Regulatory Tracker

In September 2026, EPA rescinded most GHG emissions standards from fossil fuel-fired power plants. EPA also proposed a rule that would prevent it from issuing such standards.

Through two state plan approvals, EPA finalized a new policy that eases all states’ Regional Haze planning obligations. Environmental groups are challenging the approvals.

In June 2026, EPA partially withdrew SSM SIP Call findings of failure to submit, leaving four state agencies with outstanding SSM revision obligations.

EPA rescinded the 2024 mercury and air toxics standards (MATS) for power plants and reinstated the 2012 MATS.

EPA establishes the baseline requirements for new source review (NSR) permits, which are then issued by state and local air pollution agencies. In 2025 and 2026, EPA made changes to the NSR program easing permitting requirements.

Under the Trump executive order Regulatory Freeze Pending Review, the Biden administration’s final rule setting deadlines for states to submit SIPs for nonattainment areas did not go into effect. EPA announced in June 2025 that it would reconsider the rule and, in June 2026, proposed changes that would eliminate certain SIP requirements for reclassified areas.

On March 12, 2025, EPA announced a reconsideration of the NAAQS.

The Clean Air Act’s Good Neighbor provision requires upwind states to ensure that their instate sources do not contribute to downwind states’ attainment of the NAAQS. On Mar. 12, 2025, EPA announced its plan to roll back the Biden administration’s Good Neighbor Plan, which the Supreme Court stayed in June 2024.

EPA sets NAAQS for six common and harmful pollutants: carbon monoxide, lead, PM, ozone, nitrogen dioxide, and sulfur dioxide.