40 CFR § 63.1550
Delegation of authority
June 9, 2020
(a) In delegating implementation and enforcement authority to a State under section 112(l) of the act, the authorities contained in paragraph (b) of this section must be retained by the Administrator and not transferred to a State.
(b) Authorities which will not be delegated to States: No restrictions.
[76 FR 70858, Nov. 15, 2011]