Air Plan Approval; California; Eastern Kern Air Pollution Control District; Portland Cement Kilns

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R09-OAR-2025-0058; FRL-12609-01-R9]</DEPDOC> <SUBJECT>Air Plan Approval; California; Eastern Kern Air Pollution Control District; Portland Cement Kilns</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is proposing to approve a revision to the Eastern Kern Air Pollution Control District (EKAPCD or “District”) portion of the California State Implementation Plan (SIP). This revision concerns emissions of oxides of nitrogen (NO <E T="52">X</E> ) from Portland cement kilns. We are proposing to approve a local rule to regulate these emission sources under the Clean Air Act (CAA or “Act”). We are taking comments on this proposal and plan to follow with a final action. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Comments must be received on or before July 7, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R09-OAR-2025-0058 at <E T="03">https://www.regulations.gov</E> . For comments submitted at <E T="03">Regulations.gov</E> , follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">Regulations.gov</E> . The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( <E T="03">i.e.,</E> on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit <E T="03">https://www.epa.gov/dockets/commenting-epa-dockets</E> . 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> Elijah Gordon, EPA Region IX, 75 Hawthorne St., San Francisco, CA 94105; telephone number: (415) 972-3158; email address: <E T="03">gordon.elijah@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. The State's Submittal</FP> <FP SOURCE="FP1-2">A. What rule did the State submit?</FP> <FP SOURCE="FP1-2">B. Are there other versions of this rule?</FP> <FP SOURCE="FP1-2">C. What is the purpose of the submitted rule?</FP> <FP SOURCE="FP-2">II. The EPA's Evaluation and Action</FP> <FP SOURCE="FP1-2">A. How is the EPA evaluating the rule?</FP> <FP SOURCE="FP1-2">B. Does the rule meet the evaluation criteria?</FP> <FP SOURCE="FP1-2">C. Proposed Action and Public Comment</FP> <FP SOURCE="FP-2">III. Incorporation by Reference</FP> <FP SOURCE="FP-2">IV. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. The State's Submittal</HD> <HD SOURCE="HD2">A. What rule did the State submit?</HD> Table 1 lists the rule addressed by this proposal with the date that it was adopted by the local air agency and submitted to the EPA by the California Air Resources Board (CARB). <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="xs60,12,r50,12,12"> <TTITLE>Table 1—Submitted Rule</TTITLE> <CHED H="1">Local agency</CHED> <CHED H="1">Rule No.</CHED> <CHED H="1">Rule title</CHED> <CHED H="1">Amended</CHED> <CHED H="1">Submitted</CHED> <ROW> <ENT I="01">EKAPCD</ENT> <ENT>425.3</ENT> <ENT>Portland Cement Kilns (Oxides of Nitrogen)</ENT> <ENT>11/13/2024</ENT> <ENT>12/12/2024</ENT> </ROW> </GPOTABLE> The EPA has reviewed the SIP submittal containing the document listed in table 1 and finds that it fulfills the completeness criteria in 40 CFR part 51, appendix V. <HD SOURCE="HD2">B. Are there other versions of this rule?</HD> On June 5, 2023 (88 FR 36479), we finalized a limited approval and limited disapproval of Rule 425.3 as amended on March 8, 2018. The EKAPCD adopted revisions to the SIP-approved version on November 13, 2024, and CARB submitted them to us on December 12, 2024. If we take final action to approve the November 13, 2024 version of Rule 425.3, this version will replace the previously approved version of this rule in the SIP. <HD SOURCE="HD2">C. What is the purpose of the submitted rule?