Air Plan Approval; Arizona; Maricopa County Air Quality Department; Volatile Organic Compounds; Architectural Coatings

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R09-OAR-2025-0317; FRL-12851-01-R9]</DEPDOC> <SUBJECT>Air Plan Approval; Arizona; Maricopa County Air Quality Department; Volatile Organic Compounds; Architectural Coatings</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 revisions to the Maricopa County Air Quality Department (MCAQD or “County”) portion of the Arizona State Implementation Plan (SIP). These revisions concern emissions of volatile organic compounds (VOC) from architectural coatings. Architectural coatings include house paints, stains, industrial maintenance coatings, traffic coatings, and other similar products. We are proposing to approve local rules to regulate these emission sources under the Clean Air Act (CAA or “Act”). The revisions would update the Arizona SIP by replacing an outdated rule version with the current version in effect and would lower VOC emissions limits for some architectural coatings if contingency measures are triggered in the future. 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 October 14, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R09-OAR-2025-0317 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> Allison Kawasaki, EPA Region IX, 75 Hawthorne St., San Francisco, CA 94105; telephone number: (415) 972-3922; email address: <E T="03">kawasaki.allison@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 rules did the State submit?</FP> <FP SOURCE="FP1-2">B. Are there other versions of these rules?</FP> <FP SOURCE="FP1-2">C. What is the purpose of the submitted rule revisions?</FP> <FP SOURCE="FP-2">II. The EPA's Evaluation and Action</FP> <FP SOURCE="FP1-2">A. How is the EPA evaluating the rules?</FP> <FP SOURCE="FP1-2">B. Do the rules meet the evaluation criteria?</FP> <FP SOURCE="FP1-2">C. The EPA's Recommendations To Further Improve the Rules</FP> <FP SOURCE="FP1-2">D. 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 rules did the State submit?</HD> Table 1 lists the rules addressed by this proposal with the dates that they were adopted by the local air agency and submitted to the EPA by the Arizona Department of Environmental Quality (ADEQ). This proposal addresses two versions of MCAQD Rule 335—Architectural Coatings (“Rule 335”). Because these rules have identical titles and are regulating the same source category they will be differentiated in this proposal by the year in which they were submitted to the EPA. On September 8, 2017, ADEQ submitted a SIP revision requesting that the EPA approve Rule 335, as revised on September 25, 2013, into the Maricopa County portion of the Arizona SIP (“2017 submittal”). On December 23, 2024, ADEQ submitted a SIP revision requesting that the EPA approve Rule 335, as revised on December 11, 2024, into the Maricopa County portion of the Arizona SIP (“2024 submittal”). <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="xs60,12,r50,r50,xs76"> <TTITLE>Table 1—Submitted Rules</TTITLE> <CHED H="1"> Local agency </CHED> <CHED H="1">Rule No.</CHED> <CHED H="1">Rule title</CHED> <CHED H="1">Revised</CHED> <CHED H="1">Submitted</CHED> <ROW> <ENT I="01">MCAQD</ENT> <ENT>335</ENT> <ENT>Architectural Coatings</ENT> <ENT>September 25, 2013</ENT> <ENT>September 8, 2017.</ENT> </ROW> <ROW> <ENT I="01">MCAQD</ENT> <ENT>335</ENT> <ENT>Architectural Coatings</ENT> <ENT>December 11, 2024</ENT> <ENT>December 23, 2024.</ENT> </ROW> </GPOTABLE> On March 13, 2018, the 2017 submittal was deemed by operation of law to be complete. On June 11, 2025, the 2024 submittal was deemed by operation of law to be complete. We have reviewed the submittals to ensure they meet the completeness criteria in 40 CFR part 51, appendix V. <HD SOURCE="HD2">B. Are there other versions of these rules?</HD> We approved an earlier version of Rule 335 (adopted on July 13, 1988) into the SIP on January 6, 1992 (57 FR 354). In both the 2017 submittal and 2024 submittal, ADEQ requested that, upon approval of the revised version of Rule 335, the EPA remove the 1988 version of this rule from the SIP. If we finalize this rulemaking as proposed, then both the 2017 submittal and 2024 submittal of Rule 335 will replace the 1988 version of this rule in the SIP. The 2024 submittal of Rule 335 will not become effective until and unless contingency measures are triggered for the 2015 8-hour ozone national ambient air quality standards (NAAQS). <HD SOURCE="HD2">C. What is the purpose of the submitted rule revisions?</HD> Rule 335 regulates the emissions of VOC from architectural coatings. Architectural coatings are coatings that are applied to stationary structures and their accessories. They include house paints, stains, industrial maintenance coatings, traffic coatings, and other similar products. VOC is emitted from coatings during application, curing, and from the associated solvents used for thinning and clean-up. Emissions of VOC contribute to the production of ground-level ozone and particulate matter (PM), which harm human health and the environment. Section 110(a) of the CAA requires states to submit regulations that control VOC emissions. The 2017 submittal of Rule 335 was submitted as part of an ongoing effort by the MCAQD and the EPA to update the Maricopa County portion of the Arizona SIP to reflect the current locally adopted rules. The 2024 submittal of Rule 335 was adopted by MCAQD to meet CAA requirements related to contingency measures. Reductions in VOC emissions from architectural coatings can be achieved by limiting the VOC content of coatings. Under CAA 179(c)(9), states must adopt contingency measures for nonattainment areas that become effective in the event the EPA makes a finding of a failure to attain a NAAQS or a finding of failure to make reasonable further progress. If contingency measures are triggered for the 2015 8-hour ozone NAAQS, lower VOC content limits will apply to coatings in these categories: flat coatings, non-flat coatings, dry fog coatings, industrial maintenance coatings, primers, sealers, undercoaters, roof coatings, specialty primers, stains, traffic marking coatings, and wood preservatives. The EPA prepared a technical support document (TSD) for each submittal of Rule 335. These TSDs are available in the docket and have more information about these rules. <HD SOURCE="HD1">II. The EPA's Evaluation and Action</HD> <HD SOURCE="HD2">A. How is the EPA evaluating the rules?</HD> Rules in the SIP must be enforceable and must not interfere with applicable requirements concerning attainment and reasonable further progress or other CAA requirements. They also must not modify certain SIP control requirements in nonattainment areas that were in effect before November 15, 1990, without ensuring equivalent or greater emissions reductions. See, respectively, CAA sections 110(a)(2), 110(l), and 193. Guidance and policy documents that we used to evaluate enforceability, revision/relaxation, and rule stringency requirements for the applicable criteria pollutants include the following: <EXTRACT> 1.“State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” 57 FR 13498 (April 16, 1992); 57 FR 18070 (April 28, 1992). 2.“Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations,” EPA, May 25, 1988 (the Bluebook, revised January 11, 1990). 3. “Guidance Document for Correcting Common VOC & Other Rule Deficiencies,” EPA Region 9, August 21, 2001 (the Little Bluebook). </EXTRACT> <HD SOURCE="HD2">B. Do the rules meet the evaluation criteria?</HD> We evaluated these rules to ensure they meet CAA requirements and are consisten ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 16k characters. 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