Rules and Regulations. Notice of adequacy

Agency: Environmental Protection Agency (EPA)
Action: Notice of adequacy
Citation: FR Doc. 2025-08084 · EPA-R10-OAR-2024-0595; FRL-12391-01-R10 · 40 CFR 52

Summary

The Environmental Protection Agency (EPA) is notifying the public that we have found the motor vehicle emissions budgets adequate for transportation conformity purposes for the Fairbanks North Star Borough's 2006 24-hour fine particulate matter (PM ^2.5 ) nonattainment area. The budgets were submitted on December 4, 2024, as part of Alaska's state implementation plan revisions (Fairbanks Revised 189(d) Plan). As a result of our finding, these budgets must be used when determining conformity of the Fairbanks transportation plan and transportation improvement program.

Dates

This finding is effective May 23, 2025.

Supplementary Information

Throughout this document, “we” and “our” refer to the EPA. This document is simply an announcement of a finding that we have already made. The EPA Region 10 issued a letter on April 8, 2025, to the Alaska Department of Environmental Conservation stating that the PM ^2.5 motor vehicle emissions budgets, submitted in the Fairbanks Revised 189(d) Plan, are adequate. The motor vehicle emissions budgets that we have determined are adequate for transportation conformity purposes are provided in the following table: Adequate Motor Vehicle Emissions Budgets 1 for the 24-hour PM 2.5 NAAQS in the Fairbanks North Star Borough Budget years PM 2.5 2 On-road mobile source emissions (tons/day) Clean Air Act-related milestone 2023 0.062 Reasonable further progress (RFP). 2026 0.054 RFP. 2027 0.052 Attainment. 2029 0.049 RFP. Transportation conformity is required by Clean Air Act section 176(c), 42 U.S.C. 7506(c). The EPA's Transportation Conformity Rule (40 CFR part 93, subpart A) requires that transportation plans, transportation improvement programs, and projects conform to state air quality implementation plans (SIPs) and establishes the criteria and procedures for determining whether or not they do. Conformity to a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS. See, e.g., 42 U.S.C. 7506(c)(1)(B). 1 Note 2020 was included as a base year, not a milestone year, in the SIP Submission and “Table 6—PM ^2.5 Motor Vehicle Emission Budgets by Milestone Year” in the January 8, 2025, Notice of Proposed Rulemaking. See 90 FR 1600. As such, it is not actually a motor vehicle emissions budget according to the definition in 40 CFR 93.101 and it would not be used in transportation conformity. 2 Relevant transportation-related precursor pollutants for nonattainment areas are included under 40 CFR 93.102(b)(2). According to 40 CFR 93.102(b)(2)(iv), NO ^X precursor emissions apply for PM ^2.5 areas unless a finding has been made that NO ^X is not a significant contributor to the PM ^2.5 nonattainment problem. As explained in the submitted State Air Quality Control Plan, Vol. II, III.D.7.14 (Air Quality Conformity and Motor Vehicle Emission Budget), Alaska DEC only developed budgets for directly-emitted PM ^2.5 as precursor significance modeling found that both total and motor vehicle NO ^X emissions concentrations did not exceed EPA-established significance thresholds. The EPA approved Alaska's NO ^X precursor demonstration on December 5, 2023, (88 FR 84626). The criteria by which we determine whether a SIP's motor vehicle emissions budgets are adequate for conformity purposes are outlined in 40 CFR 93.118(e)(4). The EPA has described its process for determining the adequacy of submitted SIP budgets in our July 1, 2004 (69 FR 40004) preamble starting at page 40038, and we used the information in these resources in making our adequacy determination. Please note that an adequacy review is separate from the EPA's completeness review and should not be used to prejudge the EPA's ultimate approval action for the SIP. Even if we find a budget adequate, the SIP could later be disapproved. On January 8, 2025, the EPA proposed to approve the submitted Fairbanks Revised 189(d) Plan, including the motor vehicle emissions budgets contained therein. The EPA also initiated the adequacy process for the budgets included in that submission. We reviewed the criteria in 40 CFR 93.118(e)(4) to determine whether the motor vehicle emissions budgets are adequate for conformity purposes. See Enclosure 2 of EPA's April 8, 2025 letter for how the budgets meet these criteria. 3 We also initiated a public comment period for adequacy of the budgets as required by 40 CFR 93.118(f)(1)(ii). The public comment period on the adequacy process closed February 7, 2025. We received three comments during that public comment period related to adequacy of the motor vehicle emissions budgets. * Another comment was received during Alaska DEC's state rulemaking process. The EPA's response to these comments is included as Enclosure 1 to the letter notifying the State of our transportation adequacy finding* . 4 As discussed in the response to comments, after considering the comments and based on our review, the EPA concluded that the budgets meet the adequacy criteria in 40 CFR 93.118. Therefore, the EPA found the budgets adequate for transportation conformity purposes. 3 EPA letter sent from Krishna Viswanathan, Air and Radiation Division Director, EPA Region 10, to Christina Carpenter, Acting Commissioner, Alaska Department of Environmental Conservation, April 8, 2025. The letter is included in the docket for this action. 4 EPA letter sent from Krishna Viswanathan, Air and Radiation Division Director, EPA Region 10, to Christina Carpenter, Acting Commissioner, Alaska Department of Environmental Conservation, April 8, 2025. The letter is included in the docket for this action. Authority: 42 U.S.C. 7401 et seq. Dated: April 29, 2025. Daniel D. Opalski, Deputy Regional Administrator, Region 10. [FR Doc. 2025-08084 Filed 5-7-25; 8:45 am]*