WASHINGTON — Attorneys general from 14 states and the District of Columbia on Tuesday vehemently opposed the Trump administration’s proposal to roll back a regulation known as Waters of the United States, a move they said would end federal oversight of 15 percent of streams and more than half of the nation’s wetlands.

The limit on the federal government’s authority to regulate the pollution of wetlands and tributaries that run into the nation’s largest rivers would be a major win for builders, farmers, coal miners and frackers.

In comments filed Tuesday before the end of the public comment period, the state attorneys general said that the Trump administration’s proposal in December for a more limited rule violates the Administrative Procedure Act and runs contrary to the Clean Water Act’s objective of restoring the nation’s waterways.

The scaling back of the regulation was one of President Trump’s top priorities when he took office, and he issued an executive order in February 2017 directing the Environmental Protection Agency to carry out “the elimination of this very destructive and horrible rule.”

But the Supreme Court has already ruled on this issue, and now-retired Justice Anthony Kennedy said that the standard should be that a regulated body of water must have a “significant nexus” with other, larger waterways.

“The Trump administration continues to flout the rule of law with its decision to abandon Justice Kennedy’s ‘significant nexus’ standard, even though this standard has been upheld by the federal courts countless times already,” David Hayes, executive director of the State Energy & Environmental Impact Center, said in a statement.

Given the interconnected nature of national water systems, state attorneys general worry not only about pollution their own states generate but also pollution originating from outside of their jurisdiction, potentially threatening their drinking water.

The comments Tuesday were filed by a coalition including New York, California, Connecticut, Maine, Maryland, Massachusetts, Michigan, New Jersey, New Mexico, Oregon, Rhode Island, Vermont, Virginia, Washington and the District of Columbia.

The Obama administration, under the Waters of the United States rule issued in 2015, asserted federal oversight of a variety of ditches, storm-water controls, lakes, streams and wetlands that feed into larger waterways that are clearly protected under the Clean Water Act of 1972. Many experts believed that the 1972 law already gave the EPA and the Army Corps of Engineers control over smaller U.S. waterways and tributaries.

In their comment filed Tuesday, the AGs said that the Trump rollback “abandoned both the governing ‘significant nexus’ test for defining waters” and “their prior scientific findings under that test.” The coalition wrote that the Trump agencies “have arbitrarily and capriciously reduced protections for tributaries, adjacent waters, wetlands and other important water resources that significantly affect down stream waters.”

Congressional Democrats also weighed in. Sen. Thomas Carper, D-Delaware, the top Democrat on the Senate Environment and Public Works Committee, and 15 other Democratic senators sent a letter urging the administration to reverse course.

“At best, the agencies have been careless in proposing this rule,” they wrote. “At worst, they have failed to meet their duties to inform the public, uphold the law, and protect the public and the environment.”