Air Quality State Implementation Plans; Approvals and Promulgations: Indiana; Huntington County 2010 Sulfur Dioxide Redesignation and Maintenance Plan

Air Plan Approval; Indiana; Huntington County 2010 Sulfur Dioxide Redesignation and Maintenance Plan

SUPPLEMENTARY INFORMATION:

I. Background and Redesignation Requirements

On June 22, 2010 (75 FR 35520), EPA published a new SO ₂ NAAQS of 75 parts per billion (ppb), which is met at an ambient air quality monitoring site (or in the case of dispersion modeling, at an ambient air quality receptor location) when the 3-year average of the annual 99th percentile of daily maximum 1-hour average concentrations does not exceed 75 ppb, as determined in accordance with appendix T of 40 CFR part 50.

On January 9, 2018 (83 FR 1098), EPA designated Huntington Township, a partial area of Huntington County, Indiana, as nonattainment for the 2010 SO ₂ NAAQS with an effective date of April 9, 2018, based on air quality modeling information which showed that Isolatek International (Isolatek), formerly known as U.S. Mineral Wool, may have been contributing to violations of the 2010 SO ₂ NAAQS. Section 191 of the CAA directs States to submit a SIP for an area designated as nonattainment for the 2010 SO ₂ NAAQS to EPA within 18 months of the effective date of the designation. The SIP must demonstrate that the State will achieve the NAAQS for the nonattainment area as expeditiously as practicable, but no later than five years from the effective date of designation.

On November 6, 2023, Indiana submitted Commissioner's Order 2023-Air-01, containing SO ₂ emission limits for Isolatek, along with a revision to the Indiana SIP that provides for attainment of the 2010 SO ₂ NAAQS in the Huntington County area. The revision included an Attainment Demonstration, Reasonably Available Control Measures/Reasonably Available Control Technology (RACM/RACT) requirements, Reasonable Further Progress (RFP) provisions, Contingency Measures, Emissions Inventories for the 2017 Base Year and 2023 Attainment Year, and NSR Certification. On February 12, 2024, Indiana submitted a supplemental SIP revision including Commissioner's Order 2023-Air-02, effective March 1, 2024, which revised Commissioner's Order 2023-Air-01 and established compliance requirements for the SO ₂ emission limits. Commissioner's Order 2023-Air-02 is included as attachment C of Indiana's July 30, 2024, redesignation request.

On August 14, 2025 (90 FR 39130), EPA approved Indiana's plan for attaining the 2010 SO ₂ NAAQS for the Huntington County area and for meeting other nonattainment area planning requirements of CAA sections 110, 172, 179 and 192. EPA approved Indiana's demonstration that these requirements provide for attainment of the 2010 SO ₂ NAAQS in Huntington County and that Indiana had satisfied the other applicable requirements for nonattainment areas.

II. Evaluation of Indiana's Redesignation Request and Maintenance Plan

On July 30, 2024, Indiana submitted a redesignation request and maintenance plan for the Huntington County nonattainment area for the 2010 SO ₂ NAAQS, and on September 17, 2024, submitted supplemental information.

Under section 107(d)(3)(E) of the CAA, EPA may promulgate a redesignation of a nonattainment area provided that:

1. EPA has determined that the area has attained the NAAQS;

2. EPA has fully approved the applicable implementation plan for the area under section 110(k) of the CAA;

3. EPA has determined that improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable implementation plan and applicable Federal air pollution control regulations and other permanent and enforceable reductions;

4. EPA has fully approved a maintenance plan for the area under section 175A of the CAA; and

5. The State containing such area has met all requirements applicable to the area under section 110 of the CAA and part D.

EPA's evaluation of Indiana's redesignation request and maintenance plan was based on consideration of the five redesignation criteria provided under CAA section 107(d)(3)(E) and is described in the remainder of this section.

A. Criterion (1)-The Huntington County SO ₂ Nonattainment Area Has Attained the 2010 SO ₂ NAAQS

CAA section 107(d)(3)(E)(i) requires EPA to determine that an area has attained the applicable NAAQS in order for EPA to redesignate the area from nonattainment to attainment. If dispersion modeling is used to make this determination, an area is attaining the 2010 SO ₂ NAAQS when the modeled concentration is at or below the one-hour SO ₂ NAAQS of 196.4 micrograms per cubic meter (or 75 ppb).