</HD> Emissions of NO <E T="52">X</E> contribute to the production of ground-level ozone, smog and particulate matter (PM), which harm human health and the environment. Section 110(a) of the CAA requires States to submit plans that provide for implementation, maintenance, and enforcement of the National Ambient Air Quality Standards (NAAQS). CAA sections 182(b)(2) and 182(f) in combination require that SIPs for ozone nonattainment areas classified as “Moderate” or higher implement Reasonably Available Control Technology (RACT) for any category of sources covered by a Control Techniques Guidelines (CTG) document and for any major source of volatile organic compounds (VOCs) or NO <E T="52">X</E> . The EKAPCD has jurisdiction over the Kern County (Eastern Kern) ozone nonattainment area. The area is classified as “Moderate” for the 1997 8-hour ozone NAAQS, “Severe-15” for the 2008 8-hour ozone NAAQS, and “Serious” for the 2015 8-hour ozone NAAQS. <SU>1</SU> <FTREF/> Therefore, EKAPCD must implement RACT in this area consistent with CAA sections 182(b)(2) and 182(f). The District relies on Rule 425.3 to establish RACT-level controls for Portland cement kilns at major sources of NO <E T="52">X</E> within the ozone nonattainment area. <FTNT> <SU>1</SU>   <E T="03">See</E> 40 CFR 81.305. For the 2008 ozone NAAQS, EKAPCD's voluntary reclassification to “Serious” from “Moderate” was finalized on July 5, 2018 (83 FR 31334) and the voluntary reclassification to “Severe-15” was finalized on June 7, 2021 (86 FR 30204). EKAPCD's voluntary reclassification to “Serious” for the 2015 ozone NAAQS was finalized on October 28, 2021 (86 FR 59648). </FTNT> In our June 5, 2023 limited approval and limited disapproval of the 2018 version of Rule 425.3, the EPA evaluated the RACT stringency of Rule 425.3 with respect to the Portland cement kilns covered by the rule, and the limited disapproval portion of that action started a sanctions clock based on the deficient portion of that rule. The present submission was submitted in order to address that deficiency. Rule 425.3 establishes NO <E T="52">X</E> emission limitations for the operation of Portland cement kilns within the nonattainment area under the EKAPCD's jurisdiction. The EKAPCD revised Rule 425.3 in order to correct the deficiencies identified in our June 5, 2023 limited approval and limited disapproval. The revised rule requires all kilns to comply with the 2.8 lb of NO <E T="52">X</E> /ton of clinker over a 30-operating day rolling average limit, replaces exemptions from NO <E T="52">X</E> emission limitations during startup and shutdown operations with new alternative NO <E T="52">X</E> emission limitations, and removes the exemption from NO <E T="52">X</E> emission limitations during breakdown conditions. The EKAPCD also removed the less stringent alternative emission limitation (3.4 lb of NO <E T="52">X</E> /ton of clinker over a 30-operating day rolling average) during periods of normal operation for low NO <E T="52">X</E> burners or low NO <E T="52">X</E> precalciner kilns installed and made operational by January 1, 2007. The EKAPCD added a recordkeeping requirement for Portland cement kilns, which must now record startup and shutdown daily NO <E T="52">X</E> emission rates. Finally, the EKAPCD revised the definitions of “startup” and “shutdown” to align with 40 CFR part 63, subpart LLL—National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry (see 40 CFR 63.1341). The EPA's technical support document (TSD) has more information about this rule. <HD SOURCE="HD1">II. The EPA's Evaluation and Action</HD> <HD SOURCE="HD2">A. How is the EPA evaluating the rule?</HD> Rules in the SIP must be enforceable (see CAA section 110(a)(2)) and must not interfere with applicable requirements concerning attainment and reasonable further progress or other CAA requirements (see CAA section 110(l)). Additionally, as explained above, EKAPCD must implement RACT in this area pursuant to CAA sections 182(b)(2) and (f), and the District relies on Rule 425.3 to establish RACT-level controls for Portland cement kilns at major sources of NO <E T="52">X</E> within the Kern County (Eastern Kern) ozone nonattainment area. In our June 5, 2023 action, we found that Rule 425.3 was largely consistent with the relevant CAA requirements. However, in that final rulemaking, we identified certain deficiencies that prevented full approval of Rule 425.3. This rulemaking focuses on the deficiencies identified in that June 5, 2023 limited disapproval and proposes to determine that the revisions to Rule 425.3 correct those identified deficiencies. Guidance and policy documents that we used to evaluate enforceability, interference under CAA section 110(l), and ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 20k characters. 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