The D.C. Circuit vacated an EPA memorandum directing regional air districts to apply different criteria when making source determinations in its Title V or new source review (NSR) permitting…

The D.C. Circuit upheld EPA’s decision to defer adopting new secondary NAAQS for oxides of sulfur (SOx) and nitrogen (NOx) pending further scientific study. Citing doubts about the accuracy of its…

A district court dismissed an individual's CAA lawsuit against a Colorado utility and the state's environmental agency in which he alleged that toxic fumes were emitted into his…

The D.C. Circuit upheld EPA’s decision denying environmental groups’ request to add coal mines to the regulated list of stationary source categories under the CAA. In denying the groups’…

The D.C. Circuit denied industry groups' petition for review challenging EPA's 2013 primary NAAQS for fine particulate matter. In the final rule, EPA lowered the level of the particulate…

The D.C. Circuit upheld EPA's renewable fuels standard (RFS) for 2013. Because EPA reduced the cellulosic ethanol blending requirement for 2013 but not the total renewable fuel volume,…

The U.S. Supreme Court reversed and remanded a lower court decision vacating EPA's transport rule, also known as the Cross-State Air Pollution Rule, which sets sulfur dioxide and nitrogen…

The D.C. Circuit vacated a portion of EPA's 2013 rule regulating air emissions from Portland cement kilns. The court concluded that the emission-related portions of the rule are permissible…

The D.C. Circuit upheld the emission standards EPA promulgated in 2012 for mercury and other listed hazardous air pollutants emitted by coal- and oil-fired electric utility steam generating units…

 The primary standards for carbon monoxide have remained the same since 1971. There has not been a secondary standard for carbon monoxide since EPA revoked a secondary standard in 1985.…