# Approval of plans.
**AGENCY:**
Environmental Protection Agency (EPA).
**ACTION:**
Final rule.
**SUMMARY:**
The Environmental Protection Agency (EPA) is finalizing approval of the State implementation plan (SIP) submission, submitted by the State of Alaska (Alaska or the State) on December 4, 2024, to address Clean Air Act requirements for the 2006 24-hour fine particulate matter (PM <sub>2.5</sub> ) national ambient air quality standard in the Fairbanks North Star Borough PM <sub>2.5</sub> nonattainment area. Alaska's submission includes SIP revisions to meet nonattainment planning requirements for emissions inventories, modeling and sulfur dioxide precursor demonstration for major stationary sources, control measures, attainment projection date, reasonable further progress requirements, motor vehicle emissions budgets, and contingency measures.
**DATES:**
This action is effective on December 18, 2025.
**ADDRESSES:**
The EPA has established a docket for this action under Docket ID No. EPA-R10-OAR-2024-0595. All documents in the docket are listed on the *https://www.regulations.gov* website. Although listed in the index, some information is not publicly available, *e.g.,* CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available through *https://www.regulations.gov,* or please contact the person identified in the *FOR FURTHER INFORMATION CONTACT* section for additional availability information.
**FOR FURTHER INFORMATION CONTACT:**
Matthew Jentgen, EPA Region 10, 1200 Sixth Avenue—Suite 155, Seattle, WA, 98101, (206) 553-0340, *[email protected].*
**SUPPLEMENTARY INFORMATION:**
Throughout this document wherever “we,” “us,” or “our” is used, it is intended to refer to the EPA.
**Table of Contents**
I. Background
II. Public Comments and EPA Responses
A. Emissions Inventories
B. Pollutants Addressed
C. Control Strategy
D. Attainment Demonstration and Modeling
E. Reasonable Further Progress
F. Quantitative Milestones
G. Contingency Measures
H. Motor Vehicle Emissions Budgets for Transportation Conformity
III. EPA Final Action
A. Final Approval
B. Terminating Sanctions Clocks and Lifting the Transportation Conformity Freeze
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews
**I. Background**
This action is the latest in a series of regulatory actions regarding the Fairbanks PM <sub>2.5</sub> Nonattainment Area. For a complete regulatory history of the Fairbanks PM <sub>2.5</sub> Nonattainment Area, see the EPA's proposal, published on January 8, 2025 (90 FR 1600) (Proposal). The following is a summary of the history that is pertinent to this action. In 2009, the EPA designated a portion of the Fairbanks North Star Borough as “nonattainment” (Fairbanks PM <sub>2.5</sub> Nonattainment Area) for the 2006 24-hour PM <sub>2.5</sub> National Ambient Air Quality Standards (NAAQS), which is set at the level of 35 micrograms per cubic meter (µg/m <sup>3</sup> ) (74 FR 58688, November 13, 2009). Effective July 2, 2014, the EPA classified the area as “Moderate” (79 FR 31566, June 2, 2014). Subsequently, Alaska submitted, and the EPA approved, a plan to meet the Moderate nonattainment area requirements (Fairbanks Moderate Plan) (82 FR 42457, September 8, 2017).
On May 10, 2017, the EPA determined that the Fairbanks PM <sub>2.5</sub> Nonattainment Area failed to attain the 2006 24-hour PM <sub>2.5</sub> NAAQS by the outermost statutory Moderate area attainment date of December 31, 2015 (82 FR 21711). Consequently, the area was automatically reclassified to Serious. [^1] Alaska submitted a plan to address the Serious PM <sub>2.5</sub> nonattainment area requirements on December 13, 2019 (Fairbanks Serious Plan). On September 2, 2020, prior to taking action on the Fairbanks Serious Plan, the EPA determined that the area failed to attain by the Serious area attainment date of December 31, 2019 (85 FR 54509). Alaska submitted a revised plan to meet the requirements of CAA section 189(d) on December 15, 2020 (Fairbanks 189(d) Plan).
[^1] 42 U.S.C. 7513(b)(2)(A).
On September 24, 2021, the EPA approved the 2013 base year emissions inventory and the PM <sub>2.5</sub> precursor demonstration elements for nitrogen oxides (NO <sub>X</sub> ) and volatile organic compound (VOC) emissions of the Fairbanks Serious Plan as meeting the Serious area planning requirements (86 FR 52997). In the same action, the EPA approved other plan components as SIP strengthening, including: (1) the updated Fairbanks Emergency Episode Plan that the State adopted on November 18, 2020, and submitted on December 15, 2020; and (2) various regulatory control measures included in three separate SIP submissions (December 13, 2019, October 25, 2018, and November 28, 2018). The EPA did not determine as part of the September 24, 2021, approval whether these SIP-strengthening components met specific nonattainment plan requirements. In particular, the EPA did not determine whether the Fairbanks Serious Plan or Fairbanks 189(d) Plan met the following requirements for PM <sub>2.5</sub> Serious nonattainment areas: (1) attainment projected emissions inventory, (2) control strategy, (3) attainment demonstration, (4) reasonable further progress, (5) quantitative milestones, or (6) contingency measures.
[^2] 42 U.S.C. 7502(c)(1).
On December 5, 2023, the EPA finalized its determination of whether the Fairbanks Serious Plan and Fairbanks 189(d) Plan met CAA requirements for PM <sub>2.5</sub> Serious nonattainment areas. Specifically, the EPA approved Alaska's 2019 base year emission inventory included in the Fairbanks 189(d) Plan. The EPA approved certain discrete measures as meeting best available control measure requirements. The EPA also approved the plans as meeting nonattainment NSR requirements for purposes of CAA section 189(d) on December 5, 2023 (88 FR 84629).
However, the EPA disapproved in part the Fairbanks Serious Plan and Fairbanks 189(d) Plan as not meeting the following requirements for PM <sub>2.5</sub> Serious nonattainment areas: (1) attainment projected emissions inventory, (2) control strategy, in part, as not containing all required control measures, (3) attainment demonstration, (4) reasonable further progress, (5) quantitative milestones, or (6) contingency measures.
On December 4, 2024, Alaska submitted a revision to the Fairbanks Serious and 189(d) Plans (Fairbanks Revised 189(d) Plan) to rectify the portions the EPA disapproved on December 5, 2023. The Fairbanks Revised 189(d) Plan includes an updated base year emissions inventory, attainment projected emissions inventory, major stationary source SO <sub>2</sub> precursor demonstration, control strategy, modeled attainment demonstration, reasonable further progress provisions, quantitative milestones, and contingency measures. The EPA proposed to fully approve the plan revision on January 8, 2025 (90 FR 1600). This action finalizes the EPA's proposed approval of the Fairbanks Revised 189(d) Plan as meeting nonattainment plan requirements for the Fairbanks PM <sub>2.5</sub> Nonattainment Area.
Table 1 of this preamble provides a summary of the EPA's December 5, 2023, final rule and this final rule approving the Fairbanks Revised 189(d) Plan. Table 1 illustrates how the Fairbanks Serious Plan and Fairbanks Revised 189(d) Plan collectively satisfy CAA requirements for the Fairbanks PM <sub>2.5</sub> Nonattainment Area. The EPA's reasons for this action are explained in further detail in the following sections and in the separate Response to Comment document.
| Description of CAA planning requirement | 2023 Final Rule | 2025 Final Rule |
| --- | --- | --- |
| Base year emissions inventory for areas subject to CAA section 189(d), (CAA section 172(c)(3); 40 CFR 51.1008(c)(1)) | Approval of the 2019 base year emissions inventory | Approval of the 2020 base year emission inventory. |
| Attainment projected emissions inventory, (CAA section 172(c)(1);
40 CFR 51.1008(c)(2)) | Disapproval of the 2024 attainment projected emissions inventory | Approval of the 2027 attainment projected emissions inventory. |
| Pollutants addressed/Precursor demonstrations (CAA section 189(e);
40 CFR 51.1006 | Approval of the comprehensive precursor demonstrations for NO
and VOC emissions. (
) | Approval of the existing major stationary source precursor demonstration for SO
emissions. |
| Serious area nonattainment plan control strategy that ensures that best available control measures (BACM), including best available control technologies (BACT), for the control of direct PM
and PM
precursors are implemented in the nonattainment area, (CAA section 189(b)(1)(B);
40 CFR 51.1010(a)) | Partial approval of the control strategy as meeting BACM and BACT requirements under CAA section 189(b)(1)(B)
and 40 CFR 51.1010(a) for the solid fuel home heating device source category and residential and commercial fuel oil combustion source category | Approval of the control strategy BACM and BACT requirements (CAA section 189(b)(1)(B)
and 40 CFR 51.1010(a)) for the following emissions source categories: (1) Requirements for wood sellers; (2) Coal-fired heating devices; (3) Coffee roasters; (4) Energy efficiency and weatherization measures; (5) Mobile source category. |
| | Approval of specific regulations under 18 AAC 50.075 through 077 (except disapproval of the requirements for dry wood sellers under 18 AAC 50.076(k)), and Fairbanks Emergency Episode Plan (except disapproval of the contingency measure portion) | |
| | Partial approval of Alaska's PM
and NH
BACT determinations for the Doyon-Fort Wainwright Central Heating and Power Plant; PM
and NH
BACT determination for the University of Alaska Fairbanks Campus Power Plant, except for the three small diesel fired engines (EUs 23, 26, and 27); PM
and NH
BACT determinations for the Zehnder Power Plant; PM
and NH
BACT determinations for the North Pole Power Plant | |
| Additional measures (beyond those already adopted in previous nonattainment plan SIP submissions for the area as RACM/RACT, BACM/BACT, and Most Stringent Measures (MSM)
(if applicable)) that provide for attainment of the NAAQS as expeditiously as practicable and, from the date of such submission until attainment, demonstrate that the plan will at a minimum achieve an annual five percent reduction in emissions of direct PM
or any PM
plan precursor, (CAA section 189(d);
40 CFR 51.1010(c)) | Disapproval | Approval. |
| Attainment demonstration and modeling, (CAA sections 188(c)(2) and 189(b)(1)(A);
40 CFR 51.1003(c) and 51.1011) | Disapproval of demonstration of attainment by December 31, 2024 | Approval of attainment demonstration and extension of Serious area attainment date to December 31, 2027. |
| Reasonable further progress (RFP) provisions, (CAA section 172(c)(2);
40 CFR 51.1012) | Disapproval | Approval. |
| Quantitative milestones, (CAA section 189(c);
40 CFR 51.1013) | Disapproval | Approval. |
| Motor vehicle emission budgets, (CAA section 176, 40 CFR 51.1003(d) and 93.118) | Disapproval | Approval. |
| Contingency measures applicable to Serious areas subject to CAA section 189(b), (CAA section 172(c)(9);
40 CFR 51.1014) | Disapproval of the submitted contingency measures under CAA section 172(c)(9)
and 40 CFR 51.1014 applicable to Serious areas subject to CAA sections 189(b) and 189(d). The EPA finalized a limited disapproval of the Fairbanks 189(d) Plan contingency measure because the contingency measure did not fully meet the contingency measure requirements of CAA section 172(c)(9) and 40 CFR 51.1014 but otherwise strengthened the SIP. | Approval of the contingency measures as meeting the requirements under CAA section 172(c)(9)
and 40 CFR 51.1014 applicable to Serious areas subject to CAA sections 189(b) and 189(d). |
| Nonattainment new source review provisions, (CAA sections 172(c)(5), 189(b)(3), 189(d), and 189(e), and 40 CFR 51.165, 40 CFR 51.1003(b)(1)(viii), and 40 CFR 51.1003(c)(1)(viii) | Approval | Not applicable (already approved). |
**II. Public Comments and EPA Responses**
[^3] 42 U.S.C. 7513b(e).
