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Concentration Limit Thresholds As specified in the RPCMP and RWQCB Order No. R5-2003-0049 for the Forward Landfill, the routine inorganic monitoring data obtained during the second quarter 2013 monitoring period were compared to established intrawell concentration limits (CLs) calculated for the Forward Unit. The CLs are summarized in Table 2-4 and compared to the analytical results collected during the second quarter 2013. As summarized in this table, CLs were exceeded for chloride at wells MW-2A and MW-13; nitrate as nitrogen (nitrate) at well MW-14; for sulfate at wells MW-14 and MW-15; and for sodium at background well MW-24. Trend analyses were performed for wells and constituents that exceeded respective CLs. Statistically significant increasing temporal trends were identified for nitrate-N concentrations in well MW-14, sulfate concentrations in well MW-15, and sodium concentrations in background wells MW-24. Trend analyses are included in Appendix D. Previously submitted No Release Demonstrations (NRDs) for these common inorganic constituents at the Forward Unit have concluded that the CL exceedances are not the result of a release from the Forward Unit, and as a result, retesting is not performed for these common inorganic constituents. The increasing trend for sodium at background well MW-24 suggests increases in sodium concentrations upgradient of the landfill. Vadose Zone Monitoring The current vadose-zone monitoring network at the Forward Unit consists of 17 lysimeters. The lysimeter locations are shown on Figure 2-1. Each accessible lysimeter 0 was inspected and vacuums were reset to approximately—25 inches of mercury on May 21, 2013 at each suction lysimeter. On May 28, 2013, the lysimeters were again checked and positive pressure was applied to evacuate the accumulated sample. As recorded in the field notes for lysimeters (Appendix C) and summarized on Table 2-5, lysimeters were reported dry, and as a result,no soil-pore liquid samples were collected during the current monitoring period. Of note, there was no access port to inspect pan lysimeters WMW-DO1N, WMW-DO1S, and WMW-D02. GLA and Del-Tech will be working with Forward to access these pan lysimeters for future monitoring. Leachate Monitoring Leachate sumps are inspected for the presence of leachate and observations are recorded at least weekly by Forward Landfill personnel. If leachate is detected in a sump, it is pumped into the surface impoundment (WMU F) for evaporation. During the second quarter 2013, leachate was observed at all of the holding areas except WMU D-87 and WMU D-88 A/B. Freeboard at WMU-F ranged from approximately 3.58 to 7.25 feet during the second quarter 2013 monitoring period. Appendix A presents copies of the leachate logs and the freeboard observation logs. Leachate samples were collected on a monthly basis and analyzed in the field for pH, specific conductance, temperature, and turbidity. Results of monthly field monitoring measurements for the second quarter 2013 are presented in Table 2-6. C:\2013-0021\FA_2Q13.doc 6 Geo-Logic Associates