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 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...

The Seventh Circuit denied a petition for review challenging EPA’s decisions to redesignate three geographic areas—Milwaukee-Racine, Greater Chicago, and the Illinois portion of the St. Louis area—as having attained the 1997 NAAQS for ozone. Before redesignating an area, the CAA requires EPA t...

A district court dismissed individuals' CAA citizen suit against an oil company for emission violations at the company's refinery, olefins plant, and chemical plant in Baytown, Texas. It is undisputed the company violated some emission standards or limitations under its Title V permit. Indeed, it is...

The D.C. Circuit held that EPA's regulations implementing the 2008 NAAQS for ozone exceed the Agency’s authority under the CAA. In 2008, EPA revised and strengthened the standards for ozone pursuant to the CAA. One of the revisions extended the deadline for some regions to attain the new standards...

The Ninth Circuit upheld a lower court decision dismissing an environmental group's citizen suit requesting EPA to issue more stringent regulations for ozone pollution under the PSD program. The group alleged that the EPA Administrator has a nondiscretionary duty to issue revised ozone regulations u...

The Ninth Circuit held that DOT did not violate the CAA or NEPA in its approval of a planned expressway connecting the Ports of Los Angeles and Long Beach, California. In the course of the project’s approval process, DOT conducted an air quality conformity determination under the CAA, which involv...

The D.C. Circuit dismissed automobile industry groups' petition challenging an EPA rule intended to mitigate the misfueling of vehicles and engines with gasoline containing greater than 10% ethanol (E10). Among other measures, the rule prohibits the use of E10 gasoline in certain vehicles, engines, ...