The proposed rule would amend the Agencies' regulations that prescribe AML/CFT program requirements  1 for banks  2 supervised by each of the Agencies in a way that aligns with the rule concurrently proposed by FinCEN  3 under the BSA. 4 While FinCEN has delegated its authority to examine banks for compliance with the BSA to the Agencies, the Agencies also have independent authority to prescribe regulations requiring banks to establish and maintain procedures reasonably designed to assure and monitor their compliance with the requirements of subchapter II of chapter 53 of title 31, under 12 U.S.C. 1818(s) and 12 U.S.C. 1786(q) (Sections 8(s) of the Federal Deposit Insurance Act and 206(q) of the Federal Credit Union Act, respectively). The Agencies are proposing to amend their rules concurrently with FinCEN so that their program requirements for banks remain consistent with those imposed by FinCEN. Further, with consistent regulatory text, banks will not be subject to any additional burden or confusion from needing to comply with differing standards between FinCEN and the Agencies. The proposed changes are discussed in more detail below in the section-by-section analysis.

Enacted in 1970 and amended several times since, the BSA is designed to combat money laundering, the financing of terrorism, and other illicit finance activity risks (collectively, ML/TF risks). 5 Congress has authorized the Secretary of the Treasury (Secretary) to administer the BSA. The Secretary has in turn delegated the authority to implement, administer, and enforce compliance with the BSA and its associated regulations to the Director of FinCEN (FinCEN Director). 6

The Money Laundering Control Act of 1986 (MLCA)  7 amended 12 U.S.C. 1818(s) and 12 U.S.C. 1786(q) (sections 8(s) of the Federal Deposit Insurance Act and 206(q) of the Federal Credit Union Act, respectively) to require the Agencies and the Board of Governors of the Federal Reserve System (Federal Reserve Board) to issue regulations requiring their supervised banks to “establish and maintain procedures reasonably designed to assure and monitor their compliance” with the requirements of the BSA. Consistent with the MLCA, on January 27, 1987, all the then-Federal bank regulatory agencies issued substantially similar regulations requiring their supervised banks to develop procedures for BSA compliance. 8

Since its original enactment, Congress has continued to address various aspects of AML/CFT compliance, including through expansion of the BSA. 9 In 1992, the Annunzio-Wylie Anti-Money Laundering Act  10 gave the Secretary authority to prescribe minimum standards for AML programs, including: “(A) the development of internal policies, procedures, and controls, (B) the designation of a compliance officer, (C) an ongoing employee training program, and (D) an independent audit function to test programs”—what are often called the “four pillars” of AML/CFT programs. 11 Later, the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (USA PATRIOT Act) further amended the BSA to include, among other things, customer identification program (CIP) requirements and the expansion of AML program rules to cover certain other financial industry participants ( e.g., credit unions and futures commission merchants). 12 The USA PATRIOT Act also made it mandatory for financial institutions to maintain AML programs that meet minimum prescribed standards. 13 Through the exercise of its delegated authority, FinCEN is authorized to require each financial institution to establish an AML/CFT program to ensure compliance with the BSA and guard against ML/TF risks. 14 Over time, FinCEN, the Agencies, and the Federal Reserve Board incorporated many of these standards into their respective program rules, and FinCEN implemented additional requirements for certain covered financial institutions into their respective program rules. 15

Although in practice the FinCEN AML program rule and the Agencies' compliance program rules for banks they supervise operate together, since the USA PATRIOT Act, banks under the Agencies' supervision have been required to maintain compliance programs under separate legal authorities administered by (i) FinCEN under Title 31 and (ii) the Agencies under sections 8(s) and 206(q). Because the authority for each Agency's BSA compliance program rule derives from and is required by sections 8(s) and 206(q), each Agency prescribes regulations requiring the banks they supervise to establish and maintain procedures reasonably designed to assure and monitor the compliance of such banks with the requirements of the BSA.

In 2003, FinCEN, the Agencies, the Federal Reserve Board, the Securities and Exchange Commission, and the Commodity Futures Trading Commission jointly issued final rules on CIP requirements, 16 which were mandated by amendments to the BSA under the USA PATRIOT Act requiring financial institutions to implement a CIP as part of their BSA compliance program. 17 The CIP requirements became part of the separate AML program rules for banks administered by FinCEN and each of the Agencies as well as the Federal Reserve Board, although the rules continued to function together by allowing banks to satisfy FinCEN's rule by complying with their Agency's rule or, as appropriate, the Federal Reserve Board's rule.

In 2016, FinCEN amended its AML compliance program rules to incorporate customer due diligence (CDD) requirements, including beneficial ownership information collection requirements for certain covered financial institutions, including banks. 18 Although the Agencies did not promulgate CDD requirements at that time, the Agencies examined supervised banks for compliance with those requirements under the authority of sections 8(s) and 206(q). 19 With the exception of the CDD requirement, FinCEN's rule was substantially similar to the rules of the Agencies and the Federal Reserve Board's rules, and banks must currently comply with both FinCEN's AML bank program rule and the BSA compliance rules of the Agencies and, as appropriate, the Federal Reserve Board.

On January 1, 2021, Congress enacted the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021, of which the AML Act was a component. 20 With the passage of the AML Act, Congress stated that it was seeking to modernize and strengthen the AML/CFT regulatory framework, which “had not seen comprehensive reform or modernization” since the BSA was enacted in the 1970s. 21 Among other objectives, Congress intended for the AML Act to require “more routine and systemic coordination, communication, and feedback among financial institutions, regulators, and law enforcement to identify suspicious financial activities, better focusing bank resources to the AML task, which will increase the likelihood for better law enforcement outcomes.”  22

Section 6101(b) of the AML Act made several changes to the BSA's AML/CFT program requirements.

First, section 6101(b) amended the BSA at 31 U.S.C. 5318(h)(2)(B) to state that, “[i]n prescribing the minimum standards for [AML/CFT programs], and in supervising and examining compliance with those standards, the Secretary of the Treasury, and the appropriate Federal functional regulator (as defined in section 509 of the Gramm-Leach-Bliley Act (15 U.S.C. 6809)) shall take into account” certain factors.

Second, section 6101(b) requires the Secretary, in consultation with the Attorney General, appropriate Federal functional regulators, relevant State financial regulators, and relevant national security agencies, to establish and make public government-wide AML/CFT priorities (AML/CFT Priorities). After consultation with the Federal functional regulators and relevant State financial regulators, the Secretary must promulgate regulations, as appropriate, to incorporate those priorities into revised program rules, and incorporation of the priorities must be included as a measure on which financial institutions are supervised and examined. FinCEN issued the first AML/CFT Priorities on June 30, 2021. 23

Third, section 6101(b) expands the BSA's program rule requirement to formally include an express reference to CFT in addition to AML.

Fourth, section 6101(b) provides that the duty to establish, maintain, and enforce an AML/CFT program shall remain the responsibility of, and be performed by, persons in the United States who are accessible to, and subject to oversight and supervision by, the Secretary and the appropriate Federal functional regulator.

The proposed rule also builds upon other recent efforts by FinCEN, the Agencies, and the Federal Reserve Board to modernize AML/CFT compliance program requirements for banks, both before and after the passage of the AML Act. These efforts include actions taken to revise the BSA regulatory regime through rulemakings, providing exemptive relief from regulatory requirements consistent with the purposes of the BSA, and clarifying regulatory requirements and supervisory standards through policy documents.

For example, on July 22, 2019, FinCEN, the Agencies, and the Federal Reserve Board issued a joint statement to clarify and explain their existing risk-focused approach to examinations of banks' BSA/AML compliance program. This statement was intended to increase transparency into the risk-focused approach used by the Agencies and the Federal Reserve Board for planning and performing BSA/AML examinations, which included clarifying that the Agencies and the Federal Reserve Board “generally allocate more resources to higher-risk areas, and fewer resources to lower-risk areas” based on the bank's unique risk profile. 24 FinCEN, the Agencies, and the Federal Reserve Board have also taken steps to highlight that customer relationships present varying levels of ML/TF risk and, in turn, to encourage banks to manage customer relationships and mitigate risks based on customer relationships, rather than decline to provide banking services to entire categories of customers. 25 More recently, the Agencies and the Federal Reserve Board have, with FinCEN's concurrence, issued an order permitting banks, as part of their CIP obligations, to collect Taxpayer Identification Number information from a third party rather than directly from the bank's customer, subject to certain conditions. 26 FinCEN, the Agencies, and the Federal Reserve Board have also issued Frequently Asked Questions to clarify certain obligations related to filing a suspicious activity report (SAR) to help ensure banks are not needlessly expending resources on efforts that do not provide law enforcement and national security agencies with the critical information they need to detect, combat, and deter criminal activity, as well as to combat misconceptions that banks are required to terminate customer relationships based on the filing of a SAR. 27

With respect to prior rulemaking efforts, prior to the enactment of the AML Act, FinCEN published an ANPRM seeking public comment on potential regulatory amendments intended to increase the effectiveness of program rule requirements (Effectiveness ANPRM), which was informed by recommendations of the AML Effectiveness Bank Secrecy Act Advisory Group working group. 28 While the Effectiveness ANPRM was issued by FinCEN on a standalone basis, the Agencies and Federal Reserve Board were consultative partners with FinCEN when developing the proposal. More recently, on July 3, 2024, FinCEN published an NPRM proposing revisions to its AML/CFT program requirements for all financial institutions, including those applicable to banks, 29 and on August 9, 2024, the Agencies, along with the Federal Reserve Board, issued an NPRM proposing substantially similar amendments to their respective AML program rules applicable to banks they supervise (the 2024 Program NPRM). 30

In proposing this rule in coordination with FinCEN, the Agencies considered applicable statutory requirements and prior feedback on these recent BSA modernization efforts, including comments provided on FinCEN's Effectiveness ANPRM and those received on the 2024 Program NPRMs. While building upon these prior modernization efforts, the proposed rule is distinct and separate from prior BSA modernization rulemaking efforts. 31

A central objective of the Agencies' BSA modernization efforts is to create an AML/CFT supervisory and regulatory regime that is more effective in achieving the purposes of the BSA and culminating in the development of highly useful information related to illicit financial transactions for law enforcement and national security agencies. 32 The proposed rule would further that objective by explicitly defining the requirements for a bank to establish and maintain an effective AML/CFT program. It would also adopt into regulations the AML Act's expectation that AML/CFT programs should be risk-based, including ensuring that banks direct more attention and resources toward higher-risk customers and activities, consistent with the risk profile of the bank, rather than toward lower-risk customers and activities. 33

The proposed rule would also revise the AML/CFT supervisory and examination process for banks by enhancing FinCEN's role in the Agencies' AML/CFT-related supervision and enforcement process. In support of this objective, the proposed rule would establish a mechanism in which FinCEN—as the statutory administrator of the BSA—has an opportunity to review and provide feedback to the Agencies prior to certain AML/CFT-related enforcement and supervisory actions. This change will promote consistent approaches to AML/CFT supervision, culminating in the development of highly useful information related to illicit financial transactions for both banks and the law enforcement and national security agencies that depend upon those banks' critical BSA reporting. The enforcement requirements only apply to actions by the Agencies.

As noted above, the proposed rule would require banks to establish and maintain effective AML/CFT programs and define the requirements for doing so. In order for an AML/CFT program to be effective, the proposed rule would require a bank to establish an AML/CFT program and then maintain the AML/CFT program by implementing, in all material respects, the established AML/CFT program.

As described in more detail in section IV.D a bank would be required to establish a risk-based set of internal policies, procedures, and controls that is reasonably designed to ensure compliance with the BSA and its implementing regulations, 31 CFR chapter X. The risk-based set of internal policies, procedures, and controls must also be reasonably designed to (1) identify, assess, and document the bank's ML/TF risks through risk assessment processes that evaluate the risks of the bank's business activities, review and, as appropriate, incorporate the AML/CFT Priorities, and are updated promptly upon any change that the bank knows or has reason to know significantly changes the bank's ML/TF risks; (2) mitigate the bank's ML/TF risks consistent with the bank's risk assessment processes including by directing more attention and resources toward higher-risk customers and activities, rather than toward lower-risk customers and activities; and (3) conduct ongoing customer due diligence.

The proposed rule would also require a bank to establish an ongoing employee training program and independent AML/CFT program testing as part of its AML/CFT program. Finally, the proposed rule would require a bank to designate an individual responsible for establishing and implementing the AML/CFT program and coordinating and monitoring day-to-day compliance; that individual would be required to be located in the United States and accessible to, and subject to oversight and supervision by, FinCEN or its designee and the appropriate Agency.

Under the proposed rule, in addition to establishing an AML/CFT program, the bank would be required to maintain that program by implementing, in all material respects, its established AML/CFT program. By structuring the requirement to have an effective AML/CFT program as distinct obligations to establish and maintain (via implementation) an AML/CFT program, the proposed rule is intended to clarify and reinforce the distinction between failures to establish an AML/CFT program and failures to implement a properly established program.

The distinction between establishing a program and maintaining a program by implementing it in all material respects is particularly important under the proposed rule for potential supervisory and enforcement actions. The proposed rule would not limit enforcement or supervisory actions for failures to establish an AML/CFT program. However, once a bank has properly established an AML/CFT program, the proposed rule would raise the threshold for significant supervisory or enforcement actions based solely on implementation deficiencies. Only significant or systemic failures by a bank to implement in all material respects an established program would warrant an “AML/CFT enforcement action” or a “significant AML/CFT supervisory action,” as these terms are defined in the proposed rule. In this way, the proposed rule is intended to clarify and reinforce a supervisory and enforcement focus on addressing significant or systemic failures to implement a properly established AML/CFT program, rather than on isolated, technical, or immaterial implementation issues. 34

Importantly, under the proposed regulations, having an effective AML/CFT program would be more than a one-time adoption of a risk-based set of internal policies, procedures, and controls. Rather, a bank would be required to keep its risk-based set of internal policies, procedures, and controls—and the risk assessment processes that inform them—current as the bank's risk profile changes. For example, while a bank's risk-based set of internal policies, procedures, and controls may, at one time, have been reasonably designed, they may no longer be reasonably designed given changes to the bank's risk profile. Similarly, an AML/CFT program would be more than a one-time creation of an employee training program or initiation of an independent testing mechanism: the bank would be required to keep such aspects of the AML/CFT program current as the bank's risk profile changes. Thus, even where a bank has previously established an AML/CFT program in accordance with the proposed rule, a failure to update the program to reflect significant changes in the bank's risk profile may result in the program no longer meeting the program establishment requirements, and the bank may accordingly be subject to supervisory or enforcement action for a failure to establish an effective AML/CFT program.

The proposed rule would also provide FinCEN with a greater role in the Agencies' supervisory process. To better ensure that the Agencies are performing “risk-focused” BSA supervision, the proposed rule would require that the Agencies consult with FinCEN prior to taking an AML/CFT enforcement action or a significant AML/CFT supervisory action. The Agencies would be required to give FinCEN written notice at least 30 days prior to taking such an action. FinCEN would have an opportunity to review the action and the relevant underlying information giving rise to it, and the Agencies would be required to consider any input offered by FinCEN concerning the effectiveness of the bank's AML/CFT program.

By explicitly defining the requirements for a bank to establish and maintain an effective AML/CFT program, and by standardizing the AML/CFT supervision and enforcement process for banks and across the Agencies, the proposed rule is expected to better achieve the purposes of the BSA, culminating in the development of highly useful information related to illicit financial transactions for banks and law enforcement and national security agencies. However, the Agencies do not intend for the proposed rule to provide banks permission to establish an AML/CFT program that might be interpreted as meeting the proposed rule's technical requirements on their face, but do not effectively detect and prevent ML/TF activity. To establish a compliant AML/CFT program under the proposed rule, a bank must, among other things, establish a risk-based set of internal policies, procedures, and controls that is reasonably designed to ensure compliance with the BSA and 31 CFR chapter X, including through the adoption of risk assessment processes. A critical element of this requirement is that the bank's s risk-based set of internal policies, procedures, and controls be “reasonably designed.” For example, if a bank's program testing reveals that a new customer type or new activity is high risk, but the bank does not take any action to revise the design of its risk-based set of internal policies, procedures, and controls and therefore treats the customer or activity as presenting low risk, then its program should not be considered reasonably designed. The Agencies believe that banks have a better understanding of their customer bases and businesses and are best positioned to identify and evaluate their ML/TF risks. Therefore, under this proposed rule banks will continue to have significant flexibility and discretion in their decisions and determinations related to risk identification and resource allocation. The Agencies will assess whether: (1) a bank's resource allocation decisions are consistent with a reasonably designed risk assessment processes; and (2) with respect to implementation, specifically, whether the bank knows or should know of resource-related issues involving its risk-based set of internal policies, procedures, and controls that may result in the bank failing to implement its AML/CFT program in all material respects and has failed to address such issues.

Similarly, the Agencies expect a bank to be examined for its implementation of the established AML/CFT program in all material respects. Merely designating an individual responsible for establishing and implementing the AML/CFT program and having that individual establish risk-based internal policies, procedures, and controls, an ongoing employee training program, and an independent AML/CFT program testing program, are not sufficient to satisfy the proposed rule's obligations for a bank to have an effective AML/CFT program. Rather, a bank would be examined for the implementation, in all material aspects, of its established AML/CFT program, including the determination that the bank is, in fact, allocating resources commensurate with its established AML/CFT program, which the proposed rule would require to be consistent with and its reasonably designed risk assessment processes.

This section-by-section analysis describes the specific proposed changes to the Agencies' BSA compliance program rules. Section IV.A addresses the proposed incorporation of CFT into the program rules. Section IV.B discusses the requirements for an “effective” AML/CFT program to comply with the requirements of the proposed rule. Section IV.C explains what it means to “establish” and “maintain” an effective AML/CFT program. Section IV.D describes the components of program establishment, including (1) a risk-based set of internal policies, procedures, and controls (including risk assessment processes); (2) independent program testing; (3) an individual, located in the United States and accessible to FinCEN and the Agencies, responsible for establishing and maintaining the program, and coordinating and monitoring day-to-day compliance; and (4) ongoing employee training. Section IV.E discusses the requirements that the AML/CFT program be written, accessible, and approved by a bank's Board of Directors, an equivalent governing body within the bank, or appropriate senior management. Section IV.F addresses the Customer Identification Program, Section IV.G addresses the supervision and enforcement section of the proposed rule, and Section IV.H discusses technical changes that the proposal makes to the existing rules to improve clarity and consistency across the program rules. Lastly, Section IV.I discusses disclosure of supervisory information.

Section 6101(b)(2)(A) of the AML Act amends 31 U.S.C. 5318(h)(1) to reference “countering the financing of terrorism”  35 in addition to “anti-money laundering” when describing the requirement to establish an AML/CFT program. The Agencies propose to update the AML/CFT program rules to reflect this new statutory language. For example, the proposed rule would change the title of the Agencies' program rules from “Bank Secrecy Act compliance” to “Anti-Money Laundering/Countering the Financing of Terrorism Compliance, Supervision, and Enforcement.” Similar changes would apply to the titles of relevant parts and subparts.

The inclusion of “CFT” in the BSA compliance program rule would not create new obligations for banks, insofar as the USA PATRIOT Act already requires them to account for risks related to terrorist financing. Accordingly, the Agencies expect any changes to existing AML/CFT programs from the amendments described in this subsection to be technical and therefore not have any substantive impact on banks' compliance obligations.

In prescribing the minimum standards for an AML/CFT program and in supervising and examining compliance with those standards, the AML Act requires the Secretary and the appropriate Federal functional regulator to take into account that effective AML/CFT programs safeguard national security and help law enforcement prevent the flow of illicit funds in the financial system. 36 Further, the AML Act contemplates AML/CFT requirements focusing on achieving effective outcomes rather than dictating the processes used to reach those outcomes, an orientation the Agencies intend to reflect in the proposed rule. Consistent with the Agencies' long-standing expectations regarding what effective outcomes entail, the Agencies believe that, as a practical matter, it is not possible for a bank's AML/CFT program to detect and report all potentially illicit transactions that flow through the institution. 37 Similarly, a bank's AML/CFT program can be effective without preventing every minor instance of a bank falling prey to illicit finance misuse. Accordingly, the proposed rule would set out that, from a supervisory and enforcement perspective, an AML/CFT program is “effective” and complies with the Agencies' regulatory requirements promulgated under 12 U.S.C. 1818(s) or 12 U.S.C. 1786(q), as applicable, so long as it is established and maintained in accordance with applicable requirements.

The proposed rule would provide that a bank has an “effective” program if it (1) is established in accordance with the proposed rule's establishment requirements; and (2) is maintained, meaning that a properly established AML/CFT program is implemented in all material respects.

One of the AML Act's key purposes is to “encourage technological innovation and the adoption of new technology by financial institutions to more effectively counter money laundering and financing of terrorism.”  38 Consistent with this purpose, the Agencies encourage banks to evaluate whether new technology or innovative approaches in other resources might help to combat financial crime more effectively. Innovative approaches could involve machine learning, generative artificial intelligence (GenAI), digital identity, blockchain monitoring and analytics, or application programming interfaces (APIs).

The Agencies recognize that adopting new technologies for BSA compliance may not be suitable for all banks, particularly smaller ones, and the proposed rule therefore does not reference or require the use of any particular technology. A bank may find it beneficial to consider whether its AML/CFT program appropriately uses the bank's existing resources, including technology and data. However, consistent with longstanding guidance, the Agencies encourage banks to engage in responsible AML/CFT innovation. 39 Banks that responsibly incorporate innovative technologies into their AML/CFT programs will not incur on that basis any additional risk of being subject to a significant supervisory action or enforcement action solely based on the use of innovative technologies.

The requirement that a bank establish and maintain an AML/CFT program is not new, although over time various formulations of this requirement have developed in statutes and regulations. 40

The proposed rule would harmonize and delineate the regulatory requirements that must be met for banks to have an effective AML/CFT program. That is, the proposed rule would create a two-pronged framework under which a bank's AML/CFT program would be deemed to be effective if the bank establishes and maintains its program. Under the proposed rule, a bank maintains its properly established AML/CFT program by implementing it in all material respects.

For a bank to have an effective AML/CFT program, the proposed rule would require a bank to establish an AML/CFT program and then maintain the AML/CFT program by implementing, in all material respects, the established AML/CFT program. The proposed rule describes the requirements for an effective AML/CFT program to be established and maintained. The AML/CFT program minimum components constituting program establishment, and described in further detail in Section V.D below, are: (1) a risk-based set of internal policies, procedures, and controls (including risk assessment processes); (2) independent program testing; (3) an individual, located in the United States and accessible to FinCEN and the appropriate Agency, responsible for establishing and maintaining the program, and coordinating and monitoring day-to-day compliance; and (4) ongoing employee training.

“Establishing” an AML/CFT program involves designing an AML/CFT program that incorporates all of the required components. “Maintaining,” by contrast, addresses whether the bank is implementing that program in practice. The regulation uses the term “implement” to describe this second prong. The distinction between establishing a program and maintaining a program by implementation matters because the proposed rule ties the availability of AML/CFT enforcement and significant supervisory actions based on the program rule for an established bank program to a significant or systemic failure to “implement” the properly established AML/CFT program. The distinction between establishing and “maintaining” an AML/CFT program is intended to make transparent how the individual elements of the proposed rule work together.

Separating program establishment from program maintenance therefore provides needed clarity regarding whether a supervisory concern relates to deficiencies stemming from the program's design, on the one hand, or failures in the program's operation, on the other. This two-prong framework would help promote consistent articulation of supervisory expectations and prevent conflating criticisms of program design—the remediation of which would likely be different in kind—with criticisms of day-to-day implementation. The proposed distinction does not change the substantive obligations for the bank.

As noted previously, the Agencies intend for the requirements of this proposed rule to not be limited to a one-time adoption of the elements required for program establishment, such as a risk-based set of internal policies, procedures, and controls. Rather, the Agencies intend a bank's establishment of its AML/CFT program to require the bank's risk-based set of internal policies, procedures, and controls—and the risk assessment processes that inform them—to remain current as the bank's risk profile changes. For example, if a bank begins providing a new product or service—or changes how it provides an existing product or service, such as operating in a new geographic location—under this proposed rule, a bank would need to incorporate its new product or service as part of its risk assessment processes. The proposed rule would require a bank to make a risk determination and, as appropriate, redesign its risk-based set of internal policies, procedures, and controls to account for the risks that it did not previously encounter prior to offering the new product or service, or operating in the new geographic location. Thus, under the proposed rule, even where a bank has previously established an AML/CFT program in accordance with the proposed rule, a failure to update the program to reflect significant changes in the bank's risk profile may result in the program no longer satisfying the proposed rule's requirements regarding establishment.

Once a bank has properly “established” an AML/CFT program, the bank must “maintain” the program by implementing it, in all material respects. Minor deficiencies of an AML/CFT program would not necessarily mean that a bank has failed to implement the program.

Although there are a variety of ways that a bank may not be implementing its program “in all material respects,” in the Agencies' experience, commonly observed examples may include, but would not be limited to: (1) internal policies, procedures, and controls are not being performed or not being performed on a consistent, regular, and timely basis ( e.g., consistently ignored warnings or red flags that a program was seriously deficient) due to the nature or extent of required resources becoming inadequate; (2) gaps in the risk assessment processes that result in the bank's program internal policies, procedures, and controls missing or inadequately covering higher ML/TF risks ( e.g., systems used to monitor for potentially suspicious activity failing to capture material volumes or types of transactions); or (3) deficiencies or weaknesses in the risk assessment processes that have a material impact on the bank's mitigation of ML/TF risks through its risk-based set of internal policies, procedures, and controls, including due to data-related issues involving relevant processes and systems.

Similarly, the Agencies expect that a bank could become aware of such implementation-related concerns through a variety of mechanisms, including but not limited to: (1) independent testing of the AML/CFT program; (2) examiner observations, suggestions, or other informal comments about the AML/CFT program;, (3) management information systems and related reports or other outputs ( e.g., key performance indicators or key risk indicators, such as monitoring for potentially material backlogs in relevant AML/CFT processes), and (4) issues identified by personnel involved in the operation of the bank's AML/CFT program.

As noted earlier, pursuant to 31 U.S.C. 5318(h), the Agencies' AML/CFT program requirements for banks currently require certain minimum elements, including: (1) a risk-based set of internal policies, procedures, and controls; (2) an independent audit function to test programs; (3) a designated compliance officer; and (4) an ongoing employee training program. The majority of the proposed rule's AML/CFT program components are substantially similar to the existing regulatory requirements for banks. However, the Agencies are proposing certain additions and modifications to modernize and strengthen banks' AML/CFT programs to allow banks to better mitigate illicit finance risks.

The Agencies' rules currently require banks to develop “a system of internal controls to assure ongoing compliance” with the requirements of the BSA as part of their AML/CFT programs. 41 The Agencies' existing program rules, however, do not clearly articulate what it means to establish such a system of internal policies, procedures, and controls to ensure compliance.

Under the proposal, the Agencies are amending and clarifying the current internal control pillar requirements. Specifically, the proposal provides that banks must establish a risk-based set of internal policies, procedures, and controls that is reasonably designed to: (1) identify, assess, and document ML/TF risks through risk assessment processes; (2) mitigate ML/TF risks consistent with the risk assessment processes, including by directing more attention and resources toward higher-risk customers and activities rather than toward lower-risk customers and activities; and, (3) conduct ongoing CDD. The preamble addresses each of these features below.

Under this proposal, a bank's risk-based set of internal policies, procedures, and controls should be based upon, informed by, and consistent with a bank's risk assessment processes. The internal policies, procedures, and controls should be commensurate with the size, structure, risk profile, and complexity of the bank. The requirement that a bank's risk-based set of internal policies, procedures, and controls be “reasonably designed” gives banks flexibility in how they achieve compliance with the BSA and the proposed rule's other requirements. As part of having a risk-based set of internal policies, procedures, and controls, reasonably designed to ensure compliance, banks may choose to responsibly adopt new technologies or innovative approaches to comply with BSA requirements. Consistent with this purpose, the Agencies encourage banks to evaluate whether new technology or innovative approaches in other resources might help to more effectively combat financial crime. Innovative approaches could involve machine learning, GenAI, digital identity, blockchain monitoring and analytics, or APIs.

The Agencies are proposing that, as part of a bank's risk-based set of internal policies, procedures, and controls, the bank identify, assess, and document the bank's ML/TF risk through risk assessment processes that: (1) evaluate the ML/TF risks of the bank's business activities, including products, services, distribution channels, customers, and geographic locations; (2) review and, as appropriate, incorporate the AML/CFT Priorities; and (3) update promptly upon any change that the bank knows or has reason to know significantly changes the bank's ML/TF risks.

The Agencies have traditionally viewed risk assessment processes as a critical tool of a reasonably designed BSA compliance program; a bank cannot implement a reasonably designed program to achieve compliance with the BSA unless it understands its risk profile. 42 Most banks already use risk assessments or risk assessment processes to structure their risk-based compliance programs. Despite being viewed as a critical tool, the Agencies' regulations do not currently explicitly require such risk assessment processes nor outline mandatory considerations for such processes. Thus, the proposed rule would codify into regulations the requirement for banks to establish risk assessment processes, thereby clarifying existing expectations and practices, as well as require specific factors for consideration that are responsive to the AML Act.

Importantly, the proposed rule requires, as a part of a bank's risk-based set of internal policies, procedures and controls, that it identify, assess, and document its ML/TF risks using risk assessment processes. A bank would retain flexibility in how it would document the results of its risk assessment processes. As proposed, banks would not be required to establish a single, consolidated risk assessment document solely to comply with the proposed rule. While such a document may be appropriate under the proposal, the use of the term “risk assessment processes” is intended to reflect that a financial institution may rely on multiple processes—applied as appropriate within its AML/CFT program—to identify, assess, and document its ML/TF risks and will be examined based on the totality of these processes rather than the sufficiency of a single, standalone risk assessment document.

The Agencies believe banks are best positioned to identify and evaluate their ML/TF risk and are therefore not prescribing any particular risk assessment processes or methodologies other than the critical elements described in this proposed rule. Under the proposed rule, banks would be examined for whether they have established and maintained, in all material respects, reasonably designed risk assessment processes—which need not be in the form of a singular risk assessment process. Furthermore, the Agencies are not prescribing any particular time frame for banks to update their risk assessment processes.

