Environmental Defense et al. v. Duke Energy Corporation, et al.
127 S. Ct. 1423 (2007)
Premium Feature
Subscribe to Lexplug to listen to the Case Podcast.
Rule of Law:
The presumption that an identical term used in different parts of the same statute has the same meaning is not absolute and can be rebutted by context. An administrative agency may reasonably interpret the same statutory term differently when implementing distinct regulatory programs with different statutory objectives under the same act.
Facts:
- Duke Energy Corporation operates 30 coal-fired electric generating units at eight plants, which were placed in service between 1940 and 1975.
- Between 1988 and 2000, Duke replaced or redesigned 29 major boiler tube assemblies in its units.
- The purpose of this work was to extend the operational life of the units and allow them to run for more hours each day.
- The projects did not increase the maximum hourly rate at which the units emitted pollutants.
- By enabling the units to operate for more hours annually, the projects resulted in an increase in the total annual amount of pollutants emitted.
Procedural Posture:
- The United States sued Duke Energy Corporation in the U.S. District Court for the Middle District of North Carolina, alleging that Duke performed major modifications on its power plants without obtaining the required PSD permits.
- Environmental Defense and other environmental groups intervened as plaintiffs.
- On Duke's motion for summary judgment, the District Court ruled in Duke's favor, holding that under the applicable PSD regulations, a 'major modification' occurs only if a project increases the hourly rate of emissions.
- The plaintiffs (appellants) appealed the decision to the U.S. Court of Appeals for the Fourth Circuit.
- The Court of Appeals affirmed the judgment for Duke (appellee), reasoning that because the Clean Air Act uses one statutory definition for 'modification' in both the NSPS and PSD sections, the EPA's regulations must interpret the term identically, thus mandating an hourly emissions test for PSD modifications.
- The intervenor-plaintiffs (petitioners) sought and were granted a writ of certiorari from the Supreme Court of the United States.
Premium Content
Subscribe to Lexplug to view the complete brief
You're viewing a preview with Rule of Law, Facts, and Procedural Posture
Issue:
Does the Clean Air Act, by providing a single statutory definition for the term 'modification' for both the New Source Performance Standards (NSPS) and Prevention of Significant Deterioration (PSD) programs, require the Environmental Protection Agency (EPA) to apply an identical regulatory interpretation to that term in both contexts?
Opinions:
Majority - Justice Souter
No. The Clean Air Act does not require the EPA to use an identical regulatory definition for 'modification' in both the NSPS and PSD programs, as the agency has discretion to interpret a general statutory term differently to suit distinct regulatory goals. The presumption that identical words have an identical meaning is not an 'irrebuttable' rule and readily yields to variations in context and statutory purpose. The NSPS and PSD programs have different objectives, justifying different regulatory approaches; NSPS focuses on the efficiency of technology (measured by hourly rate), while PSD aims to protect overall air quality (measured by total annual emissions). The plain text of the 1980 PSD regulations measures emissions increases in 'tons per year' based on 'actual operating hours,' which is fundamentally inconsistent with the hourly-rate test used in NSPS regulations. The Court of Appeals' attempt to 'construe' the PSD regulations to require an hourly-rate test was not a permissible interpretation but an implicit invalidation of the regulation, a challenge which is procedurally barred in an enforcement action by § 307(b) of the Act.
Concurring - Justice Thomas
I concur in the judgment but disagree with the majority's reasoning. The statutory cross-reference linking the PSD definition of 'modification' directly to the NSPS definition demonstrates clear congressional intent for a singular, unified regulatory definition. Unlike the mere repetition of a word, this explicit linkage should prevent the EPA from adopting different regulatory definitions for the same term. However, I concur in the judgment because the Court of Appeals's method of reaching its conclusion—implicitly invalidating a regulation outside the statutorily prescribed channel for judicial review—was procedurally improper. Therefore, while I disagree with the majority's reasoning on agency discretion to interpret the cross-referenced term differently, I agree that the case should be vacated and remanded.
Analysis:
This decision significantly bolsters administrative agency discretion, confirming that an agency can interpret a single statutory term differently when applying it to distinct regulatory schemes within the same statute. It rejects a rigid, textualist approach in favor of a context-sensitive one that considers the different purposes of related statutory provisions. By doing so, the Court allows agencies like the EPA to tailor regulations to the specific goals of each program, such as focusing on emission rates for technology standards (NSPS) and total annual emissions for air quality preservation (PSD). The ruling also reinforces important procedural limits on judicial review, preventing regulated parties from collaterally attacking the validity of long-standing regulations during enforcement proceedings.
