By MATTHEW DALY

WASHINGTON (AP) — The Environmental Protection Agency is poised to eliminate rules that limit greenhouse gas emissions from power plants fueled by coal and natural gas, part of a wide-ranging rollback of environmental regulations that Administrator Lee Zeldin has said would remove trillions of dollars in costs and “unleash” American energy.

The EPA also plans to weaken a regulation that requires power plants to reduce emissions of mercury and other toxic pollutants that can harm brain development of young children and contribute to heart attacks and other health problems in adults.

The planned rollbacks, set to be announced Wednesday, are meant to fulfill President Donald Trump’s repeated pledge to “unleash American energy” and make it more affordable for Americans to power their homes and operate businesses.

If approved and made final, the plans would reverse efforts by President Joe Biden’s administration to address climate change and improve conditions in areas heavily burdened by industrial pollution, mostly in low-income and majority Black or Hispanic communities.

The power plant rules are among about 30 environmental regulations that Zeldin targeted in March when he announced what he called the “most consequential day of deregulation in American history.” He said the actions would put a “dagger through the heart of climate-change religion” and introduce a “Golden Age” for the American economy.

Environmental groups vowed to challenge the rules in court.

“Power plants are among the largest sources of dangerous pollution in the nation. We have modern technologies that allow these plants to reduce pollution with available and cost-effective solutions,” said Vickie Patton, general counsel of the Environmental Defense Fund.

The clean-air standards targeted by the EPA under Trump, a Republican, “are protecting people across America today and will safeguard future generations,” Patton said.

“Ignoring the immense harm to public health from power plant pollution is a clear violation of the law,” added Manish Bapna, president and CEO of the Natural Resources Defense Council. “Our lawyers will be watching closely, and if EPA finalizes a slapdash effort to repeal those rules, we’ll see them in court.”

The EPA-targeted rules could prevent an estimated 30,000 deaths and save $275 billion each year they are in effect, according to an Associated Press examination that included the agency’s own prior assessments and a wide range of other research.

It’s by no means guaranteed that the rules will be entirely eliminated — they can’t be changed without going through a federal rulemaking process that can take years and requires public comment and scientific justification.

Even a partial dismantling of the rules would mean more pollutants such as smog, mercury and lead — and especially more tiny airborne particles that can lodge in lungs and cause health problems, the AP analysis found. It would also mean higher emissions of the greenhouse gases driving Earth’s warming to deadlier levels.

Biden, a Democrat, had made fighting climate change a hallmark of his presidency. Coal-fired power plants would be forced to capture smokestack emissions or shut down under a strict EPA rule issued last year. Then-EPA head Michael Regan said the power plant rules — the Biden administration’s most ambitious effort to roll back planet-warming pollution from the power sector — would reduce pollution and improve public health while supporting a reliable, long-term supply of electricity.

The power sector is the nation’s second-largest contributor to climate change, after transportation.

In its proposed regulation, the Trump EPA argues that carbon dioxide and other greenhouse gases from fossil fuel-fired power plants “do not contribute significantly to dangerous pollution” or to climate change and therefore do not meet a threshold under the Clean Air Act for regulatory action.

A paper published earlier this year in the journal Science found the Biden-era rules could reduce U.S. power sector carbon emissions by 73% to 86% below 2005 levels by 2040, compared with a reduction of 60% to 83% without the rules.

“Our research shows that EPA’s power plant rules make substantial strides to protect human health and the environment,” said Aaron Bergman, a fellow at Resources for the Future, a nonprofit research institution and a co-author of the Science paper.

“Carbon emissions in the power sector drop at a faster rate with the (Biden-era) rules in place than without them,” Bergman said in an email. “And we also would have seen significant reductions in sulfur dioxide and nitrogen oxides, pollutants that harm human health.”