Air Plan Approval; Colorado; Serious Attainment Plan Contingency Measures for the 2008 8-Hour Ozone National Ambient Air Quality Standards for the Denver Metro/North Front Range Nonattainment Area

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R08-OAR-2024-0622; FRL-12746-01-R8]</DEPDOC> <SUBJECT>Air Plan Approval; Colorado; Serious Attainment Plan Contingency Measures for the 2008 8-Hour Ozone National Ambient Air Quality Standards for the Denver Metro/North Front Range Nonattainment Area</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 state implementation plan (SIP) submittals under the Clean Air Act (CAA) that address contingency measures requirements for the 2008 ozone National Ambient Air Quality Standards (NAAQS) for the Denver Metro/North Front Range (DMNFR) ozone nonattainment area. The requirements at issue relate to the area's previous Serious nonattainment classification. The EPA is proposing to find that the State has met the applicable CAA requirements for Serious area contingency measures and is proposing approval of the contingency measures SIP submittals, except that we are not taking action on one of the two identified contingency measures included in the submittals. In addition, the EPA is proposing to approve regulatory revisions that Colorado adopted to implement the submitted motor vehicle coating contingency measure. The EPA is taking this action pursuant to the CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before June 9, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R08-OAR-2024-0622 to the Federal Rulemaking Portal: <E T="03">https://www.regulations.gov.</E> Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">https://www.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, 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> <E T="03">Docket:</E> All documents in the docket are listed in the <E T="03">https://www.regulations.gov</E> index. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available electronically in <E T="03">https://www.regulations.gov.</E> Please email or call the person listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section if you need to make alternative arrangements for access to the docket. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Matthew Lang, Air and Radiation Division, EPA, Region 8, Mailcode 8ARD-AQ-R, 1595 Wynkoop Street, Denver, Colorado, 80202-1129, telephone number: (303) 312-6709, email address: <E T="03">lang.matthew@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> In this document, “we,” “us,” and “our” refer to the EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. What action is the EPA proposing to take?</FP> <FP SOURCE="FP-2">II. Background</FP> <FP SOURCE="FP1-2">A. 2008 8-Hour Ozone NAAQS Nonattainment Area</FP> <FP SOURCE="FP1-2">B. The EPA's November 7, 2023 Final Rule</FP> <FP SOURCE="FP-2">III. Contingency Measures Requirements</FP> <FP SOURCE="FP-2">IV. Summary of State's SIP Submittals</FP> <FP SOURCE="FP1-2">A. Revisions to Regulation 7, Parts A and C and Reorganization Into Regulation 25, Parts A and B</FP> <FP SOURCE="FP1-2">B. 2024 DMNFR Contingency Measures Plan</FP> <FP SOURCE="FP1-2">1. One Year's Worth of Progress</FP> <FP SOURCE="FP1-2">2. Contingency Measures Infeasibility Justification</FP> <FP SOURCE="FP1-2">3. Adopted Contingency Measures</FP> <FP SOURCE="FP-2">V. Procedural Requirements</FP> <FP SOURCE="FP-2">VI. The EPA's Evaluation of Colorado's SIP Submittals</FP> <FP SOURCE="FP1-2">A. Revisions to Regulation 7, Parts A and C and Reorganization Into Regulation 25, Parts A and B</FP> <FP SOURCE="FP1-2">B. 2024 DMNFR Contingency Measures Plan</FP> <FP SOURCE="FP1-2">1. One Year's Worth of Progress</FP> <FP SOURCE="FP1-2">2. Contingency Measures Infeasibility Justification</FP> <FP SOURCE="FP1-2">3. Adopted Contingency Measures</FP> <FP SOURCE="FP1-2">4. Conclusion</FP> <FP SOURCE="FP-2">VII. Proposed Action</FP> <FP SOURCE="FP-2"> VIII. Consideration of Section 110( <E T="03">l</E> ) of the CAA </FP> <FP SOURCE="FP-2">IX. Incorporation by Reference</FP> <FP SOURCE="FP-2">X. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. What action is the EPA proposing to take?