An Arizona court overturned the state's issuance of an air permit for a proposed open-pit copper mine. An environmental group argued that the state's approval of the permit was arbitrary and capricious because the mine has the potential to violate NAAQS. They also claimed that the mine's modeling re...

The Ninth Circuit denied an environmental group's petition challenging EPA's approval of a revision to California's SIP. The revision provided alternative "not less stringent" controls to what is required in CAA §185's antibacksliding measures, which require that major stationary sources of polluti...

The Ninth Circuit upheld the dismissal of a trucking association's federal preemption challenge to a California environmental regulation on diesel trucks. The regulation requires heavy-duty diesel trucks, whose emissions contribute significantly to particulate matter and ozone pollution, to be upgra...

A district court held that BLM failed to adequately explain and support its decision to allow grazing on Sonoran Desert National Monument lands north of Interstate Highway 8 in violation of NEPA. Specifically, the court ruled that BLM's land health evaluation—an essential step in the process of de...