The Agencies recognize that banks vary significantly in size, structure, complexity, and risk profile. Under the proposed rule, bank's risk-based set of internal policies, procedures, and controls—including its risk assessment processes—should be commensurate with the bank's size, structure, risk profile, and complexity. Accordingly, banks with broader product offerings, more complex corporate structures, or greater exposure to higher-risk customers, products, services, or geographic locations would be expected to establish correspondingly more formalized or analytically complex internal policies, procedures, and controls—including risk assessment processes. By contrast, many community banks operate with more limited business activities, traditional lending and deposit services, a narrower geographic footprint, and customer bases concentrated within defined local communities. For such banks, risk assessment processes may appropriately be more streamlined or qualitative in nature, and a risk-based set of internal policies, procedures, and controls that is reasonably designed for a large, complex financial organization would not necessarily be required or appropriate for a community bank with a more limited risk profile.

As noted previously, most banks already design their BSA compliance programs based on their assessment of ML/TF risks under existing risk assessment processes. The Agencies expect that most banks will be able to leverage their existing risk assessment processes to satisfy the proposed requirement without making significant changes.

The proposed rule would require banks' risk assessment processes to evaluate the ML/TF risks of the bank's business activities, including products, services, distribution channels, customers, and geographic locations. These factors are generally well known and often incorporated into current risk assessment processes of banks. While most banks are generally familiar with these concepts, “distribution channels” may be a newer term for some banks. For purposes of this rule, the Agencies consider “distribution channels” to refer to the methods and tools through which a bank opens accounts and provides products or services, including, for example, through remote or other non-face-to-face means.

Banks may use a variety of sources to inform their risk assessment processes. Such sources may include information obtained from other financial institutions, such as emerging risks and typologies identified through section 314(b) information sharing or payment transactions that other financial institutions returned or flagged due to ML/TF risks. 43 Information a bank generates or maintains could be another source. Internal information may include, for example, customer internet protocol addresses or device logins and related geolocation information.

Feedback from FinCEN, law enforcement, and financial regulators may also inform risk assessment processes. For example, if a bank receives feedback from law enforcement about a report it has filed or potential risks at the bank, the bank may incorporate that information into its risk assessment processes. Similarly, banks may consider information identified from responding to section 314(a) requests.

In addition to feedback, reports and analyses published by Treasury and FinCEN may be particularly relevant to a bank's business activities, thereby warranting consideration when evaluating ML/TF risks. For example, Treasury describes changes in the illicit finance risk environment in its biennial National Money Laundering Risk Assessment, National Terrorist Financing Risk Assessment, and National Proliferation Financing Risk Assessment, which highlight significant illicit finance threats, vulnerabilities, and risks. 44 Regardless of the source, banks should take measures in their risk assessment processes to ensure this information is reasonably current, complete, and accurate.

The AML/CFT Priorities set out the priorities for the U.S. government's AML/CFT policy as required by the AML Act and are designed to ensure that banks' AML/CFT programs are aligned with those priorities. Recognizing the diverse nature of ML/TF threats facing the U.S. financial system and national security, and that bank AML/CFT programs benefit U.S. national security by safeguarding the financial system from ML/TF risk, the AML/CFT Priorities are intended to ensure that banks are focusing on the greatest threats to U.S. national security, as defined by Treasury.

Section 6101 of the AML Act requires that a financial institution's review and appropriate incorporation of the AML/CFT Priorities into its AML/CFT program be subject to supervision and examination for compliance with the BSA and other AML/CFT laws and regulations. 45 The Agencies are implementing this statutory requirement by proposing that, as part of their risk assessment processes, banks must review and, as appropriate, incorporate the AML/CFT Priorities. The inclusion of the AML/CFT Priorities in risk assessment processes is meant to help ensure that banks understand their exposure to risks in areas that are of particular importance nationally, which may help banks develop risk-based and reasonably designed AML/CFT programs.

The Agencies understand that the AML/CFT Priorities may not always be applicable to a bank's risk profile and activities. Therefore, the Agencies require the incorporation of the AML/CFT Priorities in a bank's risk assessment processes, as appropriate. This means that, having reviewed the AML/CFT Priorities, a bank may determine the extent to which a particular Priority is applicable and whether and how a particular AML/CFT Priority should be appropriately incorporated into its risk assessment processes.

Further, a bank may use its judgment and apply a reasonable, risk-based determination on whether to focus on a specific aspect of an AML/CFT Priority, rather than addressing all aspects of a Priority that may either not be applicable or pose lower risks to the bank. However, the Agencies caution that a surface-level, perfunctory review of an AML/CFT Priority by a bank and of the foreseeable ways in which it may manifest itself within the bank's customers, products and services, geographies, and distribution channels would not satisfy this requirement. For example, patterns of transactions that may be consistent with potential structuring should not automatically be dismissed as lower value to law enforcement and untethered to an AML/CFT Priority without determining whether there is a potential connection to various types of other illicit finance activity ( e.g., structuring or similar patterns involving transactions in narcotics trafficking proceeds).

Whenever the AML/CFT Priorities are updated, banks would no longer be required to incorporate prior versions of the AML/CFT Priorities. Banks would only be required, as appropriate, to incorporate the most recent AML/CFT Priorities into their risk-based AML/CFT programs.

The Agencies anticipate that some banks, such as community banks, may ultimately determine that their business models and risk profiles have limited exposure to some of the threats addressed in the AML/CFT Priorities but instead have greater exposure to other ML/TF risks. Additionally, some banks' risk assessment processes may determine that their AML/CFT programs already sufficiently incorporate to some extent, the AML/CFT Priorities. In either case, any changes to banks' AML/CFT program, such as internal policies, procedures, or controls would be based on the results of risk assessment processes and their impact on the AML/CFT program, including how to review and, as appropriate, incorporate the AML/CFT Priorities before making these determinations. 46 The Agencies request comment from the public on whether additional guidance related to the consideration of the AML/CFT Priorities as part of an institution's risk assessment processes would be warranted.

The proposed rule would require banks to update their risk assessment processes promptly upon any change that the bank would know or have reason to know would significantly change their ML/TF risk profile. For example, a bank may need to update its risk assessment when new products, services, and customer types are introduced; existing products, services, and customer types undergo significant changes; when the bank adopts new risk mitigation technology; or the bank as a whole expands or contracts through mergers, acquisitions, and divestitures. Banks may also need to update their risk assessment processes based on factors external to their operations that they know or have reason to know significantly change their ML/TF risk profiles. The Agencies welcome comments on whether it should further clarify when banks must review or update their risk assessment processes.

Section 6101(b) of the AML Act states that the AML/CFT programs of financial institutions should be “risk-based, including ensuring that more attention and resources of financial institutions should be directed toward higher-risk customers and activities, consistent with the risk profile of a financial institution, rather than toward lower-risk customers and activities.”  47 The proposed rule would adopt this formulation as part of a bank's obligation to establish a risk-based set of internal policies, procedures, and controls. Under the proposed rule, a bank's efforts to mitigate its ML/TF risks would involve “directing more attention and resources toward higher-risk customers and activities, consistent with the risk profile of [a bank], rather than toward lower-risk customers and activities.”

The Agencies view risk-based allocation of resources as a critical step in realizing the AML Act's BSA modernization and reform ambitions, and consistent with the Agencies' ongoing efforts to modernize AML/CFT compliance and supervision. The proposed rule envisions banks exercising more flexibility in deploying attention and resources in accordance with the proposed rule without fear of supervisory criticism or action from examiners for directing more attention and resources on higher risk customers and activities, rather than toward lower risk customers and activities.

The goal of risk-based resource allocation is for banks to spend less time, energy, and resources on lower priority activities that may result in less resources devoted to and potentially distract from more serious threats. The proposed rule would enable banks to focus more on higher risk customers and activities, which the Agencies have determined should result in banks being more effective at detecting, reporting, and preventing the flow of illicit funds and providing law enforcement with more valuable BSA reporting.

As noted above, the Agencies believe that banks are best positioned to identify and evaluate their ML/TF risk and to make decisions related to risk identification and resource allocation in accordance with risk identification. The proposed rule, therefore, does not contemplate second-guessing of a bank's reasonable determinations regarding appropriate resource allocation or conclusions regarding specific risks. However, while the Agencies do not believe that an examiner should substitute his or her own subjective judgment in place of the bank's, examiners will be expected to assess whether (1) a bank's resource allocation decisions are informed by, and consistent with, reasonably designed risk assessment processes; and (2) with respect to implementation, specifically, whether the bank knows or should know of resource-related issues involving its internal policies, procedures, and controls and other mandatory elements that may result in the bank failing to implement its AML/CFT program in all material respects and has failed to address such issues.

The proposed rule would add CDD as a required component of the Agencies' AML/CFT program rule. Appropriate risk-based procedures for conducting ongoing CDD—in the form of understanding the nature and purpose of customer relationships and conducting ongoing monitoring—is currently a required component in FinCEN's AML program rule, 48 and, therefore, banks are already required to comply with these ongoing CDD requirements under FinCEN's rule. The inclusion of risk-based procedures for conducting ongoing CDD in the Agencies' proposed rules would mirror FinCEN's existing rule and reflect the Agencies' long-standing supervisory expectations. Long before FinCEN amended its AML program rule to expressly include the CDD component requirement, the Agencies had considered CDD an integral component of a risk-based program, enabling the bank to understand its customers and its customers' activity to better identify suspicious activity. Adding the CDD component to the Agencies' AML/CFT program rule will eliminate confusion for banks concerning the current differences with FinCEN's rule. Because banks must already comply with FinCEN's CDD component requirement, the proposed change should not alter current compliance practices.

The proposed rule would incorporate CDD requirements not as a standalone pillar, but instead by making them part of the requirement that banks establish a risk-based and reasonably designed set of internal policies, procedures, and controls. As noted previously, the activities required to conduct ongoing CDD, such as monitoring customer relationships, maintaining and updating customer information on a risk basis, and identifying and reporting suspicious transactions are, in practice, subsumed by the obligation for a bank to have a risk-based and reasonably designed set of internal policies, procedures, and controls and have long been viewed by the Agencies as integral to component of a bank's internal controls. Accordingly, establishing these requirements within this pillar more accurately reflects how banks operationalize ongoing customer due diligence as part of their overall AML programs.

The Agencies have required banks to perform independent testing since the original adoption of their BSA compliance program rules. The AML Act did not change the BSA's separate requirement that each bank must independently test its AML/CFT program. 49 The proposed rule therefore retains the existing requirement for banks to establish independent AML/CFT program testing to be conducted by bank personnel or an outside party with minor, non-substantive clarifications that are not intended to change regulatory requirements.

The purpose of independent testing is to assess the bank's compliance with AML/CFT statutory and regulatory requirements, relative to its risk profile. The independent AML/CFT program testing should be focused on whether the AML/CFT program is effective, and it should identify issues and areas for remediation accordingly.

To support the effective implementations of an AML/CFT program, independent testing should be based on objective criteria designed to assess whether a bank has established and implemented an effective AML/CFT program and allocated resources consistent with its risk assessment processes. These criteria should also assess whether related project governance is sufficient to manage risks and apply compensating controls where necessary, particularly in areas where remediation is underway. This evaluation helps to inform the bank's board of directors and senior management of weaknesses or areas in need of enhancement or stronger controls. Typically, this evaluation includes a conclusion about the bank's overall compliance with AML/CFT statutory and regulatory requirements and sufficient information for the reviewer ( e.g., board of directors, senior management, AML/CFT officer, outside auditor, or an examiner) to reach a conclusion about whether the set of internal policies, procedures, and controls is reasonably-designed, and resources are well-allocated consistent with the bank's risk assessment processes.

Additionally, while banks retain some flexibility regarding who conducts the audit or testing, the proposed rule would continue to require that testing be independent. Banks that do not employ outside auditors or consultants or that do not have internal audit departments may comply with this requirement by using internal staff who are not involved in the function being tested. For these banks and banks with other types of arrangements for independent testing, the AML/CFT officer or any party who directly, and in some cases indirectly, reports to the AML/CFT officer, or an equivalent role, would generally not be considered sufficiently independent. Any individual conducting the testing, whether internal or external, would be required to be independent of other parts of the bank's AML/CFT program, including its oversight. For banks that engage outside auditors or consultants, the bank would be required to ensure that the outside parties conducting the independent testing are not involved in functions related to the AML/CFT program at the bank that may present a conflict of interest or lack of independence, such as AML/CFT training or the development or enhancement of internal policies, procedures, and controls. Additionally, for the purposes of the independent testing component, outside parties would not include government agencies, entities, or instrumentalities, such as a bank's Federal or state functional regulators. Banks with less complex operations and lower risk profiles may consider utilizing a shared resource as part of a collaborative arrangement to conduct testing, as long as the testing is independent. 50

On July 20, 2023, the Reserve Banks launched the FedNow Service. 1 The FedNow Service is an interbank real-time gross settlement service that supports instant payments in the United States 24x7x365. Currently, under Regulation J, FedNow participants may not use intermediaries, other than the Reserve Banks, for a funds transfer sent through the FedNow Service. This means that a funds transfer sent through the FedNow Service can include only two U.S. banks other than a Reserve Bank. Practically, this has meant that the service can be used only for domestic payments because participating banks located in the United States have been unable to send payments to additional banks outside the United States (such as correspondents).

The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under the ADDRESSES section. Include “Docket No. FAA-2026-3480; Project Identifier MCAI-2025-01031-T” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments.

Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.

CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Bill Ashforth, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3520; email: Bill.Ashforth@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

The FAA issued AD 2025-10-12, Amendment 39-23046 (90 FR 22457, May 28, 2025) (AD 2025-10-12), for all Airbus SAS Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; Model A320-211, -212, -214, -216, -231, -232, -233, -251N, -252N, -253N, -271N, -272N, and -273N airplanes; Model A321-211, -212, -213, -231, -232, -251N, -251NX, -252N, -252NX, -253N, -253NX, -253NY, -271N, -271NX, -272N, and -272NX airplanes; Model A330-201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342, -343, -841, and -941 airplanes; Model A350-941 and -1041 airplanes; and Model A380-841, -842, and -861 airplanes. AD 2025-10-12 was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued AD 2024-0199, dated October 18, 2024 (EASA AD 2024-0199), to correct an unsafe condition.

AD 2025-10-12 requires repetitive general visual inspections of the broadband antenna adapter plate, skirt, vents, and attachment fittings, and applicable corrective actions, and limits the installation of affected parts under certain conditions. The FAA issued AD 2025-10-12 to address the corrosion and cracks on the broadband antenna adapter plate and skirt assembly-adapter. The unsafe condition, if not addressed, could lead to in-flight detachment of the radome, antenna, and affected parts ( e.g., the broadband antenna adapter plate, skirt, vents and attachment fittings), which could impact the tail section of the airplane, possibly resulting in damage and reduced control of the airplane.

Since the FAA issued AD 2025-10-12, EASA superseded EASA AD 2024-0199 and issued EASA AD 2025-0120, dated May 26, 2025 (EASA AD 2025-0120) (also referred to as the MCAI), to correct an unsafe condition for all Airbus SAS Model:

• A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes;

• A320-211, -212, -214, -215, -216, -231, -232, -233, -251N, -252N, -253N, -271N, -272N, and -273N airplanes;

• A321-211, -212, -213, -231, -232, -251N, -251NX, -252N, -252NX, -253N, -253NX, -253NY, -271N, -271NX, -271NY, -272N, and -272NX airplanes;

• A330-201, -202, -203, -223, -243, -301, -302, -303, -321, -322, -323, -341, -342, -343, -841, and -941 airplanes;

• A350-941 and -1041 airplanes; and

• A380-841, -842, and -861 airplanes.

Model A320-215 airplanes are not certificated by the FAA and are not included on the U.S. type certificate data sheet; this AD therefore does not include those airplanes in the applicability.

The MCAI states a new Model, A321-271NY, has been certified, on which affected parts could be installed in service. Airbus has released Airbus Service Bulletin A320-44-1103 Revision 03, dated February 25, 2026, to include certain Model A321-271NY airplanes. EASA AD 2025-0120 is still considered to be an interim action, and further EASA AD action may follow.

The FAA is proposing this AD to address the unsafe condition on these products. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-3480.

Although this proposed AD does not explicitly restate the requirements of AD 2025-10-12, this proposed AD would retain all of the requirements of AD 2025-10-12. Those requirements are referenced in EASA AD 2025-0120, which, in turn, is referenced in paragraph (g) of this proposed AD.

The FAA reviewed EASA AD 2025-0120, which specifies procedures for repetitive general visual inspections for cracks and corrosion of the broadband antenna adapter plate, skirt, vents, and attachment fittings, and, depending on findings, corrective actions including repair or replacement of the affected parts. EASA AD 2025-0120 also limits the installation of affected parts under certain conditions and requires reporting of both positive and negative inspection results after the initial inspection and thereafter reporting the positive inspection results after each subsequent inspection.

This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

These products have been approved by the civil aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design.

This proposed AD would require accomplishing the actions specified in EASA AD 2025-0120 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.

In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2025-0120 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2025-0120 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2025-0120 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2025-0120. Material required by EASA AD 2025-0120 for compliance will be available at regulations.gov under Docket No. FAA-2026-3480 after the FAA final rule is published.

The FAA considers that this proposed AD would be an interim action. The FAA anticipates that further AD action will follow.

The FAA estimates that this AD, if adopted as proposed, would affect 8 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA estimates the following costs to do any necessary on-condition action that would be required based on the results of any required actions. The FAA has no way of determining the number of aircraft that might need this on-condition action:

The Part 141 Modernization Industry Recommendations Report   1 constitutes an industry-based proposal to FAA regarding modernization of 14 Code of Federal Regulations part 141 based upon the public meetings that took place between March 2025 and March 2026. The report and associated public meetings are not part of a rulemaking action and, therefore, are not subject to requirements for a public comment period. However, in recognition of the value of stakeholder participation and in continuation of the inclusive approach taken during the public meetings, FAA will afford all interested parties the opportunity to provide input on the Part 141 Modernization Industry Recommendations Report.

In accordance with the Privacy Act of 1974, the Office of Inspector General (OIG) is modifying and reissuing a current system of records titled, “Case Reporting and Information Management System Records,” CIG-04. The system of records is being retitled, “Inspector General Criminal Investigation Records (IGCIR).”

The system consists of both electronic and paper records and will be used by the DoD OIG to maintain records about individuals suspected of criminal misconduct and investigated pursuant to the Inspector General Act of 1978, as amended.

The Privacy Act permits Federal agencies to exempt eligible records in a system of records from certain provisions of the Act, including those that provide individuals with a right to request access to and amendment of their own records. If an agency intends to exempt a particular system of records, it must first go through the rulemaking process pursuant to 5 U.S.C. 553(b)(1)-(3), (c), and (e). This proposed rule explains why an exemption is being claimed for this system of records and invites public comment, which the DoD will consider before the issuance of a final rule implementing the exemption.

The DoD OIG proposes to modify 32 CFR part 310 to update the existing Privacy Act exemption rule for CIG-04, “Case Control System,” to change the system name and to add exemptions for this system of records from certain provisions of the Privacy Act because information in this system of records may fall within the scope of the following Privacy Act exemptions: 5 U.S.C. 552a(k)(1) and (k)(2). The existing exemption under 5 U.S.C. 552a(j)(2) will continue to be claimed for this system. This rulemaking seeks public comment on the addition of exemptions under 5 U.S.C. 552a(k)(1) and (k)(2).

The DoD OIG proposes this exemption because certain records may contain classified national security information, and as a result, notice, access, amendment, and disclosure (to include accounting for those records) to an individual and certain record-keeping requirement may cause damage to national security. The Privacy Act, pursuant to 5 U.S.C. 552a(k)(1), authorizes agencies to claim an exemption for systems of records that contain information properly classified pursuant to executive order. The DoD OIG is proposing to claim an exemption from several provisions of the Privacy Act, including various access, amendment, disclosure of accounting, and certain record-keeping and notice requirements pursuant to 5 U.S.C. 552a(k)(1), to prevent disclosure of any information properly classified pursuant to executive order, as implemented by DoD Instruction 5200.01 and DoD Manual 5200.01, Volumes 1 and 3.

The DoD OIG also proposes to exempt this system of records because these records support the conduct of criminal law enforcement activities, and certain requirements of the Privacy Act may interfere with the effective execution of these activities and undermine good order and discipline. Pursuant to 5 U.S.C. 552a(k)(2), agencies may exempt a system of records from certain provisions of the Privacy Act if it contains investigatory material compiled for law enforcement purposes, other than materials within the scope of 5 U.S.C. 552a(j)(2). The DoD OIG is proposing to claim exemptions from several provisions of the Privacy Act, including various access, amendment, disclosure of accounting, and certain record-keeping and notice requirements, pursuant to 5 U.S.C. 552a(k)(2), to prevent the harms articulated in this rule from occurring.

Records in this system of records are only exempt from the Privacy Act to the extent that the purposes underlying the exemption pertain to the record. A modified system of records for CIG-04 is also published in this issue of the Federal Register .

Executive Orders 12866 and 13563 direct agencies to assess all costs and benefits of available regulatory alternatives and, if regulation is necessary, to select regulatory approaches that maximize net benefits (including potential economic, environmental, public health and safety effects, distributive impacts, and equity). Executive Order 13563 emphasizes the importance of quantifying both costs and benefits, of reducing costs, of harmonizing rules, and of promoting flexibility. It has been determined that this rulemaking is not a significant regulatory action.

This rule is not subject to Executive Order 14192, because this rule is not a significant regulatory action under Executive Order 12866.

The Congressional Review Act, 5 U.S.C. 801 et seq., generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. DoD will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States. A major rule may take effect no earlier than 60 calendar days after Congress receives the rule report or the rule is published in the Federal Register , whichever is later. This rule is not a “major rule” as defined by 5 U.S.C. 804(2).

Section 202(a) of the Unfunded Mandates Reform Act of 1995 (UMRA) (2 U.S.C. 1532(a)) requires agencies to assess anticipated costs and benefits before issuing any rule whose mandates may result in the expenditure by State, local and Tribal governments in the aggregate, or by the private sector, in any one year of $100 million in 1995 dollars, updated annually for inflation. This rulemaking will not mandate any requirements for State, local, or Tribal governments, nor will it affect private sector costs.

The Director of Administration and Management has certified that this rulemaking is not subject to the Regulatory Flexibility Act (5 U.S.C. 601 et seq. ) because it would not, if promulgated, have a significant economic impact on a substantial number of small entities. This rulemaking is concerned only with the administration of Privacy Act systems of records within the DoD. Therefore, the Regulatory Flexibility Act, as amended, does not require DoD to prepare a regulatory flexibility analysis.

The Paperwork Reduction Act (44 U.S.C. 3501 et seq. ) was enacted to minimize the paperwork burden for individuals; small businesses; educational and nonprofit institutions; Federal contractors; State, local and Tribal governments; and other persons resulting from the collection of information by or for the Federal Government. The Act requires agencies obtain approval from the Office of Management and Budget before using identical questions to collect information from ten or more persons. This rulemaking does not impose reporting or recordkeeping requirements on the public.

Executive Order 13132 establishes certain requirements that an agency must meet when it promulgates a rule that has federalism implications, imposes substantial direct requirement costs on State and local governments, and is not required by statute, or has federalism implications and preempts State law. This rulemaking will not have a substantial effect on State and local governments.

Executive Order 13175 establishes certain requirements that an agency must meet when it promulgates a proposed rule (and subsequent final rule) that imposes substantial direct compliance costs on one or more Indian tribes, preempts tribal law, or affects the distribution of power and responsibilities between the Federal Government and Indian tribes. This rulemaking will not have a substantial effect on Indian tribal governments.

Accordingly, 32 CFR part 310 is proposed to be amended as follows:

The management of National Park System units in Alaska is governed by federal laws such as the 1916 Organic Act (System-wide) and the 1980 Alaska National Interest Lands Conservation Act (Alaska-specific); by regulations implementing these laws; by treaties; by Service policy; and by principles of sound resource management that may lead to standards or limits to the range of potential activities that may be allowed.

On March 10, 2026, we published a proposed rule to revise the Alaska-specific regulations at 36 CFR part 13 to restore both the procedures used to restrict public uses and opportunities to engage in those uses in Alaska park areas. These changes restore Service interpretations of law, policies, and regulations adopted to implement statutory provisions for these areas. This proposed rule addresses interests and input from the State of Alaska, Alaska Congressional Delegation, Alaska Federation of Natives, and others during previous rulemaking efforts. The purpose of the proposed rule is to realign state and federal regulations, restore the robust public engagement process Alaskans relied on to stay involved and informed on park management actions, enhance regulatory consistency across all lands and waters, and increase access to federal public lands in furtherance of Executive and Secretarial orders. The proposed rule would have no effect on the U.S. Department of the Interior and U.S. Department of Agriculture regulations governing subsistence harvest of fish and wildlife resources in Alaska park areas.

The March 10, 2026, proposed rule had a 30-day public comment period, ending April 9, 2026. During the comment period for the proposed rule, we received multiple requests for additional time to submit comments. We are extending the comment period by 15 days, to end April 24, 2026 (see DATES ), to accommodate requests for additional time to review and provide comments on our proposal.

We will accept comments and information during this extended comment period on our March 10, 2026, proposed rule to revise the public use regulations for Alaska park areas. It is the policy of the Department of the Interior, whenever practicable, to afford the public an opportunity to participate in the rulemaking process. Accordingly, we will accept written comments and information from all interested parties during the extended comment period (see DATES ) on the proposed rule. We are also soliciting public input and supporting data to gain additional information for the draft environmental assessment and the Service's regulatory impacts analysis, such as costs and benefits and trade-offs associated with the proposed rescission and restoration. As a specific example, we are soliciting information or data that would help the Service quantify the effects of restoring available harvest opportunities, including any economic impacts which might result.

Please see DATES and ADDRESSES in this document for information on providing comments and materials by one of the listed methods. We will consider information and recommendations received during the original and extended comment periods in our final determination on the March 10, 2026, proposed rule. If you already submitted comments or information on the proposed rule, please do not resubmit them. Any such comments are incorporated as part of the public record for the rulemaking and we will fully consider them in the preparation of our final determination.

If you submit information via http://www.regulations.gov, your entire submission—including your personal identifying information—may be posted on the website. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on http://www.regulations.gov where they will be available for public inspection.

Our final determination concerning the March 10, 2026, proposed action will take into consideration all comments and materials received during the open comment period. Submissions will be included in the public record for this rulemaking and we will fully consider them in the preparation of a final determination.

The primary authors of this document are Department of the Interior and National Park System staff of the Alaska regional offices.

On June 2, 2010, the EPA established a revised primary 1-hour SO 2 NAAQS with a level of 75 parts per billion (ppb), based on a 3-year average of the annual 99th percentile of daily maximum 1-hour average concentrations. 1 CAA section 110(a)(1) requires all states to submit, within three years after promulgation of a new or revised NAAQS, SIP submissions to provide for the implementation, maintenance, and enforcement of the NAAQS. 2 The EPA has historically referred to these SIPs as “infrastructure SIPs.” Specifically, section 110(a)(1) provides the procedural and timing requirements for SIP submissions. Section 110(a)(2) lists specific elements that all states must meet related to a newly established or revised NAAQS, such as requirements for monitoring, basic program requirements, and legal authority, that are designed to assure attainment and maintenance of the NAAQS.

Section 110(a)(2)(D)(i)(I) of the CAA requires that a state's SIP include provisions prohibiting any source or other type of emissions activity in the state from emitting any air pollutant in amounts that will contribute significantly to nonattainment, or interfere with maintenance, of the NAAQS in any other State. The EPA has long interpreted this language to enact a “functional prohibition” on certain emissions from upwind states, necessitating the EPA's independent assessment whether those emissions will occur or have been adequately controlled in the state where they originate. 3 The EPA often refers to these requirements as Prong 1 (significant contribution to nonattainment of the NAAQS) and Prong 2 (interference with maintenance of the NAAQS). We are addressing Prongs 1 and 2 in this action. All other applicable infrastructure SIP requirements of the New York SIP submission are addressed in separate rulemakings.

In this proposed action, the EPA has considered information from the 2010 1-hour SO 2 NAAQS designations process, as discussed in more detail in section III.C of this notice. For this reason, a brief summary of the EPA's designations process for the 2010 1-hour SO 2 NAAQS is included here. 4

After the promulgation of a new or revised NAAQS, the EPA is required to designate areas as “nonattainment,” “attainment,” or “unclassifiable” pursuant to CAA section 107(d)(1)-(2). The process for designating areas following promulgation of a new or revised NAAQS is contained in CAA section 107(d). The EPA promulgated the 2010 1-hour SO 2 NAAQS on June 2, 2010. See 75 FR 35520 (June 22, 2010). The EPA Administrator signed the first round of designations, Round 1, for the 2010 1-hour SO 2 NAAQS on July 25, 2013. See 78 FR 47191 (August 5, 2013). 5 The Agency published the Data Requirements Rule (DRR) on August 21, 2015 (80 FR 51052) to provide expectations for collection of data, either monitoring or modeling, for the remaining designations. 6 The Federal Register notices for Round 2 designations published on July 12, 2016 (81 FR 45039) and on December 13, 2016 (81 FR 89870). 7 Round 3 designations were published on January 9, 2018 (83 FR 1098) and April 5, 2018 (83 FR 14597). 8 Round 4 designations were published on March 26, 2021 (86 FR 16055) and April 14, 2021 (86 FR 19576). 9

During the second round of designations, EPA designated Erie and Niagara counties in New York State as “unclassifiable/attainment” based on an assessment and characterization of air quality performed using air dispersion modeling software analyzing actual emissions in the area surrounding Huntley and Somerset Generating Stations, and other nearby sources which may have a potential impact in the area of analysis where maximum concentrations of SO 2 are expected. 10 Huntley and Somerset were identified by EPA as meeting the criteria for further analysis to determine whether there is nonattainment. 11 Based on information received from New York in response to the DRR, the EPA identified 11 additional sources  12 for which the State of New York was required to characterize air quality through modeling or monitoring or impose federally enforceable controls, bringing the total number of DRR sources for New York to 13. 13 For New York, the EPA designated the partial St. Lawrence County area as nonattainment during the fourth round of SO 2 designations, effective April 30, 2021, based on available monitoring data. 14 In Round 4, the EPA also designated the remaining areas—the remaining portion of St. Lawrence County, Cayuga County, Seneca County, and Tompkins County—as attainment/unclassifiable, completing the area designations for the 2010 1-hour SO 2 NAAQS in New York.

