SchrodingerZ writes "A recent review of the Hanford Nuclear Reservation in Washington state (where the bulk of Cold War nuclear material was created) has found that six of its underground storage tanks are leaking badly. Estimations say each tank is leaking 'anywhere from a few gallons to a few hundred gallons of radioactive material a year.' Washington's governor, Jay Inslee, said in a statement on Friday, 'Energy officials recently figured out they had been inaccurately measuring the 56 million gallons of waste in Hanford's tanks.' The Hanford cleanup project has been one of the most expensive American projects for nuclear cleanup. Plans are in place to create a treatment plant to turn the hazardous material into less hazardous glass (proposed to cost $13.4 billion), but for now officials are trying just to stop the leaking from the corroded tanks. Today the leaks do not have an immediate threat on the environment, but 'there is [only] 150 to 200 feet of dry soil between the tanks and the groundwater,' and they are just five miles from the Colombia River."