In August 2022, the Department of Energy and Washington State Department of Ecology signed an agreement, called an Agreed Order, on how to respond to two leaking underground waste tanks and potential future leaks from tanks at the Hanford Site.

Through its tank integrity program, DOE had determined that Tank B-109 is leaking about *1.5 gallons of waste per day, and Tank T-111 is leaking less than a *gallon a day.

The agencies jointly developed the agreement following close coordination since the April 2021 announcement that Tank B-109 was leaking. DOE reported in 2013 that Tank T-111 was leaking.

The leaks do not pose a risk to the Hanford Workforce, the surrounding communities or the Columbia River. It could take more than an estimated 25 years for any leakage from Tank B-109 to reach the water table, and up to 70 years for Tank T-111.

Groundwater treatment systems installed several years ago under the areas surrounding both tanks are already capturing and removing contamination resulting from the discharge of millions of gallons of contaminated liquids to the soil during historical operations to produce materials for the U.S. nuclear weapons program.

The planned measures in the August 2022 agreement will further reduce the risk of contamination from the tanks reaching groundwater, and the agreement supports the agencies’ continued focus on safe, efficient and effective stewardship, treatment and disposition of waste.

*Current estimates as of August 2022