The Environmental Protection Agency (EPA) announced a major rollback to protections for streams and other smaller bodies of water on Thursday, saying it would institute a new rule advocated by farmers and other industry groups.
The new rule would replace the already-repealed Waters of the United States rule (WOTUS), crafted under President Obama, which expanded the types of waterways protected by federal law.
The Obama administration argued smaller bodies of water, even some seasonal ones caused by snowmelt, must be protected in order to stop pollution from reaching larger sources, including those used for drinking water. 
Critics argue the changes will eviscerate the protections guaranteed by the Clean Water Act, but President TrumpDonald John TrumpMnuchin knocks Greta Thunberg’s activism: Study economics and then ‘come back’ to usThe Hill’s Morning Report – House prosecutes Trump as ‘lawless,’ ‘corrupt’What to watch for on Day 3 of Senate impeachment trialMORE touted his plans to roll back the law when speaking to a conference of farmers over the weekend one of the chief adversaries of the previous administration’s policy and a key part of Trumps base.
Farmers and other groups have argued that law was too far-reaching, requiring grand efforts to protect relatively small bodies of water that run through their property, ultimately subjecting large swaths of land to federal oversight.
Trumps latest rule, which will be implemented in coming weeks, is likely to increase the amount of pesticides and other industrial chemicals that leach into streams, wetlands, and underground water sources, leaving much environmental regulation to state and local authorities. 
Repealing WOTUS was a campaign promise of Trumps, who called it one of the most ridiculous regulations of all when speaking at the American Farm Bureau Federation annual convention in Austin, Texas, on Sunday.
As long as Im President, government will never micromanage Americas farmers, he told the crowd.
But the changes announced by the EPA Thursday would dramatically scale back protections.
The EPAs independent Science Advisory Board reviewed the rule when it was first proposed, writing in a draft report that aspects of the proposed rule are in conflict with established science… and the objectives of the Clean Water Act.
Betsy Southerland, who was director of the Office of Science and Technology at the EPAs Office of Water under the Obama administration, called the new rule scientifically indefensible and socially unjust, forcing communities to pick up the cost of controlling pollution from miners, oil and gas producers, and land developers.
The new rule earned immediate condemnation from some of the nations largest environmental groups, some of which have already suggested they will sue.
This all-out assault on basic safeguards will send our country back to the days when corporate polluters could dump whatever sludge or slime they wished into the streams and wetlands that often connect to the water we drink, Earthjustice said in a statement, vowing to use every tool available to defend the Clean Water Act.
A diminished federal role would leave a greater share of water supervision to the states, many of which have cut budgets for their environmental regulators over the last decade.
There is no question that President Trump is making millions of Americans vulnerable to polluted water with this action. This rollback was bought and paid for by the mining industry, and it will have significant consequences for states, who will shoulder a huge burden to protect drinking water from pollution, Ryan Richards, a senior policy analyst at the Center for American Progress, said in a statement. 
Thursdays policy is the administration’s second major crack at rethinking water policy. In September the administration scraped WOTUS, reverting waterway protections back to 1986 standards.
A coalition of 14 states sued, arguing that returning the U.S. to the narrower standard ignores studies showing how small bodies of water, even seasonal snowmelt, connect with and impact larger bodies of water more typically targeted for regulation.