The John Amos coal-fired power plant in West Virginia in 2018.
CNN  — 

The Environmental Protection Agency announced Wednesday it had finalized its so-called good-neighbor rule, which aims to cut down on harmful smog and nitrogen oxide pollution from coal-fired power plants and industrial facilities.

The agency will require 23 states that are currently not meeting the requirements to adhere to the rule, which sets limits on air pollution from smog and ground-level ozone that wafts into other states. For instance, if one state generating ozone and smog through its coal-fired plants is sending ozone into another state, it could be in violation of the rule.

“We know this harmful pollution doesn’t stop at the state line,” EPA administrator Michael Regan told reporters on Wednesday. “This is about fairness; some states have done all they can do to control ozone pollution and their counterparts that are upwind are being asked to do the same.”

The EPA said the newly finalized rule would reduce nitrogen oxide pollution during peak ozone months – typically from March to November – by approximately 70,000 tons in 2026. By 2027, those levels would be half of what they were in 2021, the agency added.

In addition, starting during the 2026 ozone season, EPA will set enforceable nitrogen oxide emissions rules for both existing and new sources of emissions in heavy industry.

To meet the new rule, the EPA said most power plants and heavy industry will need to outfit themselves with specialized pollution control equipment and must run it continuously throughout peak ozone season, which varies state to state.

The good-neighbor rule is the latest in a series of EPA regulations aimed at cutting down pollution and toxic waste from coal-fired power plants. The EPA is soon expected to release its highly anticipated rule that is expected to slash planet-warming carbon pollution from coal and natural gas-fired power plants.

Democratic Sen. Joe Manchin of West Virginia recently urged the agency to delay its finalization of the good-neighbor rule, saying he was concerned the “high costs” of complying with it could force power plants to retire early. Manchin’s state still gets its electricity primarily from coal-fired power plants.

“I urge EPA to postpone finalizing this rule until the agency has addressed the warnings from our nation’s electric reliability experts and the significant concerns expressed by state environmental agencies,” Manchin said in a letter.

Regan stressed that EPA listened to the power sector about reliability concerns when it finalized the rule.

“This rule has some built-in features that we believe allow us to achieve our public health goals, but also doesn’t jeopardize reliability,” Regan said.