[^4] 42 U.S.C. 7513a(b)(1)(B).
[^5] 42 U.S.C. 7513a(b)(1)(B).
[^6]*Id.*
[^7] 42 U.S.C. 7513a(b)(1)(B).
[^8] 42 U.S.C. 7513a(b)(1)(B).
[^9] 42 U.S.C. 7513a(b)(1)(B).
[^10] 42 U.S.C. 7513a(b)(1)(B).
[^11] MSM is applicable if the EPA has previously granted an extension of the attainment date under CAA section 188(e) for the nonattainment area and NAAQS at issue. The EPA denied Alaska's request to extend the Serious area attainment date for the Fairbanks PM *2.5* Nonattainment Area.
[^12] 42 U.S.C. 7513a(d).
[^13] 42 U.S.C. 7513(c)(2) and 7513a(b)(1)(A).
[^14] 42 U.S.C. 7502(c)(2).
[^15] 42 U.S.C. 7513a(c).
[^16] 42 U.S.C. 7502(c)(9).
[^17] 42 U.S.C. 7502(c)(9).
[^18] The EPA finalized a limited approval of the Fairbanks Emergency Episode Plan, State Air Quality Control Plan, Vol. II, section III.D.7.12, as SIP-strengthening on September 24, 2021. 86 FR 52997, September 24, 2021, at pp. 52997, 53004.
[^19] 42 U.S.C. 7502(c)(9).
[^20] 42 U.S.C. 7502(c)(5), 7513a(b)(3), 7513a(d), and 7513a(e).
The EPA initially provided a 30-day period for the public to comment on the proposed action that ended on February 7, 2025. Based on public interest in the energy efficiency and weatherization measures in the Alaska SIP submission, the EPA re-opened the comment period for an additional 30 days from March 24, 2025, to April 23, 2025. Overall, 375 public comments were submitted in the docket. The following is a summary, organized by CAA requirement, of the Proposal, our final action, and the comments received and the EPA's responses. We have included in the docket a detailed “Response to Comments” document that provides a summary of public comments and the EPA's responses. [^21] The full text of all public comments may also be found in the docket for this action.
[^21] Response to Comments on the Air Plan Partial Approval and Partial Disapproval; AK, Fairbanks North Star Borough; 2006 24-hour PM <sub>2.5</sub> Serious Area and 189(d) Plan, EPA-R10-OAR-2024-0595.
**A. Emissions Inventory**
**1. Summary of Proposal**
The EPA proposed to approve the 2020 base year emissions inventory as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008. The EPA proposed to determine that Alaska had justified that 2020 is a technically appropriate inventory year consistent with 40 CFR 51.1008(c)(1). The base year emissions inventory included actual emissions of all sources within the nonattainment area. The EPA proposed to determine that a seasonal episode daily average inventory is appropriate for the Fairbanks PM <sub>2.5</sub> Nonattainment Area because the area experiences episodic elevated concentrations of PM <sub>2.5</sub> during wintertime cold weather events. The emissions inventory included direct PM <sub>2.5</sub> emissions, separately reported as filterable and condensable emissions, as well as all scientific PM <sub>2.5</sub> precursors (SO <sub>2</sub> , NO <sub>X</sub> , VOC, and NH <sub>3</sub> ). Alaska reported emissions for point sources according to the point source emissions thresholds of the Air Emissions Reporting Rule in 40 CFR part 51, subpart A. Finally, the EPA proposed to determine that the emissions inventory is consistent with the detail and data elements required by 40 CFR part 51, subpart A.
The EPA proposed to approve the 2027 projected attainment emissions inventory as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008. The EPA proposed to determine that 2027 is the most expeditious year for which projected emissions show modeled PM <sub>2.5</sub> concentrations below the level of the NAAQS. As discussed in section II.D of the proposed rule (January 8, 2025 (90 FR 1600)), Alaska included a model output for 2026 that resulted in emissions levels exceeding the 2006 24-hour PM <sub>2.5</sub> NAAQS. The attainment projected inventory included the sources in the base year emissions inventory and accounts for growth and contraction from both controls and other causes. Consistent with the base year emissions inventory, the attainment projected emissions inventory is based on episode average daily emissions. The attainment projected emissions inventory included direct PM <sub>2.5</sub> emissions, separately reported as filterable and condensable emissions, as well as all scientific precursors. The attainment projected emissions inventory included the same level of emissions detail for the same point sources and for mobile sources reported in the base year emissions inventory.
**2. Final Rule**
The EPA is finalizing approval of the base year emission inventory and the projected attainment year emission inventory.
**3. Comments and Responses**
One commenter stated that the Fairbanks Revised 189(d) Plan was not clear in how it determined the “episode days” for the purposes of the emissions inventories. The EPA disagrees with this comment. All of the data upon which Alaska relied to determine the emissions inventories, including the episode days, is included in the Fairbanks Revised 189(d) Plan. [^22] The EPA's technical assessment of Alaska's emission inventories including the State's selection of appropriate episode days is also included in the docket. [^23] This latter document summarizes and explains the data underlying Alaska's 74-day modeling episode from 2019-2020 and how the episode days were selected. Please see the EPA's Response to Comments document for a full summary of the comments and the EPA's full responses. [^24]
[^22] State Air Quality Control Plan, Vol. III, Appendix III.D.7.6.
[^23] Kotchenruther, Robert. (November 21, 2024). Technical support document for Alaska Department of Environmental Conservation's amendments to: State Air Quality Control Plan, Emission Inventory Data (version August 19, 2024). U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2024-0595.
[^24] Response to Comments, section 4.b.
**B. Pollutants Addressed**
**1. Summary of Proposal**
The EPA proposed to determine that Alaska's submission meets the requirements of 40 CFR 51.1006(a)(2) and is consistent with the EPA guidance concerning the identification of PM <sub>2.5</sub> precursors that the State must regulate in the nonattainment area. [^25] Regarding the State's analytical approach, the EPA proposed to find that the State used appropriate methods and data to evaluate PM <sub>2.5</sub> formation from precursor emissions in the Fairbanks PM <sub>2.5</sub> Nonattainment Area. Consistent with 40 CFR 51.1006(a)(2), Alaska's submission included a concentration-based contribution analysis. The concentration-based analysis indicates that the SO <sub>2</sub> emissions from existing major stationary sources do not significantly contribute to PM <sub>2.5</sub> formation in the Fairbanks PM <sub>2.5</sub> Nonattainment Area. Specifically, Alaska's analysis showed that SO <sub>2</sub> emissions from existing major stationary sources contribute 0.21 μg/m <sup>3</sup> of PM <sub>2.5</sub> at the North Pole Hurst Road air quality monitor—far below the 1.5 μg/m <sup>3</sup> threshold included in the EPA guidance. Therefore, the EPA proposed to approve Alaska's precursor demonstration submitted as part of the Fairbanks Revised 189(d) Plan as demonstrating that the contribution of SO <sub>2</sub> emissions from existing major stationary sources to PM <sub>2.5</sub> levels in the Fairbanks PM <sub>2.5</sub> Nonattainment Area is not significant in accordance with 40 CFR 51.1006(a)(2)(i). With final approval, Alaska will not be required to control SO <sub>2</sub> emissions from existing major stationary sources in the Fairbanks PM <sub>2.5</sub> Nonattainment Area, pursuant to CAA section 189 and 40 CFR 51.1010. For purposes of the Fairbanks Revised 189(d) Plan, the applicable PM <sub>2.5</sub> plan precursors are NH <sub>3</sub> for all sources and SO <sub>2</sub> for all sources except for existing major stationary sources.
[^25] “PM <sub>2.5</sub> Precursor Demonstration Guidance,” EPA-454/R-19-004, May 2019, including Memo dated May 30, 2019, from Scott Mathias, Acting Director, Air Quality Policy Division and Richard Wayland, Director, Air Quality Assessment Division, Office of Air Quality Planning and Standards (OAQPS), EPA to Regional Air Division Directors, Regions 1-10, EPA.
We note that the EPA's approval of Alaska's precursor demonstration does not extend to nonattainment NSR requirements for the area. Alaska previously determined that it was appropriate to regulate NO <sub>X</sub> , SO <sub>2</sub> , VOCs, and NH <sub>3</sub> as precursors to PM <sub>2.5</sub> with respect to nonattainment NSR and submitted rule changes to that effect on October 25, 2018. The EPA approved the submitted revised program as meeting nonattainment NSR requirements triggered upon reclassification of the Fairbanks PM <sub>2.5</sub> Nonattainment Area to Serious (84 FR 45419, August 29, 2019). The EPA approved the Alaska SIP as meeting nonattainment NSR requirements for purposes of CAA section 189(d) on December 5, 2023 (88 FR 84629).
**2. Final Rule**
The EPA is finalizing approval of Alaska's SO <sub>2</sub> precursor demonstration for existing major stationary sources. Accordingly, the EPA is concluding that the State is not required to impose additional controls on SO <sub>2</sub> emissions on such sources for purposes of the 2006 24-hour PM <sub>2.5</sub> NAAQS in the Fairbanks PM <sub>2.5</sub> Nonattainment Area.
**3. Comments and Responses**
The EPA received adverse comments generally questioning the prudence of the EPA approving the SO <sub>2</sub> precursor demonstration. Overall, the comments do not provide a technical basis that contradicts the EPA's determination that Alaska's existing major stationary source SO <sub>2</sub> precursor demonstration meets the requirements of 40 CFR 51.1006. Please see the EPA's Response to Comments document for a full summary of the comments and the EPA's full responses. [^26]
[^26] The EPA's Response to Comments, section 4.D.
**C. Control Strategy**
**1. Solid Fuel Burning**
**a. Summary of Proposal**
Alaska revised the dry wood seller measure, adopted as regulation 18 AAC 50.076(k)(3), by setting a frequency at monthly intervals to measure the moisture content. Alaska also revised regulation 18 AAC 50.076(k)(1) by improving the labeling to indicate “dry wood.”
Regarding the EPA's disapproval of coal-fired heating device requirements, Alaska revised 18 AAC 50.079 by lowering the emissions threshold to test out of the mandatory removal requirements in 18 AAC 50.079(d) from 18 grams per hour to 0.10 pounds per million British thermal units (lbs/MMBtu), which is equivalent to the pellet hydronic heater limit in 18 AAC 50.077. Alaska amended 18 AAC 50.079(d) to require a testing protocol be approved by the department prior to any test attempting to exempt a coal device from the mandatory removal requirement. Alaska revised 18 AAC 50.079(e) to limit the duration of the waiver to one calendar year.