Although SO 2 is emitted from a similar universe of point and nonpoint sources as is directly emitted fine particulate matter (PM 2.5 ) and the precursors to ozone and PM 2.5 , interstate transport of SO 2 is unlike the transport of PM 2.5 or ozone, which disperse over a wide area and can contribute to nonattainment or maintenance issues hundreds of miles from precursor-emitting sources or activities. SO 2 emissions usually do not undergo long-range transport in the atmosphere. The transport of SO 2 relative to the 2010 1-hour SO 2 NAAQS is more analogous to the transport of lead (Pb) relative to the Pb NAAQS in that emissions of SO 2 typically result in 1-hour pollutant impacts of greatest concern near the emissions source. However, ambient 1-hour concentrations of SO 2 do not decrease as quickly with distance from the source as do 3-month average concentrations of Pb, because SO 2 gas is not removed by deposition as rapidly as are Pb particles. Emitted SO 2 has wider-ranging impacts than emitted Pb, but it does not have such wide-ranging (far downwind) impacts that treatment in a manner similar to ozone or PM 2.5 would be appropriate. Accordingly, the approaches that the EPA has adopted for ozone or PM 2.5 transport are too regionally focused, and the approach for Pb transport is too tightly circumscribed to the source, to be appropriate for assessing SO 2 transport. SO 2 transport is therefore a unique case and necessitates an approach that lies between these other approaches to assessing pollutant transport.

In this proposed rulemaking, and consistent with prior SO 2 transport analyses, the EPA focused on a 50 kilometer (km)-wide zone around sources of interest because the physical properties of SO 2 result in relatively localized pollutant impacts near an emission source that drop off with distance. Given the properties of SO 2 , the EPA believes that significant impacts in a downwind State are unlikely at distances greater than 50 km from a source and thus, we are focusing our review on areas within 50 km of the state lines. This scale of analysis is consistent with the “urban scale” which is the largest appropriate spatial scale for SO 2 monitors and is useful for assessing SO 2 transport and trends in area-wide air quality. 15

As discussed in section III, and in further detail in the Technical Support Document (TSD) for this action, the EPA reviewed New York's SO 2 SIP submittal. We also have elected to review and assess other available information regarding SO 2 emissions and air quality for sources in New York to assist in our own evaluation. We independently analyzed such information to determine whether New York meets the interstate transport requirements described in the CAA. 16

Consistent with our prior evaluations of other state's SO 2 transport obligations, we conducted a weight of evidence (WOE) analysis evaluating several sources of information, including current air quality data from monitors as well as available emissions and/or source modeling for sources in New York and in neighboring states within 50 km of the New York border. A WOE approach can be appropriate in instances, such as in this case, to determine whether or not SO 2 emissions from New York contribute to nonattainment or maintenance issues in adjoining states. A WOE analysis that is based strictly on available data may not be sufficient in all instances for evaluating interstate SO 2 transport, and additional analysis may be necessary. Further, the term “WOE” does not establish the legal or technical meaning for what constitutes significant contribution to nonattainment or interference with maintenance for the 2010 SO 2 NAAQS. Rather, the term refers to the gathering and consideration of a wide range of information, on a case-by-case basis, to make a determination regarding whether a statutory or regulatory standard is met.

In other SO 2 transport SIP actions, the EPA has generally been able to use a WOE analysis of available information to reach a conclusion that there are no SO 2 nonattainment or maintenance issues in the relevant areas of other states, or that no sources in the upwind state are contributing to those issues. If the available evidence indicated, however, that an upwind source, sources, or emissions activities were contributing to an out-of-state SO 2 nonattainment or maintenance problem, then further analysis and a regulatory determination would be necessary concerning what amount of those emissions, if any, constituted “significant contribution” under Prong 1 or Prong 2 of the good neighbor provision.

We find that there is sufficient information to allow the EPA to make a determination that under baseline conditions and likely future emissions scenarios no New York sources are contributing or will contribute to any out-of-state SO 2 nonattainment or maintenance concerns. Therefore, it is not necessary for purposes of this action to render a determination concerning what amount of emissions would be “significant” and therefore subject to prohibition under the good neighbor provision. 17

On October 3, 2013, New York submitted to the EPA a SIP revision to address the requirements of CAA section 110(a)(1) and (2), including section 110(a)(2)(D)(i)(I) for the 2010 SO 2 NAAQS.

New York's SIP submittal stated that New York has no nonattainment areas for SO 2 within its own border, and the air quality modeling and monitoring information that was available at the time showed no violations of the NAAQS at the time of the submittal. New York also affirmed that it would continue to enforce all SIP measures and the regulation of construction of new or modified stationary sources to meet NNSR requirements and mitigate the interstate transport of SO 2.

New York's SIP submittal also stated the New York would continue to administer the CAIR program until a valid replacement for CSAPR was implemented.

The 2005 Clean Air Interstate Rule  18 (CAIR) covered 28 eastern states (including New York) and the District of Columbia. CAIR was designed to address interstate transport of ozone and fine particulate matter (PM 2.5 ) pollution. CAIR required the covered eastern states to make reductions in SO 2 and nitrogen oxides (NO X ) emissions that significantly contribute to the nonattainment or interference with the maintenance of the 1997 PM 2.5 and 1997 ozone NAAQS in any downwind state (70 FR 25161, May 12, 2005). CAIR addressed interstate transport for the 1997 PM 2.5 and 1997 ozone NAAQS but did not address interstate transport for the 2010 SO 2 NAAQS. Subsequently, the D.C. Circuit invalidated CAIR and required that the rule be revised. 19 The court, however, left CAIR in place in order to “temporarily preserve the environmental values covered by CAIR” until the EPA could, by rulemaking, replace CAIR consistent with the court's opinion. 20 In 2011, the EPA promulgated the Cross-State Air Pollution Rule (CSAPR) to replace CAIR. 21 CSAPR addresses interstate transport for the 1997 PM 2.5 , 1997 ozone and 2006 PM 2.5 NAAQS. CSAPR replaced CAIR beginning on January 1, 2015. 22 Neither CAIR nor CSAPR directly addresses interstate transport for the 2010 SO 2 NAAQS.

Because CAIR is no longer in place (and was only allowed to remain temporarily in place pending its replacement at the time of New York's submission, see 76 FR 48208, 48223-24 (Aug. 8, 2011)) and because it did not address the 2010 SO 2 NAAQS, New York's reliance on CAIR is not adequate on its own to demonstrate the State meets the requirements of CAA section 110(a)(2)(D)(i)(I).

In addition, both CAIR and CSAPR focused on achieving widespread reductions in PM 2.5 precursor pollutants, which include SO 2 . While the programs reduced SO 2 emissions from power plants, they did so with the goal of reducing PM 2.5 levels, not with the goal of preventing contribution to nonattainment or interference with maintenance of the SO 2 standard. These programs alone cannot be relied upon to demonstrate prohibited interstate transport of SO 2 emissions were prevented. New York did not provide an analysis to show how the reductions from these programs would sufficiently address SO 2 to prevent prohibited impacts. Moreover, these rules required emissions reductions through emissions trading programs for power plants. As such, they were not designed to ensure a particular level of emissions reduction at a particular power plant and did not address SO 2 emissions at all from nonpower plant sources or emissions activities. Thus, despite these programs, individual power plant and non-power plant sources that are near State borders may be able to continue to emit at uncontrolled levels, potentially contributing to SO 2 nonattainment or maintenance issues in other States. As such, these programs alone cannot be relied upon to demonstrate prohibited interstate transport of SO 2 emissions were prevented.

While the rationale provided by New York is not an adequate basis on its own by which the EPA can determine the approvability of the State's submission, the EPA may elect to consider additional information to assist in reaching a conclusion as to whether the submission may be approved, in whole or in part, as satisfying the Act's requirements, or does not meet the Act's requirements. Here, the EPA may consider all relevant information, or generate new data and analysis, to make an independent judgment in evaluating States' compliance with the good neighbor provision, which concerns the effects of States' emissions in other States. Therefore, the EPA considered additional available information as described below and in more detail in the TSD for this action, to determine if New York's SIP complies with 110(a)(2)(D)(i)(I) requirements.

Because (1) neither CAIR nor CSAPR directly address interstate transport for the 2010 SO 2 NAAQS (CAIR is no longer in place) and is not adequate on its own to demonstrate that the State meets the requirements of CAA section 110(a)(2)(D)(i)(I), and (2) due to the development of more detailed information concerning potential SO 2 air quality concerns in or around New York, including the partial St. Lawrence County SO 2 nonattainment area designated on March 21, 2021, the EPA is electing to consider additional information to assist in reaching a conclusion as to whether New York's submission may be approved, in whole or in part, as satisfying the Act's requirements. The EPA may consider all relevant information, or generate new data and analysis, to make an independent judgment in evaluating states' compliance with the good neighbor provision, which concerns the effects of states' emissions in other states. Therefore, the EPA considered additional available information as described below and in more detail in the TSD for this action, to reach a determination whether New York's SIP complies with 110(a)(2)(D)(i)(I) requirements.

The EPA conducted a WOE analysis for Prong 1 and Prong 2 separately. 23 In its WOE analysis, the EPA evaluated all available information, including air quality data, emission sources, and modeling and emission trends in New York and the states that border or are within 50 km of New York. To identify which sources and emissions activities in New York could potentially impact downwind air quality in other states with respect to the 2010 1-hour SO 2 NAAQS, the EPA used information in the EPA's National Emissions Inventory (NEI)  24 and Emissions Inventory System (EIS). 25 The NEI is a comprehensive and detailed database of air emissions for criteria pollutants, criteria pollutant precursors, and hazardous air pollutants from air emissions sources, updated every three years using information provided by the states and other information available to the EPA. For this analysis, we largely relied on data from the 2020 NEI, because it is the most recently available, complete, and quality assured dataset. However, in evaluating emissions trends, both state-wide and at the facility level, the EPA also considered data from prior NEI reports and EIS queries, as part of the overall WOE analysis.

As shown in Table 1, the majority of SO 2 emissions in New York originate from point sources. In 2020, total SO 2 emissions from point sources in New York comprised approximately 63.79 percent of the total SO 2 emissions in the State. Non-point sources, on road and non-road emissions sources are individually much smaller and also more dispersed throughout the State and are therefore unlikely to contribute to high ambient concentrations when compared to point source contributions. Further analysis in the TSD shows that facilities with reported emissions greater than 100 tons per year (tpy) represent approximately 2.74 percent of the total number of New York SO 2 point sources but are responsible for 5,520 tons of SO 2 or 76 percent of the total New York 2020 SO 2 point source emissions. 26 Based on this analysis, the EPA focused our WOE analysis on SO 2 emissions from New York's larger point sources ( i.e., point sources emitting over 100 tpy of SO 2 ) that are located within 50 km of one or more State borders.

As described in this section, the EPA proposes that an assessment of New York's satisfaction of the Prong 1 and 2 requirements under CAA section 110(a)(2)(D)(i)(I) for the 2010 1-hour SO 2 NAAQS may be reasonably based upon several factors. These factors include evaluation of all relevant air quality modeling or monitoring information, the predicted downwind impacts projected in previous relevant modeling studies for the relevant sources and nearby areas, assessment of New York's SO 2 point source emissions of more than 100 tpy of SO 2 per facility that are located within approximately 50 km of another state, assessment of other states' point sources emitting more than 100 tpy of SO 2 located within approximately 50 km of New York, and assessment of federal regulations and SIP-approved regulations affecting New York's SO 2 sources. The EPA's evaluation is informed by all available data at the time of this rulemaking. 27

The EPA notes that if this information were insufficient to draw a reasonable conclusion concerning whether New York is “significantly contributing” or not, then it would not be possible to propose approval based only on this information. In other words, in general, the absence of information concerning whether interstate transport is occurring is not in itself sufficient justification for approving a good neighbor SIP submission. For example, if there were inadequate monitoring or modeling information to characterize the effects of a large, near-border source of SO 2 emissions, it may be appropriate to conduct, or ask the state to conduct, further analysis to better characterize that source and its effects, in order to reach a determination concerning whether the good neighbor provision is being met. See, e.g., 88 FR 41344 (June 26, 2023) (proposing approval of Tennessee SO 2 transport SIP submission based on updated modeling conducted to better characterize emissions from the Eastman Chemical facility). In this case, the information available to the EPA, as analyzed in the accompanying TSD and summarized below, is sufficient to conclude that sources in New York are not and will not emit SO 2 pollution in violation of the good neighbor provision for the 2010 SO 2 NAAQS.

Prong 1 of the “good neighbor” provision requires states' plans to prohibit emissions that will contribute significantly to nonattainment of the NAAQS in another state. The EPA's evaluation  28 of whether New York has met its Prong 1 transport obligations was accomplished by considering all available information, including the following: SO 2 ambient air quality in New York and neighboring states; SO 2 emissions trends for New York and neighboring states; potential ambient impacts of SO 2 emissions from certain facilities  29 in New York on neighboring states; New York's SIP-approved regulations specific to SO 2 emissions and permit requirements; and other SIP-approved or federally enforceable regulations which may reduce SO 2 emissions either directly or indirectly.

Based on the EPA's analysis, we propose to determine that there are no SO 2 nonattainment issues in the relevant areas in other states bordering New York, and as such the EPA proposes to determine that New York's SIP satisfies the requirements of Prong 1 of CAA section 110(a)(2)(D)(i)(I). This proposed determination is based on the following considerations:

• There is one monitor recording violations of the 2010 1-hour SO 2 NAAQS located in New York. However, all monitors within 50 km of the New York border have design values (DV)  30 that are below the 75 ppb SO 2 NAAQS. Current DVs for New York's AQS SO 2 monitors within 50 km of another state's border have remained below the 2010 1-hour SO 2 NAAQS from 2019-2023; similarly, SO 2 monitors in neighboring states (Pennsylvania, Vermont, Connecticut, New Jersey, Massachusetts) within 50 km of New York have 2023 DVs (2021-2023) below the 2010 1-hour SO 2 NAAQS;

• Downward SO 2 emissions trends in New York and its surrounding states (Pennsylvania, Vermont, Connecticut, New Jersey, Massachusetts), when considered together with the other factors discussed as part of EPA's WOE analysis, further support that New York's sources will not significantly contribute to any other states' nonattainment of the 2010 1-hour SO 2 NAAQS;

• A source-specific analyses of every New York 100 tpy source located within 50 km of the state border indicates that the sources do not contribute to nonattainment in other states. These analyses draw upon available emissions data, monitoring data, air quality modeling, control requirements, wind rose data, and other relevant information to assess the likelihood of air quality impacts from these sources to areas in surrounding states. A detailed discussion of each source-specific analysis is contained in Section IV.B.3 of the TSD accompanying this action. Below we cover some of the principal evidence that confirms that emissions from New York do not contribute to nonattainment in other states.

• All monitors closest to the New York SO 2 Areas of Interest (Sources > 100 tpy located within 50 km of adjacent state) have consistently recorded DVs well below the standard for years 2012-2023, indicating that these facilities are not causing exceedances in New York and would not cause exceedances in Pennsylvania, Vermont, Connecticut, New Jersey and Massachusetts.

• For the St. Lawrence source—Alcoa—monitors nearby have recorded DVs above the NAAQS. However, this source being 122 km from the nearest state line (Vermont) supports a determination that emissions from these sources are not contributing to nonattainment across the border into neighboring states.

• For the remainder of the New York SO 2 Areas of Interest (Sources > 100 tpy located within 50 km of adjacent state), either wind rose data, amount of emissions in 2022, or distance between the sources and the nearest neighboring state border supported a determination that these sources will not contribute to nonattainment of the NAAQS in Massachusetts. New Jersey, Connecticut, Vermont, and Pennsylvania.

• Further there are SIP-approved and federal emissions control regulations within New York that will continue to ensure that SO 2 emissions will be effectively controlled for existing and new sources or modifications.

Based on this evaluation, as more thoroughly discussed in our TSD for this action, the EPA proposes to find that sources within New York will not significantly contribute to nonattainment of the 2010 1-hour SO 2 NAAQS in any other state.

Prong 2 of the “good neighbor” provision requires state plans to prohibit emissions that will interfere with maintenance of a NAAQS in another state. The EPA's evaluation of whether New York has met its Prong 2 transport obligations was accomplished by considering all available information, with a focus on current air quality data, SO 2 emissions trends for New York and neighboring states, and how existing and future sources of SO 2 are addressed through existing SIP-approved and federally enforceable regulations. This evaluation builds upon the analysis conducted for significant contribution to nonattainment (Prong 1), which evaluated SO 2 ambient air quality in New York and neighboring states and potential ambient impacts of SO 2 emissions from certain facilities in New York on neighboring states.

Based on the EPA's analysis, we propose to find that SO 2 levels in neighboring states near the New York border do not indicate an inability to maintain the SO 2 NAAQS that could be attributed in part to sources in New York, and as such the EPA proposes to determine that New York's SIP satisfies the requirements of Prong 2 of CAA section 110(a)(2)(D)(i)(I). This determination is based on the following considerations:

• Current 2021-2023 DVs for SO 2 monitors in New York within 50 km of another state's border and in neighboring states (Pennsylvania, New Jersey, Vermont, Connecticut, and Massachusetts) within 50 km of New York's border are below the standard except for one (Alcoa West), indicating that the areas in the vicinity of these monitors are all currently in attainment of the 2010 1-hour SO 2 NAAQS except for the partial St. Lawrence area;

• State-wide emissions trends in New York and surrounding states indicate generally declining SO 2 emissions and consequently ambient air concentrations in the relevant areas;

• Current New York statutes, SIP-approved measures, and federal emissions control programs control SO 2 emissions from certain sources within New York; and

• New York's SIP-approved PSD, major New Source Review (NSR) regulations and minor source NSR permit programs address future new and modified SO 2 sources above major and minor permitting thresholds with the intent of ensuring that the SO 2 NAAQS will not be exceeded as a result of new facility construction or existing facility modification within the state or in surrounding states.

Based on this evaluation, as more thoroughly discussed in our TSD for this action, the EPA proposes to find that sources within New York will not interfere with maintenance of the 2010 1-hour SO 2 NAAQS in any other state.

The EPA is proposing to approve the Prong 1 and Prong 2 portions of the infrastructure SIP submission submitted by the state of New York on October 3, 2013, addressing interstate transport for the 2010 1-hour SO 2 NAAQS. Based on the EPA's WOE analysis and as more thoroughly discussed in the TSD, the EPA proposes to determine that emissions from New York will not contribute significantly to nonattainment in, or interfere with maintenance of, any other state with respect to the 2010 SO 2 NAAQS. We therefore propose to find that New York's SIP contains adequate provisions consistent with CAA section 110(a)(2)(D)(i)(I).

Under the CAA, 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. 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).

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA.

Whenever the EPA promulgates a new or revised NAAQS, CAA section 110(a)(1) requires States to make SIP submissions to provide for the implementation, maintenance, and enforcement of the NAAQS. This SIP submission is a particular type of SIP commonly referred to as an “infrastructure SIP.” These submissions must meet the various requirements of CAA section 110(a)(2), as applicable. Due to ambiguity in some of the language of CAA section 110(a)(2), the EPA believes that it is appropriate to interpret these provisions in the specific context of acting on infrastructure SIP submissions. EPA has previously provided comprehensive guidance on the application of these provisions through a guidance document for infrastructure SIP submissions (EPA's 2013 Guidance) and through regional actions on infrastructure submissions. 1 Unless otherwise noted below, we are following the same approach in acting on this submission. In addition, in the context of acting on such infrastructure submissions, the EPA evaluates the submitting State's SIP for facial compliance with statutory and regulatory requirements, not for the State's implementation of its SIP. 2 The EPA has other authority to address any issues concerning a State's implementation of the rules, regulations, consent orders, etc. that comprise its SIP.

The EPA is proposing to approve Indiana's November 2, 2018 infrastructure SIP submission for the 2015 ozone NAAQS addressing the fourth component of CAA section 110(a)(2)(D)(i)(II), also known as “Prong 4”, requirement that a State's SIP contain adequate provisions prohibiting any source or other type of emissions activity within the State from emitting any air pollutant in amounts which will interfere with measures required to be included in the applicable SIP for any other State to protect visibility.

Under the applicable requirements for visibility protection of CAA section 110(a)(2)(D)(i)(II), States are subject to visibility and regional haze program requirements under part C of the CAA, which includes sections 169A and 169B. The EPA's 2013 Guidance states that the Prong 4 requirements can be satisfied by approved SIP provisions that the EPA has found to adequately address any contribution of that State's sources that impact the visibility program requirements in other States. 3 According to the EPA's 2013 Guidance, a State's infrastructure SIP may satisfy Prong 4  4 for any relevant NAAQS through an air agency's confirmation that the State has a fully approved regional haze SIP  5 meeting the requirements of 40 CFR 51.308.

For the second implementation period, the EPA's Regional Haze regulations under 40 CFR 51.308(f) require that a State consider the emission reduction measures identified by other States as being necessary to make reasonable progress towards meeting the national visibility goal in Class I Federal areas. Specifically, the regulations also require a State to include in its Regional Haze SIP all measures agreed to during that process or measures that will provide equivalent visibility improvement. 40 CFR 51.308(f)(2)(ii). Thus, in meeting the requirements of 40 CFR 51.308(f), an approved regional haze SIP meeting the statutory and regulatory requirements, including 40 CFR 51.308(f)(2)(ii), will ensure that emissions from sources under an air agency's jurisdiction are not interfering with measures required to be included in other air agencies' plans to protect visibility and will, therefore, satisfy Prong 4.

To address the requirements of CAA section 110(a)(2)(D)(i)(II), Indiana's infrastructure SIP submission for the 2015 ozone NAAQS discusses the State's regional haze program. Indiana's regional haze SIP submission for the second implementation period was fully approved on January 26, 2026, 91 FR 3057.

For the reasons stated above, by meeting the statutory and regulatory requirements of the regional haze program, including the interstate consultation requirements in 40 CFR 51.308(f)(2)(ii), Indiana's SIP adequately prohibits emissions from within the State that would interfere with visibility protection measures in any other State's SIP. Since Indiana has a fully approved regional haze SIP for the second implementation period, which meets the requirements of 40 CFR 51.308, the EPA proposes that Indiana satisfies the requirements of CAA section 110(a)(2)(D)(i)(II) relating to visibility protection for the 2015 ozone NAAQS.

The EPA proposes to approve Indiana's November 2, 2018, interstate transport infrastructure SIP submission as satisfying the requirements related to visibility protection contained in CAA section 110(a)(2)(D)(i)(II), also known as Prong 4, for the 2015 ozone NAAQS.

Under the CAA, the Administrator is required to approve 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 Clean Air Act.

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where the 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).

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA.

VOCs and NO X contribute to the production of ground-level ozone, or smog, which harms human health and the environment. The EPA has consistently defined RACT as the lowest emission limit that a particular source is capable of meeting by the application of control technology that is reasonably available considering technological and economic feasibility. 1

Sections 182(b)(2) and 182(f) of the Clean Air Act (CAA), when taken together, require States to implement RACT for VOC and NO X in ozone nonattainment areas classified as Moderate and higher. Specifically, these areas are required to implement RACT for all sources covered by a Control Techniques Guideline (CTG) and all other major stationary sources of VOCs and NO X in the area. 2 For the purposes of RACT in Moderate ozone nonattainment areas, major sources of VOCs and NO X are those that are not covered by CTGs and have the potential to emit (PTE) at least 100 tons per year (tpy).

To address non-CTG RACT requirements, Ohio adopted Ohio Administrative Code (OAC) rules 3745-21-11 and 3745-110-03(J), which require major sources of VOCs and NO X that are not covered by a CTG to submit detailed source-specific RACT studies analyzing the technological and economic feasibility of available control measures. Ohio evaluated the information provided in the required studies, made a RACT determination for each major source, and submitted the RACT determinations to the EPA for approval and incorporation into the Ohio SIP.

Effective August 3, 2018, the EPA designated the Cleveland nonattainment area as a Marginal nonattainment area for the 2015 ozone NAAQS (“Cleveland nonattainment area”). 3 The Cleveland nonattainment area consists of Cuyahoga, Geauga, Lake, Lorain, Medina, Portage, and Summit counties. On October 7, 2022, pursuant to section 181(b)(2) of the CAA, the EPA determined that the Cleveland nonattainment area failed to attain the 2015 ozone NAAQS by the August 3, 2021, Marginal area attainment deadline and thus proposed to reclassify the area from Marginal to Moderate nonattainment. 4 In that action, the EPA established January 1, 2023, as the due date for the State to submit all Moderate area nonattainment plan SIP requirements applicable to newly reclassified areas. Since the Cleveland nonattainment area was reclassified to Moderate, the area was required to meet the RACT requirements discussed above at 100 tpy. On December 17, 2024, the EPA determined that the Cleveland nonattainment area failed to attain the 2015 ozone NAAQS by August 3, 2024, Moderate area attainment deadline and thus reclassified the area from Moderate to Serious nonattainment. The new Serious RACT requirement was due on January 1, 2026, but this action addresses Moderate RACT requirements only. 5

Ohio has adopted regulations to address the NO X and VOC RACT requirements that apply to Moderate ozone nonattainment areas. The NO X RACT rules, in OAC Chapter 3745-110, effective March 25, 2022, apply to existing boilers, stationary combustion turbines, stationary internal combustion engines, reheat furnaces, and other sources at facilities that have an uncontrolled potential to emit 100 tpy or more of NO X . These rules apply to sources located in the Cleveland nonattainment area.

Similarly, the VOC RACT rules, in OAC Chapter 3745-21, effective March 27, 2022, apply to various VOC source categories in the Cleveland nonattainment area. These rules cover both CTG source categories and non-CTG major sources with an uncontrolled potential to emit 100 tpy or more of VOCs.

Ohio EPA submitted OAC Rules 3745-21-11 and 3745-110-03(J) to the EPA for approval and inclusion in the SIP on March 31, 2022. These rules require major non-CTG VOC and NO X sources located in ozone nonattainment areas classified as Moderate or higher to submit RACT studies to Ohio within one year of the rule's effective date. These RACT studies contain information on the technical and economic feasibility of VOC and NO X emission control measures to inform Ohio's RACT determinations for each major source.

On January 20, 2026 (91 FR 2308), the EPA approved portions of OAC Chapters 3745-21 and 3745-110 as satisfying certain moderate VOC RACT and NO X RACT requirements for the Cleveland nonattainment area. In the same action, the EPA also approved OAC 3745-21-11 and 3745-110-03(J) as SIP strengthening measures for the Cleveland area designated nonattainment under the 2015 ozone standard.

On February 27, 2026 (91 FR 9771), the EPA proposed to approve source-specific moderate non-CTG RACT for certain facilities in the Cleveland nonattainment area under the 2015 ozone standard subject to OAC 3745-21-11 and 3745-110-03(J). The EPA has not yet finalized that proposed action. This action addresses the remaining non-CTG major source RACT facilities subject to OAC 3745-21-11 and 3745-110-03(J) in the Cleveland nonattainment area.

The EPA is proposing to approve the following RACT determinations submitted by Ohio for major sources of VOCs and NO X in the Cleveland nonattainment area as meeting RACT requirements.

Lubrizol operates a chemical manufacturing facility located in Painesville, Ohio, within the Cleveland nonattainment area. The facility is subject to source-specific RACT requirements under OAC 3745-21-09(LL) for its process reactor systems. As a major non-CTG VOC source, Lubrizol must also submit an updated source-specific RACT study under OAC 3745-21-11. Ohio submitted a VOC RACT determination based on this study to the EPA on October 8, 2025. Lubrizol manufactures specialty chemical products, including additive systems for lubricating oils used in gasoline and diesel engines, automatic transmissions, gear drives, marine engines, tractors, and metalworking. The primary VOC emission sources are process reactor systems, drum/tote filling lines, and product loading racks.

The EPA approved OAC 3745-21-09(LL) into the Ohio SIP to address non-CTG VOC RACT for the 1-hour ozone standard on April 25, 1996 (61 FR 18255). The rule requires all reactor process vent streams to be routed to an enclosed combustion device that achieves at least 98 percent VOC destruction (or 20 parts per million by volume(ppmv) outlet concentration) or provides at least 0.75 seconds of residence time at 1600 °F. Lubrizol meets and exceeds these requirements. Reactor vent emissions are controlled by two redundant thermal oxidizers that achieve over 99.9 percent VOC destruction efficiency. Continuous temperature monitoring ensures proper combustion and consistent performance between tests. Lubrizol reviewed the EPA's RACT/BACT/LAER Clearinghouse (RBLC) for due diligence purposes and found that that BACT for process vents in the chemical manufacturing industry typically requires add-on controls achieving 98 percent destruction efficiency. The existing 98 percent control is more stringent than the non-CTC RACT catch-all provisions in other Region 5 State rules, including Illinois and Indiana (which require at least an 81 percent reduction in VOC emissions). Since Lubrizol achieves greater than BACT-level control and is more stringent than the non-CTG RACT catch-all rules described above, Ohio determined that continued compliance with OAC 3745-21-09(LL) satisfies RACT for these emission units. 6 The EPA is proposing to approve Ohio's RACT determination that these controls implement RACT.

Emission unit P132 includes four drum lines and one tote line. VOC emissions from these operations are vented to the same thermal oxidizers used for the reactor vents described in the prior paragraph, which achieve over 99.9 percent destruction efficiency. The facility is currently required to implement submerged filling and venting to a thermal oxidizer capable of at least 98 percent destruction efficiency. These practices meet or exceed recent BACT determinations for similar filling operations, which typically require submerged filling and add-on controls achieving at least 98 percent VOC reduction. Therefore, Ohio determined that submerged filling combined with thermal oxidation (≥98 percent efficiency) constitutes RACT for these operations. The EPA proposes to approve Ohio's assessment that these controls implement RACT.

