Sixty percent of the nation’s heavily polluted Superfund sites—nearly 950 of them—are at risk from the impacts of climate change, including hurricane storm surges and flooding that could spread their toxic legacies into waterways, communities and farmland, a new federal report warns.

The U.S. Government Accountability Office (GAO) report, released Monday, describes the increased risk of toxic substances being washed out by flooding at sites across the country, as well as wildfire risks that could send health-harming pollutants airborne.

It recommends that the Environmental Protection Agency, which oversees the federal Superfund program, start providing clear, agency-wide instructions on how its officials should incorporate climate change into Superfund site risk assessments and response decisions.

That would be a change for the current administration. Currently, the EPA does not include climate change in its agency-wide goals and objectives, preventing the agency from addressing the added risks at contaminated sites across the country as the planet warms, the report concluded.

“The Superfund program is not providing necessary resources and direction to regional officials that would help them assess and respond to site-specific risks due to climate change,” a dozen members of Congress, led by Sen. Tom Carper, the top Democrat on the Senate Environment and Public Works Committee, wrote in a letter to EPA Administrator Andrew Wheeler in response to the report.