51.1009—Reasonable further progress (RFP) requirements.

(a) Consistent with section 172(c)(2) of the Act, State implementation plans for areas designated nonattainment for the PM2.5 NAAQS must demonstrate reasonable further progress as provided in § 51.1009(b) through (h).
(b) If the State submits to EPA an attainment demonstration and State implementation plan for an area which demonstrates that it will attain the PM NAAQS within five years of the date of designation, the State is not required to submit a separate RFP plan. Compliance with the emission reduction measures in the attainment demonstration and State implementation plan will meet the requirements for achieving reasonable further progress for the area.
(c) For any area for which the State submits to EPA an approvable attainment demonstration and State implementation plan that demonstrates the area needs an attainment date of more than five years from the date of designation, the State also must submit an RFP plan. The RFP plan must describe the control measures that provide for meeting the reasonable further progress milestones for the area, the timing of implementation of those measures, and the expected reductions in emissions of direct PM2.5 and PM2.5 attainment plan precursors. The RFP plan is due to EPA within three years of the date of designation.
(1) For any State that submits to EPA an approvable attainment demonstration and State implementation plan justifying an attainment date of more than five and less than nine years from the date of designation, the RFP plan must include 2009 emissions milestones for direct PM2.5 and PM2.5 attainment plan precursors demonstrating that reasonable further progress will be achieved for the 2009 emissions year.
(2) For any area that submits to EPA an approvable attainment demonstration and State implementation plan justifying an attainment date of nine or ten years from the date of designation, the RFP plan must include 2009 and 2012 emissions milestones for direct PM2.5 and PM2.5 attainment plan precursors demonstrating that reasonable further progress will be achieved for the 2009 and 2012 emissions years.
(d) The RFP plan must demonstrate that in each applicable milestone year, emissions will be at a level consistent with generally linear progress in reducing emissions between the base year and the attainment year.
(e) For a multi-State nonattainment area, the RFP plans for each State represented in the nonattainment area must demonstrate RFP on the basis of common multi-State inventories. The States within which the area is located must provide a coordinated RFP plan. Each State in a multi-State nonattainment area must ensure that the sources within its boundaries comply with enforceable emission levels and other requirements that in combination with the reductions planned in other state(s) will provide for attainment as expeditiously as practicable and demonstrate reasonable further progress.
(f) In the benchmark RFP plan, the State must identify direct PM2.5 emissions and PM2.5 attainment plan precursors regulated under the PM2.5 attainment plan and specify target emission reduction levels to be achieved during the milestone years. In developing the benchmark RFP plan, the State must develop emission inventory information for the geographic area included in the plan and conduct the following calculations:
(1) For direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the attainment strategy, the full implementation reduction is calculated by subtracting the full implementation inventory from the baseline year inventory.
(2) The “milestone date fraction” is the ratio of the number of years from the baseline year to the milestone inventory year divided by the number of years from the baseline year to the full implementation year.
(3) For direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the attainment strategy, a benchmark emission reduction is calculated by multiplying the full implementation reduction by the milestone date fraction.
(4) The benchmark emission level in the milestone year is calculated for direct PM2.5 emissions and each PM2.5 attainment plan precursor by subtracting the benchmark emission reduction from the baseline year emission level. The benchmark RFP plan is defined as a plan that achieves benchmark emission levels for direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the attainment strategy for the area.
(5) In comparing inventories between baseline and future years for direct PM2.5 emissions and each PM2.5 attainment plan precursor, the inventories must be derived from the same geographic area. The plan must include emissions estimates for all types of emitting sources and activities in the geographic area from which the emission inventories for direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the plan are derived.
(6) For purposes of establishing motor vehicle emissions budgets for transportation conformity purposes (as required in 40 CFR part 93) for a PM2.5 nonattainment area, the State shall include in its RFP submittal an inventory of on-road mobile source emissions in the nonattainment area.
(g) The RFP plan due three years after designation must demonstrate that emissions for the milestone year are either:
(1) At levels that are roughly equivalent to the benchmark emission levels for direct PM2.5 emissions and each PM2.5 attainment plan precursor to be addressed in the plan; or
(2) At levels included in an alternative scenario that is projected to result in a generally equivalent improvement in air quality by the milestone year as would be achieved under the benchmark RFP plan.
(h) The equivalence of an alternative scenario to the corresponding benchmark plan must be determined by comparing the expected air quality changes of the two scenarios at the design value monitor location. This comparison must use the information developed for the attainment plan to assess the relationship between emissions reductions of the direct PM2.5 emissions and each PM2.5 attainment plan precursor addressed in the attainment strategy and the ambient air quality improvement for the associated ambient species.