Regulatory Tracker

The Clean Air Act’s “Good Neighbor” provision requires upwind states to ensure that the air pollution they create does not affect downwind states’ ability to meet the NAAQS. Upwind states are required to address interstate pollution in their State Implementation Plans for implementing the NAAQS and if EPA finds the SIP inadequate it must issue a Federal Implementation Plan.

EPA has begun proposing and finalizing approvals and disapprovals of SIP revisions in accordance with the Consent Decree.

The Clean Air Act requires EPA to review the NAAQS every five years to ensure adequacy. The review process is a multi-stage, robust evaluation of current science and requires significant expert input.

States have until May 2026 to develop state plans for existing coal-fired power plants. Litigation commenced immediately upon EPA’s finalization of the standards in the D.C. Circuit.

EPA published its final rule regulating HAPs from Coal- and Oil-Fired EGUs based on the Residual Risk and Technology Review.

EPA under the Trump administration delayed implementation of the 2015 ozone National Ambient Air Quality Standards. Under legal pressure from environmental groups, EPA under the Biden administration is working to implement the 2015 ozone NAAQS by making compliance determinations.

The NSR program is a long-established set of Clean Air Act rules that safeguards communities from increases in pollution when a new facility is built or an existing facility is modified.

The NAAQS are based solely on public health and welfare protection, meaning that the agency must not consider the cost of revising a standard if the current science demands a standard be tightened to protect public health or welfare.

Power plants and other industrial sources emit more pollution as they start up, shut down, or when they malfunction (SSM) than during normal operations. These periods of higher pollution have negative effects on air quality and human health.

We are not currently updating this rule.