The EPA previously approved 18 AAC 50.079(f), which requires the owner of a coal-fired heating device to render it inoperable no later than December 31, 2024. As a consequence of Alaska's revisions to 18 AAC 50.079(f), the latest an individual with a coal-fired heating device could remove that device is December 31, 2025—provided the individual meets the limited extension eligibility requirements in 18 AAC 50.079(e). Alaska stated that 18 AAC 50.079(f) is revised for clarity by adding section (3), which requires coal-fired heating devices to be rendered inoperable after the expiration of a waiver granted under subsection (e) of 18 AAC 50.079. Alaska stated that newly adopted section 18 AAC 50.079(h) requires documentation on the removal and rendering of the device inoperable and submitting an affidavit that the coal stove will not be reinstalled in the Fairbanks PM <sub>2.5</sub> Nonattainment Area.
Based on these updates, the EPA proposed to approve the submitted revisions to 18 AAC 50.076 and 18 AAC 50.079 as meeting the requirements of CAA sections 110(a)(2)(A), 172(c)(7), and 189(b) and 40 CFR 51.1010(a). Accordingly, the EPA proposed to determine that the Fairbanks Revised 189(d) Plan rectifies the disapproved portions of the Fairbanks Serious Plan and initial Fairbanks 189(d) Plan for the solid fuel-burning source category.
**b. Final Rule**
The EPA did not receive any comments on the BACM requirements for solid fuel burning emission sources included in the Fairbanks Revised 189(d) Plan and is finalizing approval of the Fairbanks revised 189(d) Plan as meeting the BACM requirements for solid fuel burning emission sources.
**2. Small Commercial Area Sources**
**a. Summary of Proposal**
Alaska revised its regulations for coffee roasters, under 18 AAC 50.078(d). These updated regulations include specific emission limits for coffee roasters and ensures the emission limit is enforceable as a practical matter. The EPA proposed to approve the submitted revisions to 18 AAC 50.078(d) as meeting the requirements of CAA sections 110(a)(2), 172(c)(7), and 189(b) and 40 CFR 51.1010(a) for this source category. Accordingly, the EPA proposed to determine that the Fairbanks Revised 189(d) Plan rectifies the disapproved portions of the Fairbanks Serious Plan and initial Fairbanks 189(d) Plan for coffee roasters.
**3. Energy Efficiency and Weatherization Measures**
**a. Summary of Proposal**
To address the EPA's disapproval, Alaska adopted an energy efficiency and weatherization measure at 18 AAC 50.081. The measure mandates that a building owner complete an energy rating on the building before listing it for sale. The rule requires that the seller provide the energy rating report to the buyer. The rule also requires the homeowner to register wood-fired heating devices with the State and remove any wood-fired or coal-fired heating devices that do not comply with State emissions standards (codified at 18 AAC 50.077 and 18 AAC 50.079). Finally, Alaska's rule requires that the agent involved in the home sale transaction must inform the seller and/or buyer of these obligation and, during the transaction, ensure the seller and/or buyer has complied with the requirements to render inoperable older solid-fuel heating devices under State rules 18 AAC 50.077(h) and ( *l* )-(n) and 18 AAC 50.079(b) and (f)-(h).
Alaska also committed to a robust advertising and education program that includes best practices to improve efficiency in an arctic environment and available economic and practical mechanisms that can assist homeowners in improving both efficiency and regulatory compliance.
The EPA proposed to approve the submitted revisions to 18 AAC 50.081 as meeting the requirements of CAA sections 110(a)(2), 172(c)(7), and 189(b) and 40 CFR 51.1010(a) with respect to energy efficiency and weatherization. Accordingly, the EPA proposed to determine that the Fairbanks Revised 189(d) Plan rectifies the disapproved portions of the Fairbanks Serious Plan and initial Fairbanks 189(d) Plan for lack of energy efficiency and weatherization measures.
After reviewing the comments received on the EPA's proposal, Alaska reevaluated the feasibility of the energy rating requirements and determined that they were not technologically or economically feasible. Alaska withdrew 18 AAC 50.081 on September 25, 2025.
Alaska retained its commitments to a robust advertising and education program that includes best practices to improve efficiency in an arctic environment and available economic and practical mechanisms that can assist homeowners in improving both efficiency and regulatory compliance.
**b. Final Rule**
The EPA is finalizing approval of the Fairbanks Revised 189(d) Plan as meeting the BACM requirements for energy efficiency and weatherization measures.
**c. Comments and Responses**
The EPA received several comments expressing concern about Alaska's adoption of 18 AAC 50.081. The comments expressed concern about the cost of conducting the energy rating, potential delays to completing home sales, and restrictions on a person's right to sell and buy property. Several commenters also identified ways they asserted that the State could improve the regulations to account for a variety of circumstances, such as selling a dry recreational cabin or a top-rated energy efficient home or re-selling a home that recently received an energy rating. Other commenters were supportive of the energy audit requirement.
These comments, as well as information provided by Alaska, demonstrate that an energy rating requirement as contemplated by 18 AAC 50.081 is technologically and economically infeasible. Notably, there are insufficient energy raters available in the area. Becoming a certified energy rater is a lengthy process. In addition, Alaska is not relying on the energy rating component of 18 AAC 50.081 for any emission reductions. The regulation does not mandate implementation of any of the energy efficiency recommendations from the energy rating. Hence, the emission reduction measures are not enforceable. However, the energy rating could cost as much as $1,373. [^27] Thus, the measure is not cost effective. Accordingly, the EPA has determined that the energy rating requirement is not necessary to satisfy the control strategy requirements for serious areas or serious areas that fail to attain, under CAA sections 189(b) and (d) and 40 CFR 51.1010. The remaining portions of 18 AAC 50.081 were not necessary to address the EPA's December 5, 2023, partial disapproval and are derivative of SIP-approved rules at 18 AAC 50.077 and 079. These rules already restrict the sale and transfer of solid fuel burning devices. See the EPA's Response to Comments document for a full summary of these comments and the EPA's detailed responses. [^28]
[^27] “How Much Does it Cost to Audit Home Energy in Fairbanks?,” available at: *https://www.homeyou.com/ak/home-energy-audit-fairbanks-costs.*
[^28] The EPA's Response to Comments, section 3.
**4. Emissions From Mobile Sources**
**a. Summary of Proposal**
The EPA proposed to determine that Alaska has rectified the EPA's December 5, 2023, disapproval of the Fairbanks Serious Plan and initial Fairbanks 189(d) Plan with respect to control strategy requirements for mobile sources. In the December 5, 2023, final rule, the EPA approved Alaska's rejection of several mobile source control measures designed to reduce on-road vehicle emissions as either technologically or economically infeasible ( *e.g.,* high-occupancy vehicle lanes, improved signalization, and van pools).
However, the EPA rejected Alaska's infeasibility determinations for vehicle anti-idling measures as inadequate. In the Fairbanks Revised 189(d) Plan, Alaska improved its infeasibility justifications. Therefore, based on Alaska's determination that any additional vehicle anti-idling restrictions are technologically or economically infeasible for the Fairbanks PM <sub>2.5</sub> Nonattainment Area for purposes of the 2006 24-hour PM <sub>2.5</sub> NAAQS, the EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the control strategy requirements for mobile sources.
The EPA proposed to determine that the separate, previously adopted anti-idling control measure in the Fairbanks Moderate Area Plan also satisfied the Serious area BACM requirement. Specifically, the Fairbanks Moderate Area Plan includes a requirement that businesses with 275 or more parking spaces provide power to electrical outlets at temperatures of 20 degrees Fahrenheit or lower for engine block heaters. [^29] In addition, Alaska continues to install new (vehicle preheating) plug-ins throughout the Fairbanks PM <sub>2.5</sub> Nonattainment Area. [^30]
[^29] 82 FR 42457, September 8, 2017; State Air Quality Control Plan, Vol. III, Appendix III.D.5.7, adopted December 24, 2014, at p. 43; State Air Quality Control Plan, Vol. III, Appendix III.D.5.12, adopted December 24, 2014, at p. 43.
[^30] There are nearly 10,000 plug-ins available in the nonattainment area. See State Air Quality Control Plan, Appendix III.D.7.7-17 (adopted November 19, 2019).
**b. Final Rule**
The EPA is finalizing approval of the Fairbanks Revised 189(d) Plan as meeting the BACM requirements for motor vehicle emissions.
**c. Comments and Responses**
The EPA received comments regarding the perceived role of motor vehicle emissions contributing to total PM <sub>2.5</sub> concentrations in the Fairbanks PM <sub>2.5</sub> Nonattainment Area. Importantly, none of the comments provided a detailed explanation of their disagreement with Alaska's infeasibility demonstrations with respect to vehicle idling nor suggested additional mobile source control measures that the State should have evaluated.
While the EPA acknowledges that motor vehicle emissions are identified as a significant emission source category requiring a BACM evaluation of emission controls, we disagree with comments stating generally that emissions from motor vehicles are a primary cause of PM <sub>2.5</sub> pollution in the area. We note that mobile sources account for an estimated 6% of total PM <sub>2.5</sub> levels in the Fairbanks PM <sub>2.5</sub> Nonattainment Area, and the State has established adequate PM <sub>2.5</sub> motor vehicle emissions budgets for transportation conformity purposes (see section II.H of this preamble). [^31] Please see the EPA's Response to Comments document for a summary of these comments and the EPA's responses. [^32]
[^31] See State Air Quality Control Plan, Vol. II, section III.D.7.6.9.8.
[^32] The EPA's Response to Comments, section 4.E.
**5. Alaska's Identification and Adoption of BACT**
For a description of each of the major stationary sources in the Fairbanks PM <sub>2.5</sub> Nonattainment Area, see the EPA's Proposal, section II.C.2.b.
**a. Chena Power Plant**
**i. Summary of Proposal**
Alaska revised its State Air Quality Control Plan to include its BACT determinations for PM <sub>2.5</sub> and SO <sub>2</sub> emissions for each of the emission units at the Chena Power Plant. [^33] Alaska removed its BACT evaluation and determinations for NO <sub>X</sub> emissions because the EPA approved a comprehensive NO <sub>X</sub> emissions precursor demonstration. Alaska also submitted conditions from Air Quality Control Minor Permit AQ0315MSS02 Revision 1 for the Aurora Energy, LLC—Chena Power Plant (Aurora Permit). The Aurora Permit conditions include enforceable PM <sub>2.5</sub> BACT emissions limitations for the emission units at the Chena Power Plant comprised of numerical emissions limits and work practice standards and associated monitoring, recordkeeping and reporting requirements. The permits are included in the docket for this action. [^34]
[^33]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-164. Note, Alaska's prior SIP submissions only evaluated BACT for the coal-fired boilers.
[^34]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-187.
The EPA previously reviewed Alaska's BACM/BACT evaluation for the Chena Power Plant. [^35] Alaska has since clarified that PM <sub>2.5</sub> BACT for the coal-fired boilers is operating and maintaining fabric filters (full steam baghouse) during operation. [^36] Thus, the EPA proposed to approve Alaska's PM <sub>2.5</sub> BACT determinations for the Chena Power Plant, the submitted revisions to State Air Quality Control Plan, Vol. III, Appendix III.D.7.7, related to direct PM <sub>2.5</sub> emissions, and the submitted Aurora Permit conditions [^37] as satisfying CAA section 189(b) and 40 CFR 51.1010.
