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New Historical Intrawell Maximum Values <br /> No new historical maximum values were measured in the Forward Unit groundwater <br /> monitoring wells during the second quarter 2011 monitoring event. <br /> Concentration Limit Thresholds <br /> Data obtained during the second quarter 2011 monitoring period were compared to <br /> concentration limits (CLs) as specified in the RPCMP for the Forward Landfill. CLs <br /> were calculated by Herst & Associates and are included in Appendix D. Table 2-4 <br /> summarizes CLs that were exceeded in samples collected from groundwater monitoring <br /> wells during the second quarter 2011. As summarized in this table, CLs were exceeded <br /> for chloride in well MW-21; DIPE in well MW-2A; nitrate as nitrogen in well W-19; <br /> and for sulfate in wells MW-15 and MW-22. In accordance with the RPCMP, only wells <br /> with CL exceedances of impact constituents (as defined in Table 5-3 of the RPCMP) <br /> need to be resampled, and therefore, retesting for sulfate and nitrate as nitrogen is not <br /> required. In addition, CL exceedances for low-level VOCs are not retested since similar <br /> low-level VOCs have been confirmed at the Forward Unit. Therefore, only the chloride <br /> CL exceedance measured in the sample from well MW-21 requires retesting. <br /> 2.1.5 Vadose Zone Monitoring <br /> The current vadose-zone monitoring network at the Forward Unit consists of 17 <br /> lysimeters. The lysimeter locations are shown on Figure 2-1. Each accessible lysimeter <br /> was inspected and vacuums were reset to approximately—25 inches of mercury on May <br /> 9, 2011. On May 30, 2011, the lysimeters were again checked and positive pressure was <br /> applied to evacuate the accumulated sample. As recorded in the field notes for lysimeters <br /> (Appendix Q and summarized on Table 2-5, all lysimeters were reported dry, and as a <br /> result, no soil-pore liquid samples were collected during the current monitoring period. <br /> 2.1.6 Leachate Monitoring <br /> Leachate sumps are inspected for the presence of leachate and observations are recorded <br /> at least weekly by Forward Landfill personnel. If leachate is detected in a sump, it is <br /> pumped into the surface impoundment(WMU F) for evaporation. During the second <br /> quarter 2011, leachate was observed at all of the holding areas except WMU D-87 and <br /> WMU D-88 A/B. Freeboard at WMU-F ranged from approximately 4.67 to 10.00 feet <br /> during the second quarter 2011 monitoring period. Appendix A presents copies of the <br /> leachate logs and the freeboard observation logs. <br /> Leachate samples were collected on a monthly basis and analyzed in the field for pH, <br /> specific conductance, and temperature. Results of monthly field monitoring <br /> measurements for the second quarter 2011 are presented in Table 2-6. <br /> D:\2011_0050\FA_2Q1 I.docx <br /> 6 GeoLogic Associates <br />