D.C. Circuit Invalidates CEQ's NEPA Regulations on Separation-of-Powers Grounds, Vacates Air Tour Management Plan

The D.C. Circuit held that Council on Environmental Quality regulations implementing NEPA were ultra vires because CEQ traced its rulemaking authority to a presidential executive order rather than congressional delegation, violating separation-of-powers principles. The court further ruled that FAA and National Park Service acted arbitrarily and capriciously by using existing interim flight levels as the environmental baseline for assessing a commercial air tour management plan over four national parks.