As detailed in EPA's April 23, 2014, Guidance for 1-Hour SO ₂ Nonattainment Area SIP Submissions ("April 2014 SO ₂ Guidance"), there are generally two methods available to support an attainment determination. The first component relies on air quality monitoring data. For SO _2, any available monitoring data would need to indicate that all monitors in the affected area are meeting the standard in 40 CFR 50.17. The second component relies on air quality modeling data. If there are no air quality monitors in the area, a further analysis using air quality dispersion modeling will generally be needed to estimate SO ₂ concentrations throughout the nonattainment area to demonstrate that the entire area is attaining the applicable NAAQS, based on current actual emissions or the fully implemented control strategy. ⁽¹⁾

The April 2014 SO ₂ Guidance states that EPA may make determinations of attainment based on the modeling, using allowable emissions, from the attainment demonstrations for the applicable SIP for the affected area. Attainment demonstrations for the 2010 SO ₂ NAAQS should demonstrate future attainment and maintenance of the NAAQS in the entire area designated as nonattainment ( i.e., not just at the violating monitor) by using air quality dispersion modeling ( see appendix W to 40 CFR part 51) to show that the mix of sources and enforceable control measures and emission rates in an identified area will not lead to a violation of the 2010 SO ₂ NAAQS. For a short-term ( i.e., 1-hour) standard, EPA believes that dispersion modeling, using allowable emissions and addressing stationary sources in the affected area (and in some cases those sources located outside the nonattainment area which may affect attainment in the area) is technically appropriate, efficient and effective in demonstrating attainment in nonattainment areas because it takes into consideration combinations of meteorological and emission source operating conditions that may contribute to peak ground-level concentrations of SO _2.

As there is no approved SO ₂ monitoring network in the Huntington County area, Indiana's redesignation request relies upon the air dispersion modeling analysis conducted while developing its attainment demonstration for the Huntington County area to show that the area is attaining the SO ₂ NAAQS. A more in-depth discussion of EPA's modeling requirements and Indiana's modeling analysis may be found in EPA's proposed attainment plan approval (90 FR 25968, June 18, 2025) and Indiana's modeling report, which is included as attachment D of Indiana's July 30, 2024, redesignation request.

Indiana's modeling analysis confirmed that the primary source of SO ₂ emissions in the Huntington County area is Isolatek. Therefore, Indiana's modeled demonstration of attainment of the SO ₂ NAAQS relies on Isolatek meeting the permanent and enforceable SO ₂ emission limits established in Commissioner's Order 2023-Air-02. Commissioner's Order 2023-Air-02 includes limits of 160.0 pounds per hour (lbs/hr) of SO ₂ combined for Cupola units EU #1 and EU #2, exhausting to shared Stack #1, and 20.0 lbs/hr of SO ₂ combined for blow chambers EU #3 and EU #4, exhausting to Screen Houses CE #3 and CE #4, which exhaust to Stack #3 at Isolatek.

Indiana's modeling demonstrates that the one-hour average hourly SO ₂ emission limits contained in Commissioner's Order 2023-Air-02 yield a maximum SO ₂ concentration of 195.9 micrograms per cubic meter, which is below the 2010 SO ₂ NAAQS level of 75 ppb (or 196.4 micrograms per cubic meter). EPA approved Commissioner's Order 2023-Air-02 as part of Indiana's Huntington County attainment plan on August 14, 2025 (90 FR 39130).

The April 2014 SO ₂ Guidance states that a demonstration that the control strategy in the SIP has been fully implemented is relevant when making an attainment determination based on modeling. Construction for the control measures selected at Isolatek, including increasing the cupola stack height, enclosing screenhouses, and building a new elevated stack, was completed in November 2022. Indiana's attainment plan for the Huntington County area includes Commissioner's Order 2023-Air-02, which established a compliance date of March 1, 2024, for the emission limits included in the plan. On September 17, 2024, Indiana supplemented its July 30, 2024, redesignation request with a report containing results from stack testing at Isolatek to demonstrate that the facility is complying with the SO ₂ emission limits set forth in the order.

Indiana's modeling analysis is discussed in detail in EPA's proposed approval of Indiana's attainment plan for the Huntington County area (90 FR 25968, June 18, 2025). In this action, EPA proposes to find that this modeling analysis demonstrates that the Huntington County area has attained the 2010 SO ₂ NAAQS.

