The Trump administration has taken aim at removing environmental federal protections for wetlands and isolated streams from pollution.
The Environmental Protection Agency unveiled a proposal redefining US waters under the Clean Water Act.
Farm and agriculture lobbyists have pushed for these changes since 2015.
But environmentalists say they could result in contaminating millions of acres of waters with pesticides and other agricultural pollutants.
What’s in the proposal?
The proposal seeks to remove protections on “ephemeral streams” – which only appear after rainfall – and wetlands not directly connected or adjacent to large bodies of water.
The replacement regulation would not change protections for large bodies of water and neighbouring wetlands, and any state-imposed rules will also be unaffected.
The changes would replace an Obama-era regulation, but the wetland protections impacted date back to the George HW Bush administration.
Announcing the proposal on Tuesday, Environmental Protection Agency Acting Administrator Andrew Wheeler described it as “an end to the previous administration’s power grab”.
Mr Wheeler said the changes clarified what waters the federal government had jurisdiction over while respecting “the primary role of the states” in managing environmental resources.
He added that the Obama-era definition of federal waters was “about power over farmers, developers, landowners”.
“Our goal is a more precise definition that gives the American people the freedom and certainty to do what they do best: build homes, grow crops, and develop projects that improve the environment and the lives of their fellow citizens.”
What’s the reaction?
Environmentalists say that by rescinding these federal protections, many wetlands and streams will face serious pollution from industry and farming operations.
Wetlands are a crucial part of the ecosystem, improving water quality by absorbing pollutants, acting as a barrier for flooding and supporting a diverse array of wildlife.
Blan Holdman of the Southern Environmental Law Center (SELC) told the BBC the proposal could have “immediate effects” on water quality and wildlife if it goes into effect next year.
“It’s lifted protection for wetlands and ephemeral streams, for example, that were protected under both Obama and the pre-existing regimes.”
Mr Holman pointed out that farming has not stopped in states that adopted the 2015 rule, and in those fighting the change, older regulations protecting wetlands are still in effect.
“What this proposal will do is way different than either of those situations.”
Mr Holman said the SELC’s preliminary research has shown over 70% of wetlands in the Carolinas and Virginia could lose their protections.
He added that many states rely on federal direction for water protections, and reversing decades-old protections “is wrongheaded”.
“The whole purpose of the [Clean Water] act in the beginning was because states were not getting the job done, and rivers were catching on fire,” he said.
What’s the Clean Water Rule?
The 2015 Clean Water Rule defined “waters of the US”, as mentioned in the 1972 Clean Water Act, more specifically – stating any seasonal streams or wetlands that could impact larger bodies of water were under federal protection.
The rule evaluated waters for protection not solely on whether they were directly connected to other waters, but on the potential impact based on a number of environmental factors. It did allow for existing exemptions for farmers to remain in place.
Opponents to the rule have sued in 28 states, blocking the 2015 definition from going into effect in regions across the south and west, but it has been implemented in 22 states.
Agriculture and energy advocates said the Obama-era rule was an overstep and negatively impacted development.
The Farm Bureau, a lobby group representing farm families, has said it supports all efforts to repeal and replace the 2015 rule because it gives the federal government too much power over agricultural businesses.
President Donald Trump has reiterated his support for clean air and “crystal-clean water” while attacking many of his predecessor’s environmental protections. Rescinding this 2015 rule was one of Mr Trump’s campaign promises.
Most recently, his administration has sought to weaken rules against coal plant emissions and drilling on public lands.
The changes will be finalised next year following a comment period of 60 days.