Lubrizol operates multiple product loading racks, many equipped with thermal oxidizers or carbon adsorption systems. Actual VOC emissions from these units ranged from 0.01 to 0.88 tpy during 2019-2021. Based on the EPA's estimate of the cost of additional control technologies, which is well over $30,000 per ton of VOC removed, the EPA is proposing to find that additional controls would not be economically reasonable. To minimize emissions, Lubrizol implements work practices including ensuring complete drainage of loading arms before disconnection and preventing liquid drainage when not in use. Many loading racks are also subject to VOC limits under Best Achievable Technology (BAT). 7 Ohio determined that RACT for these operations consists of existing controls, emission limits, and work practices listed in Table 3-2 of Lubrizol's RACT submittal (included in the docket). Ohio included these requirements in a construction permit and is requesting that the EPA incorporate these provisions of the permit into the SIP. The EPA proposes to approve Ohio's RACT determination that these controls implement RACT.

In sum, the EPA is proposing to approve Ohio's RACT determination for Lubrizol as adequately implementing RACT, which includes the following measures summarized above and in Table 3-3 of the docket: continued compliance with site-specific RACT under OAC 3745-21-09(LL) for all process reactor vents; use of submerged filling and venting to a thermal oxidizer achieving greater than 98 percent VOC control efficiency for the drum/tote filling operations; and implementation of existing controls, emission limits, and work practices for the loading racks as specified in the permit sections listed below. Given the already low emissions at Lubrizol (.01 to .88 tpy of VOC) and the EPA's cost estimate described above, additional controls would be economically unreasonable.

The EPA proposes to incorporate by reference the above RACT requirements from permit number P0138405 (effective date: October 1, 2025), specifically sections (B)(2)-(B)(5), (C)(1)(b)(1)(b), (C)(1)(b)(2)(a), (C)(1)(d)(1), (C)(1)(e)(1), and (C)(1)(f)(2).

Henkel US Operations Corporation operates an adhesives and sealants manufacturing facility in Mentor, Ohio, within the Cleveland ozone nonattainment area. The facility is a major source of non-CTG VOC emissions and must submit a source-specific RACT study under OAC 3745-21-11. Ohio submitted this VOC RACT determination to the EPA on November 25, 2025.

The facility produces adhesives and sealants by blending organic solvents and inert fillers in batch mixers, which are the primary sources of VOC emissions. VOC emissions are controlled with condensers that circulate a chilled water/propylene glycol mixture through coiled tubes, cooling vent gases and condensing a portion of the VOC vapors.

To fulfill requirements of the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Miscellaneous Coating Manufacturing (MCM), Henkel submitted to Ohio EPA a condenser design evaluation to demonstrate MACT compliance, establishing maximum outlet gas temperatures. 8 Using the same methodology, Henkel later submitted a design evaluation to demonstrate 85 percent VOC removal efficiency under OAC 3745-21-07(M), resulting in lower outlet temperature limits. OAC 3745-21-07(M) contains Ohio's facility-specific VOC control requirements for emissions of organic materials from stationary sources.

Achieving removal efficiencies above 85 percent would require reducing condenser outlet temperatures further-either by lowering coolant temperatures or increasing condenser surface area. However, the chilled water system already operates near the freezing point, and past attempts to reduce temperatures have caused ice formation and vent blockages. A two-stage condenser system or larger condensers could mitigate this issue but, would require significant equipment replacement and reconfiguration, with minimal additional VOC reduction, so would be economically unreasonable. Further, 85 percent reduction is higher than the non-CTG RACT catch call rules in other States in Region 5, including Illinois and Indiana, which require 81 percent reduction in VOC emissions at a minimum.

Henkel also evaluated alternative add-on controls, including incineration, carbon adsorption, and biofiltration. Biofiltration is technically infeasible because the facility's predominant VOCs are water-insoluble. Incineration and carbon adsorption are technically feasible, but not cost-effective: incineration would cost between $32,109-$43,841 per ton of VOC removed, and carbon adsorption would cost $29,482 per ton.

These analyses show that add-on controls are either technically infeasible or economically unreasonable. The existing condensers already achieve 85 percent VOC reduction, and the facility has already substantially lowered its VOC emissions by shifting production toward low- or no-VOC materials.

Based on Henkel's analysis, Ohio EPA concludes that the facility's current practices-use of low-VOC materials and condenser systems achieving 85 percent control-are RACT for this source. Ohio included these requirements in a construction permit and is requesting that the EPA incorporate these provisions of the permit into the SIP.

The EPA proposes to approve Ohio's assessment that these controls implement RACT and to incorporate by reference the above RACT requirements from permit number P0138691 (effective date: November 18, 2025), specifically sections B.4, C.1.b)1.g, C.1.c)2,C.1.d)5, C.1.e)7,C.1.f)2, C.2.b)1.f, C.2.c)2, C.2.d)6, C.2.e)7, C.2.f)2, C.3.b)1.g, C.3.c)2,C.3.d)5, C.3.e)7, C.3.f)2, C.4.b)1.g, C.4.c)4,C.4.d)5, C.4.e)6,C.4.f)2, C.5.b)1.j,C.5.c)3, C.5.d)6, C.5.e)9, C.5.f)2, C.6.b)1.d, C.6.c)2, C.6.d)2, C.6.e)4, C.6.f)3, C.7.b)1.d, C.7.c)2, C.7.d)2,C.7.e)4, and C.7.f)3.

Cleveland-Cliffs Cleveland Works LLC is an integrated steelmaking plant in the Cleveland nonattainment area. Because the facility is a major source of NO X with a PTE greater than 100 tpy, it is subject to site-specific NO X RACT under OAC 3745-110-03(J). Ohio submitted this NO X RACT determination to the EPA on November 20, 2025.

The facility emits NO X from numerous sources, including boilers, reheat furnaces, batch annealing furnaces, a continuous annealing line, blast furnaces, basic oxygen furnaces, and ladle preheaters. The facility operates under title V permit No. P0129660, effective March 9, 2021.

Boilers B001 through B007 are already subject to the NO X RACT limits in OAC 3745-110-03(C) and (D)-0.08 pounds per million British thermal units (lb/MMBtu) for gas-fired boilers, 0.2 lb/MMBtu for residual-oil-fired boilers, and 0.3 lb/MMBtu for coal-fired boilers-and are therefore already implementing RACT in accordance with these federally approved provisions. The EPA has previously approved OAC 3745-110-03(C) and (D) as satisfying moderate NO X RACT for the Cleveland nonattainment area (January 20, 2026, 91 FR 2308).

Cleveland-Cliffs operates three natural-gas-fired reheat furnaces: Reheat Furnaces #1 (P046), #2 (P047), and #3 (P048)-each rated at 630 MMBtu/hr. Cleveland-Cliffs evaluated selective catalytic reduction (SCR), selective noncatalytic reduction (SNCR), and upgraded low-NO X burners (LNBs) as potential NO X control options.

Cleveland-Cliffs found SCR technically infeasible. The batch-type furnace operation involves frequent door openings and unstable exhaust temperatures, which prevent the consistent temperature control required for effective SCR catalyst performance.

Cleveland-Cliffs also determined that SNCR is technically infeasible. Exhaust temperatures are too low for effective NO X reduction, and reheating the flue gas to reach the required temperature would significantly increase fuel use and produce additional NO X .

The reheat furnaces currently use LNBs. Cleveland-Cliffs evaluated replacing the current burners with newer LNB models capable of achieving 0.074 lb/MMBtu (compared to the current 0.35 lb/MMBtu limit). However, the high cost—$14,631 to $29,400 per ton of NO X removed—renders this option economically unreasonable.

Ohio determined that putting on additional controls for the reheat furnaces is technically infeasible and economically unreasonable. However, Ohio requires the source to submit an updated RACT study if the NO X emissions ever exceed 348.3 tpy per rolling 12-month period for each reheat furnace. If emissions are higher than 348.3 tpy for a 12-month period, then the cost of the available control technologies per ton of NO X removed may become economically reasonable.

This emission level was based on the highest maximum actual emissions among the previous three years from the effective date of OAC rule 3745-110-03. If a unit exceeds this level during any 12-month rolling period, the facility must submit a new RACT analysis to Ohio within one year. The EPA is proposing to approve Ohio's RACT determination for units P046-P048 and the requirement that the source submit an updated RACT study to Ohio if the units exceed the emission level of 348.3 tpy of NO X .

At Cleveland Works, there are currently 77 operational and nine spare batch annealing furnaces at the North Annealing (P049) and South Annealing (P050) sections. Batch annealing emissions exhaust through multiple indoor stacks, and the system lacks a common stack suitable for post-combustion controls. Therefore, SCR and SNCR are technically infeasible for batch annealing operations.

The batch annealing furnaces have existing LNBs with inherently low NO X emissions of 1.2 tpy each for units P049 and P050, as demonstrated by the current NO X emission limit of 0.10 lb/MMBtu, which is consistent with the most recent BACT determination in the EPA's RBLC database. Due to the already low NO X emission levels, installing newer model LNBs to achieve only marginal additional NO X reductions from the batch annealing furnaces would not be economically reasonable. Ohio determined that RACT for batch annealing sections P049 and P050 is continued use of the existing LNBs and continued compliance with the 0.10 lb/MMBtu limit.

The Hot Dip Galvanizing Line (HDGL) includes a 159.17 MMBtu/hr continuous annealing furnace. SCR and SNCR are technically infeasible with the current stack configuration. Its current stack configuration poses significant challenges for installing post-combustion controls. Two exhaust ducts discharge into a common stack inside the building. Installing SCR or SNCR would require removing the existing stack, consolidating the ducts into a single duct, and routing the system to a new external stack, which is economically unreasonable. Cleveland-Cliffs therefore determined that SCR and SNCR are both economically unreasonable and technically infeasible.

The furnace currently uses LNBs with expected NO X loadings of 0.27 to 0.30 lb/MMBtu. Cleveland-Cliffs evaluated the cost-effectiveness of replacing the existing burners with newer LNB models and found it would cost $31,937 to $37,998 per ton of NO X removed, which the State determined is economically unreasonable. Ohio determined that RACT for the HDGL Annealing Furnace (Unit P071) consists of continued use of the existing LNBs and compliance with the 0.23 lb/MMBtu NO X limit. The EPA proposes to approve Ohio's RACT determination that these controls implement RACT.

Cleveland-Cliffs operates two blast furnaces (P903 and P904) subject to this RACT review. Both units burn blast furnace gas (BFG), which has a low heating value and limits combustion temperature, resulting in inherently low NO X emissions and minimal potential for further reduction. NO X emissions at the blast furnaces are from the stoves, the cast house, and the flare.

In the cast house, natural gas is used for flame suppression during casting, and NO X forms when the gas exits pipe ends and ignites. Because these emissions are fugitive and lack a stack, SCR and SNCR are technically infeasible. The flare burns excess furnace gas and is an open system without a stack, making SCR and SNCR infeasible there as well.

For the stoves, SCR installation is technically infeasible due to exhaust temperatures (500 °F) below the 600 to 700 °F operating range, the need to reheat large gas volumes (which would increase NO X and GHG emissions, low inlet NO X concentrations (leading to low removal efficiency and high ammonia slip), and catalyst fouling concerns from particulates in BFG. SNCR is also technically infeasible because the furnace exhaust temperatures are far below the 1600-2100 °F required for effective operation and reheating would generate additional NO X emissions.

LNBs cannot be implemented for the cast house because it relies on pilot flames instead of burners for the flare. Ohio determined that LNBs are not economically reasonable because the stoves are already meeting a NO X limit of 0.06 lb/MMBtu, which is similar to emissions limits achieved by LNBs.

Ohio determined that RACT for this facility includes continued use of low-NO X BFG for the cast house, flare, and stoves. Also, Ohio determined that RACT includes minimizing NO X emissions from the cast house and flare through proper operation and maintenance in accordance with manufacturer specifications. For the blast furnace stoves, RACT is defined as meeting a site-specific NO X limit of 0.06 lb/MMBtu. The EPA proposes to approve Ohio's RACT determination that these controls implement RACT.

Cleveland-Cliffs operates two basic oxygen furnace (BOF) systems: a full-combustion system (No. 2 BOF, P925/P926) and a suppressed-combustion system (No. 1 BOF, P905/P906). Because BOF vessels do not use burners, LNBs are not technically feasible control options.

SCR and SNCR are also technically infeasible for BOFs. Gas temperatures within the primary hoods vary throughout the batch blow cycle, preventing the consistent temperature and residence time required for either technology to operate effectively. In addition, high particulate levels would quickly foul and poison catalysts.

Because no technically feasible control options are available to meet RACT, Ohio established additional requirements for the BOFs, including installing, maintaining, and operating each system in accordance with manufacturer specifications and good operating practices to minimize NO X emissions. The EPA proposes to approve Ohio's determination that these controls implement RACT.

Steel shops use ladle preheaters to dry or cure refractory materials. Available NO X control technologies for ladle preheaters include SCR, SNCR, and LNBs. Because emissions from the preheaters are fugitive and released directly into the melt shop without a stack, post-combustion controls such as SCR and SNCR are technically infeasible.

The preheaters already use inherently low-NO X burners. Cleveland-Cliffs evaluated newer LNB designs but found them technically infeasible for these preheaters due to the inability to maintain a tight seal between the burner and ladle lip. The equipment is designed to allow intentional air leakage to avoid suffocating the furnace, and this air flow cannot be eliminated. As a result, operators cannot control the combustion zone conditions needed to achieve or verify the performance of newer LNBs, making additional NO X reductions unlikely.

Therefore, Ohio determined that RACT includes continued use of the existing inherently low-NO X burners for the ladle preheaters. Also, RACT consists of continued compliance with the site-specific NO X limit of 0.10 lb/MMBtu. Ohio's due diligence review of control options for ladle preheaters at similar sources in the RBLC supports this limit, as it is consistent with the most recent BACT determination for comparable units. The EPA proposes to approve Ohio's RACT determination that these controls implement RACT.

Ohio included the Cleveland-Cliffs Cleveland Works NO X RACT requirements in construction permit number P0138036 and is requesting that the EPA incorporate these provisions of the permit into the SIP. In sum, the EPA is proposing to approve Ohio's RACT determination for Cleveland Works with respect to NO X emissions as adequately implementing RACT, and proposes to incorporate by reference the above RACT requirements from permit number P0138036 (Effective Date: November 13, 2025), specifically sections C.1.b)1. j., C.1.b)1. k., C.1.b)2.h, C.1.d) 6., and C.1.d) 7., C.1.e)6., and C.1.f)1.g. The EPA also proposes to incorporate by reference the above RACT requirements from permit number P0138136 (Effective Date: November 13, 2025), specifically sections C.5.b)1.e.,C.5.b)1.f., 5.b)2.d.,C.5.d)5., C.5.e)5., C.5.e)6., C.5.f)1.e., C.6.b)1.e, C.6.b)1.f., C.6.b)2.d, C.6.f)1.b, C.7.b)1.i, C.7.b)1.j., C.7.b)2.f., C.7.d)6., C.7.d)7., C.7.e)7., C.7.f)1.e., C.8.b)1.f., C.8.b)1.g., C.8.b)2.e., C.8.d)3., C.8.e)5., C.8.f)1.d., C.9.b)1.e., C.9.b)1.f., C.9.b)2.f., C.9.d)3., C.9.e)4., and C.9.f)1.e. Additionally, the EPA proposes to incorporate by reference the above RACT requirements from permit number P0138521 (Effective Date: November 13, 2025), specifically sections C.1.b)1.e., C.1.b)1.f., C.1.b)2.c., and C.1.f)1.a.

Cleveland-Cliffs Cleveland Works LLC is also a major non-CTG VOC source, with potential emissions exceeding 100 tpy, and is therefore subject to site-specific VOC RACT under OAC 3745-21-11. Ohio submitted this VOC RACT determination to the EPA on November 20, 2025. VOC emissions at the facility originate from the boilers, reheat furnaces, blast furnaces, BOF operations, and the tandem mill. The facility operates under title V Permit No. P0129660 (effective March 9, 2021).

The tandem mill is a rolling mill consisting of multiple closely spaced stands in a continuous line that emit VOCs from emulsified, water-based rolling oils that form mist during operation. The unit is equipped with a chevron-style oil demister that provides VOC reduction.

Cleveland-Cliffs evaluated multiple VOC control options:

• Thermal incineration: This is technically infeasible because the 90 °F exhaust temperature is significantly below the 1,300 °F required, and reheating the high-moisture, low-VOC stream would require excessive fuel, increasing both NO X and VOC emissions.

• Catalytic incineration: This is technically infeasible due to insufficient exhaust temperature (90 °F vs. the 850-1,100 °F required), variable VOC concentrations, and risk of catalyst poisoning.

• Carbon adsorption: This is technically infeasible because the exhaust stream would rapidly foul the carbon bed, making regeneration or replacement impractical.

• Lower-VOC materials: This is technically infeasible due to operational needs, steel quality specifications, and customer requirements. Only the mill threading compound has a potential lower-VOC substitute, but its use could destabilize the rolling oil and compromise product quality.

The tandem mill's existing oil demister removes visible and entrained oil vapor, moisture, and VOC mist. The facility is required to maintain the mill and mist eliminator consistent with good engineering practices. The tandem mill is also subject to a 12-month rolling VOC limit of 138.91 tpy under Ohio's BAT program.

Because the alternative control technologies identified above are technically infeasible, Ohio determined that RACT for the tandem mill consists of continued operation of the oil demister using good engineering practices, along with compliance with the BAT limit. The EPA proposes to approve Ohio's assessment that these controls constitute RACT.

Ohio also evaluated appropriate VOC content limits for oils used at the tandem mill and adopted limits consistent with those applied at Cleveland-Cliffs' Middletown Works facility. Ohio determined that the following VOC content limits constitute RACT:

• Rolling Oil: ≤ 4.6 lb VOC/gal (excluding water and exempt solvents)

• Rust Preventive Oil: ≤ 3.3 lb VOC/gal

• Anti-Galling Material: ≤ 1.2 lb VOC/gal

• Pre-Lube Oil: ≤ 0.8 lb VOC/gal

VOC content must be determined using the test methods in OAC 3745-21-10 or, alternatively, ASTM E1868-10 at actual operating temperature. The EPA proposes to approve Ohio's RACT determination that these controls are RACT.

This facility operates various combustion units including boilers, reheat furnaces, annealing furnaces, and BOF vessels. Each unit's actual emissions range from 0.1 to 6.6 tpy of VOCs, and add-on controls are not economically reasonable. In addition, a review of the EPA's RBLC database for comparable combustion sources installed within the past five years shows that VOC BACT consists of good combustion and operating practices.

Because the alternative control technologies for these units are not economically reasonable, Ohio determined that RACT for these sources consists of operating the units in accordance with manufacturer specifications and good engineering practices. The EPA proposes to approve Ohio's RACT determination that these controls implement RACT.

Cleveland-Cliffs evaluated four potential VOC control technologies for the combined blast furnace exhaust:

• Thermal and catalytic incineration: These are not economically reasonable due to highly dilute VOC concentrations, requiring substantial supplemental fuel. Cost-effectiveness ranges from $99,676 to $134,286 per ton of VOC removed.

• Carbon adsorption: This is technically infeasible because the exhaust temperature (500 °F) exceeds operating limits for carbon beds (<130 °F), the stream is too dilute and moisture-laden, and fire risks are significant.

• Scrubbing (absorption): This is technically infeasible because meaningful VOC removal is not achievable at such low concentrations without impractically large equipment, and scrubbers typically must be paired with controls (carbon adsorption or incineration) that are themselves infeasible.

• Condensation: This is technically infeasible because VOC concentrations are far below levels where condensation would be effective, and the required temperatures would cause moisture to freeze and plug the system.

Because the alternative VOC technologies identified above are either technically infeasible or economically unreasonable for the blast furnace exhaust, Ohio determined that RACT consists of operating the blast furnaces in accordance with manufacturer specifications and good engineering practices to minimize emissions. The EPA is proposing to approve Ohio's RACT determination that these controls constitute RACT.

In sum, the EPA is proposing to approve Ohio's RACT determination for Cleveland Works with respect to VOC emissions as adequately implementing RACT and proposes to incorporate by reference the above RACT requirements from permit number P0138035 (Effective Date: November 13, 2025), specifically sections C.1.b)1.e, C.1.b)2.a, C.1.d)2, C.1.d)3, C.1.d)4, C.1.e)2, C.1.e)3, C.1.e)5, C.1.f)1.d, C.1.f)1.f, C.1.f)2. The EPA also proposes to incorporate by reference the above RACT requirements from permit number P0138036 (Effective Date: November 13, 2025), specifically sections C.1.b)1.i, C.1.b)2.g, C.1.d)6, C.1.e)6.a. Finally, the EPA proposes to incorporate by reference the above RACT requirements from permit number P0138136 (Effective Date: November 13, 2025), specifically sections B.11, C.1.b)1.g, C.1.d)7, C.1.e)5, C.2.b)1.g, C.2.d)9, C.2.e)6, C.3.b)1.e, C.3.d)4, C.3.e)4, C.4.b)1.f, C.4.d)9, C.4.e)6, C.5.b)1.d, C.5.d)4, C.5.e)4, C.6.b)1.d, C.6.d)3, C.6.e)4, C.7.b)1.h,C.7.d)5, C.7.e)6, C.8.b)1.e, C.8.d)2, and C.8.e)4.

The EPA is proposing to approve the following as RACT in the Cleveland Moderate nonattainment area with respect to the 2015 ozone NAAQS:

• Lubrizol: continued compliance with site-specific RACT under OAC 3745-21-09(LL) for all process reactor vents; use of submerged filling and venting to a thermal oxidizer achieving greater than 98 percent VOC control efficiency for the drum/tote filling operations; and implementation of existing controls, emission limits, and work practices for the loading racks as detailed in the permit provisions described above.

• Henkel: continued current operational practices of utilizing low-VOC materials and the use of condenser systems to reduce VOC emissions by 85 percent, as detailed in the permit provisions described above.

• Cleveland-Cliffs Cleveland Works

○ NO X RACT:

Reheat Furnaces (P046-P048): Requirement to submit updated NO X RACT study per 3745-110-03(J) if NO X emissions exceed 348.3 tpy per furnace on a 12-month rolling average.

Batch annealing Furnaces (P049 and P050): Continued operation of existing LNBs and compliance with existing NO X limit of 0.10 lb/MMBtu.

HDGL Annealing Furnace (Unit P071): Continued use of the existing LNBs and compliance with the 0.23 lb/MMBtu NO X limit.

Blast Furnaces (P903 and P904): Continued use of low-NO X BFG; Casthouse and Flare- install, maintain, and operate the source in accordance with manufacturer specifications and with good operating practices for the control of NO X emissions; Blast furnace stoves- Continued compliance with existing NO X limit of 0.06 lb/MMBtu.

Basic Oxygen Furnaces and Ladle Preheaters (P905/P906 and P925/P926): BOFs—install, maintain, and operate the source in accordance with the manufacturer's specifications and with good operating practices for the control of NO X emissions; Ladle Preheaters- Continued use of the existing inherently low-NO X burners and continued compliance of the site-specific NO X limit of 0.10 lb/MMBtu.

○ VOC RACT:

Combustion Units (B001-B007, B046-B050, P903-P906): Operate the source in accordance with the manufacturer's specifications and with good operating practices for the control of VOC emissions.

Tandem Mill (P107): Continued operation of chevron-style oil demister in accordance with good engineering practices; Compliance with existing VOC BAT limit of 138.91 tons per rolling 12-month period; Compliance with proposed VOC content limits for rolling oils described in more detail in the preamble above.

In this rule, the EPA is proposing to include in a final EPA rule regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, the EPA is proposing to incorporate by reference Ohio rule 3745-21-09(LL), and the permit provisions discussed in the preamble. The EPA has made, and will continue to make, these documents generally available through www.regulations.gov and at the EPA Region 5 Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information).

Under the CAA, 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 the EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rulemaking 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).

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA. This supplementary information section is arranged as follows:

The EPA is proposing to take several related actions. The EPA proposes to determine that the Cleveland area has met the requirements for redesignation under section 107(d)(3)(E) of the CAA, and the EPA is thus proposing to change the legal designation of the Cleveland area from nonattainment to attainment for the 2015 ozone NAAQS. The EPA is also proposing to approve, as a revision to the Ohio SIP, the State's maintenance plan for the area (such approval being one of the CAA criteria for redesignation to attainment status). The maintenance plan is designed to keep the Cleveland area in attainment of the 2015 ozone NAAQS through 2038. As a part of the maintenance plan, the EPA is initiating the adequacy process and proposing to approve the newly established 2032 and 2038 motor vehicle emissions budgets for the Cleveland area. Additionally, the EPA is proposing to adjust the deadline for Ohio to submit Serious SIP revisions for the Cleveland area to no later than December 5, 2026. Finally, the EPA is also proposing to approve several elements which meet section 110 and part D of the CAA and the EPA's regulations for an area which is classified as Serious nonattainment for the 2015 ozone NAAQS. These elements include Enhanced I/M certification, CFVP certification, and EMP certification SIP revisions submitted by Ohio EPA on December 19, 2025, and supplemented on January 12, 2026.

The EPA has determined that ground-level ozone is detrimental to human health. On October 1, 2015, the EPA promulgated a revised 8-hour ozone NAAQS of 0.070 parts per million (ppm). See 80 FR 65292 (October 26, 2015). Under the EPA's regulations at 40 CFR part 50, the 2015 ozone NAAQS is attained in an area when the 3-year average of the annual fourth highest daily maximum 8-hour average concentration is equal to or less than 0.070 ppm, when truncated after the thousandth decimal place, at all of the ozone monitoring sites in the area. See 40 CFR 50.19 and appendix U to 40 CFR part 50.

Upon promulgation of a new or revised NAAQS, section 107(d)(1)(B) of the CAA requires the EPA to designate as nonattainment any areas that are violating the NAAQS, based on the most recent three years of quality assured ozone monitoring data. The Cleveland area was designated as a Marginal nonattainment area for the 2015 ozone NAAQS on June 4, 2018 (83 FR 25776) (effective August 3, 2018). On October 7, 2022 (87 FR 60897), the EPA determined that the Cleveland area did not attain the standards by the Marginal attainment date, and the area was reclassified as Moderate by operation of law. More recently, on December 17, 2024 (89 FR 101901), the EPA determined the area did not attain the standards by the Moderate attainment date, and the area was reclassified as Serious by operation of law. The EPA established Serious area SIP submission deadlines by rule at 40 CFR 51.1402(b)(1)(i). This set January 1, 2026, as the Serious area SIP submission deadline applicable to the Cleveland area. As noted in that regulatory provision, the default deadline for reclassified areas applies “unless the Administrator establishes a different deadline in a separate action.”

Section 107(d)(3)(E) of the CAA allows redesignation of an area to attainment of the NAAQS provided that: (1) the Administrator (EPA) determines that the area has attained the NAAQS; (2) the Administrator has fully approved the applicable implementation plan for the area under section 110(k) of the CAA; (3) the Administrator determines that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable SIP, applicable Federal air pollutant control regulations, and other permanent and enforceable emission reductions; (4) the Administrator has fully approved a maintenance plan for the area as meeting the requirements of section 175A of the CAA; and (5) the State containing the area has met all requirements applicable to the area for the purposes of redesignation under section 110 and part D of the CAA.

On April 16, 1992 (57 FR 13498), the EPA provided guidance on redesignations in the General Preamble for the Implementation of title I of the CAA Amendments of 1990 and supplemented this guidance on April 28, 1992 (57 FR 18070). The EPA has provided further guidance on processing redesignation requests in policy memoranda, including the September 4, 1992, memorandum from John Calcagni, Director, Air Quality Management Division, entitled “Procedures for Processing Requests to Redesignate Areas to Attainment,” (Calcagni Memorandum).

For redesignation of a nonattainment area to attainment, the CAA requires the EPA to determine that the area has attained the applicable NAAQS (CAA section 107(d)(3)(E)(i)). An area is attaining the 2015 ozone NAAQS if it meets the 2015 ozone NAAQS, as determined in accordance with 40 CFR 50.19 and appendix U of part 50, based on three complete, consecutive calendar years of quality-assured air quality data for all monitoring sites in the area. To attain the 2015 ozone NAAQS, the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentrations (ozone design values) at each monitor must not exceed 0.070 ppm. The air quality data must be collected and quality-assured in accordance with 40 CFR part 58 and recorded in the EPA's Air Quality System (AQS). Ambient air quality monitoring data for the 3-year period must also meet data completeness requirements. An ozone design value is valid if daily maximum 8-hour average concentrations are available for at least 90% of the days within the ozone monitoring seasons, 1 on average, for the 3-year period, with a minimum data completeness of 75% during the ozone monitoring season of any year during the 3-year period. See section 4 of appendix U to 40 CFR part 50.

On February 27, 2026 (91 FR 9800), the EPA proposed to determine that the Cleveland area attained the 2015 ozone NAAQS based on ozone monitoring data for the 2023-2025 period and to suspend certain planning requirements related to the attainment of the NAAQS (clean data determination or CDD). A summary of the monitoring data relied upon in that proposal is presented in Table 1. These data demonstrate that the Cleveland area is attaining the 2015 ozone NAAQS.

The Cleveland area's 3-year ozone design value for 2023-2025 is 0.070 ppm, 2 which meets the 2015 ozone NAAQS.

The EPA will not take final action to redesignate the Cleveland area to attainment if the EPA fails to finalize the CDD or if the design value of a monitoring site in the area violates the NAAQS prior to final approval of the redesignation. As discussed in section IV.D.3. below, Ohio EPA has committed to continue monitoring ozone in this area to verify maintenance of the 2015 ozone NAAQS.

For redesignation of an area from nonattainment to attainment of a NAAQS, the CAA requires the EPA to determine that the State has met all applicable requirements under section 110 and part D of title I of the CAA ( see section 107(d)(3)(E)(v) of the CAA) and that the State has a fully approved SIP under section 110(k) of the CAA ( see section 107(d)(3)(E)(ii) of the CAA). The EPA proposes to find that Ohio has met all applicable SIP requirements for purposes of redesignation under section 110 and part D of title I of the CAA (requirements specific to nonattainment areas for the 2015 ozone NAAQS). In separate actions, the EPA is proposing approval of Ohio's source specific VOC and NO X RACT determinations for sources at or above the Moderate major source threshold. Recognizing that these SIP elements must be approved on or before the date the EPA completes final rulemaking redesignating the area, the EPA proposes to determine that, providing this occurs, the EPA will have fully approved Ohio's SIP under section 110(k) of the CAA. In making these proposed determinations, the EPA ascertained which requirements are applicable for purposes of redesignation, and whether the required Ohio SIP elements are fully approved under section 110(k) and part D of the CAA. As discussed more fully below, SIPs must be fully approved only with respect to these applicable requirements of the CAA.

