Clean Data Determination and Approval of Base Year Emissions Inventory; California; Los Angeles-South Coast Air Basin; 189(d) Plan for the 2006 24-Hour PM2.5 NAAQS

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R09-OAR-2024-0472; FRL-12322-02-R9]</DEPDOC> <SUBJECT> Clean Data Determination and Approval of Base Year Emissions Inventory; California; Los Angeles-South Coast Air Basin; 189(d) Plan for the 2006 24-Hour PM <E T="0735">2.5</E> NAAQS </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 making a clean data determination (CDD) for the Los Angeles-South Coast Air Basin (“South Coast”) air quality planning area in California based on our determination that the area is attaining the 2006 24-hour fine particulate matter (PM <E T="52">2.5</E> ) national ambient air quality standards (NAAQS). As a result of this CDD, certain Clean Air Act (CAA) requirements that have applied to California will be suspended for so long as the area continues to meet the 2006 24-hour PM <E T="52">2.5</E> NAAQS. The EPA is also approving a revision to California's state implementation plan (SIP) consisting of the 2018 base year emissions inventory for the South Coast PM <E T="52">2.5</E> nonattainment area, submitted by the California Air Resources Board (CARB) on December 29, 2020. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> his rule is effective July 3, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> The EPA has established a docket for this action under Docket ID No. EPA-R09-OAR-2024-0472. 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> Ashley Graham, EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105; phone: (415) 972-3877; email: <E T="03">graham.ashleyr@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. Summary of the Proposed Action</FP> <FP SOURCE="FP-2">II. Public Comment</FP> <FP SOURCE="FP-2">III. Final Action</FP> <FP SOURCE="FP-2">IV. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Summary of Proposed Action</HD> On November 25, 2024, the EPA proposed to determine, based on the most recent three years (2021-2023) of complete (or otherwise validated), quality-assured, and certified data meeting the requirements of 40 CFR part 50, appendix N, that the South Coast PM <E T="52">2.5</E> nonattainment area attained the 2006 24-hour PM <E T="52">2.5</E> NAAQS. <E T="51">1 2</E> <FTREF/> In conjunction with and based on our proposed determination that the South Coast area had attained and was currently attaining the 2006 24-hour PM <E T="52">2.5</E> NAAQS, and in accordance with 40 CFR 51.1015, the EPA proposed to issue a CDD for the South Coast PM <E T="52">2.5</E> nonattainment area for those NAAQS. <FTNT> <SU>1</SU>  89 FR 92873 (November 25, 2024). <SU>2</SU>  The EPA also evaluated preliminary data available in the EPA's Air Quality System (AQS) for 2024 (January through June). These data indicated that the South Coast area continued to show concentrations below the level of the 2006 24-hour PM <E T="52">2.5</E> NAAQS. Id. at 92877. </FTNT> The EPA's proposal explained that if we were to finalize the proposal, the requirements for the area to submit an attainment demonstration, reasonable further progress plan, quantitative milestones and quantitative milestone reports, contingency measures, and any other SIP revisions related to attainment of the 2006 24-hour PM <E T="52">2.5</E> NAAQS would be suspended so long as the area continues to meet the standards. Our proposal noted that California had already submitted an attainment plan titled “Final South Coast Air Basin Attainment Plan for 2006 24-hour PM <E T="52">2.5</E> Standard” (“South Coast PM <E T="52">2.5</E> Plan”)  <SU>3</SU> <FTREF/> to address these requirements and that the EPA would evaluate and act on the remaining SIP elements in the submitted plan through subsequent rulemakings, as appropriate. <SU>4</SU> <FTREF/> We also explained that a CDD does not constitute a redesignation to attainment, and that the South Coast PM <E T="52">2.5</E> nonattainment area will remain designated nonattainment for the 2006 24-hour PM <E T="52">2.5</E> NAAQS until such time as the EPA determines, pursuant to sections 107 and 175A of the CAA, that the South Coast PM <E T="52">2.5</E> nonattainment area meets the CAA requirements