Docket 82-1005
Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc.
DecidedJun 25, 1984
6-0unanimous decision
Source: CourtListener.
Court upholds EPA's "bubble" rule letting plants treat all equipment as one pollution source
Impact9/10
What it does
The ruling establishes a two-step framework for courts reviewing agency interpretations of statutes: first ask whether Congress has directly addressed the precise issue, and if the statute is silent or ambiguous, defer to the agency's interpretation as long as it is reasonable. Applying that framework, the Court upheld EPA's regulation allowing states to define an entire industrial plant as a single "stationary source" for pollution permitting purposes, rather than treating each piece of equipment separately.
Who benefits
Owners and operators of industrial plants in areas that have not met federal air quality standards, who can now modify or add equipment without a permit as long as total plant emissions do not increase; and federal agencies generally, whose reasonable interpretations of ambiguous statutes they administer now receive judicial deference.
Who is affected
Environmental advocacy groups and citizens near industrial facilities who sought stricter unit-by-unit permitting review, and federal courts, whose ability to substitute their own statutory interpretation for an agency's reasonable reading is now limited.
Practical impact
Federal agencies gained substantial latitude to interpret ambiguous statutes they administer, with courts required to uphold any reasonable agency reading rather than impose their own preferred interpretation. In practice, industrial facilities in nonattainment areas could modify equipment without individualized permits as long as overall plant emissions did not rise, giving companies more flexibility to modernize equipment. This framework, known as "Chevron deference," became the dominant method for judicial review of agency action across nearly all areas of federal regulation for decades.
Majority reasoning
The majority reasoned that the Court of Appeals erred by imposing its own fixed judicial definition of "stationary source" after concluding Congress had not decided the issue, rather than asking whether EPA's interpretation was reasonable. The Court explained that when Congress has not directly spoken to a precise question, and has implicitly or explicitly left a gap for the agency to fill, courts must defer to any reasonable agency interpretation rather than substitute their own judgment. Examining the statutory text, the majority found the term "stationary source" ambiguous and the legislative history unilluminating on the plantwide-definition question, noting Congress plainly intended to balance economic growth against environmental improvement without resolving this specific method. Because EPA's plantwide definition reasonably reconciled these competing statutory purposes, articulated through a detailed rulemaking process, the Court held it must be upheld even if judges might have reached a different conclusion themselves. The majority added that this dispute was really a policy disagreement that respondents lost within the agency and the states, and such disagreements belong before elected, politically accountable officials rather than unelected judges.
Constitutional question
Whether a federal court must defer to an agency's reasonable interpretation of an ambiguous term in a statute it administers, and specifically whether EPA's plantwide ("bubble") definition of "stationary source" under the Clean Air Act was a permissible reading of the law.