ARCHIVED REPORTS_2006 - Laserfiche WebLink

Home Browse Search

Well Number Increa!!M&Trends Decreasing Trends MW-6A None Aaarent pH MW-7A None Apparent Specific Conductance,Sulfate MW-8A None arent Nitrate-N MW-9A Barium None AWarent MW-9B Sulfate Barium MW-10A Chloride Nitrate-N As shown above, CLs were exceeded for inorganic constituents in the samples collected from wells MW-6A, MW-9A, MW-9B and -10A. However,none of the constituents that exceeded a CL exhibited a significant increasing trend during the fourth quarter 2006 monitoring period. 5.5 LEACHATE MONITORING The laboratory results for leachate monitoring well MW-2, are summarized in Table 3 and time-series concentration plots are presented in Appendix D. As shown on Table 3, no VOCs were measured in leachate monitoring well MW-2 during the fourth quarter 2006 monitoring period. 5.6 SURFACE-WATER MONITORING Fourth quarter 2006 field and laboratory results for surface-water monitoring stations ® (SW-1, SW-2, and SW-3) are summarized in Table 4. Locations SW-1 and SW-2 are located upstream of the landfill within the Walker and French Camp Sloughs, respectively, and are used as background sampling points,while SW-3 is located downstream of the landfill at the confluence of the two sloughs. Water quality data from surface-water sampling stations were graphed on time-series concentration plots and are presented in Appendix D. For the surface water monitoring stations at the French Camp Landfill, CLs are used for the WQPS. The CLs shown in Table 4 were calculated by Herst&Associates using Sanitas , a state-approved statistical software program using historical data from background surface water stations SW-1 and SW-2, and are presented in Appendix D. As shown in Table 4, CL exceedances were noted for the nitrate as nitrogen concentration in samples from background stations SW-1 and SW-2, and for magnesium concentrations in the sample from station SW-3. Trend analyses indicate that turbidity at surface water stations -1, SW-2, and SW-3 depict statistically significant increasing trends. Given that turbidity exhibits a statistically significant increasing trend at background surface water stations SW-1 and SW-2, the increasing trend in turbidity at SW-3 is unlikely to be indicative of an impact from the facility. 6.0 ANNUAL SUMMARY 6.1 GENERAL During the 2006 monitoring year, groundwater elevation measurements and sampling of each of the monitoring points were performed at the French Camp Landfill on a quarterly ® basis in accordance with WDR Order No. 5-2004-0159. All of the monitoring points DA2003_021TC_W6.doc 5 Geologic Associates