[^35]*See* Hedgpeth and Sorrels. (August 24, 2022). *Review of Best Available Control Technology analyses submitted for the Aurora Energy, LLC Chena Power Plant as part of the Fairbanks PM*<sub>2.5</sub>* Nonattainment SIP.* U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
[^36]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-173.
[^37]*See* section III.A of this preamble for the specific permit conditions proposed for approval.
The EPA did not propose action on Alaska's SO <sub>2</sub> BACT determinations in State Air Quality Control Plan, Vol. III, Appendix III.D.7.7. The EPA proposed to approve Alaska's SO <sub>2</sub> precursor demonstration for existing major stationary sources. Upon final approval, Alaska will not be required to identify, adopt, or implement SO <sub>2</sub> BACT for the Chena Power Plant.
**ii. Final Rule**
The EPA did not receive comments on PM <sub>2.5</sub> BACT for the Chena Power Plant and is finalizing approval of BACT for PM <sub>2.5</sub> emissions at the Chena Power Plant. Based on the EPA's approval of the SO <sub>2</sub> and NO <sub>X</sub> precursor demonstrations, SO <sub>2</sub> and NO <sub>X</sub> emission controls are not required for this facility as part of the Fairbanks Revised 189(d) Plan.
**b. Fort Wainwright**
**i. Summary of Proposal**
As part of the Fairbanks Revised 189(d) Plan, Alaska revised its Air Quality Control Plan sections related to the Doyon-Fort Wainwright Central Heating and Power Plant (CHPP) to reflect new engines powering lift pumps and generators, correct typographical errors, improve clarity, and to include updated SO <sub>2</sub> BACT determinations. [^38] With respect to the new engines, all are EPA-certified engines ranging in size from 74 horsepower to 324 horsepower. Alaska updated its PM <sub>2.5</sub> BACT determinations for these new engines. Alaska removed its BACT evaluation and determinations for NO <sub>X</sub> emissions because the EPA approved a comprehensive NO <sub>X</sub> precursor demonstration.
[^38]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-202.
Alaska also submitted conditions from two Air Quality Control Minor Permits: AQ0236MSS03 Revision 2 (U.S. Army Garrison—USAG Alaska Fort Wainwright) and AQ1121MSS04 Revision 1 (Doyon Utilities, LLC—Fort Wainwright) (collectively referred to as the Fort Wainwright Permits). The Fort Wainwright Permits include enforceable PM <sub>2.5</sub> BACT emissions limitations for the emission units at Fort Wainwright comprised of numerical emissions limits and work practice standards and associated monitoring, recordkeeping and reporting requirements. The permits are included in the docket for this action. [^39]
[^39]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-248.
The EPA previously reviewed Alaska's BACM/BACT evaluation for the Doyon-Fort Wainwright Central Heating and Power Plant. [^40] Alaska's updated BACT determination clarified the maintenance and testing requirements for the diesel-fired boilers and added enclosed conveying system requirements. [^41] The EPA previously approved Alaska's BACT determinations for older pump engines and generator engines. Alaska updated its BACT determinations and associated permit limits to reflect grams per hour emission limits appropriate to the size and model year of the engine. Alaska also imposed limits on the hours of operations of these engines. Thus, the EPA proposed to approve Alaska's updated PM <sub>2.5</sub> BACT determinations for the emissions units at Doyon-Fort Wainwright CHPP, [^42] the submitted revisions to State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 related to direct PM <sub>2.5</sub> emissions from the Doyon-Fort Wainwright CHPP, [^43] and the submitted conditions from the Fort Wainwright Permits [^44] as satisfying CAA section 189(b) and 40 CFR 51.1010.
[^40]*See* Hedgpeth, Z. (August 24, 2022). *Review of Best Available Control Technology analyses submitted for Fort Wainwright-US Army Garrison Alaska (FWA) and Doyon Utilities, LLC (DU) as part of the Fairbanks PM*<sub>2.5</sub>* Nonattainment SIP.* U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
[^41] See State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-217; State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-225.
[^42] Industrial coal-fired boilers; diesel-fired boilers; diesel-fired engines, fire pumps, and generators; and material handling equipment.
[^43] The EPA is not proposing to approve the NO <sub>X</sub> -related emissions limits as meeting BACT for NO <sub>X</sub> . For some emission units, Alaska imposed NO <sub>X</sub> emissions limits as surrogates for direct PM <sub>2.5</sub> emissions.
[^44]*See* section III.A of this preamble for the specific permit conditions proposed to be approved.
The EPA did not propose action on Alaska's SO <sub>2</sub> BACT determinations in State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 for the same reasons discussed in the preceding paragraphs regarding the Chena Power Plant.
**ii. Final Rule**
The EPA did not receive comments on PM <sub>2.5</sub> BACT for Fort Wainwright and is finalizing approval of BACT for PM <sub>2.5</sub> emissions at Fort Wainwright. Based on precursor demonstrations, SO <sub>2</sub> and NO <sub>X</sub> emission controls are not required for this facility as part of the Fairbanks Revised 189(d) Plan.
**c. University of Alaska Fairbanks Campus Power Plant**
**i. Summary of Proposal**
In the Fairbanks Revised 189(d) Plan, Alaska updated its Air Quality Control Plan regarding the Fairbanks Campus Power Plant to reflect permanently removed emission units, add new diesel boilers and engines, update the PM <sub>2.5</sub> BACT determinations for small diesel-fired boilers and large and small engines, correct typographical errors, and improve clarity. [^45] Alaska also added updated SO <sub>2</sub> BACT determinations for the Fairbanks Campus Power Plant.
[^45]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-356.
With respect to the small diesel-fired boilers (EUs 17 through 22), Alaska updated its BACT determination for PM <sub>2.5</sub> emissions that includes a partial limit on hours of operation, an emission limit of 0.016 lb/MMBtu, [^46] compliance with 40 CFR part 63, subpart JJJJJJ, and work practice standards. Alaska evaluated whether installation of a scrubber was feasible for these boilers and determined that it was economically infeasible. [^47] Alaska noted that taking into consideration the enforceable limit on operation, the combined potential to emit PM <sub>2.5</sub> emissions from the six boilers is two tons per year.
[^46] Alaska noted that it previously selected a 0.012 lb/MMBtu limit erroneously. This limit is associated with industrial boilers while the boilers at the Fairbanks Campus Power Plant are commercial boilers.
[^47] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-369.
With respect to large diesel fired engines (EUs 8 and 35) and small diesel fired engines (EUs 24, 26, 27, 29, and 34), [^48] Alaska reevaluated the feasibility of add-on PM <sub>2.5</sub> controls, namely a diesel particulate filter (DPF). [^49] EUs 24, 29, and 34 are limited to 100 hours per year of non-emergency operation, so additional BACT controls were not evaluated for these units. Alaska determined that a DPF is not technologically feasible for EU 8 due to an unacceptable increase in back pressure. Alaska determined that DPFs were technologically feasible for the other engines, but Alaska determined that the high cost per unit of emissions reductions rendered them economically infeasible. Updating the cost-effectiveness analysis to reflect comments from the EPA's Technical Support Document, [^50] Alaska determined that the cost-effectiveness ranged from over $17,000 at EU 26 to over $20,000 per ton of PM <sub>2.5</sub> reduced at EU 27. Alaska stated that EU 35 has potential PM <sub>2.5</sub> emissions of 0.03 tons per year, which is an order of magnitude lower than the two other diesel engines, EUs 26 and 27. Therefore, Alaska did not perform a cost analysis for installing and operating a DPF on EU 35 as it would have an even higher cost per ton estimate than EUs 26 and 27. Furthermore, Alaska noted that EU 35 is limited to 100 hours per calendar year of non-emergency operation and required to combust ULSD under the existing Federal NSPS Subpart IIII requirements. [^51]
[^48] In comments, the University of Alaska Fairbanks clarified that EU 23 has been permanently removed from service and are no longer permitted EUs at the facility. See Comments on Proposed Rule—Air Plan Partial Approval and Partial Disapproval; AK, Fairbanks North Star Borough; 2006 24-Hour PM <sub>2.5</sub> Serious Area and 189(d) Plan, at p. 9, Docket ID No. EPA-R10-OAR-2022-0115.
[^49] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-372.
[^50]*See* Hedgpeth and Sorrels. (August 24, 2022). *Review of Best Available Control Technology analyses submitted for the University of Alaska, Fairbanks as part of the Fairbanks PM*<sub>2.5</sub>* Nonattainment SIP,* p.15. U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
[^51] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-374.
Alaska removed its BACT evaluation and determinations for NO <sub>X</sub> emissions because the EPA approved a comprehensive NO <sub>X</sub> precursor demonstration. [^52]
[^52] 88 FR 84626, December 5, 2023.
Alaska also submitted conditions from Air Quality Control Minor Permit AQ0316MSS08 Revision 1 (University of Alaska Fairbanks (UAF)—University of Alaska Fairbanks Campus) (UAF Permit). The UAF Permit conditions include enforceable PM <sub>2.5</sub> BACT emissions limitations comprised of numerical emissions limits and work practice standards with associated monitoring, recordkeeping, and reporting. The permits are included in the docket for this action. [^53]
[^53]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-414.
The EPA previously reviewed Alaska's BACT evaluation for the Fairbanks Campus Power Plant. [^54] The EPA proposed to approve Alaska's updated PM <sub>2.5</sub> BACT determinations for the small diesel-fired boilers (EUs 17 through 22), large diesel-fired engines (EUs 8 and 35), and small diesel-fired engines (EUs 24, 26, 27, 29, and 34) at the Fairbanks Campus Power Plant. The EPA previously approved Alaska's PM <sub>2.5</sub> BACT determinations for EUs 8, 17-19, 24, and 29. Alaska's updates are consistent with these past approvals. With respect to EUs 26, 27, and 35, the EPA proposed to approve Alaska's economic infeasibility demonstrations for DPFs. The EPA proposed to approve Alaska's PM <sub>2.5</sub> BACT emissions limits for small diesel-fired boilers (EUs 17 through 22), large diesel-fired engines (EUs 8 and 35), and small diesel-fired engines (EUs 24, 26, 27, 29, and 34) at the Fairbanks Campus Power Plant, which consist of numerical emissions limits, limits on operation, fuel requirements, and work practice standards.
[^54]*See* Hedgpeth and Sorrels. (August 24, 2022). *Review of Best Available Control Technology analyses submitted for the University of Alaska, Fairbanks as part of the Fairbanks PM*<sub>2.5</sub>* Nonattainment SIP.* U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
Therefore, the EPA proposed to approve the submitted revisions to State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 related to direct PM <sub>2.5</sub> emissions and NO <sub>X</sub> emissions [^55] from the Fairbanks Campus Power Plant and the submitted conditions from the UAF Permit [^56] as satisfying CAA section 189(b) and 40 CFR 51.1010.
[^55] The EPA is not proposing to approve the NO <sub>X</sub> -related emissions limits as meeting BACT for NO <sub>X</sub> . For some emission units, Alaska imposed NO <sub>X</sub> emissions limits as surrogates for direct PM <sub>2.5</sub> emissions.
[^56]*See* section III.A of this preamble for the specific permit conditions proposed to be approved.
The EPA did not propose action on Alaska's SO <sub>2</sub> BACT determinations in State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 for the same reasons discussed in the preceding paragraphs regarding the Chena Power Plant.
