The First Circuit amended a previous ruling vacating an air permit issued by the Massachusetts Department of Environmental Protection (MDEP) for a proposed natural gas compressor station that is part of a pipeline connecting the northeastern United States and Canada. The court had found that MDEP fa...

The Third Circuit granted a petition to review EPA's approval of Pennsylvania's proposed NAAQS for ozone. An environmental group argued the standards wrongly claimed to reduce pollution output at the state's most advanced coal-burning power plants while "simply rubberstamping an average of current p...

The D.C. Circuit denied in part and dismissed in part a petition to review EPA's guidance concerning the process of certifying cellulosic biofuel. A biofuel company argued the guidance was a legislative rule that was invalidly promulgated without notice and comment, conflicted with the regulation it...

A district court granted states' motion for summary judgment in a lawsuit concerning EPA's duty to limit air pollution drifting from upwind states into northeastern states. Connecticut, Delaware, Massachusetts, New Jersey, and New York argued that EPA failed to fulfill a nondiscretionary duty under ...

The Fifth Circuit vacated and remanded a lower court decision that imposed penalties against an oil company for alleged CAA permit violations at its industrial complex in Baytown, Texas. Environmental groups filed a CAA citizen suit against the company, alleging violations that occurred thousands of...