Superfund Site: HANFORD 100-AREA (USDOE)

Superfund Site Profile

The U.S. Department of Energy has the lead role for cleaning up the Hanford sites.

Located in southeastern Washington State, Hanford is a 586-square-mile site created in 1943 as part of the Manhattan Project (America’s effort to develop the atomic bomb).

Operation of the plutonium-producing facilities continued beyond World War II through the Cold War, and a total of nine nuclear reactors were eventually constructed along the Columbia River.

In 1989, production stopped and work shifted to cleanup of portions of the site contaminated with hazardous substances, including both radionuclides and chemical waste.

The operations at Hanford created one of the largest and most complex cleanup projects in the U.S. Weapons production resulted in more than 43 million cubic yards of radioactive waste, and over 130 million cubic yards of contaminated soil and debris. Approximately 475 billion gallons of contaminated water was discharged to the soil. Some of the contaminants have made it to groundwater under the site. Over 80 square miles of groundwater is contaminated to levels above groundwater protection standards.

Cleanup Areas

In 1988, Hanford was divided into four National Priorities List (NPL) sites, including the 100, 200, 300, and 1100 Areas.


The 25 square-mile Hanford 100-Area (USDOE) site is located 35 miles north of Richland, Washington. It is one of four areas at the Hanford Nuclear Reservation (Hanford) originally listed on EPA's National Priorities List (NPL). These areas are part of a U.S. Department of Energy (DOE) complex that includes buildings, disposal sites, a national monument and other vacant land totaling about 586 square miles. The 100-Area cleanup is focused on contamination that originated from nine nuclear reactors, the last one shutting down in 1988. Cooling water contaminated with radioactive and hazardous chemicals was discharged to both the adjacent Columbia River and infiltration cribs and trenches. Site operations also included burying contaminated solid wastes on-site. These activities contaminated soil, sludge and groundwater with radioactive constituents, heavy metals and other hazardous chemicals. EPA has divided the site into several cleanup areas, or operable units (OUs) to better address site contamination. Final remedies have not yet been selected for the site’s OUs; however, eight interim remedies have been selected and remedial investigations are underway to support selection of the site’s final remedy.