SW-1 and SW-2 are background surface water monitoring points, and trends in the surface water quality at these point are not indicative of an impact from ' the facility. Given that turbidity exhibits a statistically significant increasing trend at background surface water monitoring points SW-1 and SW-2,the increasing trend in turbidity at SW-3 should be considered reflective of regional impacts and/or non-facility impacts. ' Table 2.1 presents the VOC detections at surface water monitoring points during the second quarter 2006 monitoring event. Toluene was detected at surface water monitoring point SW-2 at a concentration(0.19 ug/L)below the laboratory practical quantitation limit(PQL). Toluene does ' not exhibit an increasing trend according to Sen's Slope analysis. Soil cover has been placed over the waste material to prevent ponding of stormwater and to protect surface water. In addition, a perimeter ditch directs stormwater to a basin in the southeast corner of the site. A smaller ditch collects stormwater from the grinding area in the northeast corner of the site. Inspection and maintenance procedures for these stormwater control structures are provided in the site's Stormwater Pollution Prevention Plan. These control structures effectively directed stormwater from the waste material during the second quarter 2006. 2.0 Groundwater Monitoring Program Groundwater samples were collected b Bryan A. Stirrat and Associates from two background P Y rY gr' monitoring wells (MW-6A and MW-7A), four detection monitoring wells (MW-8A, MW-9A, ' MW-9B, and MW-10A), and two evaluation monitoring wells (MW-IA and MW-2) during the 1