US SUPREME COURT DECISIONS

Under the Clean Air Amendments of 1970, which establish a program for controlling air pollution, the Environmental Protection Agency (EPA) is required to set "ambient air" quality standards which, in the EPA's judgment, are "requisite to protect the public health," § 109(b)(1) ("primary" standards), and

"requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air,"

§ 109(b)(2) ("secondary" standards). Each State, after promulgation of these standards, must submit an implementing and maintenance plan, which must be approved by the EPA if, inter alia, it meets eight general conditions set forth in § 110(a)(2), the principal one of which is that the plan provide for the attainment of the national primary ambient air quality standards in the State "as expeditiously as practicable," but no later than three years from the date of the plan's approval. § 110(a)(2)(A). The State's plan must include emission limitations, schedules, compliance timetables, and other measures insuring timely attainment and subsequent maintenance of the national standards. In order to develop the requisite plan within the statutory deadline, Georgia elected to follow an EPA-endorsed approach providing for immediately effective categorical emission limitations accompanied, however, by a variance procedure whereby particular sources could obtain individually tailored relief from the general requirements. Section 110(a)(3) provides that the EPA shall approve any "revision" of an implementation plan that meets the § 110(a)(2) requirements applicable to an original plan, and the EPA, concluding that that provision permits a State to grant individual variances meeting § 110(a)(2) requirements from generally applicable emission standards, both before and after the attainment date, approved the Georgia plan. Respondents initiated review proceedings in the Court of Appeals, taking the position that variances applicable to individual sources may be approved only if they meet the much chanrobles.com-red

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more stringent procedural and substantive standards of § 110(f), which, upon application prior to the compliance date for a stationary source or class of moving sources, permits "postponements" of no more than one year of any requirement of plan, subject to specified conditions. That court upheld respondents' contentions, and ordered the EPA to disapprove Georgia's variance provision.

Held: The EPA's construction of the Act permitting treatment of individual variances from state requirements as "revisions," under § 110(a)(3), of state implementation plans if they will not interfere with timely attainment and subsequent maintenance of national air quality standards, rather than as "postponements" under § 110(f), was sufficiently reasonable to preclude the Court of Appeals from substituting its judgment for that of the EPA. Pp. 421 U. S. 75-99.

(a) Section 110(f) is a safety valve by which may be accorded, under certain carefully specified circumstances, exceptions to the mandatory deadlines for meeting national standards, and, contrary to respondents' contention, does not constitute the sole mechanism by which exceptions to a plan's requirements may be obtained. Pp. 421 U. S. 78-84.

(b) This concept of § 110(f)'s limited role is reinforced by comparison with § 110(e), which permits a two-year extension of the three-year period referred to in § 110(a)(2)(A)(i) on a showing far less stringent than that required for a § 110(f) one-year postponement, which would be inexplicable were § 110(f) the sole mechanism for States to modify their initial formulations of emission limitations. Pp. 421 U. S. 84-86.

(c) Noting that § 110(f) provides that a postponement may be granted with respect to the date that "any stationary source" must comply with "any requirement of an applicable state implementation plan," the Court of Appeals reached an erroneous conclusion that the § 110(f) procedure was exclusive; the language of that provision does not mandate that all modifications of a plan's requirements necessarily be treated as postponements, precluding other forms of relief. Pp. 421 U. S. 87-88.

(d) The Court of Appeals also erred in its conclusion that "a revision is a change in a generally applicable requirement," whereas a "postponement or variance" deals with particular parties, for here the implementation plans being revised are quite detailed; moreover, the court's analysis overlooks obvious distinctions between revisions and postponements in the statutory context. Pp. 421 U. S. 88-90. chanrobles.com-red

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(e) Section 110(a)(3) revisions are granted by the EPA only if they comport with the § 110(a)(2)(A) requirement that the national standards be attained as expeditiously as practicable and thereafter maintained, so the "technology-forcing" nature of the Amendments is no reason for judging under § 110(f) variances which qualify for approval under § 110(a)(3). Pp. 421 U. S. 90-91.

(f) Congress felt that the EPA could feasibly and reliably perform the measurement and predictive functions necessary to pass on variances as revisions under § 110(a)(3). Pp. 421 U. S. 91-94.

(g) Respondents' argument that, because any variance would delay attainment of national standards beyond what was previously considered as the earliest practicable date, and that, because the Act requires attainment as soon as practicable, any variance must therefore be treated as a postponement, is not supported by the legislative history or otherwise. Pp. 421 U. S. 94-97.

(h) Respondents' contention, based on § 110(a)(2)(H), that revision authority is limited to general changes initiated by the EPA in order to "accelerate abatement or attain it in greater concert with other national goals," is specious. That provision, which does no more than impose a minimum requirement that state plans be capable of such modifications as are necessary to meet the basic goal of cleansing the ambient air to the extent necessary to protect public health, as expeditiously as possible within the three-year period, does not prevent the States from also permitting ameliorative revisions not contrary to that goal. Pp. 421 U. S. 97-98.

489 F.2d 390, reversed and remanded.

REHNQUIST, J., delivered the opinion of the Court, in which BURGER, C.J.,and BRENNAN, STEWART, WHITE, MARSHALL, and BLACKMUN, JJ., joined. DOUGLAS, J., dissented. POWELL, J., took no part in the consideration or decision of the case. chanrobles.com-red

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