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Developments and Trends in Clean Air Act Source “Aggregation”

John R. Jacus, Air Quality Issues Affecting Oil, Gas, and Mining Development in the West

The topic of Clean Air Act (“CAA”) source determinations has been a relatively hot and controversial one for the natural resources industries, and especially the oil and gas sector in recent years. The topic has been animated by high profile administrative and judicial challenges by environmental advocacy groups and permittees alike, several of which are still pending; a recent federal appellate court decision holding a long-standing internal EPA interpretation to be unlawful, and a sequence of divergent approaches for oil and gas air permitting in particular by EPA itself. This paper reviews developments in CAA source determinations against this backdrop, including a review of the statutory and regulatory basis for source determinations, and several significant recent challenges to single-source air permitting of natural resources activities and facilities that are separated by varying distances, but are connected by pipelines, conveyors, and/or roads. The paper also touches upon the separate, but related prohibition on circumvention of New Source Review (“NSR”) permitting requirements.


The Clean Air Act2 defines a stationary source of air pollutants in such a way that multiple activities and items of equipment may collectively be permitted at a single source. This frequently happens without dispute or controvers