The EPA proposed in its CDD action to determine that the Cleveland area has attained the 2015 standard, under 40 CFR 51.1318. Providing that determination is finalized, the requirements to submit certain planning SIPs related to attainment, including attainment demonstration requirements (the reasonably available control measures (RACM) requirement of section 172(c)(1) of the CAA, the reasonable further progress (RFP) and attainment demonstration requirements of sections 172(c)(2) and (6) and 182(b)(1) of the CAA, and the requirement for contingency measures of section 172(c)(9) of the CAA) would not be applicable to the area as long as it continues to attain the NAAQS and would cease to apply upon redesignation. In addition, in the context of redesignations, the EPA has interpreted requirements related to attainment as not applicable for purposes of redesignation. For example, in the General Preamble, the EPA stated that:

“The section 172(c)(9) requirements are directed at ensuring RFP and attainment by the applicable date. These requirements no longer apply when an area has attained the standard and is eligible for redesignation. Furthermore, section 175A for maintenance plans provides specific requirements for contingency measures that effectively supersede the requirements of section 172(c)(9) for these areas.” (General Preamble, 57 FR 13498 at 13564, April 16, 1992).

See also Calcagni Memorandum at 6 (“The requirements for reasonable further progress and other measures needed for attainment will not apply for redesignations because they only have meaning for areas not attaining the standard”).

1. Ohio has met all applicable requirements of section 110 and part D of the CAA applicable to the Cleveland area for purposes of redesignation.

Section 110(a)(2) of the CAA delineates the general requirements for a SIP. Section 110(a)(2) provides that the SIP must have been adopted by the State after reasonable public notice and hearing, and that, among other things, it must: (1) include enforceable emission limitations and other control measures, means or techniques necessary to meet the requirements of the CAA; (2) provide for establishment and operation of appropriate devices, methods, systems and procedures necessary to monitor ambient air quality; (3) provide for implementation of a source permit program to regulate the modification and construction of stationary sources within the areas covered by the plan; (4) include provisions for the implementation of part C prevention of significant deterioration (PSD) and part D new source review (NSR) permit programs; (5) include provisions for stationary source emission control measures, monitoring, and reporting; (6) include provisions for air quality modeling; and, (7) provide for public and local agency participation in planning and emission control rule development.

Section 110(a)(2)(D) of the CAA requires SIPs to contain measures to prevent sources in a State from significantly contributing to air quality problems in another State. To implement this provision, the EPA has required certain States to establish programs to address transport of certain air pollutants, for example, the NO X SIP call, the Clean Air Interstate Rule (CAIR), and the Cross State Air Pollution Rule (CSAPR). Like many of the 110(a)(2) requirements, however, the section 110(a)(2)(D) SIP requirements are not linked with a particular area's ozone designation and classification. The EPA concludes that the SIP requirements linked with the area's ozone designation and classification are the relevant measures to evaluate when reviewing a redesignation request for the area. The section 110(a)(2)(D) requirements, where applicable, continue to apply to a State regardless of the designation of any one particular area within the State. Thus, we believe these requirements are not applicable requirements for purposes of redesignation. See 65 FR 37890 (June 15, 2000), 66 FR 53094 (October 19, 2001), 68 FR 25418, 25426 through 25427 (May 12, 2003).

In addition, the EPA believes that other section 110 elements that are neither connected with nonattainment plan submissions nor linked with an area's ozone 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 2015 ozone NAAQS. The section 110 and part D requirements which are linked with a particular area's designation and classification are the relevant measures to evaluate in reviewing a redesignation request. This approach is consistent with the EPA's existing policy on applicability ( i.e., for redesignations) of conformity requirements, as well as with section 184 ozone transport requirements. See Reading, Pennsylvania proposed and final rulemakings, 61 FR 53174 through 53176 (October 10, 1996) and 62 FR 24826 (May 7, 1997); Cleveland-Akron-Loraine, Ohio final rulemaking, 61 FR 20458 (May 7, 1996); and Tampa, Florida final rulemaking, 60 FR 62748 (December 7, 1995). See also the discussion of this issue in the Cincinnati, Ohio ozone redesignation (65 FR 37890, June 19, 2000), and the Pittsburgh, Pennsylvania ozone redesignation (66 FR 53094, October 19, 2001).

We have reviewed Ohio's SIP and propose to find that it meets the general SIP requirements under section 110 of the CAA, to the extent those requirements are applicable for purposes of redesignation. In any case, on August 11, 2021 (86 FR 43962), the EPA approved elements of the SIP submitted by Ohio to meet the requirements of section 110 for the 2015 ozone standard.

Section 172(c) of the CAA sets forth the basic requirements of air quality plans for States with nonattainment areas that are required to submit them pursuant to section 172(b). Subpart 2 of part D, which includes section 182 of the CAA, establishes specific requirements for ozone nonattainment areas depending on the areas' nonattainment classifications.

The Cleveland area is classified as Serious under subpart 2 for the 2015 ozone NAAQS. As such, the area is subject to the subpart 1 requirements contained in section 172(c) and section 176. Similarly, the area is subject to the subpart 2 requirements contained in section 182(a) (Marginal nonattainment area requirements) and section 182(b) (Moderate nonattainment area requirements), and section 182(c) (Serious nonattainment area requirements). A thorough discussion of the requirements contained in section 172(c) and 182 can be found in the General Preamble for Implementation of Title I (April 16, 1992, 57 FR 13498). However, as discussed in section VI below, the EPA is proposing to adjust the deadline for Ohio to submit Serious SIP revisions for the Cleveland area to no later than December 5, 2026. Providing the EPA finalizes this SIP submittal deadline adjustment and the redesignation of the Cleveland area prior to December 5, 2026, Serious SIP requirements would not be applicable requirements for purposes of redesignation, because they will not have become due.

As provided in subpart 2, for ozone nonattainment areas such as the Cleveland area, the specific requirements of section 182 apply in lieu of the attainment planning requirements that would otherwise apply under section 172(c), including the attainment demonstration and RACM under section 172(c)(1), RFP under section 172(c)(2), and contingency measures under section 172(c)(9). 42 U.S.C. 7511a(a).

Section 172(c)(3) requires submission and approval of a comprehensive, accurate and current inventory of actual emissions. This requirement is superseded by the inventory requirement in section 182(a)(1) discussed below.

Section 172(c)(4) requires the identification and quantification of allowable emissions for major new and modified stationary sources in an area, and section 172(c)(5) requires source permits for the construction and operation of new and modified major stationary sources anywhere in the nonattainment area. The EPA granted limited approval of approved Ohio's NSR program on September 8, 1993 (58 FR 47211) and granted final approval on January 10, 2003 (68 FR 1366). The EPA approved revisions to Ohio's NSR program on February 25, 2010 (75 FR 8496). Most recently, the EPA approved Ohio's certification that its SIP satisfies the nonattainment NSR requirements of the CAA for the 2015 ozone NAAQS on July 7, 2025 (90 FR 29742). Nonetheless, the EPA has determined that, since PSD requirements will apply after redesignation, areas being redesignated need not comply with the requirement that an NSR program be approved prior to redesignation, provided that the area demonstrates maintenance of the NAAQS without part D NSR. A more detailed rationale for this view is described in the October 14, 1994, memorandum from Mary Nichols, Assistant Administrator for Air and Radiation, entitled, “Part D New Source Review Requirements for Areas Requesting Redesignation to Attainment.” See rulemakings for Detroit, Michigan (60 FR 12467 through 12468, March 7, 1995); Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996); Louisville, Kentucky (66 FR 53665, October 23, 2001); and Grand Rapids, Michigan (61 FR 31834 through 31837, June 21, 1996). Ohio's PSD program will become effective in the Cleveland area upon redesignation to attainment. The EPA conditionally approved Ohio's PSD program on October 10, 2001 (66 FR 51570), fully approved Ohio's PSD program on January 22, 2003 (68 FR 2909), and most recently approved revisions to Ohio's PSD program on February 25, 2010 (75 FR 8496).

Section 172(c)(6) requires the SIP to contain control measures necessary to provide for attainment of the NAAQS. Because attainment has been reached, no additional measures are needed to provide for attainment.

Section 172(c)(7) requires the SIP to meet the applicable provisions of section 110(a)(2). As noted above, we believe the Ohio SIP meets the requirements of section 110(a)(2) for purposes of redesignation.

Section 176(c) of the CAA requires that federally supported or funded projects conform to 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.) and the Federal Transit Act (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 the EPA promulgated pursuant to its authority under the CAA.

The EPA interprets the conformity SIP requirements  3 as not applying for purposes of evaluating a redesignation request under section 107(d) because State conformity rules are still required after redesignation and Federal conformity rules apply where State conformity rules have not been approved. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001) (upholding this interpretation); see also 60 FR 62748 (December 7, 1995) (redesignation of Tampa, Florida). Nonetheless, Ohio has an approved conformity SIP for the Cleveland area. See 80 FR 11133 (March 2, 2015).

Section 182(a)(1) requires States to submit a comprehensive, accurate, and current inventory of actual emissions from sources of NO X and VOC emitted within the boundaries of the ozone nonattainment area within two years of designation. The EPA approved Ohio's base year emissions inventory for the Cleveland area on March 3, 2021 (86 FR 12270) and July 7, 2025 (90 FR 29742).

Under section 182(a)(2)(A), States with ozone nonattainment areas that were designated prior to the enactment of the 1990 CAA amendments were required to submit, within six months of classification, all rules and corrections to existing VOC reasonably available control technology (RACT) rules that were required under section 172(b)(3) prior to the 1990 CAA amendments. The Cleveland area is not subject to the section 182(a)(2) RACT “fix up” requirement for the 2015 ozone NAAQS because it was designated as nonattainment for this standard after the enactment of the 1990 CAA amendments and, in any case, Ohio complied with this requirement for the Cleveland area under the prior 1-hour ozone NAAQS. See 59 FR 23796 (May 9, 1994) and 60 FR 15235 (March 23, 1995).

Section 182(a)(2)(B) requires each State with a Marginal ozone nonattainment area that implemented or was required to implement a vehicle I/M program prior to the 1990 CAA amendments to submit a SIP revision for an I/M program no less stringent than that required prior to the 1990 CAA amendments or already in the SIP at the time of the CAA amendments, whichever is more stringent. For the purposes of the 2015 ozone NAAQS and the consideration of Ohio's redesignation request for this standard, the Cleveland area is not subject to the section 182(a)(2)(B) requirement because the Cleveland area was designated as nonattainment for the 2015 ozone NAAQS after the enactment of the 1990 CAA amendments.

Regarding the source permitting and offset requirements of sections 182(a)(2)(C), 182(a)(4), and 182(b)(5), Ohio currently has a fully approved part D NSR program in place. The EPA granted limited approval of Ohio's NSR program on September 8, 1993 (58 FR 47211), and received final approval on January 10, 2003 (68 FR 1366). The EPA approved revisions to Ohio's NSR program on February 25, 2010 (75 FR 8496). Most recently, the EPA approved Ohio's certification that its SIP satisfies the nonattainment NSR requirements of the CAA for the 2015 ozone NAAQS on July 7, 2025 (90 FR 29742). In addition, the EPA conditionally approved Ohio's PSD program on October 10, 2001 (66 FR 51570), fully approved Ohio's PSD program on January 22, 2003 (68 FR 2909), and most recently approved revisions to Ohio's PSD program on February 25, 2010 (75 FR 8496). The State's PSD program will become effective in the Cleveland area upon redesignation to attainment.

Section 182(a)(3) requires States to submit periodic emission inventories and a revision to the SIP to require the owners or operators of stationary sources to annually submit emission statements documenting actual VOC and NO X emissions. As discussed below in section IV.D.4. of this proposed rule, Ohio will continue to update its emissions inventory at least once every three years consistent with the requirements of 40 CFR part 51, subpart A, and in 40 CFR 51.122. The EPA approved Ohio's emission statement SIP for the Cleveland area for the 2015 ozone NAAQS on July 11, 2017 (82 FR 31913).

Section 182(b)(1) requires the submission of an attainment demonstration and RFP plan. Ohio submitted an attainment demonstration and RFP plan for the Cleveland area on December 21, 2022. The EPA approved Ohio's RFP plan on July 7, 2025 (90 FR 29742). However, because attainment has been reached, section 182(b)(1) requirements are no longer considered to be applicable if the area continues to attain the standard. If the EPA finalizes approval of the redesignation of the area, the EPA will take no further action on the attainment demonstration submitted by Ohio.

Section 182(b)(2) requires States with Moderate nonattainment areas to implement VOC RACT with respect to each of the following: (1) all sources covered by a Control Technology Guideline (CTG) document issued between November 15, 1990, and the date of attainment; (2) all sources covered by a CTG issued prior to November 15, 1990; and (3) all other major non-CTG stationary sources. Ohio submitted a VOC RACT SIP to address the requirements applicable to Moderate nonattainment areas on March 30, 2022, and supplemented the submittal on February 1, 2023, and August 28, 2023. On January 20, 2026 (91 FR 2308) the EPA approved Ohio's submittal as satisfying the requirements of sections 182(b)(2)(A) and (B), that VOC RACT be implemented with respect to sources covered by a CTG and partially satisfying the requirement of section 182(b)(2)(C) that VOC RACT be implemented at all other major sources. Ohio subsequently submitted non-CTG VOC RACT determinations for sources at or above the Moderate major source threshold in the area on March 11, 2024, January 15, 2025, January 22, 2025, October 8, 2025, November 20, 2025, and November 25, 2025. The EPA is taking action on these VOC RACT determinations in separate rulemakings. The EPA will not finalize this redesignation unless the EPA has fully approved Ohio's Moderate VOC RACT SIP.

Section 182(b)(3) requires States to adopt Stage II gasoline vapor recovery regulations. On May 16, 2012 (77 FR 28772), the EPA determined that the use of onboard vapor recovery technology for capturing gasoline vapor when gasoline-powered vehicles are refueled is in widespread use throughout the highway motor vehicle fleet and waived the requirement that current and former ozone nonattainment areas implement Stage II vapor recovery systems on gasoline pumps.

Section 182(b)(4) requires a basic vehicle I/M program in each State with a moderate ozone nonattainment area. The EPA approved Ohio's basic I/M program of April 4, 1995 (60 FR 16986) and on January 6, 1997 (62 FR 646). The EPA approved Ohio's I/M program certification for the Cleveland area for the Moderate classification under the 2015 ozone NAAQS on July 7, 2025 (90 FR 29742).

Section 182(c) contains the requirements for areas classified as Serious. As discussed in section VI, in this action the EPA is proposing to adjust the deadline for Ohio to submit Serious SIP revisions for the Cleveland area to no later than December 5, 2026. Provided the EPA finalizes this SIP submittal deadline adjustment and the redesignation of the Cleveland area prior to December 5, 2026, Serious SIP requirements would not be considered applicable requirements for purposes of redesignation because they will not have become due and thus are not a prerequisite to redesignation. Nonetheless, Ohio has already submitted many of the Serious SIP requirements, and the EPA is proposing to approve those submittals as follows.

Section 182(c)(1) of the CAA requires States with nonattainment areas classified Serious or higher to adopt and implement a program to improve air monitoring for ambient concentrations of ozone, NO X and VOC. For the reasons discussed in section IX, EPA is proposing to approve the Ohio's EMP certification for the 2015 ozone NAAQS.

CAA section 182(c)(3) requires States with ozone nonattainment areas classified as Serious or higher to adopt and implement an Enhanced I/M program. For the reasons discussed in section VII, below, the EPA is proposing to approve the Ohio I/M certification as meeting the section 182(c)(3) Serious Enhanced I/M requirements for the Cleveland area under the 2015 ozone NAAQS.

CAA section 182(c)(4) requires States with ozone nonattainment areas classified as Serious or higher to submit a SIP revision describing implementation of a CFVP, as described in CAA title II part C (40 CFR 88). For the reasons discussed in section VIII, the EPA is proposing to approve Ohio's certification that its current CFVP meets the Serious CFVP requirements for the Ohio area for the 2015 ozone NAAQS.

Section 182(c) of the CAA also requires States with Serious nonattainment areas to implement the VOC RACT requirements of Section 182(b)(2) with the addition that a “major source” is one that emits, or has the potential to emit, at least 50 tons per year of volatile organic compounds. Ohio has submitted part of the Serious VOC RACT requirements for the Cleveland nonattainment area. The EPA is proposing to extend the deadlines for those submittals, however, as described in section VI.

The remaining section 182(c) requirements for areas classified as Serious include: an attainment demonstration, RFP, RFP contingency measures, and a transportation control demonstration. These elements are not needed to redesignate the Ohio portion because the area has attained the 2015 ozone NAAQS. This rationale is outlined in 40 CFR 51.1318, the General Preamble, and the Calcagni memorandum at 6 (“The requirements for reasonable further progress and other measures needed for attainment will not apply for redesignations because they only have meaning for areas not attaining the standard.”). The EPA believes it is reasonable to interpret these provisions as not requiring areas that are meeting the ozone standard to make the SIP submissions to the EPA described in the provisions as long as the areas continue to meet the standard. (If such an area were to monitor a violation of the standard prior to being redesignated to attainment, however, the area would have to address the pertinent requirements and submit the SIP revisions described in those provisions to the EPA.)

Section 182(f) of the CAA establishes NO X requirements for ozone nonattainment areas. Section 182(f)(1) generally requires major sources of NO X to be covered by the same levels of emission controls as required for major sources of VOC. Since section 182(b)(2)(C) of the CAA requires areas classified as Moderate (or above) to implement RACT for major VOC sources, these ozone nonattainment areas are also required to implement NO X RACT for major sources of NO X . Ohio submitted a NO X RACT SIP at the Moderate major source threshold on March 30, 2022, and supplemented the submittal on February 1, 2023, and August 28, 2023. On January 20, 2026 (91 FR 2308), the EPA approved Ohio's SIP submissions as partially meeting the NO X RACT requirements of sections 182(b)(2) and 182(f) of the CAA at the Moderate major source threshold. For the major sources not subject to category-specific NO X RACT rules, Ohio subsequently submitted source specific NO X RACT determinations on December 5, 2023, March 28, 2024, July 28, 2025, August 25, 2025, and November 20, 2025. The EPA is taking action on Ohio's source specific Moderate NO X RACT determinations in separate rules. As noted below, providing the EPA finalizes the SIP submittal deadline adjustment and the redesignation of the Cleveland area prior to December 5, 2026, NO X RACT at the Serious major source threshold would not be an applicable requirement for purposes of redesignation because it will not have become due.

Thus, as discussed above, the EPA finds that the Cleveland, Ohio area satisfies all applicable requirements for purposes of redesignation under section 110 and part D of the CAA.

2. The Cleveland area has a fully approved SIP for purposes of redesignation under section 110(k) of the CAA.

At various times, Ohio has adopted and submitted, and the EPA has approved, provisions addressing the various SIP elements applicable for the ozone NAAQS. In separate actions, the EPA is proposing to approve Ohio's VOC and NO X RACT submissions as meeting the requirements for Moderate nonattainment areas. Providing the EPA finalizes approval of these VOC and NO X RACT submissions and finalizes the SIP submittal deadline adjustment and the redesignation of the Cleveland area prior to December 5, 2026, the EPA will have fully approved the Ohio SIP for the Cleveland area under section 110(k) for all requirements applicable for purposes of redesignation under the 2015 ozone NAAQS. The EPA may rely on prior SIP approvals in approving a redesignation request ( see the Calcagni memorandum at page 3; Southwestern Pennsylvania Growth Alliance v. Browner, 144 F.3d 984, 989-990 (6th Cir. 1998); Wall v. EPA, 265 F.3d 426). Additional measures may also be approved in conjunction with a redesignation action ( see 68 FR 25426 (May 12, 2003) and citations therein).

To redesignate an area from nonattainment to attainment, section 107(d)(3)(E)(iii) of the CAA requires the 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. The EPA proposes to determine that Ohio has demonstrated that that the observed ozone air quality improvement in the Cleveland area is due to permanent and enforceable reductions in VOC and NO X emissions resulting from State measures adopted into the SIP and Federal measures.

In making this demonstration, the State has calculated the change in emissions between 2017 and 2025. The reduction in emissions and the corresponding improvement in air quality over this time period can be attributed to several regulatory control measures that the Cleveland area and upwind areas have implemented in recent years. In addition, Ohio provided an analysis to demonstrate the improvement in air quality was not due to unusually favorable meteorology. Based on the information summarized below, the EPA proposes to find that Ohio has adequately demonstrated that the improvement in air quality is due to permanent and enforceable emissions reductions.

1. Permanent and enforceable emission controls implemented.

CAIR/CSAPR. Under the “good neighbor provision” of CAA section 110(a)(2)(D)(i)(I), States are required to address interstate transport of air pollution. Specifically, the good neighbor provision provides that each State's SIP must contain provisions prohibiting emissions from within that State which will contribute significantly to nonattainment of the NAAQS, or interfere with maintenance of the NAAQS, in any other State.

On May 12, 2005 (70 FR 25152), the EPA published CAIR, which required eastern States, including Ohio, to prohibit emissions consistent with annual and ozone season NO X budgets and annual sulfur dioxide (SO 2 ) budgets. CAIR addressed the good neighbor provision for the 1997 ozone NAAQS and 1997 fine particulate matter (PM 2.5 ) NAAQS and was designed to mitigate the impact of transported NO X emissions, a precursor of both ozone and PM 2.5 , as well as transported SO 2 emissions, another precursor of PM 2.5 . The United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit) remanded CAIR to the EPA for replacement in 2008. North Carolina v. EPA, 531 F.3d 896, modified, 550 F.3d 1176 (2008). While the EPA worked on developing a replacement rule, implementation of the CAIR program continued as planned with the NO X annual and ozone season programs beginning in 2009 and the SO 2 annual program beginning in 2010.

On August 8, 2011 (76 FR 48208), acting on the D.C. Circuit's remand, the EPA published CSAPR to replace CAIR and to address the good neighbor provision for the 1997 ozone NAAQS, the 1997 PM 2.5 NAAQS, and the 2006 PM 2.5 NAAQS. Through Federal Implementation Plans, CSAPR required electric generating units (EGUs) in eastern States, including Ohio, to meet annual and ozone season NO X budgets and annual SO 2 budgets implemented through new trading programs. After delays caused by litigation, the EPA started implementing the CSAPR trading programs in 2015, simultaneously discontinuing administration of the CAIR trading programs. On October 26, 2016 (81 FR 74504), the EPA published the CSAPR Update, which established, starting in 2017, a new ozone season NO X trading program for EGUs in eastern States, including Ohio, to address the good neighbor provision for the 2008 ozone NAAQS. The CSAPR Update was estimated to result in a 20% reduction in ozone season NO X emissions from EGUs in the eastern United States, a reduction of 80,000 tons in 2017 compared to 2015 levels. On April 30, 2021 (86 FR 23054), the EPA published the Revised CSAPR Update, which fully resolved the obligations of eastern States, including Ohio, under the good neighbor provision for the 2008 ozone NAAQS. The Revised CSAPR Update is estimated to reduce ozone season NO X emissions from EGUs by 17,000 tons beginning in 2021, compared to emissions without the rule. The reduction in NO X emissions from the implementation of CAIR and then CSAPR occurred by the attainment years.

Reductions in VOC and NO X emissions have occurred statewide and in upwind areas as a result of Federal emission control measures, with additional emission reductions expected to occur in the future. Further details on the various Federal emission control measures are described in the redesignation request submittal included in the docket of this action. Some of the listed Federal emission control measures include the following:

Tier 2 Emission Standards for Vehicles and Gasoline Sulfur Standards. On February 10, 2000 (65 FR 6698), the EPA promulgated Tier 2 motor vehicle emission standards and gasoline sulfur control requirements. These emission control requirements result in lower VOC and NO X emissions from new cars and light duty trucks, including sport utility vehicles. With respect to fuels, this rule required refiners and importers of gasoline to meet lower standards for sulfur, which were phased in between 2004 and 2006. By 2006, refiners and importers were required to meet a 30 ppm average sulfur level, with a maximum cap of 80 ppm. This reduction in fuel sulfur content ensures the effectiveness of low emission-control technologies. The Tier 2 tailpipe standards established in this rule were phased in for new vehicles between 2004 and 2009. At the time of promulgation of Tier 2 standards, the EPA estimated that this rule would cut NO X and VOC emissions from light-duty vehicles and light-duty trucks by approximately 76% and 28%, respectively. NO X and VOC reductions from medium-duty passenger vehicles included as part of the Tier 2 vehicle program were estimated to be approximately 37,000 and 9,500 tons per year, respectively, when fully implemented. As projected by these estimates and demonstrated in the onroad emission modeling for the Cleveland area, a portion of these emission reductions occurred during the period 2017 through 2025, i.e., after the area was designated nonattainment for the 2015 ozone NAAQS. As discussed below, the Tier 2 vehicle and gasoline sulfur standards were replaced by the Tier 3 emission standards for vehicles and gasoline sulfur standards beginning on January 1, 2017.

Tier 3 Emission Standards for Vehicles and Gasoline Sulfur Standards. On April 28, 2014 (79 FR 23414), the EPA promulgated Tier 3 motor vehicle emission and fuel standards to reduce both tailpipe and evaporative emissions and to further reduce the sulfur content in fuels. The rule was phased in between 2017 and 2025. Tier 3 sets new tailpipe standards for non-methane organic gases (NMOG) and NO X , presented as NMOG+NO X , and for particulate matter. The VOC and NO X tailpipe standards for light-duty vehicles represent approximately an 80% reduction in fleet average NMOG+NO X and a 70% reduction in per-vehicle particulate matter (PM) standards, relative to the fleet average at the time of phase-in. Heavy-duty tailpipe standards represent about a 60% reduction in both fleet average NMOG+NO X and per-vehicle PM standards. The evaporative emissions requirements in the rule will result in approximately a 50% reduction from previous standards and apply to all light-duty and onroad gasoline-powered heavy-duty vehicles. Finally, the rule lowered the sulfur content of gasoline to an annual average of 10 ppm starting in January 2017. As projected by these estimates and demonstrated in the onroad emission modeling for the Cleveland area, some of these emission reductions occurred by the attainment years and additional emission reductions will occur throughout the maintenance period, as older vehicles are replaced with newer, compliant model years.

Heavy-Duty Diesel Engine Rules. On January 18, 2001 (66 FR 5002), the EPA issued a rule for onroad heavy-duty diesel engines that includes standards limiting the sulfur content of diesel fuel. Emissions standards for NO X , VOC and PM were phased in between model years 2007 and 2010. In addition, the rule reduced the highway diesel fuel sulfur content to 15 parts per million by 2007, leading to additional reductions in combustion NO X and VOC emissions. The EPA has estimated future year emission reductions due to implementation of this rule. The EPA estimated that by 2015 NO X and VOC emissions would decrease nationally by 1,260,000 tons and 54,000 tons, respectively, and that by 2030 NO X and VOC emissions will decrease nationally by 2,570,000 tons and 115,000 tons, respectively. As projected by these estimates and demonstrated in the onroad emission modeling for the Cleveland area, some of these emission reductions occurred by the attainment years and additional emission reductions will occur throughout the maintenance period, as older vehicles are replaced with newer, compliant model years.

Nonroad Diesel Rule. On June 29, 2004 (69 FR 38958), the EPA issued a rule adopting emissions standards for nonroad diesel engines and sulfur reductions in nonroad diesel fuel. This rule applies to diesel engines used primarily in construction, agricultural, and industrial applications. Emission standards were phased in for the 2008 through 2015 model years based on engine size. The sulfur limits for nonroad diesel fuels were phased in from 2007 through 2012. The EPA estimates that when fully implemented, compliance with this rule will cut NO X emissions from these nonroad diesel engines by approximately 90%. As projected by these estimates and demonstrated in the nonroad emission modeling for the Cleveland area, some of these emission reductions occurred by the attainment years and additional emission reductions will occur throughout the maintenance period.

Nonroad Spark-Ignition Engines and Recreational Engine Standards. On November 8, 2002 (67 FR 68242), the EPA adopted emission standards for large spark-ignition engines such as those used in forklifts and airport ground-service equipment; recreational vehicles such as off-highway motorcycles, all-terrain vehicles, and snowmobiles; and recreational marine diesel engines. These emission standards were phased in from model years 2004 through 2012. When fully implemented, the EPA estimates an overall 72% reduction in national VOC emissions from these engines and an 80% reduction in national NO X emissions. As projected by these estimates and demonstrated in the nonroad emission modeling for the Cleveland area, some of these emission reductions occurred by the attainment years and additional emission reductions will occur throughout the maintenance period as older engines are replaced with newer, compliant model years.

Category 3 Marine Diesel Engine Standards. On April 30, 2010 (75 FR 22896), the EPA issued emission standards for marine compression-ignition engines at or above 30 liters per cylinder. Tier 2 emission standards apply beginning in 2011 and are expected to result in a 15 to 25% reduction in NO X emissions from these engines. Final Tier 3 emission standards apply beginning in 2016 and are expected to result in approximately an 80% reduction in NO X from these engines. As projected by these estimates and demonstrated in the nonroad emission modeling for the Cleveland area, some of these emission reductions occurred by the attainment years and additional emission reductions will occur throughout the maintenance period as older engines are replaced with newer, complaint model years.

In its submittal, Ohio included additional permanent and enforceable Federal emission control measures that contributed to NO X and VOC emission reductions by the attainment years, and which will contribute to additional emission reductions throughout the maintenance period. Further information can be found in Chapter Five of Ohio's submittal.

Consumer Products Rules. On June 20, 2022, Ohio revised its consumer products rules to incorporate the Phase IV Ozone Transport Commission (OTC) model rule. Implementation was required by July 1, 2023.

Architectural and Industrial Maintenance (AIM) Coatings Rules. Effective December 16, 2022, Ohio revised its AIM rules to incorporate the OTC Phase II standards, with an implementation date of January 1, 2024.

