BURLINGTON, Vt. — Sen. Patrick Leahy gathered many of Vermont’s most powerful environmental leaders Friday to rail against reports of deep cuts across the federal budget and their threat to environmental efforts.

The U.S. Environmental Protection Agency will likely see about a quarter of its budget cut and 20 percent of its staff laid off if President Trump’s budget proposal passes, Leahy said.

About half of the state budget comes from various federal sources.

“Deep cuts have drastic consequences, and the Trump administration’s budget would have devastating impacts on Vermont,” the Vermont Democrat said.

The Republican president’s new EPA chief, Scott Pruitt, has spent much of his career as Oklahoma’s attorney general suing the agency that he now leads over regulations opposed by the oil and gas industry.

“Certainly there is not much in his background or his statement that indicates he understands or cares,” Leahy said. “We’ve got our work cut out for us for those of us who want to save the environment.”

Leahy and other lawmakers on the Senate Appropriations Committee will meet Pruitt as they shape the federal budget.

State agency and environmental protection group leaders detailed on Friday how a diminished budget would affect them. They gathered at a news conference at the ECHO, Leahy Center for Lake Champlain. The center, named after Leahy, houses an aquarium and community space on Burlington’s waterfront.

One third of the state Agency of Natural Resources is federally funded, said agency Secretary Julie Moore. Much of that money goes to towns so they can maintain safe drinking water.

Federal money makes up 80 percent of the Lake Champlain Basin Program budget, said Eric Howe, the program’s executive director. The program directs government money to clean up Lake Champlain.

Vermont’s radon prevention program is entirely federally funded, said Health Department official David Grass. Radon kills about 50 people in Vermont a year, Grass said.

Lawyers are gearing up to combat cuts to federal programs that still have legal obligations, said Chris Kilian, director of the Conservation Law Foundation in Vermont.

“One of the great ironies here is unless you change the statutes, the EPA’s obligations will remain the same. Once you slash budgets, you’re not only putting budgets at risk, you’re putting industry, municipalities in the face of legal liability,” Kilian said.

The Conservation Law Foundation has about 30 lawyers and scientists in New England who help create environmental policy. The foundation has sued governments and businesses it considers in violation of environmental laws.

If the proposed budget is cut the way Trump wants, Kilian said, a flurry of litigation can be expected from the group and others like it.

“We’re kind of bracing for impact,” Kilian said.