B. Criterion (2) and Criterion (5)-Indiana Has Met All Applicable Requirements Under CAA Section 110 and Part D of the CAA, and EPA Has Fully Approved the Applicable Implementation Plan Under CAA Section 110(k)

In order for EPA to redesignate a nonattainment area to attainment under a NAAQS, the State must have met all applicable requirements (CAA section 107(d)(3)(E)(v)), and EPA must have fully approved the applicable implementation plan (CAA section 107(d)(3)(E)(ii)). EPA's long-standing interpretation of the CAA is that not every requirement under CAA section 110 and part D are applicable for purposes of CAA section 107(d)(3)(E)(ii) and (v). EPA's interpretation of the statute limiting evaluation of section 110 and part D requirements to only those that are applicable for purposes of redesignation was first articulated shortly after the passage of the 1990 CAA Amendments in Agency guidance documents and has been consistently applied in notice-and-comment redesignation actions over the last three decades.

Many of the section 110 elements that are unrelated to an area's SO ₂ attainment status are not applicable requirements for purposes of redesignation. The area will still be subject to these requirements after the area is redesignated to attainment of the 2010 SO ₂ NAAQS. For example, the CAA section 110(a)(2)(D) interstate transport requirements for a State are not linked with a nonattainment area's designation and classification in that State and continue to apply to States regardless of the designation status of areas within that State. Even though many of the section 110 requirements are not applicable for purposes of redesignation, EPA in any case approved Indiana's section 110 infrastructure SIP for the 2010 SO ₂ NAAQS on August 14, 2015 (80 FR 48733).

EPA proposes to determine that Indiana has met, and EPA has fully approved, those part D requirements that are applicable for purposes of redesignation. Part D is comprised of the general nonattainment area plan requirements in subpart 1 (section 172) as well as pollutant-specific subparts, including section 191 (in subpart 5), which applies to areas designated nonattainment for SO ₂ . While some nonattainment planning requirements are not applicable for purposes of CAA section 107(d)(3)(E)(ii) and (v) for areas that are attaining the NAAQS, Indiana has in any case submitted a complete attainment plan for the Huntington County area, including emissions inventories, RACT/RACM, RFP, and contingency measures, and has therefore met Part D requirements.

On August 14, 2025 (90 FR 39130), EPA fully approved a revision to Indiana's SIP intended to provide for attainment of the 2010 SO ₂ NAAQS for the Huntington County area, including one-hour SO ₂ emission limits and associated requirements for Isolatek set forth in Commissioner's Order 2023-Air-02 and described above in the Criteria 1 section of this notice. Indiana's program for NSR will address emissions from potential new sources in the area (94 FR 24837, October 7, 1994).

Section 176(c) of the CAA requires States to establish criteria and procedures to ensure that federally supported or funded projects conform to the air quality planning goals in the applicable SIP. The requirement to determine conformity applies to transportation plans, programs, and projects that are developed, funded, or approved under title 23 of the United States Code (U.S.C.) or the Federal Transit Act (49 U.S.C. 1601) (transportation conformity) as well as to all other federally supported or funded projects (general conformity). State transportation conformity SIP revisions must be consistent with Federal conformity regulations relating to consultation, enforcement, and enforceability that EPA promulgated pursuant to its authority under the CAA. EPA's longstanding interpretation of the CAA is that because CAA section 176(c) conformity requirements continue to apply after areas are redesignated to attainment, meeting those requirements is not a prerequisite to redesignating an area. In addition, based on EPA's April 2014 SO ₂ Guidance, transportation conformity only applies to SO ₂ SIPs if transportation-related emissions of SO ₂ as a precursor are a significant contributor to a fine particulate matter (PM _2.5 ) nonattainment problem or if the SIP has established an approved or adequate budget for such emissions as part of the attainment or maintenance strategy, neither of which applies to the Huntington County area. EPA concluded that highway and transit vehicles are not significant sources of SO ₂ in this area. As a result, transportation conformity determinations are not required in the Huntington County SO ₂ maintenance area. Therefore, transportation plans, improvement programs, and projects are presumed to conform to applicable implementation plans for SO ₂ . EPA approved Indiana's general conformity SIP revision on January 14, 1998 (63 FR 2146). This SIP revision adopted the Federal general conformity rules set forth at 40 CFR part 51, subpart W.

