The D.C. Circuit, on remand from the U.S. Supreme Court, invalidated EPA's 2014 emissions budgets under the transport rule, also known as the Cross-State Air Pollution Rule, as applied to various states. The CAA's "good neighbor" provision requires upwind states to prevent sources within their borde...

The D.C. Circuit denied petitions challenging an EPA regulation that revised the NESHAP for hexavalent chromium, a carcinogenic compound that gets emitted into the air during the chrome-finishing process. The new rule, issued in 2012, imposes more stringent emissions limitations than its predecessor...

The Tenth Circuit upheld on constitutional grounds Colorado's mandate that 20% of the electricity that generators sell to Colorado consumers come from renewable sources. A conservative energy group claimed that the renewable energy standard will harm out-of-state coal producers in violation of the C...

The D.C. Circuit upheld an EPA regulation that requires automobile manufacturers to use "commercially available" fuel when testing the emissions of new vehicles under the CAA. Several producers of E30, a fuel that contains 30% ethanol, argued that a fuel shouldn't have to be commercially available i...

A district court ordered Oklahoma to file a brief by July 16 explaining why the court should have jurisdiction over the state's lawsuit challenging EPA's proposed "Clean Power Plan" to reduce carbon dioxide emissions on a nationwide basis. Numerous states, including Oklahoma, recently filed a case i...