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 ...

The D.C. Circuit granted in part and denied in part a petition challenging EPA's update to the Cross-State Air Pollution Rule. Environmental groups and Delaware argued that EPA violated the CAA by failing to require upwind states to eliminate their significant contributions in accordance with the de...