Through its tank integrity program, DOE determined that underground single-shell tank B-109 at the Hanford Site is likely leaking to the soil beneath the tank. The determination was made after monthly monitoring detected a small drop in the level of liquid in the tank, and a formal leak assessment began in July 2020 and concluded on April 29, 2021. There is no increased health or safety risk to the Hanford workforce or the public.
Contamination in this area is not new and mitigation actions have been in place for decades to protect workers, the public and the environment. Tank B-109 was previously emptied of pumpable liquids, leaving a very small amount of liquid waste in the tank.
Active groundwater pump and treat systems operating near the tank capture and remove contaminants that reach the groundwater and ensure the protection of the Columbia River. The water table in the area ranges 210-240 feet below Tank B-109. DOE estimates it could take more than 25 years for any contamination from Tank B-109 to reach the water table, which would then be captured and removed by the pump and treat systems. Safely managing all Hanford tank waste is a top priority for DOE