After reviewing hundreds of public comments on a proposed plan released in October 2007 and based on the results of decades of research data on the contents of the landfill, the agencies have agreed to exhume a minimum of 6,238 cubic meters of targeted waste from a minimum combined area of 5.69 acres. Targeted waste for retrieval contains transuranic elements, such as plutonium, as well as uranium and co-located organic solvents, such as carbon tetrachloride.

The Subsurface Disposal Area (SDA) at DOE’s Idaho site began receiving waste in 1952. The area contains radioactive and chemical wastes, located in approximately 35 acres of disposal pits, trenches and soil vaults on a 97-acre site.

Transuranic (plutonium-contaminated) waste from DOE’s Rocky Flats Plant in Colorado, which was deposited in the landfill from 1954 to 1970, is distributed unevenly in pits and trenches throughout roughly 14 percent of the landfill. Disposal records, including geophysical evaluations, helped to identify the retrieval areas based on densities of waste. A review of risks to cleanup workers, the public and the environment was also conducted.

DOE ‘s contractor began retrieving waste in 2005. The targeted and co-located organic waste that is retrieved is then packaged, certified and shipped out of Idaho. DOE’s contractor will begin a third excavation this fall that will address a pit area containing some of the highest concentrations of organic solvents in the SDA.

In addition to expanding current waste retrieval, the record of decision addresses remaining contamination in the SDA through a combination of continued vacuuming of solvent vapors from the subsurface, grouting of some mobile contaminants and construction of a moisture-inhibiting surface barrier over the entire landfill.

This project is expected to cost approximately $1.3 billion, and will take approximately 20 years to complete. Retrieval of targeted waste will continue until approximately 2025, followed by construction of a surface barrier, which is expected to be completed in 2028.

DOE will maintain the remedy after construction is complete. Long-term monitoring, institutional control and re-evaluation of cleanup performance will occur at least every five years to ensure that the selected remedy continues to protect the public and safeguard the aquifer in the future.

Cleanup of the SDA has long been the subject of dispute between Idaho and DOE. In 2002, Idaho brought legal proceedings in U.S. District Court to determine DOE’s obligation to Idaho under the 1995 Settlement Agreement regarding transuranic waste in the Subsurface Disposal Area. In May 2006, U.S. District Court Judge Edward Lodge determined the 1995 Settlement Agreement obligates DOE to remove transuranic waste from the Subsurface Disposal Area, with safety of waste removal taken into account. The 9th U.S. Circuit Court of Appeals recently upheld Judge Lodge’s decision. Idaho and DOE reached an Agreement to Implement the court order on July 3, 2008.

The record of decision is available at: https://idahocleanupproject.com. Additional information is available in the Administrative Record for Operable Unit 7-13/ -14. The Administrative Record can be accessed at http://ar.inel.gov/ or by visiting the DOE Reading Room of the INL Technical Library in Idaho Falls or Albertsons Library at the Boise State University Campus.

ICP-08-009