⚖ Oral Arguments, with Context

The D.C. Circuit hears a challenge to EPA's rules for toxic air pollution. Large industrial facilities are generally subject to strict standards called maximum achievable control technology, or MACT. A facility is normally a major source if it emits, or has the potential to emit considering controls, at least ten tons a year of one hazardous air pollutant, or twenty-five tons of combined hazardous pollutants. Other stationary sources are called area sources and can face less demanding requirements. EPA's former 'once in, always in' policy kept facilities under major-source standards even after those standards brought emissions below the thresholds. In 2020, EPA changed course: a facility could leave those standards by reducing its emissions and potential emissions below the cutoffs, becoming subject instead to any applicable area-source rules. Environmental organizations filed a direct challenge here in 2021, joined in a consolidated case by state and local governments. They warn that a factory could relax its pollution controls and increase emissions while still staying below the major-source cutoffs. EPA and industry supporters say classification should track a facility's current emissions and potential to emit, not permanently bind it to its former status. The court must decide whether the rule violates the Clean Air Act and whether EPA adequately explained its changed approach. Sanjay Narayan will argue first for the environmental groups, seeking to keep facilities bound by the stricter standards once they apply.

California Communities Against v. EPA (No. 21-1024) — U.S. Court of Appeals for the D.C. Circuit, argued October 5, 2026.