VOC and NO X RACT. While VOC and NO X regulations have been in place in Ohio for many years, Ohio revised certain source categories to establish new or more stringent RACT controls. Revisions to Ohio's VOC and NO X RACT rules became effective March 27, 2022, and March 25, 2022, respectively.

The Avon Lake Power Plant (Facility ID: 0247030013) ceased operations in April 2022. In its submittal, Ohio EPA estimated this shutdown would reduce annual point source NO X emissions by 1,069.10 tons.

2. Emission reductions.

Ohio is using a 2017 emissions inventory to represent nonattainment level emissions (nonattainment year inventory or nonattainment inventory), which is appropriate because it was a year the area monitored nonattainment due to an exceedance of the NAAQS, and it corresponds to the base year approved by the EPA on July 7, 2025 (90 FR 29742), for Ohio EPA's Moderate attainment demonstration request and RFP demonstration. Ohio is using a 2025 emissions inventory to represent attainment level emissions (attainment year inventory or attainment inventory), which is appropriate because it is one of the years in the 2023-2025 period used to demonstrate monitored attainment with the NAAQS.

For both 2017 and 2025, Ohio has provided inventories for point, nonpoint, onroad, and nonroad sources. The point source category includes facilities that report their emissions directly to Ohio EPA, as well as sources such as airports and rail yards. Nonpoint sources, sometimes called area sources, include emissions from sources that are more ubiquitous, such as consumer products or architectural coatings. Onroad sources are vehicles that are primarily used on public roadways, such as cars, trucks, and motorcycles. Nonroad sources include engine-based emissions that do not occur on roads, such as trains or boats.

For its onroad emissions inventory, Ohio submitted an analysis developed by Ohio's Department of Transportation (ODOT), the Akron Metropolitan Area Transportation Study (AMATS), and the Northeast Ohio Areawide Coordinating Agency (NOACA), in consultation with Ohio EPA and the EPA. This analysis used the EPA's Motor Vehicle Emission Simulator (MOVES) model to generate July weekday onroad emissions informing the inventories for both 2017 and 2025. However, Ohio EPA used 2026 modeled emissions as a conservative estimate for mobile emissions used in their demonstration to represent 2025 emissions. The MOVES5 model was the latest model version available at the time the inventory was developed. NOACA, AMATS, and ODOT's analysis relied on local travel inputs including demographic data, travel demand forecasting, road types, Vehicle Miles of Travel (VMT), Vehicle Hours of Travel, vehicle population, and vehicle age, as well as meteorological data. In appendix C of its submittal, Ohio has included a detailed narrative of ODOT, AMATS, and NOACA's methods.

For its point, nonpoint, and nonroad emissions inventories, Ohio's primary data sources were the EPA's 2017gb emissions modeling platform based on the 2017 National Emissions Inventory (NEI)—Version 2 dataset, and the EPA's 2022v1 emissions modeling platform, based on the 2020 NEI. The 2017 NEI includes emissions data only for the year 2017, and the 2022v1 modeling platform includes emissions data for the years 2026, 2032, and 2038. The 2022v1 modeling platform and 2017 NEI have been quality-assured, and documentation regarding these datasets and their methods is available on the EPA's website. 4

For the 2017 inventories, Ohio EPA used the 2017gb emissions modeling platform  5 as the basis of its point, nonpoint, and nonroad inventories and these emissions are presented in terms of monthly or annual emissions.

To derive point inventories for 2025, Ohio EPA relied on 2023 actual point emissions to represent 2025 since at the time of the request, actual point emissions for 2024 and 2025 were not available. Ohio EPA determined that 2023 actual point source emissions would be a conservative estimate for 2025 actual point source emissions. Ohio EPA performed a review and did not find any new sources in the area and also reviewed to ensure any shutdown sources were removed. The 2023 actual point source inventory is submitted to the EPA's Emissions Inventory System (EIS). In appendix B of its submittal, Ohio has included a detailed listing of the facilities used to create the point source inventory for 2025. To derive nonpoint and nonroad inventories for 2025, Ohio EPA based 2025 emissions on 2026 projected emissions from the 2022v1 emissions modeling platform.

Ohio EPA summed the annual totals of NO X and VOC emissions for each county and each source category in tons per ozone season day (TPOSD) using conversion factors derived from the EPA's 2017gb emissions modeling platform. The derived ozone season day emissions include weekend days. Ohio EPA determined that this is appropriate because ozone values measured on weekend days have a significant impact on the monitor design values in the Cleveland area. Monitoring data from 2017 through 2022 show the Cleveland nonattainment area had between 5 and 7 days with one or more monitors recording values over the 2015 ozone standard each year, with up to 3 of those days in a year falling on a weekend. In addition, for each year from 2017 to 2022, between 5 and 18 of the 1st through 4th high values that contributed to the design value for a monitor occurred on a weekend day. As such, Ohio EPA determined that it was appropriate to include weekend emissions in the calculation of ozone season day emissions.

Ohio EPA derived ozone season day emissions in TPOSD emissions by dividing July emissions by the number of days in July where only monthly data was available. Where only annual data were available, Ohio EPA applied a conversion factor to annual emissions. Conversion factors were derived as a ratio of the 2017 average July day emissions to 2017 annual emissions, and then dividing by 31 to represent the number of days in July. Ohio EPA selected July as representative of the standard ozone season month as it is typically the warmest month and had the highest monthly emissions as a result of an analysis showing that July had the most days with high ozone values in recent years.

Using the inventories described above for all categories of sources, Ohio's submittal documents changes in NO X and VOC emissions from 2017 to 2025 for the Cleveland area. Emissions data are shown in Table 2. Data are expressed in terms of tons per ozone season day.

As shown in Table 2, Ohio's inventories demonstrate that NO X and VOC emissions in the Cleveland area declined by 45.45 tons per ozone season day and 48.07 tons per ozone season day, respectively, between 2017 and 2025.

3. Meteorology and temporary adverse economic conditions.

To further support Ohio EPA's demonstration that the improvement in air quality is due to permanent and enforceable emission reductions, and not unusually favorable meteorology or temporary adverse economic conditions, the demonstration includes two analyses performed by the Lake Michigan Air Directors Consortium (LADCO).

The first LADCO analysis compared trends in ozone to trends in ozone season temperatures, examining the relationship between these two factors. LADCO utilized two different metrics of ozone, the annual fourth-high daily maximum eight-hour average (MDA8) ozone value, and the number of days in a year with MDA8 ozone greater than 70 parts per billion (ppb) for the years 2005 to 2025. The ozone values were compared with two measures of “hotness” of an ozone season: (1) average May to September temperatures and (2) the number of days with a temperature exceeding 80 °F.

LADCO conducted a meteorological analysis based on 22 years of data collected at the Cleveland-Hopkins International Airport, WBAN 14820 meteorological station, representative of the area conditions and used for New Source Review and Prevention of Significant Deterioration air quality permit modeling applications. LADCO analyzed ozone values for May, June, July, August, and September, for years 2005 to 2025. First, the annual fourth high MDA8 ozone concentration at the Eastlake Monitor (Site ID: 39-085-0003) was compared to the average May to September temperature at the airport. Second, LADCO examined the relationship between the number of days with temperatures over 80 °F and the number of days with MDA8 ozone above 70 ppb. The data with the ozone parameters was plotted against the temperature parameters and grouped into 7-year time periods. These analyses show that over the last 22 years, the amount of ozone production for a given level of “hotness” has decreased in each subsequent time period. In contrast, temperatures have increased, with the area showing an overall warming trend. Because the correlation between temperature and ozone formation is well established, these data suggest that reductions in precursors are responsible for the reductions in ozone concentrations in the area, and not unusually favorable summer temperatures.

To further support Ohio EPA's demonstration that the improvement in air quality is not due to unusually favorable meteorology, a second analysis was performed by LADCO. A classification and regression tree (CART) analysis was conducted with 2001 through 2023 data from Cleveland area ozone sites. The goal of the analysis was to determine the meteorological and air quality conditions associated with ozone episodes, and construct trends for the days identified as sharing similar meteorological conditions. Regression trees were developed for the Cleveland area ozone data to classify each summer day by its ozone concentration and associated meteorological conditions. By grouping days with similar meteorology, the influence of meteorological variability on the underlying trend in ozone concentrations is partially removed and the remaining trend is presumed to be due to trends in precursor emissions or other non-meteorological influences. The CART analysis showed the resulting trends in ozone concentrations declining over the period examined, supporting the conclusion that the improvement in air quality was not due to unusually favorable meteorology. In appendix D of its submittal, Ohio included a detailed report of LADCO's analysis.

To determine attainment was not due to adverse economic conditions, the EPA analyzed Ohio employment status data taken from the U.S. Census Bureau's American Community Survey from 2015 through 2023, noting an overall increasing trend in employment rates in the Cleveland area. 6 Additionally, the gross domestic product (GDP) of the Cleveland metropolitan statistical area from 2013-2023 shows an increasing trend. 7 Despite increases employment and GDP, ozone concentrations in the Cleveland area show a decreasing trend, leading to attainment of the 2015 ozone NAAQS and indicating attainment of the 2015 standard was not due to temporary adverse economic conditions.

As discussed above, Ohio identified numerous Federal rules that resulted in the reduction of VOC and NO X emissions from 2017 to 2025. In addition, Ohio's analyses of meteorological variables associated with ozone formation demonstrate that the improvement in air quality in the area between the year violations occurred and the year attainment was achieved is not due to unusually favorable meteorology. The EPA reviewed employment and GDP data for the Cleveland area to verify that emissions reductions were not due to temporary adverse economic conditions but rather were consistent with a longer-term trend of decreasing ozone concentrations. Therefore, the EPA proposes to find that Ohio has shown that the air quality improvements in the Cleveland area are due to permanent and enforceable emissions reductions.

To redesignate an area from nonattainment to attainment, section 107(d)(3)(E)(iv) of the CAA requires the 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 the Administrator 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 the EPA deems necessary, to assure prompt correction of the future NAAQS violation.

The Calcagni Memorandum provides further guidance on the content of a maintenance plan, explaining that a maintenance plan should address five elements: (1) an attainment emission inventory; (2) a maintenance demonstration; (3) a commitment for continued air quality monitoring; (4) a process for verification of continued attainment; and (5) a contingency plan. In conjunction with its request to redesignate the Cleveland area to attainment for the 2015 ozone NAAQS, Ohio submitted a SIP revision to provide for maintenance of the 2015 ozone NAAQS through 2038, more than 10 years after the expected effective date of the redesignation to attainment. As discussed below, the EPA proposes to find that Ohio's ozone maintenance plan includes the necessary components and to approve the maintenance plan as a revision of the Ohio SIP.

In the CDD, the EPA proposed to determine that the Cleveland area has attained the 2015 ozone NAAQS based on monitoring data for the period of 2023-2025. See 91 FR 9771 (February 27, 2026). Ohio selected 2025 as the attainment emissions inventory year to establish attainment emission levels for VOC and NO X . The attainment emissions inventory identifies the levels of emissions in the Cleveland area that are sufficient to attain the 2015 ozone NAAQS. The derivation of the attainment year emissions is discussed above in section IV.C.2. of this proposed rule. The emissions for the 2025 attainment year, by source category, are summarized in Table 2 above.

Ohio has demonstrated maintenance of the 2015 ozone NAAQS through 2038 by projecting that current and future emissions of VOC and NO X for the Cleveland area remain at or below attainment year emission levels. A maintenance demonstration need not be based on modeling. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), Sierra Club v. EPA, 375 F. 3d 537 (7th Cir. 2004). See also 66 FR 53094, 53099 through 53100 (October 19, 2001), 68 FR 25413, 25430-25432 (May 12, 2003).

Ohio is using emissions inventories for the years 2032 and 2038 to demonstrate maintenance. The year 2038 was selected because it is more than 10 years after the expected effective date of the redesignation to attainment, and 2032 was selected to demonstrate that emissions are not expected to spike in the interim between the 2025 attainment year and the 2038 final maintenance year.

To develop emissions inventories for the years 2032 and 2038, Ohio used the same data sources discussed above in section IV.C.2. of this proposed rule.

For its onroad emissions inventory, Ohio again relied upon the ODOT, AMATS, and NOACA's analysis, which used the EPA's MOVES5 model to generate July weekday onroad emissions for 2032 and 2038. This interagency analysis relied on local travel inputs including demographic data, travel demand forecasting, road types, VMT, Vehicle Hours of Travel, vehicle population, and vehicle age, as well as meteorological data. In appendix C of its submittal, Ohio has included a detailed narrative of ODOT, AMATS, and NOACA's methods.

For its point, nonpoint, and nonroad emissions inventories, Ohio again used the EPA's 2022v1 emissions modeling platform for the 2025 attainment year, and the 2032 and 2038 projected inventories. Both the 2032 and 2038 emissions data for the area were derived from the EPA-projected 2032 and 2038 emissions from the 2022v1 modeling platform, version 2032hc and 2038hc respectively, without modification. For both the 2032 and 2038 inventories, to convert annual emissions totals into a value of tons per ozone season day, Ohio EPA calculated conversion factors using the same methodology described in section IV.C.2. of this proposed rule.

Emissions data for the 2017 nonattainment year, 2025 attainment year, 2032 interim year, and 2038 maintenance year are shown in Tables 3 and 4 below. Data are expressed in terms of tons per ozone season day.

As shown in Tables 3 and 4, NO X and VOC emissions in the Cleveland area are projected to decrease by 14.63 tons per ozone season day and 13.17 tons per ozone season day, respectively, between the 2025 attainment year and 2038 maintenance year. Ohio's maintenance demonstration for the Cleveland area shows maintenance of the 2015 ozone NAAQS by providing emissions information to support the demonstration that future emissions of NO X and VOC will remain at or below 2025 emission levels when considering both future source growth and implementation of future controls.

Ohio has committed to continue to operate its ozone monitors in the Cleveland area for the duration of the maintenance period. Ohio remains obligated to meet monitoring requirements, to continue to quality assure monitoring data in accordance with 40 CFR part 58, and to enter all data into the AQS in accordance with Federal guidelines.

Ohio has confirmed that it has the legal authority to enforce and implement the requirements of its SIP. Ohio has further committed that it has the authority to implement the requested SIP revision, which would include the maintenance plan for the Cleveland area. This includes the authority to adopt, implement, and enforce any subsequent emission control measures determined to be necessary to correct future ozone attainment problems.

Verification of continued attainment is accomplished through operation of the ambient ozone monitoring network and the periodic update of the area's emissions inventory. Ohio will continue to operate the ozone monitors located in the Cleveland area. There are no plans to discontinue operation, relocate, or otherwise change the existing ozone monitoring network other than through revisions in the network approved by the EPA.

In addition, to track future levels of emissions, Ohio will continue to develop and submit to the EPA updated emission inventories for all source categories at least once every three years, consistent with the requirements of 40 CFR part 51, subpart A, and in 40 CFR 51.122. The Consolidated Emissions Reporting Rule (CERR) was promulgated by the EPA on June 10, 2002 (67 FR 39602). The CERR was replaced by the Annual Emissions Reporting Requirements on December 17, 2008 (73 FR 76539). The most recent triennial inventory for Ohio was compiled for 2020, and 2023 is in progress. Point source facilities covered by Ohio's emission statement rule, Ohio Administrative Code Chapter 3745-24, will continue to submit VOC and NO X emissions on an annual basis.

Section 175A of the CAA requires that the State adopt a maintenance plan as a SIP revision that includes such contingency measures as the EPA deems necessary to assure that the State will promptly correct a violation of the NAAQS that occurs after redesignation of the area to attainment of the NAAQS. The maintenance plan must identify: the contingency measures to be considered and, if needed for maintenance, adopted and implemented; a schedule and procedure for adoption and implementation; and a time limit for action by the State. The State should also identify specific indicators to be used to determine when the contingency measures need to be considered, adopted, and implemented. The maintenance plan must include a commitment that the State will implement all measures with respect to the control of the pollutant that were contained in the SIP before redesignation of the area to attainment in accordance with section 175A(d) of the CAA.

As required by section 175A of the CAA, Ohio has adopted a contingency plan for the Cleveland area to address possible future ozone air quality problems. The contingency plan adopted by Cleveland has two levels of response, a warning level response and an action level response.

In Ohio's plan, a warning level response will be triggered when an annual fourth-highest monitored value of 0.074 ppm or higher is monitored within the maintenance area. A warning level response will require Ohio to conduct a study. The study would assess whether the ozone value indicates a trend toward a higher ozone value and whether emissions appear to be increasing. The study will evaluate whether the trend, if any, is likely to continue and, if so, the control measures necessary to reverse the trend, taking into account ease and timing of implementation, as well as economic and social considerations. Any implementation of necessary controls in response to a warning level response trigger will occur within 12 months of the conclusion of the most recent ozone season. Additionally, the warning level study will assess whether ozone values were recorded as a result of a wildfire or other event that would qualify for data exclusion under the EPA's exceptional events rule, and the appropriate action level response control measures to follow.

In Ohio's plan, an action level response would be triggered when the fourth-highest monitored value, averaged over two years of 0.071 ppm or higher is monitored within the maintenance area. The action level response will also be triggered by a violation of the NAAQS (a three-year average fourth high value exceeding 0.071 ppm). When an action level response is triggered and not found to be due to an exceptional event, malfunction, or noncompliance with a permit condition or rule requirement, Ohio in conjunction with the metropolitan organization or regional council of governments, will determine what additional control measures are needed to assure future attainment of the 2015 ozone NAAQS. Control measures selected will be adopted and implemented within 18 months from the close of the ozone season that prompted the action level. As part of this response strategy, Ohio may also consider whether new regulations not currently included as part of the maintenance provisions will be implemented in a timely manner and would thus constitute an adequate contingency measure response.

Ohio's plan has a prescriptive process for determining if an action level response was due to an exceptional event. The purpose of this process is to differentiate between exceedances that are not within the State's control ( i.e., exceedances that occur despite the implementation of reasonable measures), and exceedances that are within the State's control and should be included in the trigger calculation. It is important to note that, should Ohio EPA exclude an exceedance from the contingency trigger calculation using this process, it would not constitute the EPA's concurrence under 40 CFR 50.14 that the exceedance was caused by an exceptional event. The exceedance will therefore continue to be included in design value calculations for the area unless Ohio EPA, following opportunity for public comment, submits a request for the EPA to concur on the exceedance as an exceptional event pursuant to 40 CFR 50.14, and the EPA reviews the submittal and formally concurs.

Under this process, following a contingency triggering event, Ohio EPA will review impacted monitoring data to determine if exceptional events occurred, transmit an initial notification to the EPA, prepare a report of any exceptional events, and provide that report to the EPA. 8 Within 5 months of the conclusion of the ozone season, Ohio will complete and submit to the EPA a list of exceedances that occurred during that previous ozone season, and Ohio will designate proposed days as potential exceptional event exceedances, flag the relevant data, and provide initial event description in AQS.

Following submittal of the ozone season reports, the EPA will review the submitted information and notify Ohio if the submitted information is insufficient to support exclusion from the contingency plan trigger calculations, in which case Ohio will begin implementation of potential contingency measures described below. Ohio has the opportunity to provide additional information to the EPA. If the EPA finds this additional information is sufficient to support the conclusion that the exceedance meets the criteria for exclusion from the contingency plan trigger calculation, the EPA will notify Ohio that the trigger calculation will be adjusted. If the resulting value is less than 0.071 ppm, implementation of the contingency plan can be halted unless triggered in a subsequent ozone season.

The EPA proposes to find the contingency provisions of the Cleveland area clearly identify specific contingency measures, contain triggering mechanisms to determine when contingency measures are needed, contain description of the process recommending and implementing contingency measures, and contain specific and appropriate timelines for action. The EPA also proposes to find that the contingency trigger screening process, including the associated the EPA review, is reasonably designed to distinguish between exceedances that are the type that have been deemed exceptional events in the past and exceedance for which new tightened control measures might be effective. The EPA's assessment indicates that the screening process is an appropriate element of the contingency plan for the Cleveland area due to the possibility of exceedances related to wildfire smoke events impacting this area. Thus, the EPA proposes to conclude that the contingency plan in the Cleveland redesignation request is adequate to ensure prompt correction of any violation of the 2015 ozone NAAQS that occurs after redesignation, as required by section 175A(d) of the CAA.

Ohio included the following list of potential contingency measures in its maintenance plan. Ohio may choose measures beyond those on this:

1. Tighten VOC or NO X RACT rules for existing sources covered by Control Technique Guidelines issued after the 1990 CAA;

2. Application of VOC RACT on existing, smaller sources;

3. Alternative fuel and diesel retrofit programs for fleet vehicle operations;

4. VOC or NO X control on new minor sources emitting less than 100 tons per year;

5. Increased ratio of emission offsets for new sources;

6. VOC or NO X emission offsets for new and modified major sources;

7. Adoption of additional NO X RACT for existing combustion sources;

8. Trip reduction programs;

9. Traffic flow and transit improvements; and

10. New or innovative transportation measures that local governments deem appropriate that are not yet widely implemented.

To qualify as a contingency measure, emissions reductions from that measure must not be factored into the emissions projections used in the maintenance plan. Ohio EPA also included a list of potential VOC and NO X sources subject to further future control under VOC RACT and NO X RACT. Control measures are subject to necessary administrative and legal processes such as publication of notices, public comment period, and other measures as required by Ohio law for rulemaking.

The EPA has concluded that Ohio's maintenance plan adequately addresses the five basic components of a maintenance plan: attainment inventory, maintenance demonstration, monitoring network, verification of continued attainment, and a contingency plan. In addition, as required by section 175A(b) of the CAA, Ohio has committed to submit to the EPA an updated ozone maintenance plan eight years after redesignation of the Cleveland area to cover an additional ten years beyond the initial 10-year maintenance period. Thus, the EPA finds that the maintenance plan SIP revision submitted by Ohio for the Cleveland area meets the requirements of section 175A of the CAA, and the EPA proposes to approve it as a revision to the Ohio SIP.

Under section 176(c) of the CAA, new transportation plans, programs, or projects that receive Federal funding or support, such as the construction of new highways, must “conform” to ( i.e., be consistent with) the SIP. Conformity to the SIP means that transportation activities will not cause or contribute to any new air quality violations, increase the frequency or severity of any existing air quality problems, or delay timely attainment or any required interim emissions reductions or any other milestones. Regulations at 40 CFR part 93 set forth the EPA policy, criteria, and procedures for demonstrating and ensuring conformity of transportation activities to a SIP. Transportation conformity is a requirement for nonattainment and maintenance areas.

Under the CAA, States are required to submit, at various times, control strategy SIPs for nonattainment areas and maintenance plans for areas seeking redesignations to attainment of the ozone standard and maintenance areas. See the SIP requirements for the 2015 ozone standard in the EPA's December 6, 2018 (83 FR 62998), implementation rule. These control strategy SIPs (including RFP and attainment plans) and maintenance plans must include motor vehicle emissions budgets for criteria pollutants, including ozone, and their precursor pollutants (VOC and NO X ) to address pollution from onroad transportation sources. The budgets are the portion of the total allowable emissions that are allocated to highway and transit vehicle use that, together with emissions from other sources in the area, will provide for attainment or maintenance. See 40 CFR 93.101.

Under 40 CFR part 93, a budget for an area seeking a redesignation to attainment must be established, at a minimum, for the last year of the maintenance plan. A State may adopt budgets for other years as well. The budget serves as a ceiling on emissions from an area's planned transportation system. The budget concept is further explained in the preamble to the November 24, 1993 (58 FR 62188), Transportation Conformity Rule. The preamble also describes how to establish the budget(s) in the SIP and how to revise the budget(s), if needed, after initially establishing a budget in the SIP.

As discussed earlier, Ohio's maintenance plan includes NO X and VOC budgets for the Cleveland area for 2032, which is an interim year, as well as 2038, which is the last year of the maintenance period. The EPA has reviewed Ohio's NO X and VOC budgets for the area and, in this action, is proposing to approve them. 9 We are also starting the adequacy review process for these budgets to determine if they meet the adequacy criteria in the transportation conformity regulations (40 CFR 93.118(e)(4)). Ohio's December 8, 2025, maintenance plan submission, including the budgets for this area, is available for public comment via this proposed rulemaking. The submission was endorsed by the Governor's designee and Ohio provided opportunity for a public hearing. The budgets were developed as part of an interagency consultation process which includes Federal, State, and local agencies. The budgets were clearly identified and precisely quantified. These budgets, when considered together with all other emissions sources, are consistent with maintenance of the 2015 ozone NAAQS.

Throughout this document whenever “we,” “us,” “our,” or “Agency” is used, we mean the EPA.

The EPA redesignated the Canton-Stark County, Ohio area from an unclassifiable/attainment area to a nonattainment area for the 2008 Pb NAAQS pursuant to CAA section 107(d)(3), effective April 10, 2023. The redesignation was based on ambient air quality monitoring that resulted in a 2019-2021 design value of 0.40 micrograms per cubic meter (μg/m 3 ), exceeding the 2008 Pb NAAQS of 0.15 μg/m 3 . The ambient air quality data was provided by a source-oriented monitor near a plant owned and operated by Republic Steel in Canton, Ohio (Republic Steel—Canton Plant), which manufactured leaded steel and other steel products at the time. 1

The redesignation of the Canton, Ohio area from unclassifiable/attainment to nonattainment for the 2008 Pb NAAQS imposed certain planning requirements on the State of Ohio to reduce Pb concentrations within this area. 88 FR 14920, March 10, 2023. These included the requirement under CAA sections 191(a) and 192(a) to submit, within 18 months of the redesignation to nonattainment, a revision to the Ohio State Implementation Plan (SIP) which demonstrates attainment of the 2008 Pb NAAQS as expeditiously as practicable, but no later than 5 years after April 10, 2023, the effective date of redesignation to nonattainment. 2

On August 10, 2023, the parent company of Republic Steel, Grupo Simec, publicly announced the Republic Steel—Canton Plant would be idled indefinitely.

On September 10, 2023, Grupo Simec announced the Republic Steel—Canton Plant would permanently close, and all associated air permits were terminated effective July 26, 2024.

On September 19, 2024, Ohio EPA submitted a revision to its SIP for the 2008 Pb NAAQS in the Canton Nonattainment Area, which was comprised of an attainment plan with ambient air monitoring data, emissions inventory, attainment demonstration, and contingency measures. (Ohio's 2024 Canton Pb SIP Revision)

By the end of 2024, ambient air monitoring demonstrated that airborne Pb levels had declined to 0.00 μg/m 3 and that the three-year design value for 2022-2024 for the Canton Nonattainment Area had achieved 0.15 μg/m 3 , thereby meeting the 2008 Pb NAAQS.

Then, on April 25, 2025, Ohio EPA provided the first 10-year maintenance plan for keeping the Canton Nonattainment Area in attainment of the 2008 Pb NAAQS as required under CAA section 175A and submitted a request to the EPA to redesignate the Canton Nonattainment Area from nonattainment to attainment. (Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request)

In this rulemaking, the EPA is proposing to approve all of Ohio's required SIP elements simultaneously in conjunction with proposing to act in accordance with Ohio's request to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS. Specifically, the EPA is proposing the following separate, but related, actions:

1. To approve Ohio's September 19, 2024, Canton Pb SIP Revision as meeting the applicable requirements of CAA sections 110(a)(2)(D)(i)(I), 110(a)(2)(I), 110(a)(2)(K), 110(l), 172, 191, and 192(a) and 40 CFR 51 subparts F and G. ( See section II.D. of this preamble.)

2. To determine that the Canton Nonattainment Area is attaining the 2008 Pb NAAQS. ( See section III.A. of this preamble.)

3. To approve Ohio EPA's comprehensive Pb emissions inventory for the Canton Nonattainment Area as meeting the applicable requirements of CAA section 172(c)(3). ( See section II.A.2.e. of this preamble.)

4. To approve Ohio's 2025 Canton Pb Maintenance Plan as meeting the applicable requirements of CAA section 175A. ( See section III.B. of this preamble.)

5. To determine that Ohio's 2024 Canton Pb SIP Revision as well as Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request have met the applicable requirements for the EPA to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS under CAA section 107(d)(3)(E). ( See section IV.C. of this preamble.)

6. To act in accordance with Ohio's April 25, 2025 Canton Pb Redesignation Request and to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS in accordance with CAA section 107(d)(3)(E)(i)-(v). ( See section IV.C. of this preamble.)

In proposing these separate actions, we note that the EPA has previously determined that approval actions on SIP elements for a nonattainment area and the associated redesignation may occur simultaneously. 3 4 Information supporting each of these actions is further summarized and discussed in the EPA's December 11, 2025, Technical Support Document (TSD) for this proposed rulemaking, which is included in the docket.

Lead (Pb) is a metal found naturally in the environment, as well as in some manufactured products. Industrial sources of Pb emissions include industrial, commercial, and institutional boilers as well as utility boilers, iron and steel foundries, and primary Pb smelters. 5 6 7 The major sources of Pb for air emissions have historically been from fuels used in industrial sources and on-road motor vehicles, such as cars and trucks. As a result of the EPA's regulatory efforts to remove Pb from on-road motor vehicle gasoline, emissions of Pb from the transportation sector declined by 95 percent between 1980 and 1999, and levels of Pb in the air generally decreased by 98 percent between 1980 and 2014. 8 More recently, the predominant sources of Pb emissions in the ambient air are from ore and metals processing as well as piston-engine aircraft operating on leaded aviation fuel. 9

Pb is generally emitted in the form of particles, which can end up being deposited in water, soil, and dust. This deposited Pb, when disturbed, may be re-entrained into the ambient air. People may be exposed to Pb by inhaling it or by ingesting Pb-contaminated food, water, soil, or dust. Pb may have serious public health effects and, depending on the level of exposure, can adversely affect the nervous system, kidney function, immune system, cardiovascular system, as well as reproductive and developmental systems. Infants and young children are especially sensitive to even low levels of Pb, which may contribute to behavioral problems, learning deficits, and lowered intelligence quotient. 10 11

On November 12, 2008 (73 FR 66964), the EPA established the 2008 primary and secondary Pb NAAQS at 0.15 μg/m 3 based on a maximum arithmetic three-month mean concentration for a three-year period. 40 CFR 50.16. The EPA refers to this maximum rolling three-month average over a three-year period as the “design value,” and the design value is to be rounded to two significant figures using conventional rounding methodology. A violation of the 2008 Pb NAAQS occurs if any arithmetic three-month mean concentration is greater than 0.15 μg/m  3 . See 72 FR 71488; 71541, December 17. 2007. See also 40 CFR 50.16.

