The Trump administration is expected to propose weakening Obama-era wetland protections

The Trump administration is expected to propose weakening protections for U.S. wetlands on Tuesday, in a move sought by ranching and mining interests but one that will likely be held up in the courts amid opposition from environmentalists.

The U.S. Environmental Protection Agency (EPA) will make a water policy announcement at 11:25 Eastern Time (1625 GMT), the agency said without elaborating.

The EPA is expected to relax protection standards in the Waters of the United States (WOTUS) rule that went into effect during the administration of former President Barack Obama.

President Donald Trump, who accused Obama of over-reaching on regulations on oil, gas and agriculture, made rolling back WOTUS one of his top environmental policy priorities.

The 2015 rule defines which streams and wetlands are protected by federal clean water law from pollutants such as pesticides, fertilizers and mine waste. Trump’s EPA is expected to propose relaxing the definitions of what waters should be protected.

The rule required farmers to get permits before applying pesticides and fertilizers that could run into certain bodies of water, protections that could be lifted. But the plan may leave at least some ditches regulated, to the consternation of agriculture groups.

Mark Ryan, a lawyer at Ryan & Kuehler PLLC who spent 24 years as a clean water expert and litigator at the EPA, said water systems called headwaters in high regions of the country could lose protections under the new definitions being proposed by the Trump administration.

“I think the mining is going to benefit from this because mines tend to be up in the mountains near headwater systems,” Ryan said.

Miners may no longer need to apply for a permit before pushing waste from operations, such as rubble from mountain-top coal mining in the eastern United States, into some streams.

Ephemeral streams that make up a large percentage of the total river miles in the United States could lose protections, as could intermittent streams, but the extent of the losses was not clear.

The proposal will undergo a comment period of a few months before the EPA moves to finalize it. Ryan said finalization may not happen soon, if ever. “I don’t think this rule is ever going to see the light of day,” he said.

“This is going to be tied up in litigation for at least two years and if Trump doesn’t get re-elected (in 2020), then it’s dead,” Ryan said.

Reporting by Timothy Gardner; Editing by Paul Tait