Natural Res. Def. Council v. Envtl. Prot. Agency

Griffith, Circuit Judge:

The Clean Air Act calls upon the Environmental Protection Agency to protect air quality by enforcing state and local limits on the amount of pollution. The agency need not count against those limits pollution caused by "exceptional events." In this case, Natural Resources Defense Council and Sierra Club challenge a rule the agency uses to determine whether an event caused by recurring activity is "natural," and thus "exceptional," or "caused by human activity," and thus not. 42 U.S.C. § 7619 (b)(1)(A)(iii). We think the agency's rule is permitted by the Clean Air Act.

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