Air Plan Revisions; Arizona; Maricopa County Air Quality Department; Volatile Organic Compounds; Solvent Cleaning

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R09-OAR-2025-0321; FRL-12854-01-R9]</DEPDOC> <SUBJECT>Air Plan Revisions; Arizona; Maricopa County Air Quality Department; Volatile Organic Compounds; Solvent Cleaning</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) portion of the Arizona State Implementation Plan (SIP). These revisions concern rules that regulate volatile organic compounds (VOC) emissions from solvent cleaning operations. We are proposing to approve the revisions 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 October 14, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R09-OAR-2025-0321 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 did the State submit?</FP> <FP SOURCE="FP1-2">B. Are there other related submittals?</FP> <FP SOURCE="FP1-2">C. What is the purpose of the submittal?</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 and the request for rescission and replacement?</FP> <FP SOURCE="FP1-2">B. Do the SIP revisions 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 did the State submit?</HD> On October 3, 2024, the Arizona Department of Environmental Quality (ADEQ) submitted a SIP revision to the EPA from MCAQD requesting that the EPA approve MCAQD Rule 331—Solvent Cleaning (“Rule 331”), as revised on September 25, 2024 (“2024 SIP Submittal”). Additionally, the 2024 SIP Submittal requests that we rescind two sets of requirements from the SIP: MCAQD Rule 331, as revised on April 21, 2004, and paragraphs F, G, H, I, J, and K of Rule 34—Organic Solvents—Volatile Organic Compounds (VOC) (“Rule 34”), as revised on June 23, 1980. Table 1 lists the rule we are proposing for approval with the dates that it was adopted by the local air agency and submitted to the EPA by the ADEQ. Table 2 lists the rules proposed to be rescinded from the SIP with the dates that they were adopted by the local air agency and approved into the SIP. <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="xs60,10,r50,r50,xs72"> <TTITLE>Table 1—Submitted Rule for Approval</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>331</ENT> <ENT>Solvent Cleaning</ENT> <ENT>September 25, 2024</ENT> <ENT>October 3, 2024.</ENT> </ROW> </GPOTABLE> <GPOTABLE COLS="6" OPTS="L2,nj,i1" CDEF="xs60,r50,r60,xs72,xs72,xs56"> <TTITLE>Table 2—Rules Requested To Be Rescinded or Replaced</TTITLE> <CHED H="1"> Local agency </CHED> <CHED H="1">Rule No.</CHED> <CHED H="1">Rule title</CHED> <CHED H="1">Local revision date</CHED> <CHED H="1">SIP approved date</CHED> <CHED H="1">FR citation</CHED> <ROW> <ENT I="01">MCAQD</ENT> <ENT>34—paragraphs F, G, H, I, J, and K</ENT> <ENT>Organic Solvents—Volatile Organic Compounds (VOC)</ENT> <ENT>June 23, 1980</ENT> <ENT>May 5, 1982</ENT> <ENT>47 FR 19326.</ENT> </ROW> <ROW> <ENT I="01">MCAQD</ENT> <ENT>331</ENT> <ENT>Solvent Cleaning</ENT> <ENT>April 21, 2004</ENT> <ENT>December 21, 2004</ENT> <ENT>69 FR 76417.</ENT> </ROW> </GPOTABLE> On April 3, 2025, the 2024 SIP Submittal was deemed by operation of law to be complete. We have reviewed the submittal to ensure it meets the completeness criteria in 40 CFR part 51, appendix V. <HD SOURCE="HD2">B. Are there other related submittals?</HD> In 2016, the EPA reformatted the Arizona SIP as codified in the Code of Federal Regulations (CFR) into a tabulated “notebook” format. While developing the updated SIP tables for that conversion, the EPA worked closely with ADEQ and the local air agencies to clarify what was in their applicable SIP, including older provisions that had not been updated or replaced to reflect local rulemakings. On September 13, 2017, because of that coordination, the ADEQ submitted a SIP revision from MCAQD that requested to rescind or replace many obsolete rules in their federally enforceable SIP in favor of rules that reflect their current locally enforceable rulebook (“2017 SIP submittal”). The 2017 SIP Submittal included requests related to Rule 34, MCAQD Rule 330—Volatile Organic Compounds (“Rule 330”), and Rule 331. The submittal requested that paragraphs F, G, H, I, J, and K of Rule 34  <SU>1</SU> <FTREF/> be replaced in the SIP by approval of Rule 330, as adopted on September 25, 2013. The submittal also requested that the EPA remove SIP-approved Rule 331  <SU>2</SU> <FTREF/> and replace it in the SIP with Rule 331, as revised on September 24, 2013. As clarified by MCAQD in the 2024 SIP Submittal, these requests have been superseded by the 2024 SIP Submittal. Although these requests have been superseded, this action is a part of this ongoing effort. <FTNT> <SU>1</SU>  Approved into the SIP on May 5, 1982 (47 FR 19326). </FTNT> <FTNT> <SU>2</SU>  Approved into the SIP on December 21, 2004 (69 FR 76417). </FTNT> If we finalize this rulemaking as proposed, Rule 331, as revised on September 25, 2024, would replace Rule 34—paragraphs F, G, H, I, J, and K and Rule 331, as revised on April 21, 2004, in the Maricopa County portion of the Arizona SIP. <HD SOURCE="HD2">C. What is the purpose of the submittal?</HD> Under title I of the CAA, the EPA has established ambient air quality standards for six common air pollutants (“criteria pollutants”) known to be harmful to human health and the environment: carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO <E T="52">2</E> ), ozone, particulate matter (PM), and sulfur dioxide (SO <E T="52">2</E> ). These standards are known as the National Ambient Air Quality Standards (NAAQS). Section 110(a) of the CAA requires states to submit SIP requirements for the attainment and maintenance of the NAAQS. Rules 34 and Rule 331 regulate emissions of VOC from solvent cleaning operations, including metal degreasing. Emissions of VOC contribute to the production of ground-level ozone and PM. Cleaning solvents are used to remove contaminants such as adhesives, inks, paint, dirt, soil, oil, and grease from parts, products, tools, machinery, equipment, vessels, floors, walls, and other work production related work areas. These operations take place for a variety of reasons, including safety, operability, and to avoid product contamination. Additionally, MCAQD submitted revised Rule 331 to meet CAA reasonably available control technology (RACT) requirements. CAA sections 182(b)(2) and (f) require RACT for each category of sources covered by a Control Techniques Guidelines (CTG) document as well as each major source of VOC or oxides of nitrogen (NO <E T="52">X</E> ) in ozone nonattainment areas classified as “Moderate” or above. MCAQD regulates air quality in the Maricopa County portion of the Phoenix-Mesa ozone nonattainment area, which is classified as “Moderate” for the 2008 and 2015 8-hour ozone standards. <SU>3</SU> <FTREF/> Rule 331 regulates categories of sources covered by CTG documents related to solvents. For the 2008 8-hour ozone standard, MCAQD relied on Rule 331, as revised on April 21, 2004, to meet RACT requirements for certain CTG categories. MCAQD revised Rule 331 to meet RACT requirements for the 2015 8-hour ozone stan ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 20k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━