**ii. Final Rule**
The EPA did not receive comments on PM <sub>2.5</sub> BACT for the University of Alaska Campus Power Plant and is finalizing approval of BACT for PM <sub>2.5</sub> emissions at the University of Alaska Campus Power Plant. Based on precursor demonstrations, SO <sub>2</sub> and NO <sub>X</sub> emission controls are not required for this facility as part of the Fairbanks Revised 189(d) Plan.
**d. Zehnder Facility**
**i. Summary of Proposal**
In the Fairbanks Revised 189(d) Plan, Alaska revised its Air Quality Control Plan for the Zehnder Facility to correct errors and improve clarity. [^57] Alaska also submitted conditions from Air Quality Control Minor Permit AQ0109MSS01 Revision 1 (Golden Valley Electric Association—Zehnder Facility) (Zehnder Permit). The Zehnder Permit contains enforceable PM <sub>2.5</sub> BACT emissions limitations for the emission units at the Zehnder Facility comprised of numerical emissions limits and work practice standards with associated monitoring, recordkeeping, and reporting. The permits are included in the docket for this action. [^58]
[^57] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-316.
[^58]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-342.
Similar to the small diesel-fired boilers (EUs 17 through 22) at the Fairbanks Campus Power Plant discussed in the preceding paragraphs of section II.C of this preamble, Alaska imposed, in the Fairbanks Serious Plan and Fairbanks 189(d) Plan, an erroneous emissions limit on the small diesel fired boilers at the Zehnder Facility. The revised Air Quality Control Plan and associated conditions in the Zehnder Permit reflect the corrected limit. [^59]
[^59] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-327.
The EPA previously reviewed Alaska's BACT evaluation for the Zehnder Facility. [^60] In EPA's prior analysis, the EPA agreed with Alaska's BACT determinations for PM <sub>2.5</sub> . For the turbines, no technologically feasible add-on control options exist to reduce PM <sub>2.5</sub> emissions. For the emergency generators, the EPA agreed that the limits on annual hours of operation of 100 hours per year or less will result in add-on control equipment such as a DPF being cost prohibitive. Further, the EPA stated that similar to the turbines, no technologically feasible add-on control options exist to reduce PM <sub>2.5</sub> emissions from the small diesel and propane fired boilers. [^61]
[^60]*See* Hedgpeth, Z. (August 24, 2022). *Review of Best Available Control Technology analyses submitted for the Golden Valley Electric Association (GVEA) Zehnder and North Pole Power Plants as part of the Fairbanks PM*<sub>2.5</sub>* Nonattainment SIP.* U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
[^61]*Id.* at p. 11.
Thus, the EPA proposed to approve the submitted revisions to State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 related to direct PM <sub>2.5</sub> emissions and NO <sub>X</sub>[^62] emissions from Zehnder and the submitted Zehnder Permit conditions as satisfying CAA section 189(b) and 40 CFR 51.1010.
[^62] The EPA is not proposing to approve the NO <sub>X</sub> -related emissions limits as meeting BACT for NO <sub>X</sub> . For some emission units, Alaska imposed NO <sub>X</sub> emissions limits as surrogates for direct PM <sub>2.5</sub> emissions.
The EPA did not propose action on Alaska's SO <sub>2</sub> BACT determinations in State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 for the same reasons discussed in the preceding paragraphs regarding the Chena Power Plant.
**ii. Final Rule**
The EPA did not receive comments on PM <sub>2.5</sub> BACT for the Zehnder facility Campus Power Plant and is finalizing approval of BACT for PM <sub>2.5</sub> emissions at the Zehnder facility. Based on precursor demonstrations, SO <sub>2</sub> and NO <sub>X</sub> emission controls are not required for this facility as part of the Fairbanks Revised 189(d) Plan.
**e. North Pole Power Plant**
**i. Summary of Proposal**
In the Fairbanks Revised 189(d) Plan, Alaska revised its Air Quality Control Plan for the North Pole Power Plant to correct errors and improve clarity. [^63] Alaska also submitted conditions from Air Quality Control Minor Permit AQ0110MSS01 Revision 1 (Golden Valley Electric Association—North Pole Power Plant) (NPPP Permit). The NPPP Permit conditions include enforceable PM <sub>2.5</sub> BACT emissions limitations for the emission units at the North Pole Power Plant comprised of numerical emissions limits and work practice standards with associated monitoring, recordkeeping, and reporting. The permits are included in the docket for this action. [^64]
[^63] State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-267.
[^64]*See* State Air Quality Control Plan, Vol. III, Appendix III.D.7.7-300.
The EPA previously reviewed Alaska's BACT evaluation for the North Pole Power Plant. [^65] The EPA agreed with Alaska that no additional PM <sub>2.5</sub> BACT controls are feasible for emission units at the North Pole Power Plant. [^66] Thus, the EPA proposed to approve the submitted revisions to State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 related to direct PM <sub>2.5</sub> emissions and NO <sub>X</sub>[^67] emissions from the North Pole Power Plant and the submitted NPPP Permit conditions [^68] as satisfying CAA section 189(b) and 40 CFR 51.1010.
[^65]*See* Hedgpeth, Z. (August 24, 2022). * Review of Best Available Control Technology analyses submitted for the Golden Valley Electric Association (GVEA) Zehnder and North Pole Power Plants as part of the Fairbanks PM *<sub>2.5</sub>* Nonattainment SIP.* U.S. Environmental Protection Agency, Region 10, Laboratory Services and Applied Science Division, EPA-R10-OAR-2022-0115.
[^66]*Id.* at p. 11.
[^67] The EPA is not proposing to approve the NO <sub>X</sub> -related emissions limits as meeting BACT for NO <sub>X</sub> . For some emission units, Alaska imposed NO <sub>X</sub> emissions limits as surrogates for direct PM <sub>2.5</sub> emissions.
[^68]*See* section III.A of this preamble for the specific permit conditions proposed to be approved.
The EPA did not propose action on Alaska's SO <sub>2</sub> BACT determinations in State Air Quality Control Plan, Vol. III, Appendix III.D.7.7 for the same reasons discussed in the preceding paragraphs regarding the Chena Power Plant.
**ii. Final Rule**
The EPA did not receive comments on PM <sub>2.5</sub> BACT for the North Pole Power Plant and is finalizing approval of BACT for PM <sub>2.5</sub> and NH <sub>3</sub> emissions at the North Pole Power Plant. Based on precursor demonstrations, SO <sub>2</sub> and NO <sub>X</sub> emission controls are not required for this facility.
**6. Alaska's Identification and Adoption of Additional Measures and Demonstration of 5% Reduction in Emissions Pursuant to CAA section 189(d)**
**a. Summary of Proposal**
The EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the requirements of CAA section 189(d) for Serious areas for the PM <sub>2.5</sub> NAAQS that fail to attain by the Serious area attainment date. In the Fairbanks Revised 189(d) Plan the State retained the identification of all sources of direct PM <sub>2.5</sub> emissions and PM <sub>2.5</sub> plan precursors, identification of all potential controls to reduce direct PM <sub>2.5</sub> emissions and PM <sub>2.5</sub> plan precursors, and reevaluation of previously rejected control measures included in the initial Fairbanks 189(d) Plan.
As part of its reevaluation of control measures, Alaska provided additional information for many of the control measures the State considered in the BACM analysis. The Fairbanks Revised 189(d) Plan includes additional explanation of the State's consideration of potential measures such as banning installation of solid-fuel devices in new construction, limiting heating oil to ultra-low sulfur diesel, dry wood requirements, emissions controls for small area sources, mobile sources, and MSMs. [^69]
[^69] State Air Quality Control Plan, Vol. II, section III.D.7.7.12 (adopted November 5, 2024).
Alaska identified a burn-down period as part of other jurisdictions' solid fuel-fired heating device curtailment program. Accordingly, Alaska adopted a burn down period of three hours for solid-fuel heating devices that begins upon the effective date and time of a curtailment announcement. In addition, Alaska added specific requirements to document economic hardship as part of a No Other Adequate Source of Heat (NOASH) curtailment program waiver for solid-fuel devices.
Regarding the requirement of CAA section 189(d) for the plan revision to achieve at least five percent annual reductions of PM <sub>2.5</sub> or PM <sub>2.5</sub> plan precursor emissions each year until attainment, Alaska included in the Fairbanks Revised 189(d) Plan a control strategy analysis that projects annual reductions of direct PM <sub>2.5</sub> emissions that are greater than five percent per year through 2027, Alaska's projected attainment year. [^70] Alaska noted that the State can demonstrate either five percent annual reductions in emissions of direct PM <sub>2.5</sub> or a five percent annual reductions in emissions of a PM <sub>2.5</sub> plan precursor. Alaska elected to demonstrate five percent annual reductions in direct PM <sub>2.5</sub> emissions. Thus, the EPA proposed to approve the control strategy included in the Fairbanks Revised 189(d) Plan as meeting the requirements of CAA section 189(d) and 40 CFR 51.1010(c).
[^70] State Air Quality Control Plan, Vol. II, section III.D.7.9.2.3, Table 7.9-9.
**b. Final Rule**
The EPA did not receive comments on this requirement and is finalizing the approval as proposed.
**D. Attainment Demonstration and Modeling**
**1. Summary of Proposal**
The EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the attainment demonstration and modeling requirements of CAA section 189 and 40 CFR 51.1011. The State included an updated attainment demonstration in the Fairbanks Revised 189(d) Plan. [^71] In the plan, Alaska asserted that calendar year 2027 reflects attainment “as expeditiously as practicable,” based on air quality improvements from the base year to attainment year, as measured by the quantified emissions reductions associated with the implementation of control measures. [^72]
[^71] State Air Quality Plan, Vol. II, section III.D.7.9 (adopted November 5, 2024).
[^72] State Air Quality Plan, Vol. II, section III.D.7.9.
The EPA proposed to approve Alaska's attainment demonstration as meeting the requirements under 40 CFR 51.1011(b). Alaska demonstrated that the 2027 projected attainment date for the Serious nonattainment area is as expeditious as practicable. The EPA proposed to determine that the attainment demonstration met the requirements of Appendix W and included inventory data, modeling results, and emissions reduction analyses on which the State has based its projected attainment date. As discussed in section II.A of the Proposal, the base year for the emissions inventories for Alaska was 2020, which the EPA proposed to determine is the technically appropriate inventory year. The EPA proposed to determine that the control strategies in Alaska's SIP as rectified by the Fairbanks Revised 189(d) Plan satisfy the requirements of 40 CFR 51.1010. Therefore, the control strategies modeled as part of the attainment demonstration are consistent with the control strategies required pursuant to 40 CFR 51.1003 and 51.1010. With respect to the required timeframe for obtaining emissions reductions, all control measures needed for attainment will be implemented as expeditiously as practicable and implemented to attain the PM <sub>2.5</sub> NAAQS by December 31, 2027.
