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Concentration Limits <br /> For DMP monitoring wells at the French Camp Landfill, concentration limits (CLs) <br /> provided in the WDRs are used for the water quality protection standards (WQPS). <br /> Based on a comparison of the data obtained during the current monitoring period,the <br /> following analytes were found to exceed a CL: <br /> CONSTITUENT Concentration I DMP Monitoring Wells <br /> Limit MW-6A* MW-7A* MW-8A I MW-9A I MW-913 MW-l0A <br /> GENERAL CHEMISTRY(mg/1) <br /> Temperature °C) 21.69 23.4 23.0 23.2 23.1 <br /> Chloride 249 360 620 <br /> Specific Conductance(µmhos/cm) 2500 3275 <br /> Total Dissolved Solids(TDS) 1600 2000 <br /> Trichlorofluoromethane 0.5 2.0 <br /> NOTES: (*)—Background Well, <br /> Trend Analysis <br /> In order to evaluate changes in water quality in DMP wells at the French Camp Landfill, <br /> historical groundwater data were evaluated using Sen's Slope trend analyses to determine <br /> if statistically significant increasing or decreasing trends were evident. Trend analyses, <br /> performed by Herst& Associates, are presented in Appendix D and summarized below. <br /> Well Number Increasing Trends Decreasing Trends <br /> MW-6A Not Sampled/Dry Sampled/DryNot Sampled/Dry <br /> MW-7A - Chloride,Specific Conductance,TDS <br /> MW-8A - Bicarbonate,Chloride,Nitrate,TDS <br /> MW-9A - Chloride,Nitrate,Sodium,TCFM <br /> MW-9B Potassium, Sulfate - <br /> MW-10A Chloride Nitrate <br /> During the monitoring period, statistically significant increasing trends were calculated <br /> for potassium and sulfate in well MW-913, and for chloride in well MW-10A. However, <br /> with the exception of chloride in well MW-10A, none of the constituents that exceeded a <br /> WDR established CL exhibited a statistically significant increasing trend. In January <br /> 2005,a No Release Demonstration(NRD) was performed by Herst&Associates(2005) <br /> as a result of CL exceedances for chloride and TDS at groundwater monitoring well <br /> MW-10A. The NRD concluded that French Camp Landfill, located within the central <br /> Stockton area,has been impacted by saltwater intrusion and the elevated chloride and <br /> TDS concentrations measured in well MW-l0A are believed to be the result of this <br /> condition and not the result of landfill-related impacts. With the exception of well <br /> MW-9B, one or more statistically significant decreasing trends were calculated for <br /> inorganic constituent concentrations in all of the groundwater monitoring wells sampled <br /> during the third quarter 2012 at the French Camp Landfill. In addition,a decreasing <br /> trend was also calculated for TCFM in well MW-9A. <br /> CA2012-002"C2sAl2.doe 4 Geo-Logic Associates <br />