D.C. Circuit Hands Green Groups a Win on Trump Smog Rule (1)

Environmentalists got a win Friday after the D.C. Circuit threw out three provisions in a Trump-era smog air quality rule that green groups argued weakened national standards for ozone pollution.

Three of four contested provisions from the Environmental Protection Agency’s 2018 ozone pollution implementation rule violated the plain language of the Clean Air Act, the U.S. Court of Appeals for the District of Columbia said. Ozone is one of six pollutants for which the EPA has set national air quality standards.

“We vacate two provisions—the interprecursor trading program and the interpretation of the Clean Air Act’s contingency measures requirements—because ...