</HD> The EPA is proposing to approve Colorado SIP revisions for three submittals related to the Serious area contingency measures requirement for the DMNFR area for the 2008 ozone NAAQS. These submittals also address certain organizational revisions affecting the submitted regulations, including the relocation of existing portions of Colorado's Regulation Number 7 (“Reg. 7”) into new standalone regulations and renumbering of existing regulatory provisions. On June 26, 2023, Colorado submitted SIP revisions to address certain Moderate and Severe nonattainment requirements for the 2015 and 2008 ozone NAAQS, respectively, which included revisions to Reg. 7. <SU>1</SU> <FTREF/> Of relevance to this proposed rulemaking, the June 26, 2023 SIP submittal identifies motor vehicle coatings emission control requirements as a contingency measure for the Moderate ozone nonattainment area plan for the DMNFR area for the 2015 ozone NAAQS, but as described below, this measure was not triggered by a failure to attain with respect to the 2015 ozone NAAQS Moderate nonattainment plan requirements in the DMNFR area. The State is now repurposing the requirement as a contingency measure for the Serious ozone nonattainment area plan requirements for the 2008 ozone NAAQS. <FTNT> <SU>1</SU>  June 2023 SIP Submittal, Document Set 1 of 7, “Submittal Letter to EPA_Ozone SIP.” The letter is dated June 22, 2023, but the SIP was submitted to EPA on June 26, 2023.The June 2023 SIP Submittal was deemed complete on September 7, 2023. </FTNT> On May 23, 2024, Colorado submitted SIP revisions to the existing approved Reg. 7 to separate out certain components of Reg. 7 and create Regulation Number 24 (“Reg. 24”), Regulation Number 25 (“Reg. 25”), and Regulation Number 26 (“Reg. 26”) as new standalone regulations. <SU>2</SU> <FTREF/> On April 2, 2025, Colorado submitted SIP revisions to address the contingency measures requirement for Serious ozone nonattainment areas for the 2008 ozone NAAQS, which includes associated revisions to Reg. 25. <SU>3</SU> <FTREF/> The EPA had finalized a disapproval of a prior Colorado SIP submittal with respect to the 2008 ozone NAAQS Serious area contingency measures requirement in November 2023. <SU>4</SU> <FTREF/> In this rulemaking, we are proposing action only on the portions of the June 26, 2023, May 23, 2024, and April 2, 2025 submittals related to contingency measures, including associated revisions to Reg. 7, parts A and C as well as Reg. 25, parts A and B. The relevant portions of these submittals implement motor vehicle coatings emission control requirements, including provisions that function as a contingency measure for the Serious nonattainment classification of the DMNFR area for the 2008 ozone NAAQS. <FTNT> <SU>2</SU>  May 2024 SIP Submittal, “Submittal Letter to EPA_Regs 7, 24, 25, 26_signed.” The letter is dated May 21, 2024, but the SIP was submitted to EPA on May 23, 2024. The May 2024 SIP Submittal was deemed complete by operation of law on November 23, 2024. </FTNT> <FTNT> <SU>3</SU>  April 2025 SIP Submittal, Document Set 1 of 2, “Signed Submittal Letter to EPA.” </FTNT> <FTNT> <SU>4</SU>  Final Rule, Air Plan Approval and Disapproval; Colorado; Serious Attainment Plan Elements and Related Revisions for the 2008 8-Hour Ozone Standard for the Denver Metro/North Front Range Nonattainment Area; 88 FR 76676 (Nov. 7, 2023). </FTNT> More specifically, the EPA is also proposing to approve the June 26, 2023 revisions to Reg. 7, Part A that define new and existing sources and the applicability of requirements based on the nonattainment area in which they are located; revisions to Reg. 7, Part C, section I.P. regarding motor vehicle coating requirements that include provisions for those requirements to function as a contingency measure; and revisions to Reg. 7, Part C, section I.A. that update reference dates to the Code of Federal Regulations (CFR). In addition, the EPA is proposing to approve the May 23, 2024 revisions reorganizing Reg. 7, parts A and C into Reg. 25, parts A and B as well as the April 2, 2025 revisions to Reg. 25, parts A and B concerning motor vehicle coating provisions. The remaining revisions from the June 26, 2023, May 23, 2024 and April 2, 2025 submittals not described above, and not identified in table 3 of this preamble, will be addressed by the EPA in future ru ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 90k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━