EPA Modestly Tightens Secondary NAAQS, But Requires No Emissions Cuts

EPA’s just-issued rule modifying “secondary” national ambient air quality standards (NAAQS) slightly tightens a limit for sulfur oxides (SOx) but requires no new emissions cuts, leaving other limits unchanged and providing states and industry with “streamlined” compliance options, although the incoming Trump EPA may reverse the rule anyway. In its rule signed Dec. 10, but not yet published in the Federal Register , EPA revises the SOx limit using different metrics than the current limit set in 1971. Secondary NAAQS...