Air and Climate Standards Top EPA’s 2023 Rulemaking To-Do List

January 31, 2023

Photographer: Dane Rhys/Bloomberg
Originally published in Bloomberg Law.   Reported by Jennifer Hijazi in Washington
  • EPA plans busy 2023 for air rule commitments

  • Greenhouse gases, ozone, particulate matter all on agenda

The Environmental Protection Agency is preparing to move ahead with a slate of major air and climate rules this year to make gains on the Biden administration’s long-promised climate goals.

The agency is due as early as the spring to propose and finalize closely watched emissions rules, including legal underpinnings for mercury regulations, ozone transport standards, and greenhouse gas regulations for existing coal-fired power plants.

Emissions rulemaking is a priority for the agency this year, including power sector rules and a proposed review of mercury standards, according to EPA Deputy Administrator Janet McCabe.

“You’re going to see a lot of progress on our regulatory agenda in 2023,” McCabe said at an event hosted by Resources for the Future this month.

President Joe Biden’s regulatory agenda is especially important for his climate goals to reduce net greenhouse gas emissions 50% from 2005 levels by 2023. The administration has already released multiple emission rules in the last year, as well as begun implementation of a historic climate law, but some of the heaviest-hitting proposals are still due or yet to be finalized.

“The regulatory responsibility of the EPA under the country’s fundamental environmental statutes is a really necessary part of the country’s response to the climate change challenge,” McCabe said.

Here are the rules to watch for in 2023:

Mercury and Air Toxics

The Biden administration in January 2022 reversed course on a Trump-era mandate that stripped legal justification for bedrock mercury standards.

The proposal reinstates an “appropriate and necessary” finding for Mercury and Air Toxics Standards, which provides stronger legal justification for one of the EPA’s most potent air and water rules.

A residual risk and technology review process is also forthcoming from the agency to determine whether the standards should be tightened from their 2012 levels—a move that environmental groups have been calling for. That finalization is likely coming at the “beginning of the year,” according to McCabe.

Particulate Matter

New limits for deadly particulate matter pollution are on the horizon after an extensive reevaluation of 2020 status quo standards starting in 2021. A 500-page proposal for new standards was published in the Federal Register on Friday, seeking public comment on where the levels should land when finalized.

But the agency is in for an uphill battle while deliberating on a final number.

The proposal strengthens the 2012 standards from 12 micrograms per cubic meter to within the range of 9 to 10, levels environmental groups say are still too weak to protect public health. The agency estimates a final rule before the end of 2023.

Power Plant Carbon

Long contested standards to limit greenhouse gas emissions from existing coal-fired power plants are scheduled for release in the spring, according to agency officials and the administration’s unified regulatory agenda.

The process of setting limits for coal-fired utilities has been fraught with legal challenges since the Obama administration.

The 2022 Supreme Court decision in West Virginia v. EPA ultimately limited how far Biden could go in crafting new rules, though McCabe assured observers at the Resources for the Future event that the agency doesn’t expect the ruling “to be a major barrier.”

Ozone Good Neighbor Plan

New emission limits for certain states and industries will be finalized this year as part of a “good neighbor” ozone plan to stem ozone pollution that wanders into downwind states.

The proposal adds four new western states that now must comply with ozone limits typically imposed on East Coast states. Natural gas, power plant, cement, glass, and paper industries—many of which oppose the tighter limits—are among the new sectors also included in the proposal.


A broader plan to stem methane leaks from oil and gas wells is due for finalization “fairly soon,” according to McCabe.

EPA proposed New Source Performance Standard updates in 2021, followed by a supplemental rule proposal in 2022 that further tightens leak requirements for abandoned and low-producing oil and gas wells.

The supplemental proposal also improves methane monitoring by requiring that high-volume leaks be reported by third parties as part of a “Super-Emitter Response Program.” Groups urged the EPA in January 2023 public hearings to finalize the rule as soon as possible. The comment period ends Feb. 13.

Heavy-Duty Trucks

Phase Two of the EPA’s plan to limit emissions from heavy duty trucks is due this year, a proposal that will set greenhouse gas limits for models years 2027 and later.

The EPA finalized the first update to its smog-forming emission limits in over two decades in December 2022. That rule—Phase One of a broader Clean Trucks Plan—sets nitrous oxide limits for 18-wheelers and other heavy-duty vehicles. Phases two and three of the plan will deal with greenhouse gases.

Tailpipe Emissions

The EPA is set to release multi-pollutant emission standards for light- and medium-duty vehicles later this spring, specifically for model years 2027 and beyond.

The proposal is the next step in auto emission rules finalized by the Biden administration in 2021.