The Environmental Protection Agency (EPA) intends to rewrite limits on toxic waste from power plants, the agency said in a court filing this week.

Agency officials in April delayed compliance deadlines for the rule, a 2015 directive from the Obama administration that set limits on toxic water pollution from certain coal-fired power plants.

The agency said this week that it would rewrite the limits on pollution from bottom ash, scrubbers and coal gasification plants, signaling a new deregulatory push for the fossil fuel sector.

“I have decided that it is appropriate and in the best public interest to conduct a rule-making to potentially revise” some of the rule, EPA Administrator Scott Pruitt wrote in a letter to the Small Business Association and lawyers for the Utility Water Act Group on Friday. The two organizations had asked the EPA to reconsider the regulations.

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In a Monday court filing, the agency said it would begin the process of revising and reissuing the rule.

The regulation, finalized by former President Barack Obama Barack Hussein ObamaMomentum growing among Republicans for Supreme Court vote before Election Day Warning signs flash for Lindsey Graham in South Carolina Majority of voters say Trump should not nominate a Supreme Court justice: poll MORE’s EPA on Sept. 30, 2015, sets the first federal limits on toxic wastewater discharge from power plants while taking into account technological improvements in the industry.

The EPA estimates the rule would reduce toxic metals and other discharged pollutants by 1.4 billion pounds. If implemented, the rule would cost about $480 million per year and its potential benefits are worth $451 million to $566 million, the agency says.

Opponents of the rule say it could lead to the closure of coal-fired power plants and economic harm for small utilities.

But environmental groups support the regulation and have challenge the agency’s decision to delay its implementation.