The US Court of Appeals for the District of Columbia Circuit ruled Friday that a stricter air quality rule imposed by the US Environmental Protection Agency (EPA) in 2016 is constitutional under its authority established by the Clean Air Act.
The Clean Air Act includes a Good Neighbor provision to address problems of upwind states’ pollution impairing downwind states’ air quality. This provision prohibits states from “emitting any air pollutant in amounts” that will “contribute significantly to non-attainment” or “interfere with maintenance” of air quality in other states, the ruling explains. This provision was upheld by the Supreme Court in 2014.