Pursuant to CAA section 172(a)(2)(A) and 40 CFR 51.1004(a)(3), the EPA proposed to extend the attainment date for the Fairbanks PM <sub>2.5</sub> Nonattainment Area to December 31, 2027. As shown in Table 5 of the Proposal, the 2020 base year design value at the Hurst Road monitoring station is 64.9 µg/m <sup>3</sup> . This design value is well above the PM <sub>2.5</sub> 24-hour NAAQS of 35 µg/m <sup>3</sup> , indicating the air quality problem in the Fairbanks PM <sub>2.5</sub> Nonattainment Area remains severe. However, Alaska has demonstrated that attainment earlier than 2027 is not feasible. Moreover, the EPA has reviewed Alaska's evaluations (and re-evaluations) of available control measures and proposes to determine that Alaska's control strategy meets the requirements of CAA section 189(b) and 189(d) and 40 CFR 51.1010. By extension, the EPA proposed to determine that there are no other feasible measures that Alaska could implement that would advance attainment to a date earlier than December 31, 2027.
As discussed in section II.E of the Proposal regarding Reasonable Further Progress, the primary drivers of emissions reductions will be continued implementation of the wood stove change out program, the Solid Fuel-Burning Appliance Curtailment Program, and the switch from diesel no. 2 fuel oil to diesel no. 1 fuel oil. The rate of wood stove change-outs in a single season is constrained based on the availability of certified installers and residential demand. Similarly, higher sulfur fuel cannot feasibly be eliminated from the Fairbanks PM <sub>2.5</sub> Nonattainment Area until 2026 [^73] due to the time necessary to expend all residual diesel no. 2 fuel oil and for diesel no. 1 to fully flush out any remaining higher sulfur residue. Finally, Alaska conducted a recent assessment of compliance with the Solid Fuel-Burning Appliance Curtailment Program that indicated a compliance rate of 38 percent. [^74] Given the variability of compliance with this program in past, Alaska did not project a near-term improvement in the compliance rate. Therefore, the EPA considered the severity of nonattainment and the availability and feasibility of control measures as required under CAA section 172(a)(2)(A) and 40 CFR 51.1004(a)(3).
[^73] State Air Quality Control Plan, Vol. II, section III.D.7.10, Table 7.10-4.
[^74] State Air Quality Control Plan, Vol. III, Appendix III.D.7.9, at p. Appendix III.D.7.14-12.
**2. Final Rule**
The EPA is finalizing approval of the attainment demonstration and modeling as proposed. Pursuant to CAA sections 172(a)(2)(A) and 179(d)(3) and 40 CFR 51.1004(a)(3), the Serious area attainment date for the Fairbanks PM <sub>2.5</sub> Nonattainment Area is December 31, 2027. In its December 5, 2023, final action, the EPA disapproved Alaska's attainment demonstration projecting attainment by December 31, 2024. Finalizing approval of Alaska's revised attainment demonstration submitted as part of the Fairbanks Revised 189(d) Plan, rectifies this prior disapproval.
**3. Comments and Responses**
The EPA received comments on the EPA's proposed approval of Alaska's attainment demonstration. In general, the comments questioned whether the Fairbanks PM <sub>2.5</sub> Nonattainment Area can reach attainment and the appropriateness of tolling the sanctions clocks and initiating steps to lift the transportation conformity freeze at this time. The EPA disagrees with these comments. The commenters primarily focused on the current air quality and on Alaska's historic challenges projecting emissions reductions. The commenters argued that these were sufficient bases for retaining the transportation conformity freeze and sanctions clocks. However, under the CAA, once a State makes a SIP submission intended to rectify the deficiencies that form the basis for a prior disapproval of a SIP submission, and the EPA takes final action to approve that SIP submission, sanctions clocks started due to the deficiencies are eliminated. [^75] In this action, the EPA is determining that Alaska has rectified the deficiencies in the initial Fairbanks 189(d) Plan that formed the basis for the EPA's 2023 disapproval.
[^75] CAA section 179(a), 42 U.S.C. 7509(a).
Similarly, in a separate action, the EPA found the budgets submitted by the State as part of the Fairbanks Revised 189(d) Plan adequate and is also approving those budgets as part of this action. Therefore, the area's metropolitan planning organization, the Fairbanks Area Surface Transportation (FAST) Planning, may determine conformity of its transportation plan and transportation improvement program (TIP) to the adequate budgets. [^76] Once FAST Planning and the U.S. Department of Transportation (DOT) makes a transportation conformity determination for its transportation plan and TIP, the freeze will end. Please see the EPA's Response to Comments document in the docket for this action for a summary of those comments and the EPA's detailed responses. [^77]
[^76] 40 CFR 93.120.
[^77] The EPA's Response to Comments, section 4.E.
**E. Reasonable Further Progress**
**1. Summary of Proposal**
The EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the RFP requirements in CAA section 172(c)(2) and 40 CFR 51.1012. The Fairbanks Revised 189(d) Plan included updated RFP provisions at State Air Quality Control Plan, Vol. II, section III.D.7.10. [^78] Consistent with the attainment demonstration provisions discussed in the preceding paragraphs, these updated RFP provisions reflect the attainment year of 2027. [^79] The updated RFP analysis included a schedule that includes 2020 as the base year, 2027 as the attainment year, and the following years as RFP and quantitative milestone analysis years: 2023, 2026, and 2029. [^80]
[^78] Adopted November 5, 2024.
[^79] RFP provisions in prior SIP submissions for the Fairbanks PM <sub>2.5</sub> Nonattainment Area reflected varying projected attainment dates. Initially Alaska submitted an RFP plan in the Fairbanks Serious Plan based on the projected attainment year of 2029. Alaska withdrew and replaced the RFP plan in the Fairbanks 189(d) plan based on the revised 2024 attainment projection.
[^80]*See* State Air Quality Plan, Vol. II, section III.D.7.10.2.
The RFP provisions in the Fairbanks Revised 189(d) Plan met each of the requirements in 40 CFR 51.1012(a)(1) through (4). First, the RFP provisions included a schedule describing the implementation of control measures during each year of the applicable attainment plan. [^81] Second, the Fairbanks Revised 189(d) Plan included RFP projected emissions for direct PM <sub>2.5</sub> and all PM <sub>2.5</sub> plan precursors for each applicable milestone year based on the phase-in schedule. [^82] Third, the Fairbanks Revised 189(d) Plan included an analysis that presents the schedule of control measures and estimated emissions changes to be achieved by each milestone year: 2023, 2026, and 2029. [^83] This analysis relies on information from the base year inventory and attainment projected inventories in State Air Quality Control Plan, Vol. II, section III.D.7.8, as well as the RFP projected emissions. The analysis demonstrated that the control strategy will achieve reasonable progress toward attainment between the applicable base year and the attainment year. [^84]
[^81]*Id.* at section III.D.7.10.3.2; *See also* State Air Quality Control Plan, Vol. III, Appendix III.D.7.10.
[^82]*Id.* at section III.D.7.10.3.3, Table 7.10-5.
[^83]*Id.* at section III.D.7.10.3.2, Table 7.10-4.
[^84]*Id.* at section III.D.7.10.3, Tables 7.10-4-7.10-5; Figures 7.10-3—7.10-5. Note that NH <sub>3</sub> emissions are projected to increase from base year to the projected attainment year. As discussed in the preceding paragraphs regarding the control strategy, the EPA either has previously approved Alaska's control strategy as meet planning requirements for sources of NH <sub>3.</sub> This is primarily because there are either no controls for sources of NH <sub>3</sub> emissions in the Fairbanks PM <sub>2.5</sub> Nonattainment Area or the direct PM <sub>2.5</sub> emissions controls are sufficient to control NH <sub>3</sub> emissions.
Finally, the Fairbanks Revised 189(d) Plan included an analysis that demonstrates that by the end of the calendar year for each milestone date, pollutant emissions will be at levels that reflect either linear progress or stepwise progress in reducing emissions on an annual basis between the base year and attainment year. In its December 5, 2023, final action, the EPA disapproved the reasonable further progress provisions included in the initial Fairbanks 189(d) Plan. Finalizing approval of Alaska's revised reasonable further progress provisions included in the Fairbanks Revised 189(d) Plan, rectifies this prior disapproval.
**2. Final Rule**
The EPA did not receive comments on the Reasonable Further Progress requirement and is finalizing the approval as proposed.
**F. Quantitative Milestones**
**1. Summary of Proposal**
The EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the quantitative milestone requirements of CAA section 189(c)(1) and 40 CFR 51.1013. First, in accordance with 40 CFR 51.1013(a)(3)(ii) and (a)(4), the Fairbanks Revised 189(d) Plan included quantitative milestones for the years 2023, 2026, and 2029. Second, the Fairbanks Revised 189(d) Plan included phase-in metrics for each measure in the control strategy, including measures necessary to meet the BACM and BACT requirements in CAA section 189(b) and 40 CFR 51.1010(a) and the requirements of CAA section 189(d) and 40 CFR 51.1010(c). Finally, the EPA proposed to find that the quantitative milestones selected by the State allowed for objective evaluation of whether the State is meeting the RFP requirements of the Fairbanks Revised 189(d) Plan.
**2. Final Rule**
The EPA did not receive comments on the Reasonable Further Progress requirement and is finalizing the approval as proposed.
**G. Contingency Measures**
**1. Summary of Proposal**
In the Proposal, the EPA reviewed the three measures that the State included in the Fairbanks Revised 189(d) Plan to meet the contingency measures requirement for the 2006 24-hour PM <sub>2.5</sub> NAAQS. The EPA proposed to approve one of the State's submitted measures as a contingency measure, reducing the solid fuel-burning device curtailment thresholds. This contingency measure would achieve approximately 0.086 tons per day PM <sub>2.5</sub> emissions reductions with an increase of 0.047 tons per day SO <sub>2</sub> emissions. The EPA proposed to approve the other two measures as SIP-strengthening, enforceable commitments to enhance enforcement of the Solid Fuel-Burning Appliance Curtailment Program and removal of wood stoves. These SIP-strengthening measures would achieve surplus emissions reductions by increasing the compliance rate with the curtailment program from 38 percent to 65 percent and the wood stove removal measure from 30 percent to 45 percent.
The EPA proposed to find that the State provided an adequate reasoned justification that no other contingency measures are feasible for the Fairbanks PM <sub>2.5</sub> Nonattainment Area for purposes of the 2006 24-hour NAAQS. The EPA proposed to approve the Fairbanks Revised 189(d) Plan as meeting the contingency measure requirements in CAA section 179(c)(9) and 40 CFR 51.1014(a). See the Proposal, section II.G.4, for the EPA's detailed evaluation of Alaska's contingency measures.
**2. Final Rule**
The EPA did not receive comments on the Contingency Measure requirement and is finalizing the approval as proposed.
**H. Motor Vehicle Emissions Budgets for Transportation Conformity**
**1. Summary of Proposal**
The Fairbanks Revised 189(d) Plan included budgets for direct PM <sub>2.5</sub> for each of the upcoming RFP years (2023, 2026, and 2029) and the 2027 attainment year identified by Alaska. Alaska did not include budgets for NO <sub>X</sub> emissions because Alaska previously demonstrated that NO <sub>X</sub> emissions do not significantly contribute to PM <sub>2.5</sub> formation in the Fairbanks PM <sub>2.5</sub> Nonattainment Area, and the EPA finalized approval of that precursor demonstration on December 5, 2023. [^85] For VOC, SO <sub>2</sub> and NH <sub>3</sub> emissions, in accordance with 40 CFR 93.102(b)(2)(v), transportation-related emissions of these precursors have not been found to be significant and thus the State included no budgets for them. [^86] Therefore, in the Fairbanks PM <sub>2.5</sub> Nonattainment Area, transportation conformity applies only with respect to direct emissions of PM <sub>2.5</sub> .
