Note: This story was last updated at 3:20 p.m. September 4.

The U.S. Department of Energy is responsible for more than 80 percent of the U.S. government’s estimated $450 billion in environmental liabilities, a federal agency said in a report published this year.

The agency, the U.S. Government Accountability Office, added the government’s environmental liabilities to a high-risk list of federal programs and operations in a report published in February.

Total environmental liabilities for the federal government are estimated at $447 billion. DOE is responsible for about $372 billion of them, or 83 percent, according to a fiscal year 2016 estimate, the GAO said.

Most of DOE’s environmental liability is related to nuclear waste cleanup, the GAO said. Fifty percent of it is at two cleanup sites: the Hanford Site in Washington state and the Savannah River Site in South Carolina.

The GAO—an independent, nonpartisan agency that works for Congress—said DOE’s total reported environmental liability has generally increased since 2000. It’s roughly doubled from a low of $176 billion in fiscal year 1997 to the higher estimate of $372 billion in fiscal year 2016.

“In the last six years alone, EM (environmental management) has spent $35 billion, primarily to treat and dispose of nuclear and hazardous waste and construct capital projects to treat the waste, while EM’s portion of the environmental liability has grown over this same time period by over $90 billion, from $163 billion to $257 billion,” the GAO said.

In the past few fiscal years, DOE environmental management has spent about $6 billion per year. The budget request submitted to Congress by President Donald Trump in May asked for $6.5 billion for the DOE Office of Environmental Management, the largest request in a decade.

Oak Ridge has a DOE environmental management program. It received more than $400 million in funding per fiscal year between 2013 and 2016. The Oak Ridge Office of Environmental Management has major cleanup projects at the East Tennessee Technology Park (the former K-25 site), Oak Ridge National Laboratory, and Y-12 National Security Complex. Cleanup work depends upon funding, but it could continue into the mid-2040s. Although they might be in various stages, projects that are under way now include finishing demolition work at ETTP by 2020, disposing of uranium-233 at ORNL, addressing high-risk excess facilities at ORNL and Y-12, building a Mercury Treatment Facility at Y-12, and shipping transuranic waste to the Waste Isolation Pilot Plant in New Mexico. [Read more…]