The D.C. Circuit vacated EPA's new source review (NSR) rule for Indian country, which established a federal implementation plan (FIP) covering all Indian country nationwide except where EPA had already approved a tribal NSR program or expressly authorized a SIP to be enforced. Because SIPs did not o...

A district court dismissed Native American and environmental groups' CAA citizen suit asking the court to order EPA to issue a final rule that establishes best available retrofit technology (BART) for the Navajo Generating Station, a coal-fired power plant in northern Arizona near the Grand Canyon. ...

The D.C. Circuit dismissed Arizona's objection to a consent decree that established a timeline for EPA to approve a SIP, or promulgate a federal implementation plan (FIP), that would meet the requirements of the Regional Haze Rule. A lower court held that it lacked jurisdiction to hear the objection...

The D.C. Circuit vacated an EPA rule establishing nonconformance penalties (NCPs) for on-highway, heavy-duty diesel engines. NCPs are intended to protect "technological laggards" by allowing them to pay a penalty for engines temporarily unable to meet new or revised emission standards. EPA establish...

The D.C. Circuit remanded for reconsideration EPA's revisions to the secondary, welfare-based NAAQS for ozone, but denied petitions challenging revisions to the primary, health-based ozone NAAQS. Primary standards set limits to protect public health, including the health of "sensitive" populations s...