Air Plan Approval; California; State Implementation Plan Revision for Chico, Modesto and Stockton Carbon Monoxide Maintenance Areas

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R09-OAR-2024-0473; FRL-12323-02-R9]</DEPDOC> <SUBJECT>Air Plan Approval; California; State Implementation Plan Revision for Chico, Modesto and Stockton Carbon Monoxide Maintenance Areas</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is taking final action to approve a revision to the California state implementation plan (SIP) that removes carbon monoxide (CO) contingency measures and monitoring requirements from the maintenance plan for three CO maintenance areas: Chico Urbanized Area, Modesto Urbanized Area, and Stockton Urbanized Area. We are approving the revision under the Clean Air Act (CAA or “Act”). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective October 6, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> The EPA has established a docket for this action under Docket ID No. EPA-R09-OAR-2024-0473. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available through <E T="03">https://www.regulations.gov,</E> or please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section for additional availability information. If you need assistance in a language other than English or if you are a person with a disability who needs a reasonable accommodation at no cost to you, please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Ginger Vagenas, EPA Region 9, 75 Hawthorne Street, San Francisco, CA 94105; phone: (415) 972-3964; email: <E T="03">vagenas.ginger@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document, “we,” “us,” and “our” refer to the EPA. <HD SOURCE="HD1">Table of Contents </HD> <EXTRACT> <FP SOURCE="FP-2">I. Proposed Action</FP> <FP SOURCE="FP-2">II. Public Comments and EPA Responses</FP> <FP SOURCE="FP-2">III. EPA Action</FP> <FP SOURCE="FP-2">IV. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Proposed Action</HD> On March 31, 2025, <SU>1</SU> <FTREF/> the EPA proposed to approve the “2023 Revision to the California State Implementation Plan for Carbon Monoxide”  <SU>2</SU> <FTREF/> as a SIP revision to remove CO contingency measures and monitoring requirements from the “2004 Revision to the California State Implementation Plan for Carbon Monoxide”  <SU>3</SU> <FTREF/> for the Chico, Modesto, and Stockton maintenance areas. The proposal includes the EPA's analysis of monitoring data demonstrating that ambient levels of CO in the three maintenance areas were well below the CO national ambient air quality standards (NAAQS) throughout the maintenance period, as well as the EPA's evaluation of the California Air Resources Board's (CARB) demonstration that future CO emissions are consistent with continued compliance with the CO NAAQS through 2050. <SU>4</SU> <FTREF/> We proposed to approve this revision because we determined that it complies with the relevant CAA requirements. Our proposed action contains more information on the revision and our evaluation. <FTNT> <SU>1</SU>  90 FR 14224, March 31, 2025. </FTNT> <FTNT> <SU>2</SU>  CARB, “2023 Revision to the California State Implementation Plan for Carbon Monoxide,” February 9, 2024. </FTNT> <FTNT> <SU>3</SU>  California Air Resources Board (CARB), “2004 Revision to the California State Implementation Plan for Carbon Monoxide,” adopted July 22, 2004. </FTNT> <FTNT> <SU>4</SU>  See CARB, “2023 Revision to the California State Implementation Plan for Carbon Monoxide,” February 9, 2024, table 4. </FTNT> <HD SOURCE="HD1">II. Public Comments and EPA Responses</HD> The EPA's proposed action provided a 30-day public comment period that closed April 30, 2025. During this period, we received one non-germane comment and one comment opposing our action due to the human health and climate effects of CO. The commenter correctly notes CO is a precursor for ozone, which is a greenhouse gas, and that high levels of CO have negative human health effects. However, as noted in our proposal, the ambient concentration of CO in the Chico, Stockton, and Modesto maintenance areas is well below the NAAQS for CO (the level that the EPA has determined to be protective of human health and the environment) and this action will not interfere with the maintenance of the CO NAAQS or other CAA requirements related to this standard. <SU>5</SU> <FTREF/> Further, these areas have been attaining the CO NAAQS for at least 20 years, CARB has demonstrated that they will likely continue to maintain the NAAQS due to declining CO emissions, <SU>6</SU> <FTREF/> and assessing the indirect effect of CO on the formation of greenhouse gases is beyond the scope of this action. Finally, CARB has satisfied the requirements in 40 CFR 58.14 to discontinue the CO monitors in the Chico Urbanized Area, Stockton Urbanized Area, and Modesto Urbanized Area. <FTNT> <SU>5</SU>  90 FR 14224, 14226-14227 (March 31, 2025). </FTNT> <FTNT> <SU>6</SU>  Id. </FTNT> <HD SOURCE="HD1">III. EPA Action</HD> No comments were submitted that change our assessment of the SIP revision, as described in our proposed action. Therefore, as authorized in section 110(k)(3) of the Act and for the reasons provided in our March 31, 2025 proposed rulemaking, the EPA is taking final action to approve into the California SIP the “2023 Revision to the California State Implementation Plan for Carbon Monoxide,” submitted to the EPA on April 5, 2024. <HD SOURCE="HD1">IV. Statutory and Executive Order Reviews</HD> Under the Clean Air Act, the Administrator is required to approve a SIP submission that complies with the provisions of the Act 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 they meet the criteria of the Clean Air Act. 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 <E T="03">et seq.</E> ); • 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 <E T="03">et seq.</E> ); • 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). This action is subject to the Congressional Review Act, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is not a “major rule” as defined by 5 U.S.C. 804(2). Under section 307(b)(1) of the Clean Air Act, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by November 4, 2025. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2).) <LSTSUB> <HD SOURCE="HED">List of Subjects in 40 CFR Part 52</HD> Environmental protection, Air pollution control, Carbon monoxide, Incorporation by reference, Intergovernmental relations, Reporting and recordkeeping requirements. </LSTSUB> <SIG> <DATED>Dated: August 25, 2025.</DATED> <NAME>Joshua F.W. Cook,</NAME> Regional Administrator, Region IX. </SIG> For the reasons stated in the preamble, the Environmental Protection Agency amends part 52, chapter I, title 40 of t ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 13k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━