Based on the above findings, EPA is proposing to find that Indiana has met the applicable requirements of section 110 and part D of title I of the CAA for purposes of the redesignation of the Huntington County nonattainment area. Furthermore, EPA has fully approved a revision to Indiana's applicable SIP that provides for attainment of the 2010 SO ₂ NAAQS for the Huntington County area.

C. Criterion (3)-The Air Quality Improvement in the Huntington County SO ₂ Nonattainment Area Is Due to Permanent and Enforceable Emission Reductions

To redesignate an area from nonattainment to attainment, section 107(d)(3)(E)(iii) of the CAA requires EPA to determine that the air quality improvement in the area is due to permanent and enforceable reductions in emissions resulting from the implementation of the SIP and applicable Federal air pollution control regulations and other permanent and enforceable emission reductions.

As described in the Criterion 1 section above, Indiana's modeling analysis confirmed that the primary source of SO ₂ emissions in the Huntington County area is Isolatek. Therefore, Indiana evaluated control options and established emission limits for Isolatek. Construction of the relevant control projects was completed in November 2022, and Indiana submitted Commissioner's Order 2023-Air-02 containing permanent and enforceable SO ₂ emission limits for Isolatek as part of its Huntington County attainment plan.

Commissioner's Order 2023-Air-02, included as attachment C to Indiana's July 30, 2024, redesignation request, establishes a compliance date of March 1, 2024, for the emission limits included in the Huntington County attainment plan and specifies that Isolatek must incorporate reporting and recordkeeping requirements into its part 70 operating permit within 90 days of EPA's approval of Indiana's attainment plan for the Huntington County area. On September 17, 2024, Indiana submitted stack testing to demonstrate that Isolatek is complying with the SO ₂ emission limits set forth in Commissioner's Order 2023-Air-02. On August 14, 2025 (90 FR 39130), EPA approved Commissioner's Order 2023-Air-02 as part of Indiana's Huntington County attainment plan.

The modeling that Indiana's attainment plan relies upon includes the emission limits for Isolatek and shows attainment of the 2010 SO ₂ NAAQS throughout the Huntington County area. EPA is proposing to find, consistent with the approval of the State's attainment plan, that the modeling results demonstrate attainment and continued maintenance of the 2010 SO ₂ NAAQS and that the air quality improvement in the Huntington County nonattainment area is due to permanent and enforceable reductions in emissions.

D. Criterion (4)-The Huntington County SO ₂ Nonattainment Area Has a Fully Approved Maintenance Plan Pursuant to Section 175A

To redesignate an area from nonattainment to attainment, section 107(d)(3)(E)(iv) of the CAA requires EPA to determine that the area has a fully approved maintenance plan pursuant to section 175A of the CAA. Section 175A of the CAA sets forth the elements of a maintenance plan for areas seeking redesignation from nonattainment to attainment. Under section 175A, the maintenance plan must demonstrate continued attainment of the NAAQS for at least 10 years after EPA approves a redesignation to attainment. Eight years after the redesignation, the State must submit a revised maintenance plan which demonstrates that attainment of the NAAQS will continue for an additional 10 years beyond the initial 10-year maintenance period. To address the possibility of future NAAQS violations, the maintenance plan must contain contingency measures, as EPA deems necessary, to ensure prompt correction of any future NAAQS violation.

Specifically, the maintenance plan should address five requirements: an attainment emissions inventory, a maintenance demonstration, a commitment for continued air quality monitoring, a process for verification of continued attainment, and a contingency plan. EPA is proposing to determine that Indiana's July 30, 2024, redesignation request contains a maintenance plan that includes all the necessary components, which Indiana has committed to review eight years after the redesignation. EPA is further proposing to approve the maintenance plan as part of Indiana's federally enforceable SIP.

As a part of a State's maintenance plan, the air agency should develop an attainment emissions inventory to identify the level of emissions in the affected area which is sufficient to attain and maintain the SO ₂ NAAQS. ⁽²⁾ In its redesignation request, Indiana provided an emissions inventory for SO ₂ in the nonattainment area for 2023, the first year after construction of the relevant emissions control projects at Isolatek was completed. Total SO ₂ emissions in the Huntington County area for the 2023 attainment year are 792 tons, including 788 tons from Isolatek, which was calculated using the maximum allowable hourly emission limits established in Commissioner's Order 2023-Air-02. This level of emissions, as shown in Indiana's attainment demonstration, is sufficient to maintain the NAAQS, and Indiana submitted a stack testing report on September 17, 2024, to demonstrate that Isolatek is in compliance with the emission limits set forth in Commissioner's Order 2023-Air-02. The modeling that Indiana relied upon for its redesignation request for the Huntington County area, based on SO ₂ emission limits set forth in Commissioner's Order 2023-Air-02, resulted in a design value of 195.9 micrograms per cubic meter, below the SO ₂ NAAQS of 75 ppb (or 196.4 micrograms per cubic meter). Indiana's modeling report is included as attachment D of its July 30, 2024, redesignation request.

