Supreme Court of the United States / October Term 2006

Environmental Defense, et al. v. Duke Energy Corporation, et al.

Decided April 2, 2007. David Hackett Souter delivered the opinion of the Court.

Docket 05-848 · 549 U.S. 561 (2007) · Cited 190 times

Holding

The Fourth Circuit’s reading of the PSD regulations in an effort to conform them with their NSPS counterparts on “modification” amounted to the invalidation of the PSD regulations, which must comport with the Act’s limits on judicial review of EPA regulations for validity.

The Court’s statement of the holding, from the opinion’s syllabus. The syllabus is prepared by the Reporter of Decisions and is not part of the opinion of the Court — read the official opinion for authority.

How the Justices voted

Decided 9–0.

“Concurring” means agreeing with the outcome; any split shown is the Court’s judgment, not each Justice’s reasoning. Source: the Supreme Court Database (Spaeth et al.), Washington University.

Precedents cited

Supreme Court decisions this opinion relies on, ordered by how often it cites each. Cases in our collection link through; others are named.

Cited by

Later Supreme Court opinions in our collection that cite this case.

Official text

Read the official opinion (U.S. Reports, govinfo.gov)

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David Hackett Souter’s profile · All Supreme Court opinions · The Supreme Court

Source: Supreme Court of the United States, slip opinions (2007). Citation count from the Free Law Project’s CourtListener bulk data. Data last verified 2026-07-03. Informational only; verify against the primary source before relying. Not a consumer report (FCRA).