42 U.S.C. § 7478
Section 7478 · Period before plan approval
Amended 3 times on record
Applied in 10 court decisions — leading case Environmental Defense v. Duke Energy Corporation (2007)
Most recently applied in California v. U.S. E.P.A. (December 2018)
How often courts cite this section
Court decisions citing this, by year.Markers show enactment, consequential amendments, and circuit splits over this section — watch for a citation surge after a change or a disagreement. The dip in the last several years is a data-coverage gap, not a real trend — our corpus holds fewer opinions from the most recent years, so recent citations are undercounted.
Until such time as an applicable implementation plan is in effect for any area, which plan meets the requirements of this part to prevent significant deterioration of air quality with respect to any air pollutant, applicable regulations under this chapter prior to August 7, 1977, shall remain in effect to prevent significant deterioration of air quality in any such area for any such pollutant except as otherwise provided in subsection (b) of this section.
If any regulation in effect prior to August 7, 1977, to prevent significant deterioration of air quality would be inconsistent with the requirements of section 7472(a), section 7473(b) or section 7474(a) of this title, then such regulations shall be deemed amended so as to conform with such requirements. In the case of a facility on which construction was commenced (in accordance with the definition of “commenced” in section 7479(2) of this title) after June 1, 1975, and prior to August 7, 1977, the review and permitting of such facility shall be in accordance with the regulations for the prevention of significant deterioration in effect prior to August 7, 1977.
Editorial notes U.S. Code · Office of the Law Revision Counsel
Amendments
1977—Subsec. (b). Pub. L. 95–190 substituted “(in accordance with the definition of ‘commenced’ in section 7479(2) of this title)” for “in accordance with this definition”.