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summarized on Table 2.2. The historical groundwater data for the detection monitoring wells are presented in Appendix D. The data are graphed on time series concentration plots, presented in Appendix E. For VOCs, only those compounds that exhibited detections for the first quarter 2009 monitoring event were plotted. The concentration limits presented on Table 2.2 were calculated by Herst & Associates, Inc. from data collected through the first quarter 2000 monitoring event. The statistical analysis calculations for detection monitoring wells are included in Appendix E. Information on the development of the concentration limits can be found in the Fourth Quarter/Annual 1999 Monitoring Report, Austin Road Landfill, prepared by CH2M Hill in January 2000. A copy of the statistical analysis methodology is presented in Appendix C. During the first quarter 2009 monitoring event,barium at AMW-13 and AMW-14 and hexavalent chromium at AMW-6 and AMW-7 exceeded their respective concentration limits. The first quarter 2009 barium concentration at AMW-13 (0.29 mg/L) is comparable to concentrations observed at that well consistently since May 1995, and is well below the National Primary Drinking Water Standard (2 mg/L). The first quarter 2009 barium concentration at AMW-14 (0.24 mg/L) is comparable to concentrations observed at that well consistently since March 1996, and is well below the National Primary Drinking Water Standard(2 mg/L). The first quarter 2009 hexavalent chromium concentration at AMW-6 (0.0057 mg/L) is comparable to concentrations observed at that well intermittently since February 1997, and is well below the National Primary Drinking Water Standard for chromium(0.1 mg/L). The first quarter 2009 hexavalent chromium concentration at AMW-7 (0.0062 mg/L) is comparable to concentrations observed at that well intermittently since July 1995, and is well below the National Primary Drinking Water Standard for chromium(0.1 mg/L). During the first quarter 2009 monitoring event,no VOCs were detected above the laboratory PQL in samples collected from detection monitoring wells -2, -6, -7, or -12. cis-1,2-Dichloroethene, dichlorodifluoromethane, tetrachloroethene, and trichloroethene were detected above the PQL at AMW-13. Dichlorodifluoromethane, tetrachloroethene and trichloroethene were detected above the PQL at AMW-14. The first quarter 2009 concentration of cis-l,2-dichloroethene at AMW-13 (0.64 ug/L) is comparable to concentrations observed at that well intermittently since March 2003, and is well below the National Primary Drinking Water Standard (70 ug/L). The first quarter 2009 concentration of dichlorodifluoromethane at AMW-13 (0.89 ug/L) is comparable to concentrations observed at that well intermittently since April 1995. The first quarter 2009 concentration of dichlorodifluoromethane at AMW-14 (0.83 ug/L) is comparable to concentrations observed at that well intermittently since May 1996. The first quarter 2009 concentration of tetrachloroethene at AMW-13 (13 ug/L) is comparable to concentrations observed at that well intermittently since March 1996. The first quarter 2009 concentration of tetrachloroethene at AMW-14 (12 ug/L) is comparable to concentrations observed at that well intermittently since March 1996. The first quarter 2009 concentration of trichloroethene at AMW-13 (3.9 ug/L) is comparable to concentrations observed at that well intermittently since November 2000, and is below the National Primary Drinking Water Standard(5 ug/L). The first quarter 2009 concentration of trichloroethene at AMW-14 (0.85 ug/L) is comparable to concentrations observed at that well intermittently since March 1996, and is below the National Primary Drinking Water Standard(5 ug/L). Historical data from the detection monitoring wells were analyzed for temporal trend using Sen's Slope trend analysis. Graphs of the Sen's Slope analyses for detection monitoring wells are included in Appendix E. The following inorganic constituents exhibited an increasing trend according to the Sen's Slope analysis: barium at AMW-6 and AMW-14,bicarbonate at AMW-6, 2