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with historical concentrations. During the monitoring period, chloroform was measured <br /> above the PQL in the sample collected from background well MW-6A. Retest sample <br /> collected on June 30, 2009 confirm the presence of chloroform in well MW-6A. <br /> However, the presence of chloroform in well MW-6A is not believed to the result of a <br /> release from the landfill since chloroform has been rarely detected in on-site wells and <br /> background well MW-6A is located approximately 1200 feet cross-gradient from the <br /> landfill. <br /> Concentration Limits <br /> For DMP monitoring wells at the French Camp Landfill, concentration limits (CLs) are <br /> used for the water quality protection standards (WQPS). Based on a comparison of the <br /> data obtained during the current monitoring period, the following analytes were found to <br /> exceed a CL: <br /> CONSTITUENT Concentration DMP Monitoring Wells <br /> I Limit MW-6A- MW-7A- MW-8A MW-9A MW-9B MW-10A <br /> GENERAL CHEMISTRY(mg/1) <br /> Chloride 249 480 600 <br /> Nitrate as N 19.3 20 <br /> pH 6.9-10.21 6.65 6.72 6.31 6.77 6.22 <br /> Total Dissolved Solids(TDS) 1600 2000 <br /> Volatile Organic Compounds(pg/1) <br /> Chlorofonn 0.5 1.5 <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 significant increasing or decreasing trends were evident. Trend analyses, performed by <br /> Herst& Associates, are presented in Appendix D and summarized below. <br /> Well Number Increasing Trends Decreasing Trends <br /> MW-6A None Apparent Calcium,pH <br /> MW-7A Bicarbonate,Potassium Chloride,Specific Conductance,Sulfate,TDS <br /> MW-8A None Apparent Calcium,Magnesium,Nitrate-N,pH, Sodium <br /> MW-9A None Apparent None Apparent <br /> MW-9B Potassium, Sulfate pH <br /> MW-10A Chloride,Specific Conductance Nitrate-N,pH <br /> As shown above, CLs were exceeded for one or more constituents in the samples <br /> collected from wells MW-6A, MW-8A, MW-9A, MW-9B, and MW-10A. Ofnote, with <br /> the exception of the chloride concentration measured in the sample collected from well <br /> MW-1 OA, none of the constituents that exceeded a CL exhibited a statistically significant <br /> increasing trend during the monitoring period. As shown in the time-series plots <br /> (Appendix D), concentrations of chloride measured in well MW-I OA(600 mg/L) are <br /> generally similar to concentrations observed in this well intermittently since April 2002. <br /> In January 2005 a No Release Demonstration(NRD) for groundwater monitoring well <br /> D:0008-0012\FC2sA09.doc <br /> — <br /> 4 Geologic Associates <br />