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during the fourth quarter 2009 monitoring event. However, the new values slightly exceed the previous maximum values. New Historical Intrawell Maximum Values Well Analyte New Value Previous Value MW-10 Dichlorodifluoromethane 0.83 jig/L 0.55 pg/L MW-24 Barium 0.15 m 0.14 m Concentration Limit Thresholds Data obtained during the fourth quarter 2009 monitoring period were compared to concentration limits (CLs) as specified in the RPCMP for the Forward Landfill. CLs were calculated by Herst &Associates using upper tolerance limits and are included in Appendix D. Excluding suspected field/laboratory contaminants, only one CL was exceeded for trichlorofluoromethane(TCF )in the sample collected from well MW-10 during the current monitoring period. However, the measured value does not represent a new intrawell maximum value. As discussed previously, the sporadic detection of low- level VOCs in groundwater(and lysimeter samples) at the Forward Unit are most likely due to landfill gas from unlined unit WMU-B and have been previously documented in a letter report dated February 14, 2001 (RCB Case No. 2209). 2.1.5 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 was inspected and vacuums were reset to approximately—10 to—25 inches of mercury on November 19, 2009. On January 8, 2010, 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 2-4, only lysimeter LY-BGI had a sufficient volume of soil-pore liquid for sample collection. However, due to the limited sample volumes (200 mL), the lysimeter sample was only analyzed for VOCs. As summarized in Table 2-4, no VOCs were detected in the lysimeter sample collected from lysimeter LY-BG I during the fourth quarter 2009 monitoring period. 2.1.6 Surface Water Monitoring Site run-on and run-off control facilities are designed to effectively channel surface water to site stormwater/sedimentation ponds. According to the Operations Manager,no surface water was discharged from the facility during the reporting period. On November 17, 2009, surface-water monitoring stations FSW-I and FSW-2 were reported dry, and as a result, no samples were collected for the fourth quarter 2009 monitoring period. 2.1.7 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 D:U009_0017\FA_4Q09.doc 6 GeoLogic Associates