Resisting Environmental Destruction on Indigenous Lands v. United States Environmental Protection Agency

Since 1990, the Environmental Protection Agency (“EPA”) has been responsible for regulating air pollution from offshore sources on the Outer Continental Shelf (“OCS”) under the Clean Air Act (“the Act”). 42 U.S.C. § 7627 . We consider here whether the EPA’s Environmental Appeals Board (“EAB”) properly upheld two air permits authorizing exploratory drilling operations in the Arctic Ocean by a drillship and its associated fleet of support vessels. The petition for review challenges two aspects of the permits: (1) the determination that support vessels, unlike the drillship itself, do not require the best available control technology (“BACT”) to control emissions; and (2) the exemption of the area within a 500-meter radius of the drillship from ambient air quality standards.

The application of BACT to support vessels requires us to reconcile conflicting provisions of the Act. In doing so, under Chevron U.S.A., Inc. v. NRDC, Inc., we defer to the EAB’s reasonable interpretation of those provisions and related regulations. 467 U.S. 837 , 104 S.Ct. 2778 , 81 L.Ed.2d 694 (1984). Likewise, we evaluate whether the EAB’s decision on the ambient air boundary is a permissible…