The Hanford 300-Area covers 53 square miles one mile north of Richland, Washington, next to the Columbia River. During the Cold War, the site was used for uranium reactor fuel manufacturing and nuclear weapons research. From the 1940s through the 1970s, the Department of Energy and its predecessors disposed of roughly 27 million cubic yards of solid and liquid waste in unlined ponds, trenches, and landfills. Those liquids percolated into the ground and reached the Columbia River, contaminating soil, groundwater, and surface water.
The site holds more than 140 contaminants of concern. Volatile organic compounds, including trichloroethene, tetrachloroethene, and benzene, are found in soil and groundwater. Metals and metalloids, such as arsenic, lead, chromium, mercury, and uranium, contaminate soil across the site. Radioactive substances in soil include plutonium, uranium, americium-241, strontium-90, and tritium, among others. Polychlorinated biphenyls, petroleum hydrocarbons, cyanide, and nitrate are also present.
Cleanup has been underway since 1989 under a tri-party agreement among the Department of Energy, EPA, and Washington State. The site is divided into four operable units. Three of those units have substantially completed remedial actions. The fourth, which addresses all media in the FF-2 and FF-5 areas, began work in June 2015, completed one phase in May 2021, and has additional phases planned for 2027 and 2028. A Final Record of Decision was signed in 2013. Completed work includes demolition of contaminated buildings, natural attenuation of groundwater contaminants, and disposal of contaminated soil at an on-site landfill. Current work includes demolition of the 324 building and remediation of the 618-11 burial grounds.
Human exposure pathways across the entire site are currently under control, meaning no unacceptable exposures are occurring. However, contaminated groundwater continues to migrate beyond the original contamination area and is not yet stabilized. Physical construction is not complete, cleanup goals have not been fully met across the whole site, and the site has not been deleted from the National Priorities List. Some facilities remain active for use by the Department of Energy's Pacific Northwest National Laboratories and the Department of Homeland Security, with operations continuing until 2045.
Community members can stay informed and involved by contacting EPA's Community Involvement Coordinators. To join the project mailing list or get information about public meetings and site updates, contact the Community Involvement Coordinators. The Public Information Repository for site documents is located at 2440 Stevens Center Place, Room 1101, in Richland, Washington.