EPA's "Procedures for Processing Requests to Redesignate Areas to Attainment" (Calcagni Memo)  ⁽³⁾ describes two ways for a State to demonstrate maintenance of the NAAQS following the redesignation of the area: (1) the State can show that future emissions of a pollutant will not exceed the level of the attainment inventory, or (2) the State can provide modeling to show that the future mix of sources and emission rates will not cause a violation of the NAAQS. In both instances, the demonstration should be for a period of 10 years following the redesignation. Furthermore, where modeling is relied upon to demonstrate maintenance, the plan should contain a summary of air quality concentrations expected to result from control measures implemented. Indiana's maintenance demonstration consists of the attainment plan air quality modeling analysis showing that the emission limits now in effect in the Huntington County area will provide for attainment of the 2010 SO ₂ NAAQS. The permanent and enforceable SO ₂ emission limits described above ensure that the area emissions will be equal to or less than the emission levels that were evaluated in the air quality modeling analysis, and Indiana's enforceable emission requirements will ensure that the Huntington County area SO ₂ emission limits are met continuously. Indiana's redesignation request contains an emissions inventory for 2035, the maintenance year, which does not show any increases in maximum allowable emissions from the attainment year. Additionally, Indiana has a fully approved NSR program (94 FR 24837, October 7, 1994), including requirements to assess the impacts of any plans to construct or resume operations of an emission unit on maintaining NAAQS attainment.

For verification of continued attainment, Indiana commits to periodically reevaluate the modeling assumptions and input data used in its Huntington County attainment plan. As there is no approved SO ₂ monitoring network to characterize air quality in the Huntington County area, Indiana commits to examine Isolatek's annual emissions as part of Indiana's annual assessment for ongoing data requirements for the 2010 SO ₂ NAAQS. Indiana has the legal authority, necessary resources, and structural components to implement and enforce all measures needed to attain and maintain the 2010 SO ₂ NAAQS.

Section 175A(d) of the CAA provides that a maintenance plan must contain contingency provisions that will promptly correct any violation of the 2010 SO ₂ NAAQS after the area is redesignated to attainment (Calcagni Memo). The maintenance plan should identify the contingency measures to be adopted, a schedule and procedure for adoption and implementation, and a time limit for action by the State. A State should also identify specific indicators to be used to determine when the contingency measures need to be implemented. The maintenance plan must also include a requirement that a State will implement all measures with respect to control of the pollutant that were contained in the SIP before redesignation of the area to attainment in accordance with section 175A(d). Unlike CAA section 172(c)(9), section l75A of the CAA does not explicitly require that contingency measures must take effect without further action by the air agency for the maintenance plan to be approved. However, if this action is finalized, the contingency plan would become an enforceable part of the SIP and should ensure that contingency measures are adopted and implemented as expeditiously as practicable once they are triggered. ⁽⁴⁾

In the "General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990," published on April 16, 1992 (57 FR 13498), EPA provides further discussion of contingency measures for SO ₂ . This guidance states that in many cases, attainment revolves around compliance of a single source or a small set of sources with emission limits shown to provide for attainment. Although this guidance applies to contingency measures under section 172(c)(9), EPA applies a similar policy with respect to contingency measures for SO ₂ required in maintenance plans under section 175A(d). The requirement to submit contingency measures in accordance with section 175A of the CAA can be adequately addressed for SO ₂ by the operation of a comprehensive enforcement program, ⁽⁵⁾ which can quickly identify and address sources that might be causing exceedances of the NAAQS.

