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Water Quality Monitoring Report French Camp Landfill 4.4 Detection Monitoring Program Field and laboratory results from the current monitoring period for DMP monitoring wells (MW-6A, MW-7A, MW-8A, MW-9A, MW-913, and MW-10A) are summarized in Table 2 and time-series concentration plots are presented in Appendix D. 4.4.1 Non-Statistical Data Analysis The non-statistical VOC mater analyses were performed on the DMP well data collected during the monitoring period. Non-statistical exceedances were identified at wells MW- 6A, MW-9A, and MW-913. These exceedances are the result of quantifiable concentrations of chloroform measured in well MW-6A,trichlorofluoromethane (TCFM) measured in well MW-9A, and trace-level concentrations of 1,2-dichloroethane and toluene in well MW-96. For well MW-6A and MW-9A, confirmation sampling was not performed since these compounds have already been confirmed in each respective well. However, trend analyses were performed which indicate no statistically significant increasing trends were calculated. Trend analyses are included in Appendix D. The TCFM concentration measured in well MW-9A is well below risk-based concentrations and has been attributed to landfill gas(LFG). Given the distance well MW-6A is from the landfill (approximately 0.25 miles), the chloroform concentrations recently measured in well MW-6A are not believed to be the result of a release from the landfill. In a letter dated June 23, 2014, the RWQCB was notified of the non-statistical exceedance in well MW-913 and confirmation samples were collected in June 2014. The results of the confirmation sampling for well MW-9B will be reported under separate cover. 4.4.2 Concentration Limits For DMP monitoring wells at the French Camp Landfill, concentration limits (CLs) provided in WDR RS-2007-0046 are used for the water quality protection standards (WQPS). All CLs are provided in Table 2 for comparison with current monitoring data. The following table presents constituents that were found to exceed a CL: CONSTITUENT ICONCENTRATIONI DMP MONITORING WELLS LIMIT MW-6A* MW-7A* I MW-8A I MW-9A I MW-9B MW-10A GENERAL CHEMISTRY(mg/L) pH(Units) 6.9-10.21 6.75 Chloride 249 530 750 Specific Conductance 2500 3657 (µmhos/cm) Total Dissolved Solids 1600 2200 (TDS) NOTES: (*)—Background Well. A shaded cell indicates that the current value was measured below the CL. Only constituents that exceeded a CL are provided in the table above. All CLs are provided in Table 2. M:\2014.0012\FC 1SA14.doc 4 7/10/2014,Rev.0