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 dismissed EPA's lawsuit against an Oklahoma utility under the CAA alleging that it failed to properly project whether modifications made to two coal-fired power plants would result in an increase in emissions. The plants were constructed before Congress enacted the PSD program. As a...