The U.S. Environmental Protection Agency (EPA) has proposed a suite of regulations that would place stricter limits on wastewater released by coal plants.

The agency said that the changes will see pollutants in discharged wastewater reduced by around 584 million pounds, in what EPA Administrator Michael Regan called the “strongest ever” limits offered under any president.

The legislation will run through effluent limitation guidelines (ELGs), a mechanism allowing the agency to regulate wastewater associated with specific industries. E&E News reported that includes steam electric plants, including coal-fired power facilities. Regulators are targeting that subset of plants through the new ELGs, which hit several major wastewater streams including flue gas desulfurization wastewater, bottom ash transport water and combustion residual leachate.

Additionally, EPA is looking to establish a new group of definitions for legacy wastewaters, or streams that are present in surface impoundments before more aggressive limitations underlined in a permit go into effect. The agency said it will seek public comment around whether to develop tighter standards for those legacy wastewaters.

The National Mining Association (NMA) said the new rules ignore America’s electricity reality.

“With each rule that targets well-operating coal plants – the very same plants that are called on to keep the lights on when renewables or natural gas are unavailable and consumer demand soars – our electricity grid becomes increasingly vulnerable to crippling supply shortfalls. We’ve seen more near misses in the last two years than ever before, and the EPA’s response is to force the closure of even more capacity before any replacement solutions are identified, permitted, built or operational,” the NMA said in a statement. “Whether it is the transport rule, new effluent limitations guidelines or other rules expected this spring, the EPA is acting on its longstanding threat to make it impossible for utilities to make decisions based on the merits of what keeps the lights on, forcing those utilities to make decisions solely based on the EPA’s agenda, an agenda formed absent consideration of America’s energy reality. As a result, Americans and American businesses will continue to pay increasingly more for electricity that is less and less reliable. Even worse, the EPA is unilaterally making these decisions for the states – more than 18 of which use coal as their most common source of electricity generation.

“The nation’s grid regulators and operators have repeatedly warned EPA that its regulatory plans pose an ominous threat to reliability, and the EPA’s response is to paper over the problem with meaningless memorandums of understanding. Intermittent renewable power additions will require a massive expansion of transmission infrastructure and energy storage — an effort that will take years to complete — in order to fill the gulf left by coal plant retirements. In fact, in 2022, as many as 40 planned coal plant retirements were postponed or scrapped largely due to acute grid reliability challenges where utilities and grid operators have made it clear closing plants would be reckless,” said NMA. “The U.S. coal fleet continues to play an outsized role in providing dispatchable fuel diversity, fuel security and ramping up power supply during periods of surging demand when other sources of power cannot. EPA’s willful disregard of the repercussions of its decisions on Americans and on our energy future is plainly irresponsible.”

The EPA said plants would have additional time if they were in the process of installing technologies to be in compliance with different standards introduced under prior presidential administrations. Moreover, plants that are in the process of closing or moving to natural gas can continue to meet those prior standards.

To that end, EPA is also finalizing a regulation allowing plants to opt into the early retirement subcategory, phasing down their operations by 2028. Officials declined to speak to specifics about how many plants might be interested in taking that route, but said that conversations with industry members had indicated that a number of operators were hoping to take advantage of the opportunity.