All control requirements associated with a FIP or approved SIP in effect for an area pursuant to obligations arising from CAA section 110(a)(2)(D)(i) and (ii) as of October 24, 2016, such as the CAIR or the CSAPR, shall continue to apply after revocation of the 1997 primary annual PM2.5 NAAQS. Control requirements associated with a FIP or approved into the SIP pursuant to obligations arising from CAA section 110(a)(2)(D)(i) and (ii), including 40 CFR 51.123, 51.124, 52.35, 52.36, 52.38 and 52.39, may be modified by the state only if the requirements of §51.123, 51.124, 52.35, 52.36, 52.38 and 52.39, including statewide annual SO2 and annual NOX emission budgets, continue to be in effect. Any such modification must meet the requirements of CAA section 110(l).
40 CFR § 51.1016
Continued applicability of the FIP and SIP requirements pertaining to interstate transport under CAA section 110(a)(2)(D)(i) and (ii) after revocation of the 1997 primary annual PM2.5 NAAQS
June 9, 2020