Attorneys General from 10 states and the District of Columbia are suing the Trump administration for delaying an update to the Clean Water Act, according to Bloomberg.  

The update, known as Waters of the United States, seeks to curb industrial and other forms of pollution in the nation’s water sources and increase how many bodies of water are subject to heightened federal regulation.

If enacted, the rule would further protect the drinking water of 117 million US citizens.

Take Action: Urge Governments And Businesses To Invest In Clean Water And Toilets

Since it was released in 2015, however, the update has been tangled up in the courts by legal challenges that claim the rule steps outside the bounds of the Clean Water Act, initially signed into law in 1972.

The Supreme Court threw out these challenges in favor of the update in 2017, but then the Environmental Protection Agency decided to stall its implementation for two years, Bloomberg reports.

The EPA’s director, Scott Pruitt, is also working to eliminate the rule entirely.

"The Trump Administration’s suspension of the Clean Water Rule is clearly illegal, threatening New York’s decades-long efforts to ensure our residents have access to safe, healthy water," New York Attorney General Eric Schneiderman, who is leading the coalition, said after announcing the lawsuit on Tuesday.

Read More: It's 2018 and People in the US Are Actually Drinking 'Raw Water' by Choice

At the heart of the dispute are long-standing disagreements over what the Clean Water Act covers.

Proponents of the rule argue that all lakes, rivers streams, wetlands, and other bodies of water should be protected under the regulation.

The Waters of the United States rule was developed with the input of 1 million public comments and based on over 1,200 peer-reviewed studies, according to the lawsuit.

“The American people have made it crystal-clear they want to see our rivers and streams protected,” said Jan Goldman-Carter, the director for wetlands and water resources at the National Wildlife Federation, which is also challenging the Trump administration over the regulation’s delay with the Natural Resources Defense Council.

“They want to be able to fish in the local stream, swim in a nearby lake, and turn on the tap and get a glass of safe, clean water to drink,” she added.

Opponents argue that the rule should only apply to waters that are navigable by boat.

Read More: This Doctor Could Become the First Muslim Governor in the US

The lawsuit by the attorneys general was filed in the US District Court for the Southern District of New York.

It argues that the federal government does not have the authority to suspend a rule that has already been formalized and cleared by the courts; that the Trump administration has failed to provide a public comment period for the steps it has taken; and that no meaningful scientific evidence has been provided to counter the rule’s implementation.

If successful, the EPA and the Army Corps. of Engineers would be compelled to enforce water quality standards on all of the nation’s bodies of water, which would mean a significant curtailment of industrial pollution, according to Bloomberg. Currently, around 60% of US waters are not regulated.

The case comes at a time of growing concern over the safety of the nation’s drinking water because of a lack of regulation. For instance, water in hundreds of US towns has dangerous levels of Nitrate from agricultural fertilizer; lead contamination has become a national crisis outside of Flint, Michigan. and the NRDC found that 77 million Americans live in towns with harmful levels of water pollution.   

“The administration’s attack on clean water violates the law and runs roughshod over public concern about their waterways,” said Jon Devine, a senior attorney for NRDC in a press release. “It’s dangerous, and that’s why we’re going to court.”

Global CItizen campaigns on universal access to clean water and you can take action on this issue here.