Indiana's enforcement program is active and capable of prompt action to remedy compliance issues. Indiana commits to undertake aggressive follow-up to ensure compliance with and enforcement of all rules related to SO ₂ emissions in the Huntington County area, including Commissioner's Order 2023-Air-02, which EPA approved as part of Indiana's Huntington County attainment plan (90 FR 39130, August 14, 2025). Indiana has the authority to expeditiously adopt, implement, and enforce any subsequent emission control measures deemed necessary to correct any future SO ₂ violations. Indiana commits to adopting and implementing such corrective actions as necessary to address violations of the 2010 SO ₂ NAAQS. Based on the foregoing, EPA proposes to find that Indiana has addressed the contingency measure requirement.

EPA is proposing to find that Indiana's maintenance plan adequately addresses the five basic components of a maintenance plan necessary to maintain the SO ₂ NAAQS in the Huntington County nonattainment area. Therefore, EPA proposes to find that the redesignation and maintenance plan SIP revision submitted by Indiana for the 2010 SO ₂ Huntington County nonattainment area meets the requirements of section 175A of the CAA and proposes to approve this plan as part of Indiana's federally enforceable SIP.

III. What action is EPA taking?

EPA is proposing to redesignate the Huntington County area from nonattainment to attainment for the 2010 SO ₂ NAAQS in accordance with Indiana's July 30, 2024, request. EPA has determined that the area is attaining the 2010 SO ₂ NAAQS and that the improvement in air quality is due to permanent and enforceable SO ₂ emission reductions in the area. EPA is also proposing to approve Indiana's maintenance plan, which is designed to ensure that the area will continue to maintain attainment of the 2010 SO ₂ NAAQS. Once approved, the maintenance plan will become a part of Indiana's federally enforceable SIP.

IV. Statutory and Executive Order Reviews

Redesignation of an area to attainment and the accompanying approval of a maintenance plan under CAA sections 107 and 175A are actions that affect the status of a geographical area and do not impose any additional regulatory requirements on sources beyond those imposed by State law. A redesignation to attainment does not in and of itself create any new requirements but rather results in the applicability of requirements contained in the CAA for areas that have been redesignated to attainment. Moreover, 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, 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.

A. Executive Order 12866: Regulatory Planning and Review

This action is not a significant regulatory action and was therefore not submitted to the Office of Management and Budget (OMB) for review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action is not subject to Executive Order 14192 (90 FR 9065, February 6, 2025) because SIP approval and redesignation actions under the CAA are exempt from review under Executive Order 12866.

C. Paperwork Reduction Act

This rule does not impose an information collection burden under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq. ).

D. Regulatory Flexibility Act

This action merely approves State law as meeting Federal requirements and imposes no additional requirements beyond those imposed by State law. Accordingly, the Administrator certifies that this rule will not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq. ).

E. Unfunded Mandates Reform Act (UMRA)

This action does not contain any unfunded mandate as described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. This action does not impose additional requirements beyond those imposed by State law. Accordingly, no additional costs to State, local, or tribal governments, or to the private sector, will result from this action.

F. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

Executive Order 13175 (65 FR 67249, November 9, 2000), requires EPA to develop an accountable process to ensure "meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications." This rule does not have Tribal implications, as specified in Executive Order 13175. It will not have substantial direct effects on Tribal governments. Thus, Executive Order 13175 does not apply to this rule.

H. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks

This action is not subject to Executive Order 13045 because it is not 3(f)(1) significant as defined in Executive Order 12866, and because EPA does not believe the environmental health or safety risks addressed by this action present a disproportionate risk to children because it does not establish an environmental standard intended to mitigate health or safety risks.

I. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use

This action is not subject to Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer Advancement Act

This rulemaking does not involve technical standards.

[FR Doc. 2025-18594 Filed 9-24-25; 8:45 am]

BILLING CODE 6560-50-P

⁽¹⁾   EPA's Guidance for 1-Hour Sulfur Dioxide (SO ₂ ) Nonattainment Area State Implementation Plans (SIP) Submissions can be found at https://www.epa.gov/so2-pollution/guidance-1-hour-sulfur-dioxide-so2-nonattainment-area-state-implementation-plans-sip.

⁽²⁾ See April 2014 SO ₂ Guidance, page 66.

⁽³⁾  Calcagni, John, Director, Air Quality Management Division, EPA Office of Air Quality Planning and Standards, "Procedures for Processing Requests to Redesignate Areas to Attainment," September 4, 1992.

⁽⁴⁾ See April 2014 SO ₂ Guidance, page 74.

⁽⁵⁾ See April 2014 SO ₂ Guidance, page 41-42.