ARCHIVED REPORTS_2009_12 - Laserfiche WebLink

Home Browse Search

separate cover. On behalf of Forward, GLA has submitted a request to the DISC to update the CLs for the Forward Unit. 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 February 11, 2009. On March 11, 2009, 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 E-2, W-2, LY-A, and LY-BG1 had a sufficient volume of soil-pore liquid for sample collection. However, due to the limited sample volumes, lysimeter samples were only analyzed for select inorganic constituents and/or VOCs. As shown in Table 2-6, diisopropyl ether was measured above the PQL in the sample collected from lysimeter LY-A and t-butyl alcohol was measured above the PQL in the sample collected from lysimeter E-2. 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 quarter. During the first quarter 2009 monitoring period, no surface-water was observed at monitoring stations FSW-1 and FSW-2, and as a result, surface water samples were not collected. 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 pumped into the surface impoundment (WMU F) for evaporation. During the first quarter 2009, leachate was observed at holding areas WMU D-89, WMU D-93/94, WMU D-01, WMU D-02, WMU FU-03, WMU FU-04,WMW FU-05, WMU FU-06, and WMU FU-08. The other holding areas were reported to be dry by Forward Landfill personnel. Freeboard at WMU-F ranged from approximately 8.67 feet to 12.08 feet during the first quarter 2009 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 and specific conductance. Results of monthly field monitoring measurements for the first quarter 2009 are presented in Table 2-7. 2.2 SUMMARY Groundwater quality conditions beneath the Forward Unit during the first quarter 2009 monitoring period are generally similar to those observed in previous monitoring periods. During the first quarter 2009 monitoring period, four new historical intrawell maximum D:\2009_0017\FA_1Q09.doc 7 Geologic Associates