(a) Effective March 2, 2022, the EPA has determined that the Hayden nonattainment area failed to attain the 2008 primary and secondary lead (Pb) national ambient air quality standards (NAAQS) by the applicable attainment date of October 3, 2019. This determination triggers the requirements of CAA section 179(d) for the State of Arizona to submit a revision to the Arizona SIP for the Hayden nonattainment area to the EPA by January 31, 2023. The SIP revision must, among other elements, provide for attainment of the 2008 Pb NAAQS in the Hayden Pb NAA as expeditiously as practicable but no later than January 31, 2027.

(b) [Reserved]