The Fifth Circuit upheld EPA's approval of Louisiana's SIP for controlling regional haze. Environmental groups challenged the approval of Louisiana's selection of low-sulfur coal over a more effective pollutant control as the best available retrofit technology to curb emissions at a coal-fired power...

A district court ordered an electric utility company to obtain a PSD permit to address CAA violations at its coal-fired power plant in Festus, Missouri. EPA argued that the company increased the risk of negative health impacts and premature deaths by releasing excess tons of sulfur dioxide from its ...

The D.C. Circuit vacated EPA's 2018 update to the Cross-State Air Pollution Rule (CSAPR). States and environmental groups argued that EPA violated the CAA by failing to require upwind states to reduce their contribution of ozone precursors to downwind states in accordance with the deadline by which ...