42 U.S.C. § 7416 : US Code - Section 7416: Retention of State authority

Search 42 U.S.C. § 7416 : US Code - Section 7416: Retention of State authority

Except as otherwise provided in sections 1857c-10(c), (e), and
(f) (as in effect before August 7, 1977), 7543, 7545(c)(4), and
7573 of this title (preempting certain State regulation of moving
sources) nothing in this chapter shall preclude or deny the right
of any State or political subdivision thereof to adopt or enforce
(1) any standard or limitation respecting emissions of air
pollutants or (2) any requirement respecting control or abatement
of air pollution; except that if an emission standard or limitation
is in effect under an applicable implementation plan or under
section 7411 or section 7412 of this title, such State or political
subdivision may not adopt or enforce any emission standard or
limitation which is less stringent than the standard or limitation
under such plan or section.