§ 51.1013 Quantitative milestone requirements.
(a) Consistent with CAA section 189(c)(1), the state must submit in each attainment plan for a PM2.5 nonattainment area specific quantitative milestones that demonstrate reasonable further progress toward attainment of the applicable PM2.5 NAAQS in the area and that meet the following requirements:
(1) Nonattainment areas initially classified as Moderate. (i) Except as provided in paragraph (a)(4) of this section, each attainment plan submittal for a Moderate PM2.5 nonattainment area shall contain quantitative milestones to be achieved no later than a milestone date of 4.5 years and 7.5 years from the date of designation of the area.
(ii) The plan shall contain quantitative milestones to be achieved by the milestone dates specified in paragraph (a)(1)(i) of this section, as applicable, and that provide for objective evaluation of reasonable further progress toward timely attainment of the applicable PM2.5 NAAQS in the area. At a minimum, each quantitative milestone plan must include a milestone for tracking progress achieved in implementing the SIP control measures, including RACM and RACT, by each milestone date.
(2) Nonattainment areas reclassified as Serious. (i) Except as provided in paragraph (a)(4) of this section, each attainment plan submission that demonstrates that a Serious PM2.5 nonattainment area can attain a particular PM2.5 NAAQS by the end of the tenth calendar year following the effective date of designation of the area with the implementation of control measures as required under § 51.1010(a) shall contain quantitative milestones to be achieved no later than milestone dates of 7.5 years and 10.5 years, respectively, from the date of designation of the area.