Air Plan Approval; Oklahoma; Revisions to Air Pollution Control Rules

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R06-OAR-2025-0012; FRL-11140-01-R6]</DEPDOC> <SUBJECT>Air Plan Approval; Oklahoma; Revisions to Air Pollution Control Rules</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> Pursuant to the Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is proposing to approve revisions to the State Implementation Plan (SIP) for Oklahoma submitted by the State of Oklahoma on November 25, 2024. The submittal addresses updates to the Oklahoma SIP, specifically, Oklahoma Administrative Code (OAC) Title 252 Chapter 100 Subchapter 13, Open Burning. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before August 6, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket No. EPA-R6-OAR-2025-0012, at <E T="03"> https:// </E> or via email to <E T="03">shahin.emad@epa.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 Mr. Emad Shahin, 214-665-6717, <E T="03">shahin.emad@epa.gov.</E> 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> <E T="03">Docket:</E> The index to the docket for this action is available electronically at <E T="03">www.regulations.gov.</E> While all documents in the docket are listed in the index, some information may not be publicly available due to docket file size restrictions or content ( <E T="03">e.g.,</E> CBI). <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> For information on the revisions addressing open burning, please contact Mr. Emad Shahin, EPA Region 6 Office, Infrastructure and Ozone Section, 214-665-6717, <E T="03">shahin.emad@epa.gov.</E> We encourage the public to submit comments via <E T="03">https://www.regulations.gov.</E> Please call or email the contact listed above if you need alternative access to material indexed but not provided in the docket. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document “we,” “us,” or “our” means the EPA. <HD SOURCE="HD1">I. Background</HD> Section 110 of the CAA requires states to develop air pollution regulations and control strategies to ensure that air quality meets the EPA's National Ambient Air Quality Standards (NAAQS). These ambient air quality standards are established under CAA section 109 and currently address six criteria pollutants: carbon monoxide, nitrogen dioxide, ozone, lead, particulate matter (PM), and sulfur dioxide. A SIP is a collection of regulations and documents used by a state, territory, or local air district to implement, maintain, and enforce the NAAQS, and to fulfill other requirements of the CAA. The SIP must be submitted to EPA for approval and any changes a state makes to the approved SIP also must be submitted to the EPA for approval. In a letter dated November 22, 2024, the Secretary of Energy and Environment for the State of Oklahoma (the State) submitted a revision of the Oklahoma SIP to the EPA on November 25, 2024. In this action, we are proposing to approve into the SIP the updates to OAC Title 252 Chapter 100 Subchapter 13, Open Burning (OAC 252:100-13). ODEQ promulgated these updates to the Oklahoma open burning regulations in compliance with the Oklahoma Administrative Procedures Act and published them in the <E T="03">Oklahoma Register,</E> the official state publication for rulemaking actions. These updated regulations are posted in the docket for this action as part of the State's submittal. <HD SOURCE="HD1">II. The EPA's Evaluation</HD> Subchapter 13 imposes requirements for controlling the open burning of refuse and other combustible materials. The changes made to the open burning rules revised the requirement for using an Air Curtain Incinerator (ACI) for certain open burning operations in the Oklahoma City and Tulsa Metropolitan Statistical Areas (MSAs). An ACI is an incineration unit, operating by forcefully projecting a curtain of air across an open integrated combustion chamber or open pit or trench, in which combustion occurs. These regulatory changes clarify the State's open burning rules and comply with Oklahoma Senate Bill 246 (2021) which revised the rules and requirements for the use of ACI for open burn operations. A summary of the updates to the open burning rules follows: <EXTRACT> 1. OAC 252:100-13-8 requires the use of ACI for land clearing operations and burning of clean wood waste and transported yard brush in non-attainment areas, areas where an ambient air quality monitor has documented a violation of the primary NAAQS, or counties with a population of greater than 500,000. The requirements for using an ACI for land clearing, burning of clean wood, and burning of transported yard brush are now only applicable to Oklahoma and Tulsa counties. Previously, all seven counties in the Oklahoma City MSA and all seven counties in Tulsa MSA were included and required the use of an ACI for open burning operations. If combustible material from land clearing operations, yard brush, clean wood waste, and clean lumber is transported for open burning, OAC 252:100-13-8.1 is modified to clarify that open burning of transported materials shall not be conducted in non-attainment areas, areas where an ambient air quality monitor has documented a violation of the primary NAAQS, or counties with a population of greater than 500,000. 2. OAC 252:100-13-7 modifies the open burning requirements for Land Clearing Operations in OAC 252:100-13-7(4)(B) and the Yard Brush disposal in 100-13-7(7) to reflect that the new requirements are in OAC 252:100-13-8, or if waste is being transported, in OAC:252:100-13-8.1. 3. OAC 252:100-13 adds 13-7(9) to specify the type of material that is allowed to be open burned, namely wood waste, and clean lumber. The type of material allowed to be open burned was previously found within the ACI provisions of 13-8. 4. OAC 252:100-13 moves requirements for the use of ACI in Subchapter 17 and NSPS to Subchapter 13, OAC 252:100-13-8(c). </EXTRACT> ODEQ provided an analysis that the SIP revisions are not expected to cause or contribute to nonattainment and reasonable further progress, or interfere with any other applicable requirements of the CAA. ODEQ added that the updates do not change the types of activities that are allowed under the open burning rules and only revise when an ACI is required for land clearing operations and the disposal of clean wood waste and transported yard brush. Oklahoma also determined that the impact of these updated regulations on emissions of PM would be minimal. Oklahoma estimates that prescribed fire in the impacted counties only accounts for 7% of Oklahoma's PM emission because much of those emissions come from land clearing and other types of open burning, such as range management in the Flint Hills grass land. <SU>1</SU> <FTREF/> <FTNT> <SU>1</SU>  See ODEQ 110(l) Demonstration for the Removal of the Air Curtain Incinerator requirement in land clearing operations in certain counties of the Oklahoma City and Tulsa Metropolitan Statistical Areas in OAC 252:100-13. November 2024, at 14. (Available in docket) </FTNT> EPA reviewed the SIP submittal and determined that the MSAs for both Tulsa and Oklahoma City are attaining the PM NAAQS. ODEQ maintains an ambient air quality monitoring network that covers both the Oklahoma and Tulsa Counties in addition to the other counties in their broader MSAs. Prior to the updates, areas needed to be designated nonattainment or in a MSA with a population of greater than 900,000 to trigger ACI requirements. With this action, areas with monitors indicating violations of the primary NAAQS or a population greater than 500,000 will trigger ACI requirements. The revisions to OAC 252:100-13 add clarity and consistency to the State's open burning rules. These revisions do not interfere with continued attainment of the NAAQS or any other applicable CAA requirements. We are proposing to approve these revisions to OAC 252:100-13, Subchapter 13. ODEQ analysis can be found in the docket as part of the state's submittal. As additional information, EPA has also reviewed monitoring data from 2024 (note this monitoring data hasn't completed all quality assurance for certification) indicating that all monitors in Oklahoma are attaining the standard. <HD SOURCE="HD1">III. Impact on Areas of Indian Country</HD> Following the U.S. Supreme Court decision in <E T="03">McGirt</E> v. <E T="03">Oklahoma,</E> 140 S. Ct. 2452 (2020), the Oklahoma Governor requested approval under Section 10211(a) of the Safe, Accountable, Flexible, Efficient Transportation Equity Act of 2005: A Legacy for Users, Public Law 109-59, 109 Stat. 1144, 1937 (August 10, 2005) (“SAFETEA”), to administer in certain areas of Indian country (as defined at 18 U.S.C. 1151) the State's environmen ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 19k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━