Editors' Summary: In the second of two Articles, Professor Craig. N. Oren examines the controversial recent opinion, and subsequent denial of rehearing en banc, in American Trucking Ass'n v. U.S. Environmental Protection Agency, in which a panel ofthe D.C. Circuit Court of Appeals remanded EPA's air quality standards for ozone and particulate matter. In his first Article, Professor Oren analyzed the reasons, logic, alternatives to, and likely consequences of the court's remand of the air quality standards based on the delegation doctrine. In this month's Article, Professor Oren examines the court's holding that apparently requires EPA to enforce revised ozone standards only under Subpart 2 of Part D of the CAA.

The Article begins by describing EPA's approach to setting the revised ozone standards and, more specifically, how the Agency adopted its implementation strategy for the revised ozone NAAQS. The Article next discusses the language and provisions of the CAA on which the court relied in reaching its holding. The Article suggests that the decision means that EPA cannot require states to revise their implementation plans to include measures beyond what assures attainment of the previous ozone standard. The Article argues that such a holding conflicts with the CAA's language, structure, and legislative history. CAA § 181(a)(1) and other CAA sections appear to allow further implementation measures for the new revised standards. Moreover, the court's holding appears in conflict with the language and structure of Subpart 1 of Part D. Further, in addressing the policy behind the court's holding, the Article contends that allowing enforcement under Subpart 1 will not negate the congressional purpose behind Subpart 2. In addition, the Article asserts that the court ignored additional implementation measures that EPA authorizes during the CAA's pre-1990 practice of requiring additional control measures to implement revised ambient air quality standards, and failed to understand that Congress intended to tighten that approach rather than make it more lax. Thus, the Article concludes that the court should vacate the portion of its opinion addressing implementation of the revised standards and remand the matter to EPA for further consideration. EPA could then formulate a solution aided by notice and comment that would resolve the issue that Congress failed to address in the 1990 Amendments.