for redesignation to attainment, including an approved maintenance plan showing that the area will continue to meet the standards for 10 years. <SU>5</SU> <FTREF/> <FTNT> <SU>3</SU>  Letter dated December 28, 2020, from Richard W. Corey, Executive Officer, CARB, to John W. Busterud, Regional Administrator, EPA Region 9, with enclosures (submitted electronically December 29, 2020). </FTNT> <FTNT> <SU>4</SU>  89 FR 92873, 92880 (November 25, 2024). </FTNT> <FTNT> <SU>5</SU>  Id. </FTNT> Finally, as authorized in CAA section 110(k)(3), we proposed to approve the base year emissions inventory in the South Coast PM <E T="52">2.5</E> Plan as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008(c)(1) based on our evaluation and finding that the inventory fulfills all relevant requirements. Please see our November 25, 2024 proposed rulemaking  <SU>6</SU> <FTREF/> for additional background and a detailed explanation of the rationale for our proposed action. <FTNT> <SU>6</SU>  89 FR 92873 (November 25, 2024). </FTNT> <HD SOURCE="HD1">II. Public Comment</HD> The public comment period on the proposed rulemaking opened on November 25, 2024, <SU>7</SU> <FTREF/> the date of its publication in the <E T="04">Federal Register</E> , and closed on December 26, 2024. We did not receive any public comments on our proposal. <FTNT> <SU>7</SU>  Id. </FTNT> <HD SOURCE="HD1">III. Final Action</HD> Preliminary data available in the EPA's Air Quality System (AQS) for 2024 (January through December) indicate that the area continues to show concentrations consistent with attainment of the 2006 24-hour PM <E T="52">2.5</E> NAAQS. <SU>8</SU> <FTREF/> Thus, for the reasons discussed in detail in the proposed rulemaking and summarized herein, the EPA is taking final action to determine, based on the most recent three years (2021-2023) of complete (or otherwise validated), quality-assured, and certified data meeting the requirements of 40 CFR part 50, appendix N, that the South Coast PM <E T="52">2.5</E> nonattainment area has attained the 2006 24-hour PM <E T="52">2.5</E> NAAQS. <FTNT> <SU>8</SU>  EPA, AQS Design Value Report (AMP480), Report Request ID: 2277348, April 1, 2025. </FTNT> Based on our determination that the South Coast area has attained and is currently attaining the 2006 24-hour PM <E T="52">2.5</E> NAAQS, in accordance with 40 CFR 51.1015, the EPA is issuing a CDD for the South Coast PM <E T="52">2.5</E> nonattainment area for the 2006 24-hour PM <E T="52">2.5</E> NAAQS. Consequently, the requirements for this area to submit any remaining attainment-related SIP revisions will be suspended for so long as the area continues to attain those NAAQS. These attainment-related SIP revisions include the attainment demonstration, reasonable further progress plan, quantitative milestones and quantitative milestone reports, contingency measures, and any other SIP revisions related to the attainment of the 2006 24-hour PM <E T="52">2.5</E> NAAQS. As discussed in our proposal, on December 29, 2020, California submitted a SIP revision to address these requirements. The EPA intends to evaluate and act on the remaining SIP elements in this submission through subsequent rulemakings, as appropriate. This CDD does not constitute a redesignation to attainment. The South Coast PM <E T="52">2.5</E> nonattainment area will remain designated nonattainment for the 2006 24-hour PM <E T="52">2.5</E> NAAQS until such time that the EPA determines, pursuant to sections 107 and 175A of the CAA, that the South Coast PM <E T="52">2.5</E> nonattainment area meets the CAA requirements for redesignation to attainment, including an approved maintenance plan showing that the area will continue to meet the standards for 10 years. We are also finalizing approval of the South Coast PM <E T="52">2.5</E> Plan's 2018 base year emissions inventory as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008(c)(1). As authorized in section 110(k)(3) of the Act, the EPA is approving the submitted base year emissions inventory based on our determination that it fulfills all relevant requirements. <HD SOURCE="HD1">IV. Statutory and Executive Order Reviews</HD> Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 18k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━