[^85] See section II.B.2 (December 5, 2023 (88 FR 84629). Note that 40 CFR 93.102(b)(2)(iv) indicates that NO <sub>X</sub> emissions would apply in transportation conformity in PM <sub>2.5</sub> areas unless the appropriate finding has been made or if the SIP does not establish a budget for NO <sub>X</sub> emissions.
[^86] Under 40 CFR 93.102(b)(2)(v), the requirements of the transportation conformity rule apply for VOC, SO <sub>2</sub> , and/or NH <sub>3</sub> emissions in a PM <sub>2.5</sub> area if either (1) the EPA Regional Administrator or the director of the state air agency makes a finding that transportation-related emissions of any of these precursors within the nonattainment area are a significant contributor to the PM <sub>2.5</sub> nonattainment problem and has so notified the MPO and the DOT, or (2) if the applicable implementation plan or submission establishes an approved or adequate budget for such emissions as part of the reasonable further progress, attainment or maintenance strategy. Because neither criterion is met for the Fairbanks area, budgets were not included for VOC, SO <sub>2</sub> , and NH <sub>3</sub> emissions.
The EPA evaluated the motor vehicle emissions budgets developed by Alaska against the adequacy criteria in 40 CFR 93.118(e)(4) as part of our review of this SIP submission. Because the budgets met the criteria in the transportation conformity regulation at 40 CFR 93.118(e)(4), the EPA proposed to approve them as part of this SIP submission that addresses attainment and RFP.
In addition to proposing approval of the budgets, the EPA initiated the adequacy review process for the budgets in the Proposal, as described by 40 CFR 93.118(f)(2). When reviewing SIP submissions containing conformity budgets, the EPA reviews the budgets using the adequacy criteria in 40 CFR 93.118(e)(4). Once the EPA affirmatively finds the submitted budgets are adequate for transportation conformity purposes, those budgets must be used by FAST Planning and the U.S. Department of Transportation when determining whether proposed transportation activities conform to the SIP as required by section 176(c) of the CAA. *See* 40 CFR 93.109(c)(1) and 93.118(e)(1); *see also* 93.118(a) through (d). [^87] The EPA issued its finding of adequacy for the budgets via letter on April 4, 2025, [^88] and published an accompanying Notice of Adequacy on May 8, 2025 (88 FR 19423) in the *Federal Register* .
[^87] However, the budgets in submitted implementation plans do not supersede the budgets in an approved SIP submission for the same CAA requirement and the period of years addressed by the previously approved SIP submission, unless the EPA specifies otherwise in its approval of a SIP submission. 40 CFR 93.118(e)(1).
[^88] Letter from Krishna Viswanathan, Director, Air and Radiation Division, U.S. Environmental Protection Agency to Christina Carpenter, Acting Commissioner, Alaska Department of Environmental Conservation, April 4, 2025.
**2. Final Rule**
The EPA is finalizing approval of the Motor Vehicle Emission Budgets for Transportation Conformity.
**3. Comments and Responses**
The EPA received adverse comments on the EPA's proposed approval of Motor Vehicle Emission Budgets for Transportation Conformity. Specifically, commenters expressed concern regarding increased diesel particulate emissions from ore truck hauling through the nonattainment area. The EPA acknowledges the concerns regarding diesel particulate emissions. Alaska accounted for increased diesel particulate emissions from ore truck hauling in the emissions analysis used to develop the budgets. Alaska used conservative assumptions regarding the frequency of truck trips and truck size when estimating ore truck emissions. Thus, the EPA's position remains that the motor vehicle emissions budgets meet the adequacy criteria in 40 CFR 93.118(e)(4). The EPA provides a more detailed response to these comments in the Response to Comments document in the docket for this action. [^89]
[^89] The EPA's Response to Comments, section 4.E.
**III. EPA Final Action**
**A. Final Approval**
1. In this action, the EPA is finalizing approval of the submitted revisions to the Alaska SIP as meeting the following Serious Plan and CAA section 189(d) [^90] required elements for the 2006 24-hour PM <sub>2.5</sub> NAAQS Fairbanks Nonattainment Area:
[^90] 42 U.S.C. 7513a(d).
a. Base year emissions inventory requirements of CAA section 172(c)(3) [^91] and 40 CFR 51.1008(c)(1) for areas subject to CAA section 189(d)).
[^91] 42 U.S.C. 7502(c)(3).
b. Attainment projected emissions inventory requirements of CAA section 172(c)(1) [^92] and 40 CFR 51.1008(c)(2)).
[^92] 42 U.S.C. 7502(c)(1).
c. BACM and BACT requirements (CAA section 189(b)(1)(B) [^93] and 40 CFR 51.1010(a)) for the following emission source categories:
[^93] 42 U.S.C. 7513a(b)(1)(B).
i. Requirements for wood sellers
ii. Coal-fired heating devices
iii. Coffee roasters
iv. Energy efficiency and weatherization measures
v. Mobile source emissions
vi. Control strategy BACT requirements for direct PM <sub>2.5</sub> emissions meeting the requirements of CAA section 189(b)(1)(B) [^94] and 40 CFR 51.1010(a) for the following emissions sources: [^95]
[^94] 42 U.S.C. 7513a(b)(1)(B).
[^95] For specific emission units, see State Air Quality Control Plan, Vol. II, section III.7.7.13.8.2.
• Chena Power Plant
• Fort Wainwright
• University of Alaska Fairbanks
• Zehnder Facility
• North Pole Power Plant
d. Additional measures (beyond those already adopted in previous nonattainment plan SIP submissions for the area as RACM/RACT and BACM/BACT) under CAA section 189(d) and 40 CFR 51.1010(c).
e. Attainment demonstration and modeling requirements of CAA sections 172(a)(2), 189(b)(1)(A), and 189(d) and 40 CFR 51.1003(c) and 51.1011.
f. Reasonable further progress (RFP) requirements of CAA section 172(c)(2) [^96] and 40 CFR 51.1012.
[^96] 42 U.S.C. 7502(c)(2).
g. Quantitative milestones requirements of CAA section 189(c) [^97] and 40 CFR 51.1013.
[^97] 42 U.S.C. 7513a(c).
h. Contingency measures requirements of CAA section 172(c)(9) [^98] and 40 CFR 51.1014 applicable to Serious areas subject to CAA sections 189(b) and 189(d).
[^98] 42 U.S.C. 7502(c)(9).
i. Motor vehicle emission budgets requirements under 40 CFR 51.1003(d) and 93.118.
2. The EPA is finalizing approval of the submitted chapters of the Alaska Air Quality Control Plan for the Fairbanks PM <sub>2.5</sub> Nonattainment Area, State effective December 14, 2024:
a. Volume II, section III.D.7.06 and Volume III, Appendix III.D.7.06 Emissions Inventory for purposes of the 2020 baseline emissions inventory and 2027 attainment year emissions inventory.
b. Volume II, section III.D.7.07 and Volume III, Appendix III.D.7.07 Control Strategies for purposes of the wood seller requirements, coal-fired heating devices, coffee roasters, energy efficiency and weatherization, light-duty vehicle anti-idling, and PM <sub>2.5</sub> BACT determinations for the Chena Power Plant, Fort Wainwright Power Plant, University of Alaska Fairbanks Campus Power Plant, Zehnder Power Plant, and the North Pole Power Plant.
c. Volume II, section III.D.7.08 Modeling and Volume III, Appendix III.D.7.08 Modeling.
d. Volume II, section II.D.7.09 Attainment Demonstration and Volume III, Appendix II.D.7.09 Attainment Demonstration.
e. Volume II, section II.D.7.10 Reasonable Further Progress and Quantitative Milestones and Volume III, Appendix II.D.7.10 Reasonable Further Progress and Quantitative Milestones.
f. Volume II, section II.D.7.11 Contingency Measures. [^99]
[^99] The EPA is approving enforceable commitments in the State Air Quality Control Plan, Vol. II, section III.D.7.2.1 as SIP-strengthening and not as contingency measures meeting the requirements of CAA section 172(c)(9).
g. Volume II, section II.D.7.12 Emergency Episode Plan.
h. Volume II, section II.D.7.14 Conformity and Motor Vehicle Emissions Budgets and Volume III, Appendix II.D.7.14 Conformity and Motor Vehicle Emissions Budgets.
3. The EPA is also finalizing approval and incorporating by reference submitted regulatory provisions into the Alaska SIP at 40 CFR 52.70(c), State effective December 8, 2024:
a. 18 AAC 50.055 (industrial processes and fuel-burning equipment requirements), except (d)(2)(B).
b. 18 AAC 50.076 (solid fuel-fired heating device fuel requirements; registration of commercial wood sellers), except (g)(11).
c. 18 AAC 50.077 (standards for wood fired heating devices), except (g).
d. 18 AAC 50.078 (additional control measures for a serious PM <sub>2.5</sub> nonattainment area), except (c).
e. 18 AAC 50.079 (provisions for coal-fired heating devices).
4. The EPA is also approving and incorporating by reference submitted source-specific provisions into the Alaska SIP at 40 CFR 52.70(d), State effective December 14, 2024:
a. Minor Permit AQ1121MSS04 Rev. 1, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only, (Doyon Utilities, LLC—Fort Wainwright (Privatized Emission Units)).
b. Minor Permit AQ0236MSS03 Rev. 2, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only (U.S. Army Garrison Fort Wainwright).
c. Minor Permit AQ0110MSS01 Rev. 1, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only, (Golden Valley Electric Association, North Pole Power Plant).
d. Minor Permit AQ0109MSS01 Rev. 2, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only, (Golden Valley Electric Association, Zehnder Facility).
e. Minor Permit AQ0315MSS02 Revision 1, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only, (Aurora Energy LLC, Chena Power Plant).
f. Minor Permit AQ0316MSS08 Revision 1, Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only, (University of Alaska Fairbanks, University of Alaska Fairbanks Campus).
**B. Terminating Sanctions Clocks and Lifting the Transportation Conformity Freeze**
Additionally, the EPA is affirmatively determining that the State has made a SIP submission correcting each of the deficiencies identified in the EPA's December 5, 2023, partial approval partial disapproval action (88 FR 84626). In accordance with CAA section 179(a) and 40 CFR 52.31(d)(5), the sanctions clocks triggered by the EPA's partial disapprovals in the prior action are now permanently stopped and eliminated.
The EPA issued the Notice of Adequacy for the Motor Vehicle Emissions Budgets in a separate action on May 8, 2025 (88 FR 19423). The adequacy finding for the budgets, which the EPA are also approving through this action, allows FAST Planning, and subsequently the U.S. DOT, to make conformity determinations for the transportation plan and TIP that would end the transportation conformity freeze, see 40 CFR 93.120(a)(2). Lastly, in accordance with CAA section 110(c), this final approval eliminates the EPA's obligation to promulgate a Federal implementation plan (FIP) for the disapproved portions of Alaska's SIP submission in the EPA's December 5, 2023, final rule (88 FR 84626). [^100]
[^100] CAA section 110(c), 42 U.S.C. 7410(c).
