US SUPREME COURT DECISIONS

The Clean Air Act Amendments of 1977 impose certain requirements on States that have not achieved the national air quality standards established by the Environmental Protection Agency (EPA) pursuant to earlier legislation, including the requirement that such "nonattainment" States establish a permit program regulating "new or modified major stationary sources" of air pollution. Generally, a permit may not be issued for such sources unless stringent conditions are met. EPA regulations promulgated in 1981 to implement the permit requirement allow a State to adopt a plantwide definition of the term "stationary source," under which an existing plant that contains several pollution-emitting devices may install or modify one piece of equipment without meeting the permit conditions if the alteration will not increase the total emissions from the plant, thus allowing a State to treat all of the pollution-emitting devices within the same industrial grouping as though they were encased within a single "bubble." Respondents filed a petition for review in the Court of Appeals, which set aside the regulations embodying the "bubble concept" as contrary to law. Although recognizing that the amended Clean Air Act does not explicitly define what Congress envisioned as a "stationary source" to which the permit program should apply, and that the issue was not squarely addressed in the legislative history, the court concluded that, in view of the purpose of the nonattainment program to improve, rather than merely maintain, air quality, a plantwide definition was "inappropriate," while stating it was mandatory in programs designed to maintain existing air quality.

Held: The EPA's plantwide definition is a permissible construction of the statutory term "stationary source." Pp. 467 U. S. 842-866.

(a) With regard to judicial review of an agency's construction of the statute which it administers, if Congress has not directly spoken to the precise question at issue, the question for the court is whether the chanrobles.com-red

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agency's answer is based on a permissible construction of the statute. Pp. 467 U. S. 842-845.

(b) Examination of the legislation and its history supports the Court of Appeals' conclusion that Congress did not have a specific intention as to the applicability of the "bubble concept" in these cases. Pp. 467 U. S. 845-851.

(c) The legislative history of the portion of the 1977 Amendments dealing with nonattainment areas plainly discloses that, in the permit program, Congress sought to accommodate the conflict between the economic interest in permitting capital improvements to continue and the environmental interest in improving air quality. Pp. 467 U. S. 851-853.

(d) Prior to the 1977 Amendments, the EPA had used a plantwide definition of the term "source," but in 1980, the EPA ultimately adopted a regulation that, in essence, applied the basic reasoning of the Court of Appeals here, precluding use of the "bubble concept" in nonattainment States' programs designed to enhance air quality. However, when a new administration took office in 1981, the EPA, in promulgating the regulations involved here, reevaluated the various arguments that had been advanced in connection with the proper definition of the term "source" and concluded that the term should be given the plantwide definition in nonattainment areas. Pp. 467 U. S. 853-859.

(e) Parsing the general terms in the text of the amended Clean Air Act -- particularly the provisions of §§ 302(j) and 111(a)(3) pertaining to the definition of "source" -- does not reveal any actual intent of Congress as to the issue in these cases. To the extent any congressional "intent" can be discerned from the statutory language, it would appear that the listing of overlapping, illustrative terms was intended to enlarge, rather than to confine, the scope of the EPA's power to regulate particular sources in order to effectuate the policies of the Clean Air Act. Similarly, the legislative history is consistent with the view that the EPA should have broad discretion in implementing the policies of the 1977 Amendments. The plantwide definition is fully consistent with the policy of allowing reasonable economic growth, and the EPA has advanced a reasonable explanation for its conclusion that the regulations serve environmental objectives as well. The fact that the EPA has from time to time changed its interpretation of the term "source" does not lead to the conclusion that no deference should be accorded the EPA's interpretation of the statute. An agency, to engage in informed rulemaking, must consider varying interpretations and the wisdom of its policy on a continuing basis. Policy arguments concerning the "bubble concept" should be addressed to legislators or administrators, not to judges. The EPA's interpretation of the statute here represents a reasonable accommodation of manifestly competing interests, and is entitled to deference. Pp. 467 U. S. 859-866.

222 U.S.App.D.C. 268, 685 F.2d 718, reversed. chanrobles.com-red

Page 467 U. S. 839

STEVENS, J., delivered the opinion of the Court, in which all other Members joined, except MARSHALL and REHNQUIST, JJ., who took no part in the consideration or decision of the cases, and O'CONNOR, J., who took no part in the decision of the cases.