The SDA at the INL received waste from the Rocky Flats Plant in Colorado from approximately 1952 through 1970. It has been determined that about 15 acres of pits and trenches of the 97-acre SDA landfill are contaminated with transuranic (plutonium-contaminated) waste.

Six years of litigation, extensive technical analyses, and intense negotiations preceded the 2008 agreement. In 2002, Idaho brought legal proceedings in the U.S. District Court to determine DOE’s obligation to Idaho to address transuranic waste in the SDA. In 2006, U.S. District Court Judge Edward Lodge determined that the Settlement Agreement reached between Idaho, DOE, and the U.S. Navy in 1995 obligates DOE to remove transuranic waste from the SDA. The 9th U.S. Circuit Court of Appeals recently upheld Judge Lodge’s decision.

The agreement implements Judge Lodge’s court order in coordination with ongoing Superfund cleanup of the area under the 1991 Federal Facilities Agreement/Consent Order (FFA/CO) between DOE, the U.S. Environmental Protection Agency, and the state of Idaho.

It specifies areas where retrieval is to take place and quantities to be retrieved, based on density of waste identified in disposal records and geophysical evaluations, and potential risks to cleanup workers, the public, and the environment.

Following are the major provisions of the agreement:

• Requires retrieval of five targeted waste types most likely to contain transuranics and uranium.
• Requires excavation and retrieval from at least 5.7 acres and up to 7.4 acres of the SDA likely to contain most of the transuranics, hazardous solvents, and uranium.
• Requires shipment of all retrieved transuranic waste and at least 7,485 cubic meters of targeted waste out of Idaho.
• Coordinates cleanup with the 1991 FFA/CO to ensure protection of the Aquifer.
• Establishes checks and balances to review assumptions and ensure performance.
• Requires assumptions to be reviewed and revisited if they do not prove out.
• Allows vigorous oversight by DEQ.
• Continues Judge Lodge’s jurisdiction over disputes the parties cannot resolve.

In coordination with a Record of Decision for the SDA which will be issued pursuant to the FFA/CO, the agreement addresses remaining contamination in the SDA through a combination of continued vacuuming of hazardous chemical vapors, grouting of mobile contaminants, installation of a cap over the entire area, and long-term monitoring and evaluation.