**IV. Incorporation by Reference**
In this document, the EPA is finalizing regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, the EPA is incorporating by reference regulatory provisions as described in section III of this document. The EPA has made, and will continue to make, these materials generally available through *https://www.regulations.gov* and at the EPA Region 10 Office (please contact the person identified in the *FOR FURTHER INFORMATION CONTACT* section of this document for more information).
**V. Statutory and Executive Order Reviews**
Under the Clean Air Act, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve State choices, provided that they meet the criteria of the CAA. Accordingly, this action merely approves State law as meeting Federal requirements and does not impose additional requirements beyond those imposed by State law. For that reason, this action:
• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Is not subject to Executive Order 14192 (90 FR 9065, February 6, 2025) because SIP actions are exempt from review under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 *et seq.* );
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 *et seq* );
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it approves a State program;
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001); and
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA.
In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rule does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
This action is subject to the Congressional Review Act, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is not a “major rule” as defined by 5 U.S.C. 804(2).
Under section 307(b)(1) of the CAA, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by January 20, 2026. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. See section 307(b)(2).
**List of Subjects in 40 CFR Part 52**
Environmental protection, Air pollution control, Carbon monoxide, Incorporation by reference, Intergovernmental relations, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping requirements, Sulfur oxides, Volatile organic compounds.
**Authority:**
42 U.S.C. 7401 *et seq.*
Dated: October 29, 2025.
Daniel Opalski,
Deputy Regional Administrator, Region 10.
For the reasons set forth in the preamble, the EPA amends 40 CFR part 52 as follows:
**PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS**
**40 CFR Part 52**
1. The authority citation for part 52 continues to read as follows:
**Authority:**
42 U.S.C. 7401 *et seq.*
**Subpart C—Alaska**
**40 CFR Part 52**
2. In § 52.70:
a. Amend table 1 in paragraph (c) by revising the entries for “18 AAC 50.055”, “18 AAC 50.076”, “18 AAC 50.077”, “18 AAC 50.078”, and “18 AAC 50.079”;
b. Revise table 4 to paragraph (d); and
c. Amend table 5 in paragraph (e) by:
i. Revising the second entries for “II.III.D.7.06 Fairbanks Emissions Inventory Data” and “III.III.D.7.06 Appendix to Fairbanks Emissions Inventory Data” and the entries for “II.III.D.7.07 Control Strategies”, “III.III.D.7.07 Appendix to Control Strategies”, “II.III.D.7.08 Modeling”, and “III.III.D.7.08 Appendix to Modeling” under the heading “Recently Approved Plans”; and
ii. Adding entries for “II.III.D.7.09 Attainment Demonstration”, “III.III.D.7.09 Appendix to Attainment Demonstration”, “II.III.D.7.10 Reasonable Further Progress and Quantitative Milestones”, “III.III.D.7.10 Appendix to Reasonable Further Progress and Quantitative Milestones”, “II.III.D.7.11 Contingency Measures”, “II.III.D.7.12 Fairbanks Emergency Episode Plan”, “II.III.D.7.14 Conformity and Motor Vehicle Emission Budgets”, and “III.III.D.7.14 Appendix to Conformity and Motor Vehicle Emission Budgets” at the end of the table.
The revisions and additions read as follows:
§ 52.70
(c) * * *
| State citation | Title/subject | State effective date | EPA approval date | Explanations |
| --- | --- | --- | --- | --- |
| | | | | |
| | | | | |
| | | | | |
| * * * * * * * | | | | |
| 18 AAC 50.055 | Industrial Processes and Fuel-Burning Equipment | 12/8/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Except (d)(2)(B). |
| | | | | |
| * * * * * * * | | | | |
| 18 AAC 50.076 | Solid Fuel-Fired Heating Device Fuel Requirements; Requirements for Wood Sellers | 12/8/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Except (g)(11). |
| 18 AAC 50.077 | Standards for Wood-Fired Heating Devices | 12/8/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Except (g). |
| 18 AAC 50.078 | Additional Control Measures for a Serious PM-2.5 Nonattainment Area | 12/8/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Except (c). |
| 18 AAC 50.079 | Provisions For Coal-Fired Heating Devices | 12/8/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | |
| | | | | |
| * * * * * * * | | | | |
(d) * * *
| Name of source | Order/permit number | State effective date | EPA approval date | Explanations |
| --- | --- | --- | --- | --- |
| Doyon Utilities, LLC—Fort Wainwright (Privatized Emission Units) | Minor Permit AQ1121MSS04 Rev. 1 | 10/31/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
| U.S. Army Garrison Fort Wainwright. | Minor Permit AQ0236MSS03 Rev. 2 | 10/28/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
| Golden Valley Electric Association, North Pole Power Plant | Minor Permit AQ0110MSS01 Rev. 1 | 10/30/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
| Golden Valley Electric Association, Zehnder Facility | Minor Permit AQ0109MSS01 Rev. 2 | 10/28/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
| Aurora Energy LLC, Chena Power Plant | Minor Permit AQ0315MSS02 Revision 1 | 10/28/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
| University of Alaska Fairbanks, University of Alaska Fairbanks Campus | Minor Permit AQ0316MSS08 Revision 1 | 10/31/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Title Page, Table of Contents, List of Abbreviations and Acronyms, Section 1, Section 3, Section 4, and Section 6, only. |
(e) * * *
| Name of SIP provision | Applicable geographic or nonattainment area | State submittal date | EPA approval date | Explanations |
| --- | --- | --- | --- | --- |
| | | | | |
| * * * * * * * | | | | |
| | | | | |
| | | | | |
| * * * * * * * | | | | |
| II.III.D.7.06 Fairbanks Emissions Inventory Data | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks 189(d) Plan 2020 base year emissions inventory and 2027 attainment projected emissions inventory. |
| III.III.D.7.06 Appendix to Fairbanks Emissions Inventory Data | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks 189(d) Plan 2020 base year emissions inventory and 2027 attainment projected emissions inventory. |
| II.III.D.7.07 Control Strategies | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| III.III.D.7.07 Appendix to Control Strategies | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| II.III.D.7.08 Modeling | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious and Fairbanks 189(d) Plan for the PM
precursor demonstration for NOx and VOC emissions and SO
emissions from existing major stationary sources as it relates to control strategy requirements for areas subject to CAA section 189(b) and (d), 42 U.S.C. 7513a(b) and (d). |
| III.III.D.7.08 Appendix to Modeling | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan for the PM
precursor demonstrations for NO
and VOC emissions and SO
emissions from existing major stationary sources as it relates to control strategy requirements for areas subject to CAA section 189(b) and (d), 42 U.S.C. 7513a(b) and (d). |
| | | | | |
| * * * * * * * | | | | |
| II.III.D.7.09 Attainment Demonstration | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. Pursuant to CAA sections 172(a)(2)(A) and 179(d)(3), 42 U.S.C. 7502(a)(2)(A) and 42 U.S.C. 7509(d)(3), and 40 CFR 51.1004(a)(3), the Serious area attainment date for the Fairbanks PM
Nonattainment Area is December 31, 2027. |
| III.III.D.7.09 Appendix to Attainment Demonstration | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. Pursuant to CAA sections 172(a)(2)(A) and 179(d)(3), 42 U.S.C. 7502(a)(2)(A) and 42 U.S.C. 7509(d)(3), and 40 CFR 51.1004(a)(3), the Serious area attainment date for the Fairbanks PM
Nonattainment Area is December 31, 2027. |
| II.III.D.7.10 Reasonable Further Progress and Quantitative Milestones | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| III.III.D.7.10 Appendix to Reasonable Further Progress and Quantitative Milestones | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| II.III.D.7.11 Contingency Measures | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| II.III.D.7.12 Fairbanks Emergency Episode Plan | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| II.III.D.7.14 Conformity and Motor Vehicle Emission Budgets | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
| III.III.D.7.14 Appendix to Conformity and Motor Vehicle Emission Budgets | Fairbanks North Star Borough | 12/4/2024 | 11/18/2025, 90 FR [INSERT
PAGE WHERE THE DOCUMENT BEGINS] | Approved for purposes of the Fairbanks Serious Plan and Fairbanks 189(d) Plan. |
**40 CFR Part 52**
3. Amend § 52.73 by revising paragraph (e)(2)(ii) to read as follows:
§ 52.73
(e) * * *
(2) * * *
(ii) The EPA approves the revisions to the Alaska State Implementation Plan submitted on December 4, 2024, as meeting the following requirements applicable to the Fairbanks North Star Borough 2006 24-hour PM <sub>2.5</sub> Nonattainment Area:
(A) 2020 base year emissions inventory (Clean Air Act section 172(c)(3), 42 U.S.C. 7502(c)(3), 40 CFR 51.1008(c)(1)) for areas subject to Clean Air Act section 189(d), 42 U.S.C. 7513a(d);
(B) 2027 attainment projected emissions inventory (Clean Air Act section 172(c)(1), 42 U.S.C. 7502(c)(1), 40 CFR 51.1008(c)(2)) for areas subject to Clean Air Act section 189(d), 42 U.S.C. 7513a(d));
(C) PM <sub>2.5</sub> precursor demonstrations for SO <sub>2</sub> emissions for existing major stationary sources (Clean Air Act section 189(e), 42 U.S.C. 7513a(e); 40 CFR 51.1006(a));
(D) The control strategy as meeting BACM and BACT requirements under Clean Air Act section 189(b)(1)(B), 42 U.S.C. 7513a(b)(1)(B), and 40 CFR 51.1010(a) for the following emission source categories: PM <sub>2.5</sub> control measures for major stationary sources, requirements for wood sellers, coal-fired heating devices, coffee roasters, energy efficiency and weatherization measures, mobile source category;
(E) Additional measures (beyond those already adopted in previous nonattainment plan SIP submissions for the area as RACM/RACT, BACM/BACT, and MSM (if applicable)) under Clean Air Act section 189(d), 42 U.S.C. 7513a(d), and 40 CFR 51.1010(c);
(F) Attainment demonstration and modeling requirements of Clean Air Act sections 172(a)(2), 189(b)(1)(A), and 189(d), 42 U.S.C. 7502(a)(2), 42 U.S.C. 7513a(b)(1)(A) and 7513a(d), and 40 CFR 51.1003(c) and 51.1011 (Pursuant to CAA section 172(a)(2)(A), 42 U.S.C. 7502(a)(2), and 40 CFR 51.1004(a)(3), the Serious area attainment date for the Fairbanks PM <sub>2.5</sub> Nonattainment Area is December 31, 2027);
(G) Reasonable further progress (RFP) requirements of Clean Air Act section 172(c)(2), 42 U.S.C. 7502(c)(2), and 40 CFR 51.1012;
(H) Quantitative milestones requirements of Clean Air Act section 189(c), 42 U.S.C. 7513a(c), and 40 CFR 51.1013;
(I) Contingency measures requirements of Clean Air Act section 172(c)(9), 42 U.S.C. 7502(c)(9), and 40 CFR 51.1014 applicable to Serious areas subject to Clean Air Act sections 189(b) and 189(d), 42 U.S.C. 7513a(b) and 7513a(d); and
(J) Motor vehicle emission budgets requirements under 40 CFR 51.1003(d) and 93.118.