Area 6 Decontamination Pond Corrective Action Unit 92 Post-Closure Inspection Annual Report for the Period January 2000-December 2000

The Area 6 Decontamination Pond, Corrective Action Unit 92, was closed in accordance with the Resource Conservation and Recovery Act (RCRA) Part B Operational Permit (Nevada Division of Environmental Protection [NDEP, 1995]) and the Federal Facility Agreement and Consent Order (NDEP, 1996) on May 11, 1999. Historically the Decontamination Pond was used for the disposal of partially treated liquid effluent discharged from the Decontamination Facility (Building 6-05) and the Industrial Laundry (Building 6-07) (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1996). The Decontamination Pond was constructed and became operational in 1979. Releases of RCRA-regulated hazardous waste or hazardous waste constituents have not been discharged to the Decontamination Pond since 1988 (DOE/NV, 1996). The pipe connecting the Decontamination Pond and Decontamination Facility and Industrial Laundry were cut and sealed at the Decontamination Pad Oil/Water Separator in 1992. The Decontamination Pond was closed in place by installing a RCRA cover. Fencing was installed around the periphery to prevent accidental damage to the cover. Post-closure monitoring at the site consists of quarterly inspections of the RCRA cover and fencing, and a subsidence survey. Additional inspections are conducted if: Precipitation occurs in excess of 1.28 centimeters (cm) (0.50 inches [in]) in a 24-hour period, or An earthquake occurs with a magnitude exceeding 4.5 on the Richter scale within 100 kilometers (km) (62 miles [mi]) of the closure