After setting or revising any NAAQS, the EPA is required by CAA section 107(d) to designate areas throughout the nation as attaining or not attaining the NAAQS. The EPA initially designated all areas of the country as “unclassifiable,” “unclassifiable/attainment,” or “nonattainment” for the 2008 Pb NAAQS in two rounds on November 16, 2010, based on air quality monitoring data for 2007-2009, and on November 8, 2011, based on monitoring data for 2008-2010. 12

In the November 8, 2011 action, the EPA originally designated Stark County, Ohio, including the Canton area, along with the remaining areas of Ohio, as unclassifiable/attainment based on monitoring data for 2008-2010. 13

Effective April 10, 2023, the EPA redesignated a defined area within Canton, Stark County, Ohio as nonattainment for the 2008 Pb NAAQS pursuant to CAA section 107(d)(3). 14 The redesignation was based on ambient air quality monitoring from the Republic Steel monitoring site (Air Quality System (AQS) ID 39-151-0024) that resulted in a Pb 2019-2021 design value of 0.40 μg/m 3 , exceeding the 2008 Pb NAAQS of 0.15 μg/m 3 .

The Canton Nonattainment Area for the 2008 Pb NAAQS surrounds the Republic Steel—Canton Plant located at 2633 Eighth Street NE in Canton, Ohio. The boundaries of the Canton Nonattainment Area for the 2008 Pb NAAQS encompass the portions of Stark County that are bounded on the north by State Route OH-153 (12th Street NE; Mahoning Road), on the east by Broadway Avenue, on the south by State Route OH-172 (Tuscarawas Street E; Lincoln Street E), and the west by State Route OH-43—Northbound (Cherry Avenue NE). The jurisdictional boundaries in Ohio comprise a portion of the city of Canton, a portion of the city of Louisville, a portion of Canton Township, a portion of Osnaburg Township, a portion of Nimishillen Township, and a portion of Plain Township.

Both before and after the Canton area was designated as nonattainment for the 2008 Pb NAAQS, Ohio EPA, Canton APC, 15 Republic Steel, Stark County Court of Common Pleas, United States District Court for the Northern District of Ohio, and the EPA took various actions that addressed Pb emissions from the Republic Steel—Canton Plant and the ambient air quality in the Canton area.

In the first of these actions, Ohio EPA issued permit modifications on December 2, 2016, and October 18, 2017, to set federally enforceable restrictions on Pb emissions, and required Republic Steel to submit a written proposal of actions if Pb monitoring reached 0.11 μg/m 3 or greater as a three-month average. Ohio EPA also issued Director's Final Findings and Orders to Republic Steel on June 29, 2018, April 30, 2019, May 14, 2019, and February 26, 2021, as well as a letter on June 11, 2021, which included various requirements including suspending leaded steel production, submitting an investigative report on elevated Pb concentrations, providing an action plan to reduce Pb emissions, evaluating options to control fugitive Pb emissions, and taking specific actions based on certain daily monitored Pb levels. 16 In April 2022, Ohio EPA and Canton APC installed a second monitoring site across the street from the Republic Steel—Canton Plant known as the Republic Community monitoring site (AQS ID 39-151-0025).

On November 3, 2021, the EPA issued a notice of violation to the Republic Steel—Canton Plant for violating the terms of the facility's air permit regarding the FlexCast Vacuum Tank Degasser by exceeding the permitted emissions limit for Pb during Pb degassing, failing to perform an emissions test for Pb, and failing to perform parametric monitoring and recordkeeping. 17 On March 10, 2023, the EPA then redesignated the area in Canton surrounding the Republic Steel—Canton Plant property from unclassifiable/attainment to nonattainment for the 2008 Pb NAAQS. 18

On August 10, 2023, the parent company of Republic Steel, Grupo Simec, publicly announced the Republic Steel—Canton Plant would be idled indefinitely. On September 10, 2023, Grupo Simec announced the Republic Steel—Canton Plant would permanently close. The permanent and enforceable closure of the Canton Plant was subsequently required by a Final Consent Order and Final Judgment Entry that was filed in the Stark County Court of Common Pleas on December 12, 2023. 19 In this Final Consent Order, Republic Steel agreed to an enforceable, permanent cessation of operations and to submit to Ohio EPA a request for the permanent shutdown and termination of all air permits associated with the facility within 30 days.

In a letter dated January 11, 2024, Republic Steel requested the permanent shutdown of all emission units requiring air permits and the termination of the associated air permits at the Republic Steel—Canton Plant, except for those associated with the temporary use of certain emission units in connection with the facility shut down activities. Ohio EPA and Canton APC approved this request on January 22, 2024. On July 26, 2024, Republic Steel requested the permanent shutdown of all remaining emission units requiring air permits and the termination of the associated air permits at the Republic Steel—Canton Plant. Ohio EPA and Canton APC also approved this request and terminated the remaining associated air permits effective July 26, 2024.

On September 17, 2024, Ohio EPA issued Director's Final Findings and Orders  20 requiring Republic Steel or any subsequent owner or operator of the Canton Plant to take certain actions to control fugitive dust if the Republic Steel or Republic Community monitoring sites recorded Pb daily average concentrations of 0.75 μg/m 3 or greater or 1-month average concentrations of 0.10 μg/m 3 or greater. These Orders also required Republic Steel or any subsequent owner or operator to provide a plan to Ohio EPA for approval for sitewide control of fugitive dust prior to undertaking any activities related to demolition or deconstruction of any portion of the facility.

All States must submit SIPs or SIP revisions to show they have the basic air quality management program components in place to implement a new or revised NAAQS, as specified in CAA section 110(a)(1). These plans are called “infrastructure SIPs.”

For areas designated nonattainment for a specific NAAQS, States must also submit “nonattainment plans” that outline the strategies and emissions control measures and demonstrate how the area will improve in air quality as well as attain and maintain the NAAQS. 21 22 Nonattainment plans must meet the applicable requirements of the CAA, specifically CAA title I, section 110 and part D. The EPA's regulations governing SIP submissions are set forth at 40 CFR part 51 with general procedural requirements under subpart F and specific control strategy requirements under subpart G for attaining and maintaining the NAAQS.

CAA section 110 contains the general requirements for SIPs for attaining and maintaining the national and primary and secondary NAAQS.

Under CAA sections 110(a)(1) and (2), States are required to submit “infrastructure SIPs” to ensure that they have the basic air quality management program components in place to provide for implementation, maintenance, and enforcement of the NAAQS, including the 2008 Pb NAAQS. In this regard, the EPA approved Ohio's infrastructure SIP for the 2008 Pb NAAQS on September 22, 2014, and on February 17, 2015. 23 24 25 For the 2008 Pb NAAQS, Ohio's infrastructure SIP addressed CAA sections 110(a)(2)(A) through (H), and (J) through (M) except the Prevention of Significant Deterioration (PSD) and New Source Review (NSR) requirements in CAA sections 110(a)(2)(C), (D)(i)(II), and (J), as well as the visibility protection portion of (J). CAA sections 110(a)(2)(I) and (K), which specifically address the nonattainment plan provisions, are addressed in sections II.B and II.D of this preamble and in sections 4.1, 4.2, and 4.4 of the TSD.

As part of the broader set of the infrastructure requirements, CAA section 110(a)(2)(D) requires SIPs to contain measures to prevent sources of emissions within the State from significantly contributing to air quality problems in another State or internationally as well as from interfering with programs to prevent significant deterioration of air quality or to protect visibility at mandatory Class I Federal areas in any other State. The EPA has historically referred to these as “transport SIPs.” Within CAA section 110(a)(2)(D)(i), there are four so-called “prongs.” CAA section 110(a)(2)(D)(i)(I) contains prongs 1 and 2, while CAA section 110(a)(2)(D)(i)(II) includes prongs 3 and 4.

With respect to prongs 1 and 2, analyses in Ohio's 2011 Infrastructure SIP and 2024 Canton Pb SIP Revision found no Pb sources in Ohio that would interfere with attainment or maintenance of the 2008 Pb NAAQS in a neighboring State. As such, consistent with the EPA's guidance  26 and prior actions, 27 the EPA proposes to find that Ohio's September 19, 2024 and April 25, 2025, SIP Revisions meet the requirements of CAA section 110(a)(2)(D)(i)(I).

With respect to prong 3 in addressing measures to prevent significant deterioration of air quality, the EPA previously approved Ohio's PSD permitting program  28 and NSR program in nonattainment areas  29 for all new major sources and major modifications in Ohio to help achieve the 2008 Pb NAAQS. 30

With respect to prong 4 and CAA section 110(a)(2)(J), the EPA guidance  31 32 explains that the visibility impairment from Pb emissions in mandatory Class I Federal areas would be negligible and these requirements may be satisfied by a State's approved regional haze SIP revision. 33 In this regard, the EPA previously approved Ohio's regional haze SIP revisions for the first and second implementation periods. 34 35

CAA section 110(l) contains two main provisions applicable to SIPs, including nonattainment plans.

First, CAA section 110(l) requires that each SIP revision submitted by a State must be adopted by a State after reasonable notice and public hearing. To meet this requirement, on July 8, 2024, Ohio EPA notified the public and provided an opportunity for public comment and hearing on its proposed Pb SIP revision for an attainment plan  36 and attainment demonstration for the Canton Pb Nonattainment Area. The public comment period closed on August 7, 2024, and no comments were received during this time. However, on August 8, 2024, Republic Steel requested an additional comment period until August 21, 2024, which was granted by Ohio EPA. With no hearing requested, Ohio submitted its Pb SIP revision for an attainment plan and attainment demonstration for the Canton Pb Nonattainment Area to the EPA on September 19, 2024, which included the comments received and Ohio EPA's responses in appendix P. Then, on March 17, 2025, Ohio EPA notified the public and provided an opportunity for public comment and hearing on its proposed redesignation request and proposed Pb SIP revision for a maintenance plan for the Canton Nonattainment Area. The public comment period closed on April 18, 2025, and, with no hearing requested or comments received, Ohio submitted its redesignation request and Pb SIP revision to the EPA on April 25, 2025. As such, the EPA proposes to find that Ohio has met this requirement of CAA section 110(l) with its September 19, 2024, and April 18, 2025, SIP revisions.

Second, under CAA section 110(l), the EPA may not approve a SIP if it would interfere with any applicable requirement concerning NAAQS attainment, reasonable further progress toward attainment, or any other applicable requirement of the CAA. This requirement is often referred to the “anti-backsliding” provision of the CAA. As demonstrated in sections II.A.2.c, II.B, III.A of this preamble and in sections 4.1.2.3, 4.2.2, and 5.1 of the TSD, Ohio's September 19, 2024, and April 18, 2025, SIP Revisions are not a relaxation of any existing requirements and are expected to preserve or improve the ambient air quality in the Canton Nonattainment Area as it existed when the area was designated as nonattainment on April 10, 2023. Thus, the EPA proposes to find that Ohio's September 19, 2024, and April 18, 2025, SIP revisions meet the anti-backsliding provisions of CAA sections 110(l).

The EPA does not expect infrastructure SIP submittals to include regulations or emission limits developed specifically for attaining a particular NAAQS. To address plan requirements for nonattainment areas, there are two elements of CAA section 110(a)(2) pertaining to part D in title 1 of the CAA that are outside the scope of infrastructure SIPs. The first is CAA section 110(a)(2)(C) to the extent it refers to a permit program known as “nonattainment new source review” (nonattainment NSR) under part D of title I of the CAA, and the second is CAA section 110(a)(2)(I) in its entirety. 37 For the first of these two elements, the EPA previously approved Ohio's SIP revisions comprising the State's rules for nonattainment NSR procedures on December 6, 2001. 38 For the second of these two elements, the EPA's “SIP Lean Toolkit for Collaboration Between EPA and Air Agencies,” December 6, 2019 (2019 SIP Lean Toolkit)  39 identifies CAA sections 172, 191, and 192 as the applicable planning requirements specific to Pb nonattainment areas. Each of these are discussed below.

In areas designated as not attaining a particular NAAQS, CAA section 172 includes nonattainment plan provisions that require States to submit SIPs which demonstrate the affected area will attain the relevant NAAQS as expeditiously as practicable, but no later than the applicable statutory attainment date. To support such an attainment demonstration for Pb nonattainment plans, the EPA's 2019 SIP Lean Toolkit specifies the applicable provisions of the CAA as sections 172(a)(2), (b), (c)(1) through (c)(6), and (c)(9). As discussed in sections II.A.2.a.-h. of this preamble and in sections 4.1.2.1-4.1.2.8 of the TSD, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision meets each of these applicable provisions of CAA section 172.

For a nonattainment area, CAA section 172(a)(2) establishes that the attainment date shall be the date by which attainment can be achieved as expeditiously as practicable, but no later than 5 years from the date the area was designated nonattainment, unless the Administrator determines an extension of up to 10 years is appropriate. The effective date of the redesignation of the Canton area to nonattainment was April 10, 2023, 40 and 5 years from that date would be April 10, 2028. The EPA proposes to find that Ohio EPA appropriately oriented the attainment demonstration in its 2024 Canton Pb SIP Revision, as discussed in section II.B. of this preamble and in sections 4.1.2.1 and 4.2.2 of the TSD, to ensure attainment of the 2008 Pb NAAQS as expeditiously as practicable and earlier than the April 10, 2028, date by projecting an attainment date of July 1, 2025. In section III.A. of this preamble and in section 5.1 of the TSD, the EPA also examines the actual monitored Pb concentrations and proposes to determine that, as of the end of 2024, the Canton Nonattainment Area achieved attainment of the 2008 Pb NAAQS as expeditiously as practicable, approximately 1.5 years after the April 10, 2023, effective date of the redesignation, and earlier than the April 10, 2028, date based on the full 5 years allowed under CAA section 172(a)(2).

Under CAA section 172(b) and consistent with CAA section 191(a), the Administrator required Ohio to submit a SIP revision for the Canton Nonattainment Area within 18 months of the April 10, 2023, effective date of the nonattainment redesignation. 41 The EPA proposes to find that Ohio EPA met this requirement by submitting its SIP revision for an attainment plan in the Canton Nonattainment Area on September 19, 2024, which was sooner than 18 months from the April 10, 2023, effective date of the nonattainment designation.

CAA section 172(c)(1) requires plans for all nonattainment areas to provide for the implementation of all reasonably available control measures (RACM), including reasonably available control technology (RACT) for existing sources, as expeditiously as practicable and to provide for attainment of the NAAQS.

Ohio's 2024 Canton Pb SIP Revision identified two stationary sources of Pb emissions located within the boundaries of the Canton Nonattainment Area that report to Ohio EPA's Emissions Inventory System and the National Emissions Inventory: (1) Republic Steel—Canton Plant and (2) United Rolls, Inc. Ohio's 2024 Canton Pb SIP Revision describes United Rolls, Inc. as an iron and steel roll manufacturing facility located at 1400 Grace Avenue Northeast, Canton, Ohio. Based on emissions data from 2017 to 2023, only the Republic Steel—Canton Plant met the EPA's recommended threshold of 0.5 tons per year (tpy) for a RACT analysis. 42 43 As such, Ohio EPA considered potential RACM applications for this facility as identified in the 2012 Pb RACM Guidance  1 for fugitive dust control.

Ohio EPA documented the decline in Pb emissions from the Republic Steel—Canton Plant from 4.3561 tons in 2020, to 0.8249 tons in 2021, to 0.1398 tons in 2022, to 0.0672 in 2023. 44 Ohio EPA also documented the corresponding sharp decrease in monitored Pb concentrations and improvement in air quality. The three-month rolling average Pb concentrations measured at the Republic Steel monitoring site have decreased significantly from 0.40 μg/m 3 in 2021 to 0.00 μg/m 3 in 2024. Over the course of one month, between the time that Republic Steel was idled in August 2023 to the time the shutdown was announced in September 2023, the three-month rolling average Pb concentrations declined from 0.11 μg/m 3 to 0.03 μg/m 3 . Further decreases occurred over the next two months with Pb concentrations decreasing from 0.01 μg/m 3 in October 2023 to 0.00 μg/m 3 in November 2023, where the ambient air concentrations have remained since. 45 The EPA notes that Ohio fully demonstrated that these improvements in ambient air quality are due to permanent and enforceable reductions in emissions resulting from the permanent shutdown of all emission units requiring air permits and the termination of the associated air permits at the Republic Steel—Canton Plant, which became effective July 26, 2024. Additionally, Ohio EPA documented that no source of Pb emissions would be allowed to construct, reopen, modify, or reconstruct without meeting all applicable NSR requirements in Ohio's SIP at 40 CFR 51.1870(c) as a new source.

Given the permanent shutdown of all emission units requiring air permits at the Republic Steel—Canton Plant, Ohio EPA reasoned that any fugitive Pb-bearing dust control measures implemented outside of activities associated with potential cleanup, shutdown, deconstruction, and/or remediation at the facility would likely have no significant impact on monitored ambient Pb concentrations at the Republic Steel or Republic Community monitoring sites. Consistent with the 2008 Pb NAAQS Final Rule, 46 Ohio determined, and the EPA agrees, that no RACM exists that would appreciably reduce fugitive dust emissions from the Republic Steel—Canton Plant or expedite attainment of the 2008 Pb NAAQS as this time.

However, to meet the requirements of CAA section 172(c)(9) and 175A, Ohio EPA is requiring that the Republic Steel—Canton Plant implement certain contingency measures, similar to the measures identified in the 2012 Pb RACM Guidance, during cleanup and/or remediation activities if either the Republic Steel or Republic Community monitoring sites measure ambient Pb concentrations above specific trigger levels. These contingency measures are set forth in the Ohio EPA Director's Final Findings and Orders, effective September 17, 2024, 47 and are addressed in sections II.A.2.h. and III.B. of this preamble and in sections 4.1.2.8 and 5.2.5 of the TSD.

As discussed above and consistent with the 2008 Pb NAAQS final rule, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision has met the RACM provisions of CAA section 172(c)(1).

CAA section 172(c)(2) sets forth that nonattainment plans must require reasonable further progress (RFP)  48 in annual incremental reductions of emissions to ensure attainment by the attainment date. While the EPA believes that RFP for Pb nonattainment areas should yield significant emission reductions under an ambitious compliance schedule, the Canton Nonattainment Area has already achieved significant permanent and enforceable reductions in Pb emissions, declining from 4.4224 tpy in 2020 to 0.1508 tpy in 2023 as shown in Table 1 and discussed in section III.B. of this preamble and in sections 4.1.2.3 and 5.2.2 of the TSD. These reductions have led to sustained monitored ambient Pb concentrations below the 2008 Pb NAAQS substantially earlier than the applicable attainment date, as demonstrated in Tables 4 and 5 of the TSD. With the permanent and enforceable emission reductions already achieved resulting in sustained ambient Pb concentrations below the 2008 Pb NAAQS, the EPA is proposing to find that RFP has already been made and that Ohio 2024 Canton Pb SIP Revision has met the RFP provisions of CAA section 172(c)(2).

CAA section 172(c)(3) requires SIPs for nonattainment areas to include a comprehensive, accurate, and current inventory of actual emissions from all sources of the relevant pollutants in the nonattainment areas. In terms of Pb emissions inventories, the threshold level of the emissions inventory reporting requirement for point sources in Pb SIP inventories is 0.5 tpy consistent with the 2008 Pb NAAQS Final Rule, 49 40 CFR 51.117(e)(1), the Air Emissions Reporting Requirements (AERR), 50 and 40 CFR part 58 appendix D. As shown in Table 1, Ohio's 2024 Canton Pb SIP Revision included a comprehensive Pb emissions inventory for the Canton Nonattainment Area for the years 2017 through 2023, which accounted for emissions from the Republic Steel—Canton Plant, which was the only source in the Canton Nonattainment Area with Pb emissions of 0.5 tpy or greater, as well as United Rolls, Inc. even though its emissions were below the inventory threshold. 51 Ohio clarified that no area, mobile, non-road, or marine/air/rail sources of Pb emissions contribute to nonattainment in the Canton Nonattainment Area. The EPA is proposing to approve the Pb emissions inventory for the Canton Nonattainment Area that was submitted by Ohio EPA in Table 2 and appendix C of the 2024 Canton Pb SIP Revision and in Table 3 of the 2025 Canton Pb Redesignation Request, including the 2020 base year Pb emission inventory, as fully meeting the comprehensive emissions inventory requirement of CAA section 172(c)(3) for sources that emit more than 0.5 tpy Pb as required by 40 CFR 51.117(e)(1).

CAA section 172(c)(4) requires the identification and quantification of emissions from any new or modified stationary source in the nonattainment area and a demonstration that such emissions will not interfere with attainment by the applicable attainment date. CAA section 172(c)(5) requires permits for the construction and operation of new and modified major stationary sources anywhere in the nonattainment area. In this regard, as addressed in section II.A.1.a. of this preamble and in section 4.1.1.1 of the TSD, the EPA previously approved Ohio's PSD permitting program  52 and NSR permitting program for nonattainment areas  53 for all new major sources and major modifications in Ohio to help achieve the 2008 Pb NAAQS. 54 Therefore, Ohio has already met the applicable requirements of CAA sections 172(c)(4) and (c)(5).

CAA section 172(c)(6) requires the nonattainment plan to include enforceable emission limitations and other control measures, means, or techniques, as well as schedules and timetables for compliance as necessary to provide for attainment by the attainment date.

To account for control measures that were put into place as expeditiously as possible, Ohio's 2024 Canton Pb SIP Revision fully documented the permanent shutdown of all emission units requiring air permits at the Republic Steel—Canton Plant and the termination of all associated air permits effective July 26, 2024. Additionally, as discussed in section II.A.2.h. of this preamble and in section 4.1.2.8 of the TSD, Ohio's 2024 Canton Pb SIP Revision contains contingency measures that would be enacted within specified timeframes in the event ambient air monitoring exceeds certain Pb levels to ensure attainment of the 2008 Pb NAAQS by the attainment date. As such, Ohio ensured appropriate enforceable control measures and timetables were put into place as expeditiously as practicable to result in three years of monitored clean data by the attainment date. Therefore, the EPA is proposing that Ohio's 2024 Canton Pb SIP Revision has met the applicable requirements of CAA section 172(c)(6) for the Canton Nonattainment Area.

CAA section 172(c)(9) requires that nonattainment plans contain contingency measures that take effect without further action by the State or the Administrator if the nonattainment area fails to make RFP or attain the NAAQS by the attainment date.

Ohio's 2024 Canton Pb SIP Revision contains contingency measures consistent with the EPA's examples  55 and 2012 Pb RACM Guidance for fugitive Pb-bearing dust that are geared toward ensuring attainment by the attainment date, including additional watering, additional cleaning, building/equipment repairs, additional closing of building openings, updated work practices, and/or application of chemical suppressant to control fugitive dust from the facility. These contingency measures would be triggered if monitored Pb concentrations at either the Republic Steel or Republic Community monitoring sites exceed certain levels and would require certain actions by Republic Steel or any subsequent owner or operator of the Canton Plant. Ohio EPA placed these contingency measures in the December 12, 2023, Final Consent Order and Final Judgment Entry as well as the September 17, 2024, Ohio EPA Director's Final Findings and Orders.

Under the contingency measures of the December 12, 2023, Final Consent Order, the action level responses are triggered in the event the individual daily value exceeds 0.75 μg/m  3 and/or the three-month average Pb concentration exceeds the 2008 Pb NAAQS of 0.15 μg/m  3 . The required responses include both immediate actions to cease activities possibly contributing to the NAAQS exceedance as well as certain other actions within 14 days.

The September 17, 2024, Director's Final Findings and Orders set forth an additional action level for measured ambient Pb concentrations at 0.10 μg/m  3 , which would trigger these contingency measures. These Orders also require a sitewide plan to be approved by Ohio EPA prior to undertaking activities related to demolition or deconstruction to further ensure control of fugitive Pb-bearing dust. Importantly, since ownership of the Canton Plant may one day be transferred, the EPA reiterates that the contingency measures contain legally binding assurances that the obligations contained therein apply to Republic Steel or any subsequent owner or operator of the Canton Plant. For all these reasons and as further addressed in section 4.1.2.8 of the TSD, the EPA is proposing to find that Ohio's contingency measures in the 2024 Canton Pb SIP Revision satisfy the applicable requirements of CAA section 172(c)(9).

CAA section 176(c) requires States to establish criteria and procedures in the applicable SIPs to ensure that federally supported or funded activities are consistent with (“conform to”) the NAAQS air quality planning goals. The requirements of CAA 176(c) apply to transportation plans, programs and projects developed, funded or approved under title 23 of the U.S. Code and the Federal Transit Act  56 (transportation conformity) as well as to all other federally supported or funded projects (general conformity). In this regard, the EPA approved Ohio's general conformity SIP on February 12, 1996. 61 FR 9644; 9646, March 11, 1996. In the 2008 Pb NAAQS Final Rule, the EPA determined that “In light of the elimination of Pb additives from gasoline, transportation conformity does not apply to the Pb NAAQS.” 73 FR 66964; 67043, November 12, 2008.

CAA section 191(a) directs States to submit SIPs to the EPA for areas designated as nonattainment with respect to the primary NAAQS for sulfur oxides, nitrogen dioxide, or Pb within 18 months of the effective date of the designation. The EPA proposes to find that Ohio EPA met this requirement by submitting its attainment plan and attainment demonstration for the Canton area on September 19, 2024, which was sooner than 18 months from the April 10, 2023, effective date of the nonattainment designation.

CAA section 192(a) requires that SIPs for nonattainment areas must provide for attainment of the relevant NAAQS as expeditiously as practicable, but no later than 5 years from the effective date of the nonattainment designation. Ohio's 2024 Canton Pb SIP Revision includes an attainment demonstration for the Canton Nonattainment Area that demonstrated attainment of the 2008 Pb NAAQS as expeditiously as practicable, by July 1, 2025, and in less than 5 years from the April 10, 2028, effective date. As such, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision meets the applicable requirements of CAA section 192(a).

To demonstrate future attainment of the NAAQS by predicting the effect of air emissions on ambient air quality, States may be required, under CAA section 110(a)(2)(K), to include air quality modeling and the associated data in a SIP submittal.

To demonstrate that Ohio's control strategy will provide for timely attainment of the 2008 Pb NAAQS as expeditiously as practicable, but no later than the April 10, 2028, attainment date, Ohio EPA's attainment demonstration included a modeling analysis, which followed the procedures in the EPA's Guideline on Air Quality Models. 57 Although all emission units requiring permits at the Republic Steel—Canton Plant have been permanently shut down, Ohio EPA performed an atmospheric dispersion modeling analysis using AERMOD which accounted for potential cleanup and/or remediation efforts at the site in the future. As discussed in more detail in section 4.2.2 of the TSD and in appendix M of Ohio's 2024 Canton Pb SIP Revision, the model predicted a maximum three-month rolling average Pb concentration for the Canton Nonattainment Area of 0.099440 μg/m 3 , a value below 0.15 μg/m 3 that demonstrates attainment of the 2008 Pb NAAQS will be attained by April 10, 2028. Based on results of the modeling and Ohio EPA's approach, the EPA proposes to find that Ohio's attainment demonstration satisfies the requirements under CAA section 110(a)(2)(K) by performing appropriate air quality modeling and providing the associated data.

The EPA's regulations governing the preparation, adoption, and submittal of SIPs are set forth at 40 CFR part 51.

Subpart F  58 contains the general procedural requirements for all SIPs that cover definitions, stipulations, public hearings, submission of plans, revisions, and approval of plans. How Ohio's 2024 Canton Pb SIP Revision met the State's obligations under these general procedural requirements is addressed under the discussion of CAA section 110(l) in section II.A. of this preamble and in section 4.1.1 of the TSD.

Subpart G  59 addresses the control strategy generally applicable to SIPs as well as specific additional requirements for Pb nonattainment areas. How Ohio's 2024 Canton Pb SIP Revision addressed each of the applicable requirements of subpart G in 40 CFR 51.110 through 51.117, including specific requirements for Pb nonattainment areas, is described in section II.C. of this preamble and in section 4.3 of the TSD. Based on this information, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision adequately addressed each of the requirements of 40 CFR 51.110 through 51.117.

Based on the EPA's review and evaluation of the information in sections II.A.-II.C. of this preamble of this preamble and in sections 4.1-4.3 of the TSD, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision satisfies the applicable requirements of CAA sections 110(a)(2)(D)(i)(I), 110(a)(2)(I), 110(a)(2)(K), 110(l), 172, 191, and 192(a) to fully address the nonattainment plan provisions for the Canton Nonattainment Area.

As shown in Table 2, Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request documented the Canton Nonattainment Area had monitored attainment and achieved a design value of 0.15 μg/m 3 for the most recent three-year period 2022-2024, thereby attaining the 2008 Pb NAAQS of 0.15 μg/m 3 . Furthermore, data in AQS for 2025 (January through September) indicate that the area continues to show concentrations consistent with attainment of the 2008 Pb NAAQS. The complete, quality-assured, and certified ambient air monitoring data from the Republic Steel monitoring site along with the three-month rolling averages and the associated design values are included in Ohio's 2025 Canton Pb Redesignation Request as appendix D as well as Tables 4, 5, and 6 of the TSD.

Based on a review of the data in accordance with the 40 CFR part 50, appendix R, and 40 CFR part 58, and the design value for 2022-2024, the EPA is proposing to determine that the Canton Nonattainment Area is attaining the 2008 Pb NAAQS.

Since the Canton Nonattainment Area has monitored attainment of the 2008 Pb NAAQS as discussed in section III.A. of this preamble and in section 5.1 of the TSD, Ohio's April 25, 2025 SIP Revision included a maintenance plan for continued attainment (2025 Canton Pb Maintenance Plan) as required by CAA section 175A. CAA section 175A(a) requires such maintenance plans to provide for maintenance of the NAAQS for at least 10 years after the redesignation and to contain measures that may be necessary to ensure such maintenance. To address the possibility of future NAAQS violations, the maintenance plans must contain contingency provisions, as required by CAA section 175A(d), to assure the State will promptly correct any violation of the NAAQS which occurs after the area is redesignated to attainment. Then, 8 years after the redesignation, CAA section 175A(b) requires States to submit a SIP revision with a revised maintenance plan to continue maintaining the NAAQS for another 10 years following the initial 10-year maintenance period.

The EPA has identified the following list of five core provisions to ensure maintenance of the relevant NAAQS in an area for which a State is seeking redesignation from nonattainment to attainment: attainment inventory, maintenance demonstration, monitoring network, verification of continued attainment, and contingency plan. 60

For the attainment inventory, as discussed in section 5.2.1 of the TSD, the EPA proposes to find that Ohio's attainment inventory appropriately identified the 2024 level of Pb emissions in the Canton Nonattainment Area at the time the monitoring data showed attainment, a level which is considered sufficient to attain the 2008 Pb NAAQS. 61

For the maintenance demonstration, as discussed in section 5.2.2 of the TSD, the EPA proposes to find that Ohio fully documented that the improvement in air quality is based on permanent and enforceable emission reductions as well as NSR provisions that will ensure continued attainment. To demonstrate the NAAQS will be maintained for 10 years following the redesignation, Ohio effectively showed that future emissions would not exceed the level of the 2024 attainment inventory and that modeling of its control strategy demonstrated the future mix of sources will not cause a violation of the 2008 Pb NAAQS through 2037. 62

For the monitoring network, as discussed in section 5.2.3 of the TSD, the EPA proposes to find that Ohio's 2025 Canton Pb Maintenance Plan appropriately provides a commitment to continue monitoring and reporting the ambient Pb levels at both the Republic Steel and Republic Community monitoring sites to ensure continued maintenance of the 2008 Pb NAAQS as well as a commitment to consult with the EPA prior to making any changes to the State's approved air monitoring network.

For the verification of continued attainment, as discussed in section 5.2.4 of the TSD, the EPA proposes to find that Ohio EPA met this provision by committing to track future Pb emissions inventories and compare them with the Pb inventories for the 2020 base year, 2024 attainment year, and 2037 future maintenance year to assess emission trends and to ensure continued compliance with the 2008 Pb NAAQS.

For the contingency plan, as discussed in section 5.2.5 of the TSD, Ohio EPA carried forward the contingency measures from the September 17, 2024, Director's Final Findings and Orders into Ohio's 2025 Canton Pb Maintenance Plan that set action levels for measured Pb ambient concentrations to trigger certain responses. These contingency measures require Republic Steel or any subsequent owner or operator of the Canton Plant to take certain actions if the Republic Steel or Republic Community monitoring sites reach Pb daily average concentrations of 0.75 μg/m 3 or 1-month average concentrations of 0.10 μg/m 3 . These actions include additional watering, additional cleaning, building/equipment repairs, additional closing of building openings, updated work practices, and/or application of chemical suppressant to control fugitive Pb-bearing dust from the Canton Plant within 14 days of being notified of the monitoring results. Additionally, these Orders require Republic Steel or any subsequent owner or operator to submit to Ohio EPA a plan for approval for sitewide control of fugitive Pb-bearing dust at least 30 days prior to undertaking any activities related to demolition or deconstruction of any portion of the facility. These Orders also require that any subsequent owner assume all obligations with these Orders if the Canton Plant changes ownership. Based on these measures, the EPA proposes to find that Ohio has fully satisfied the requirement for contingency provisions for a maintenance plan under CAA section 175A(d).

Based on the information in sections 5.2.1-5.2.5 of the TSD, the EPA is proposing to approve Ohio's 2025 Canton Pb Maintenance Plan as containing all these necessary provisions to maintain the 2008 Pb NAAQS for the initial 10 years under CAA section 175A as well as a commitment from the State to review the maintenance plan 8 years after redesignation for the next 10 years.

As noted above, on April 25, 2025, Ohio requested the EPA redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS since the area has achieved a design value of 0.15 μg/m 3 for the most recent three-year period 2022-2024, thereby meeting the 2008 Pb NAAQS of 0.15 μg/m 3 .

While the EPA is proposing to determine that the Canton Nonattainment Area has monitored attainment of the 2008 Pb NAAQS in section III.A. of this preamble and section 5.1 of the TSD, the EPA notes that this, in and of itself, does not constitute a redesignation to attainment. 63 There are five criteria for redesignating an area from nonattainment to attainment that are found in CAA section 107(d)(3)(E):

(i) the Administrator determines that the area has attained the NAAQS;

(ii) the Administrator has fully approved the applicable implementation plan for the area under CAA section 110(k);

(iii) the Administrator determines that the 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 pollutant control regulations and other permanent and enforceable reductions;

(iv) the Administrator has fully approved a maintenance plan for the area as meeting the requirements of CAA section 175A; and

(v) the State containing such area has met all requirements applicable to the area under CAA section 110 and part D of CAA title 1.

How Ohio's submittals met each of these five criteria for redesignation of the Canton Nonattainment Area to attainment is addressed in section IV.B. of this preamble and section 6.2 of the TSD.

In reviewing Ohio's 2024 Canton Pb SIP Revision and 2025 Canton Pb Maintenance Plan and Redesignation Request, the EPA addresses each of the five criteria under CAA section 107(d)(3)(E) for redesignating an area from nonattainment to attainment in turn below.

In acting upon a redesignation request, the EPA may rely on any prior SIP approvals plus any additional approvals it may perform in conjunction with acting on the redesignation. The 1992 Calcagni Redesignations Memo and 1992 Calcagni SIP Actions Memo both note, “[A]pproval action on SIP elements and the redesignation request may occur simultaneously,” and the EPA has frequently taken this approach in its redesignation actions. 64 As such, the EPA is proposing to approve all required SIP elements simultaneously in conjunction with acting in accordance with Ohio EPA's request to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS.

Based on the information presented in section III.A. of this preamble and in section 5.1 of the TSD, the EPA is proposing to determine that, as of the end of 2024, the Canton Nonattainment Area achieved attainment of the 2008 Pb NAAQS as expeditiously as practicable, approximately 1.5 years after the April 10, 2023, effective date of the redesignation, and earlier than the April 10, 2028, date based on the full 5 years allowed under CAA section 172(a)(2).

As summarized in section II.D. of this preamble and in section 4.4 of the TSD, the EPA is proposing to fully approve Ohio's 2024 Canton Pb SIP Revision under CAA section 110(k) as satisfying all the applicable requirements of title 1 under CAA sections 110(a)(2)(D)(i)(I), 110(a)(2)(I), 110(a)(2)(K), 110(l), 172, 191, and 192(a) as well as 40 CFR 51 Subparts F and G.

From the time the Republic Steel—Canton Plant shutdown and all air permits were terminated in July 2024, Ohio documented the corresponding sharp decrease in monitored Pb concentrations and improvement in air quality. Based on the information presented in sections II.A.2.c. and III.A. of this preamble and in sections 4.1.2.3 and 5.1 of the TSD, the EPA proposes to determine that the improvement in ambient air quality is due to permanent and enforceable reductions in Pb emissions resulting from the permanent shutdown of all emission units requiring air permits and the termination of the associated air permits at the Republic Steel—Canton Plant.

As addressed in section III.B. of this preamble and in section 5.2 of the TSD, the EPA is proposing to approve Ohio's 2025 Canton Pb Maintenance Plan under CAA section 175A as effectively addressing each of the five core provisions identified by the EPA to maintain the 2008 Pb NAAQS for the initial 10 years (attainment inventory, maintenance demonstration, monitoring network, verification of continued attainment, and contingency plan) as well as providing a commitment from the State to review the maintenance plan 8 years after redesignation for the next 10 years.

Based on the information addressed in sections III.A. and III.B. of this preamble and in section 6.2.5 of the TSD, the EPA is proposing to determine that Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request have satisfied all the applicable requirements for the purposes of redesignation under CAA section 110 and part D of title 1.

For CAA section 110, the EPA previously approved Ohio's Infrastructure and Transport SIPs, and the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision satisfies the applicable requirements under CAA sections 110(a)(2)(D)(i)(I), 110(a)(2)(I) and 110(a)(2)(K) that specifically address the nonattainment plan provisions for the Canton Nonattainment Area as well as the anti-backsliding provisions of CAA section 110(l).

For CAA part D of title I, the EPA is proposing to find that Ohio's 2024 Canton Pb SIP Revision, which was comprised of an attainment plan with monitoring data, emissions inventory, attainment demonstration, and contingency measures to demonstrate attainment as expeditiously as practicable and no later than five years after the April 10, 2023 effective date of the nonattainment designation, meets each of the applicable provisions of CAA sections 172, 191(a), and 192(a).

Based on the EPA's proposed findings and approvals in the synopsis in section IV.B. of this preamble and in section 6.2 of the TSD, the EPA is proposing to determine that Ohio's 2024 Canton Pb SIP Revision as well as Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request have met the requirements for the EPA to redesignate the Canton Nonattainment Area from nonattainment to attainment under CAA section 107(d)(3)(E). As such, the EPA is proposing to approve Ohio's April 25, 2025 Canton Pb Maintenance Plan and to act in accordance with Ohio's request to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS in accordance with CAA sections 107(d)(3)(E)(i) through (v).

The EPA is proposing to approve all of Ohio's required SIP elements simultaneously in conjunction with proposing to act in accordance with Ohio's request to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS. Specifically, the EPA is proposing the following separate, but related, actions:

1. To approve Ohio's September 19, 2024 Canton Pb SIP Revision as meeting the applicable requirements of CAA sections 110(a)(2)(D)(i)(I), 110(a)(2)(I), 110(a)(2)(K), 110(l), 172, 191, and 192(a) and 40 CFR 51 Subparts F and G;

2. To determine that the Canton Nonattainment Area is attaining the 2008 Pb NAAQS;

3. To approve Ohio EPA's comprehensive Pb emissions inventory for the Canton Nonattainment Area as meeting the applicable requirements of CAA section 172(c)(3);

4. To approve Ohio's 2025 Canton Pb Maintenance Plan as meeting the applicable requirements of CAA section 175A;

5. To determine that Ohio's 2024 Canton Pb SIP Revision as well as Ohio's 2025 Canton Pb Maintenance Plan and Redesignation Request have met the applicable requirements for the EPA to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS under CAA section 107(d)(3)(E); and thus

6. To act in accordance with Ohio's April 25, 2025 Canton Pb Redesignation Request and to redesignate the Canton Nonattainment Area from nonattainment to attainment of the 2008 Pb NAAQS in accordance with CAA section 107(d)(3)(E)(i)through(v).

Under the CAA, 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 the EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rulemaking 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).

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA.

On June 22, 2010 (75 FR 35520), the EPA established a new 1-hour SO 2 NAAQS of 75 parts per billion (ppb), which can be 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 is less than or equal to 75 ppb, as determined in accordance with appendix T of 40 CFR part 50. 40 CFR 50.17(a)-(b).

On September 12, 2016 (81 FR 45039), the EPA designated part of St. Clair County, Michigan as nonattainment for the 2010 SO 2 NAAQS based on computer modeling that incorporated SO 2 data from Continuous Emissions Monitors (CEM) at the DTE Belle River and St. Clair power plants.

Section 191 of the CAA directs States to submit a State Implementation Plan (SIP) for an area designated as nonattainment for the 2010 SO 2 NAAQS to the 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. As a result, Michigan was required to submit a nonattainment SIP to the EPA by March 12, 2018, to bring the St. Clair area into attainment by the attainment date of September 12, 2021. Michigan did not submit a nonattainment SIP for the St. Clair area by the March 12, 2018, deadline, instead relying on the EPA's Clean Data Policy, described in more detail below, to address the requirement.

On July 24, 2020, Michigan submitted a request that the EPA make a Clean Data Determination (CDD) under the CAA and the EPA's Clean Data Policy, based on both local monitored air quality data and a new dispersion modeling analysis, demonstrating that the St. Clair nonattainment area attained the 2010 SO 2 NAAQS. When a nonattainment area is attaining the 2010 SO 2 NAAQS based on the most recent available data, the EPA may issue a CDD suspending certain planning requirements for as long as the area continues to attain the NAAQS. On June 30, 2021, Michigan submitted the St. Clair area's emissions inventory and nonattainment new source review (NNSR) verification required by CAA section 172 to the EPA. The EPA issued a CDD for the St. Clair area on December 7, 2021 (86 FR 69173), and approved Michigan's submittal of the emissions inventory and NNSR elements on February 9, 2022 (87 FR 7387). Additionally, to address requirements under CAA section 179(c), the EPA made a determination of attainment by the attainment date, finding that the St. Clair nonattainment area attained the 2010 SO 2 NAAQS for the relevant period associated with the attainment date of September 12, 2021 (89 FR 104884, December 26, 2024).

Michigan submitted a request for redesignation and a maintenance plan for the St. Clair nonattainment area on December 15, 2023, and supplemented the request on July 24, 2025. In addition to information addressing CAA redesignation and maintenance plan requirements, the submittal addresses the DTE Energy St. Clair Power Plant closure and the reduction of SO 2 emissions from the DTE Belle River Power Plant.

Under section 107(d)(3)(E) of the CAA, the EPA may not promulgate a redesignation of a nonattainment area (or portion thereof) unless:

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

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

3. The 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. The 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.

The EPA's evaluation of Michigan'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.

In accordance with CAA section 107(d)(3)(E)(i), to redesignate a nonattainment area to attainment, the EPA must determine that the area has attained the applicable NAAQS. An area is attaining the 2010 SO 2 standard when the three-year average of the annual 99th percentile of daily maximum 1-hour average concentrations is less than or equal to 75 ppb consistent with 40 CFR 50.17 and appendix T of Part 50. 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 stated in the EPA's April 23, 2014, Guidance for 1-Hour SO 2 Nonattainment Area SIP Submissions (April 2014 SO 2 Guidance), there are two components needed to support an attainment determination: (1) a review of representative air quality monitoring data; and (2) a further analysis, where there are no monitors, or the monitors are not located in the area of maximum concentration, using air quality dispersion modeling, which 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. Michigan's redesignation request submission for the St. Clair nonattainment area provides a demonstration that the area is attaining based on ambient air monitoring data and a dispersion modeling analysis for the nonattainment area.

Per component (1), ambient air monitoring data was collected from 2017 to 2021 by two SO 2 monitors located in the nonattainment area: the Remer monitor near the St. Clair Power Plant and the Mills monitor near the Belle River Power Plant. Because of the nonattainment designation, DTE installed these two on-site SO 2 monitoring and meteorology stations in late 2016. A Michigan Air Quality Division SO 2 monitor, known as the Port Huron monitor, is located approximately 12 miles north of the power plants but is outside the nonattainment area; this monitor is addressed in the Technical Support Document (TSD) accompanying this action.

Monitoring data at the two DTE SO 2 monitors for the period from 2017 through 2019 showed attainment of the SO 2 NAAQS and served as justification for Michigan's July 24, 2020, CDD submittal to the EPA. The DTE monitors continued to collect SO 2 data through the end of 2022 showing that the NAAQS continued to be met. Table 1 details the attaining values of ambient air monitoring data in the St. Clair area in accordance with 40 CFR 50.17(b).

Per component (2), Michigan conducted air quality dispersion modeling in accordance with 40 CFR part 51, appendix W to demonstrate attainment of the 2010 SO 2 NAAQS for the St. Clair nonattainment area based on the fully implemented control strategy. A more in-depth discussion of the EPA's modeling requirements, including an assessment of longer-term average limits, as well as Michigan's modeling analysis is included in the TSD for this action.

Michigan's modeled demonstration of attainment of the SO 2 NAAQS relies upon the permanent and enforceable SO 2 emission limits for the Belle River Power Plant established in Permit to Install 51-22 and the shutdown of the St. Clair Power Plant, which ceased operation in 2022. Permit to Install 51-22, which implemented revised lower emissions limits for the Belle River facility in April 2022, includes limits for each of the Belle River Power Plant boilers of 0.680 pounds per million British thermal units (lbs/MMBtu) for a 30-day rolling average emission rate and 1.2 pounds per lbs/MMBtu based upon any 3-hour average. The EPA is proposing to incorporate Permit to Install 51-22 into Michigan's SIP in this action.

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. Pursuant to the Belle River Renewable Operating Permit, (ROP) MI-ROP-B2796-2024, the facility submitted quarterly Opacity Excess Emissions Reports containing monthly SO 2 emission rate averages for 2023-2024 to Michigan. These monthly emission rate averages are all within the SO 2 emission limits set forth in Permit to Install 51-22.

Michigan's modeling analysis demonstrates that the SO 2 emission limits contained in Permit to Install 51-22, governing Belle River Power Plant SO 2 emissions, in combination with the St. Clair Power Plant shutdown and background concentrations, yield a maximum SO 2 concentration of 62.8 ppb, which is below the 2010 SO 2 NAAQS of 75 ppb. Therefore, the EPA proposes to conclude that the dispersion modeling analysis demonstrates that the St. Clair nonattainment area has attained the 2010 SO 2 NAAQS.

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

Many of the CAA 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 1-hour primary SO 2 NAAQS.

The EPA is proposing to determine that Michigan has met the part D requirements and the EPA has fully approved those requirements that are applicable for purposes of redesignation. Part D is comprised of the general nonattainment area plan requirements in subpart 1 (CAA section 172) as well as pollutant-specific subparts, including CAA section 191 (or subpart 5), which applies to areas designated nonattainment for SO 2 , nitrogen dioxide, or lead. In lieu of an attainment SIP for St. Clair, Michigan submitted a CDD consistent with the Clean Data Policy that determined the nonattainment area has attained the 2010 SO 2 NAAQS. In designated nonattainment areas where monitored data demonstrate that the NAAQS have been achieved, the EPA interprets certain requirements of the CAA as no longer applicable for so long a time as air quality continues to meet the standard. Under the Clean Data Policy, the EPA may issue a determination of attainment after notice and comment rulemaking determining that a specific area is attaining the relevant standard. For such areas, the requirement to submit to the EPA those SIP elements related to attaining the NAAQS is suspended for as long as the area continues to attain the standard; these planning elements include reasonable further progress requirements, attainment demonstrations, reasonably available control measures, contingency measures, and other State planning requirements related to attainment of the NAAQS. In the April 2014 SO 2 Nonattainment Area Guidance, the EPA provides guidance and a rationale for the application of the Clean Data Policy to the 2010 SO 2 NAAQS.

The EPA approved Michigan's CDD request in lieu of an attainment SIP, and the determination became effective December 7, 2021 (86 FR 69173). The EPA's final determination suspended the requirements for Michigan to submit an attainment demonstration and other associated nonattainment planning requirements for the St. Clair nonattainment area as long as the St. Clair area continues to attain the 2010 SO 2 NAAQS. Michigan was still required to submit an emissions inventory under CAA section 172(c)(3) and a nonattainment new source review program under CAA section 172(c)(5). Michigan submitted the St. Clair area's emissions inventory and NNSR verification to the EPA on June 30, 2021, which were approved on February 9, 2022 (87 FR 7387).

CAA sections 172(c)(1) and 172(c)(6) direct States with areas designated as nonattainment to demonstrate that the submitted plan and its emission limitations and control measures provide for attainment of the NAAQS. 40 CFR part 51, subpart G further delineates the control strategy requirements that SIPs must meet, and the EPA has long required that all SIPs and control strategies reflect the four fundamental principles of quantification, enforceability, replicability, and accountability. See “General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” (General Preamble) published on April 16, 1992 (57 FR 13498), at 13567 through 13568. SO 2 attainment plans must consist of two components: (1) enforceable emission limits and other control measures that assure implementation of permanent, enforceable and necessary emission controls, and (2) a modeling analysis which meets the requirements of 40 CFR part 51, appendix W. As discussed above in section II.A., Criterion (1), of this document, Michigan's redesignation request addresses both components, because it includes permanent and enforceable emission reductions for the SO 2 sources in the area and a modeling analysis that demonstrates that Michigan's control strategy provides for attainment of the 2010 SO 2 NAAQS. The EPA is proposing to incorporate Permit to Install 51-22, governing Belle River Power Plant SO 2 emissions, into Michigan's SIP in this action, which will render it Federally enforceable.

Based on the above details and the approval of Michigan's CDD, the EPA is proposing to find that Michigan has met the applicable requirements of section 110 and part D of the CAA for purposes of the redesignation of the St. Clair nonattainment area.

To redesignate an area from nonattainment to attainment, section 107(d)(3)(E)(iii) of the CAA requires the 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.

Permanent and enforceable improvements in air quality for the St. Clair area were focused on the two large sources in the area: the St. Clair Power Plant, which shut down in 2022, and the Belle River Power Plant, which implemented lower emission limits that took effect in April 2022. There are no other sources of significant size emitting SO 2 in the area. Michigan's redesignation request contains permanent and enforceable SO 2 strategies for both DTE power plants. As discussed above in section II.A., Criterion (1), of this document, the reduced emission limits at the Belle River facility are contained within Permit to Install 51-22, which the EPA is proposing to incorporate into Michigan's SIP in this action. The Belle River Power Plant will be required to operate emissions controls following redesignation of the area unless such a change is first approved by the EPA as a revision to Michigan's SIP consistent with section 110(l) of the CAA. As part of the closure of the St. Clair Power Plant, the Acid Rain permit for the facility was revoked by the State on December 15, 2022.

If the area is redesignated to attainment, CAA Prevention of Significant Deterioration (PSD) Requirements for permitting any new sources or modifications to sources in the area will apply.

Michigan's computer modeling analysis assesses nonattainment years (pre-2022) and the modeled attainment year (2022) for the Belle River and St. Clair Power Plants. In this analysis, the State modeled nonattainment (pre-2022) allowable emissions of 38,798 pounds per hour (lbs/hr) which declined to 9,268 lbs/hr after permanent and enforceable reductions were put in place for the area. The dispersion modeling analysis demonstrates that the St. Clair area is attaining the 2010 NAAQS with the closure of the St. Clair Power Plant and implementation of lower emission limits at the Belle River Power Plant. The TSD, which is included in the docket for this action, contains further detail on Michigan's modeling analysis.

The EPA is proposing to find that the St. Clair area modeling results demonstrate attainment and continued maintenance of the 2010 SO 2 NAAQS and that the air quality improvement in the St. Clair nonattainment area is due to permanent and enforceable reductions in emissions.

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 plan must demonstrate continued attainment of the applicable NAAQS for at least ten years after the nonattainment area is redesignated to attainment. Eight years after the redesignation, the State must submit a revised maintenance plan demonstrating that attainment will continue to be maintained for the ten years following the initial ten-year period. To address the possibility of future NAAQS violations, the maintenance plan must contain contingency measures as the EPA deems necessary to ensure prompt correction of any future violations of the 2010 SO 2 NAAQS.

Specifically, the maintenance plan should address five requirements: the attainment emissions inventory, maintenance demonstration, monitoring, verification of continued attainment, and a contingency plan. The EPA is proposing to determine that Michigan's redesignation request contains all the necessary components and commitments. The EPA is further proposing to approve the maintenance plan as part of Michigan's federally enforceable SIP.

As part of a State's maintenance plan, the EPA's Redesignation Guidance requires States to identify the level of emissions in an affected area sufficient to attain and maintain the NAAQS. In its redesignation request, Michigan provided modeled SO 2 emissions of the emission units in the nonattainment area for 2022, a year in which the permanent and enforceable reductions reduced the emission rates for the two large facilities in St. Clair. As discussed above in section II.A., Criterion (1), of this document, the Belle River facility lowered its allowable limits in revised Permit to Install 51-22, and the St. Clair Power Plant shut down, causing allowable emissions in the area to decline heavily. The pre-2022 total emissions were 39,798 lbs/yr from both large SO 2 emitting facilities, with 2019-2021 design values from the near monitors of 43.7 ppb at DTE Mills Compressor Station Monitor and 37.0 ppb at DTE Remer Road Monitor. The emissions then decreased to 9,268 lbs/yr for the post-2022 modeled rates, summarized in Table 2 of this document below. Michigan's modeling analysis, based on the post-2022 emission rates in Table 2, resulted in a design value of 62.8 ppb, below the SO 2 NAAQS of 75 ppb. Michigan's modeling analysis is discussed further in the TSD, which is included in the docket for this action.

The EPA's “Procedures for Processing Requests to Redesignate Areas to Attainment” 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 model to show that the future mix of sources and emission rates will not cause a violation of the standard. In both instances, the demonstration should be for a period of 10 years following the redesignation. Furthermore, the plan should contain a summary of air quality concentrations resulting from control measures implemented in instances where modeling is relied upon to demonstrate maintenance. Michigan's maintenance demonstration consists of modeling showing total 1-hour SO 2 concentration values ( i.e., maximum 1-hour SO 2 concentrations added to background concentration values) now in effect in the St. Clair area which meet attainment of the 2010 SO 2 NAAQS. The modeling was based on maximum allowable rates that are protective of the SO 2 NAAQS. Because there are no large sources of SO 2 projected to enter the St. Clair area, the St. Clair Power Plant closed in 2022, and the Belle River facility plans to convert from coal to natural gas by 2027, the nonattainment area can be expected to demonstrate attainment of the standard for the requisite 10 years and beyond. Table 3 below shows Michigan's base year inventory and attainment year inventory to demonstrate that the area will remain in attainment to projected year 2035.

While the State's maintenance plan submission expressly documents that the area's emissions inventories will remain below the attainment year inventories through 2035, emissions are projected to continue to remain below attainment levels into 2036 and beyond due to the 2022 closure of the St. Clair facility and the projected 2027 conversion of the Belle River facility to natural gas. Along with Table 3 of this document above, Michigan provides additional support within its Permit to Install APP-2024-0273, which shows that the conversion to natural gas from coal will continue to allow the St. Clair area to meet attainment. Detailed within the permit, the baseline actual emissions of the highest consecutive 24-month period from the Belle River facility was calculated at 21,470 tons per year (tpy). After its conversion to natural gas, the Belle River facility's actual emissions are projected to decline to 24 tpy. Therefore, even if the redesignation action is finalized in 2026, the maintenance plan provides continued maintenance for at least ten years after redesignation in accordance with the requirements of section 175A.

DTE voluntarily installed and operated two SO 2 monitors in the nonattainment area and within the vicinity of the two power plants in late 2016 until the end of 2022 to determine whether the modeled violations of SO 2 in fact reflected ambient SO 2 impacts. In 2022, DTE discontinued its monitors due to cost, consistent attainment, and the fact that modeling shows NAAQS attainment will be maintained into the future. The monitoring data showed that monitored SO 2 consistently stayed well below the SO 2 NAAQS for the six years that the monitors were in operation. Additionally, Michigan has long implemented air rules, including the New Source Review (NSR) and PSD programs that aim to prevent new sources and major modifications from significantly contributing to air quality violations and to continue to protect public health and welfare. Both programs look to safeguard economic growth in a manner consistent with the preservation of existing clean air resources. The NSR and PSD programs will ensure attainment of the SO 2 NAAQS is maintained within the St. Clair area.

For continued verification, Michigan has committed to periodically reevaluate the modeling assumptions and input data used in the redesignation SIP development, as well as to monitor contingency plan indicators and triggers. As Michigan's SO 2 monitoring network does not include a monitor in the St. Clair County nonattainment area, Michigan commits to providing the EPA with an annual emissions report for the Belle River Power Plant in order to provide ongoing verification of attainment in the manner required by the EPA's SO 2 Data Requirements Rule (80 FR 51052, August 21, 2015).

Section 175A(d) of the CAA provides that a maintenance plan must also contain contingency provisions that will promptly correct any violation of the SO 2 NAAQS after the area is redesignated to attainment. 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 in order for the maintenance plan to be approved. However, the maintenance plan's 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. 1

In the General Preamble, the 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), the 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, 2 which can quickly identify and address sources that might be causing NAAQS exceedances.

Michigan's enforcement program is active and capable of prompt action to remedy compliance issues. Additionally, Michigan commits to the implementation of necessary contingency measures in the event of future violations of the 2010 SO 2 NAAQS. Michigan will consider various contingency measures which will be selected from a comprehensive list of measures deemed appropriate. Listed below are example measures that may be considered, but not a complete comprehensive list:

All of the listed contingency measures are potentially effective or proven methods of obtaining significant reductions of SO 2 emissions. Because it is not possible at this time to determine what control measure(s) will be appropriate at an unspecified time in the future, the list of contingency measures outlined is not comprehensive. The selection of measures will be based upon cost-effectiveness, emission reduction potential, economic and social considerations, or other factors that Michigan deems appropriate. Michigan will solicit input from all interested and affected persons in the maintenance area prior to selecting appropriate contingency measures. Additionally, no contingency measure shall be implemented without providing the opportunity for full public participation during which the relative costs and benefits of individual measures, at the time they are under consideration, can be fully evaluated. Based on the foregoing, the EPA proposes to find that Michigan has addressed the contingency measure requirement.

The EPA is proposing to find that the Michigan maintenance plan adequately addresses the five components of a maintenance plan necessary to attain the NAAQS in the St. Clair nonattainment area. Therefore, the EPA proposes to find that the maintenance plan submitted by Michigan for the St. Clair SO 2 nonattainment area meet the requirements of section 175A of the CAA and proposes to approve this plan.

The EPA is proposing to take several related actions. The EPA is proposing to redesignate the St. Clair area from nonattainment to attainment for the 2010 SO 2 NAAQS in accordance with Michigan's December 15, 2023, request for redesignation. The EPA has determined that the area is attaining the 2010 SO 2 NAAQS and has met the requirements for redesignation under section 107(d)(3)(E) of the CAA. The EPA is also proposing to approve Michigan's maintenance plan, which is designed to ensure that the area will continue to maintain attainment of the SO 2 NAAQS. Additionally, the EPA is proposing to approve into the Michigan SIP Permit to Install 51-22, governing Belle River Power Plant SO 2 emissions.

In this rulemaking, the EPA is proposing to include in a final EPA rule regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, the EPA is proposing to incorporate by reference Michigan Permit to Install 51-22, approved April 26, 2022 and revised May 25, 2023, discussed in sections II and III of this preamble. The EPA has made, and will continue to make, these documents generally available through www.regulations.gov and at the EPA Region 5 Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information).

Under the CAA, redesignation of an area to attainment and the accompanying approval of a maintenance plan 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, 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 these reasons, this action:

• 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 the 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).