2024 PM_2.5 NAAQS Final Reconsideration

On March 6, 2024, EPA revised the primary annual PM_2.5 national ambient air quality standard (NAAQS) by lowering the level from 12.0 µg/m³ to 9.0 µg/m³ (89 FR 16202). The Clean Air Act (CAA) section 107(d) outlines the timeline and processes for designating all areas of the United States as nonattainment, attainment, or unclassifiable compared to the current NAAQS. Within one year of a final revised NAAQS, the Governor of each state must submit documentation to EPA recommending classification for all areas of the respective state. For this NAAQS, area designation recommendations are due to EPA by February 7, 2025. DEQ is currently analyzing available data and guidance to provide Arkansas area designation and boundary recommendations to Governor Sanders for consideration.

The public comment period for 2022-2023 Exceptional Events demonstrations began January 19, 2025, and ends at 4:30 P.M. on February 18, 2025. The full public notice may be accessed below.

• EPA's Final Rule for PM_2.5 NAAQS Reconsideration

PM_2.5 Exceptional Events

The Arkansas Department of Energy and Environment, Division of Environmental Quality (DEQ) has prepared proposed draft Exceptional Events Demonstration (EED) for 2022-2023 Canada and Mexico wildfire events impacting Arkansas' air quality. The days and sites for which DEQ is requesting concurrence were impacted by events consistent with the EPA's definition of "unusual or naturally occurring events that can affect air quality but are not reasonably controllable using techniques that tribal, state, or local air agencies may implement in order to attain and maintain the NAAQS" (PM_2.5 NAAQS Memorandum, EPA 2024).

The public comment period for this demonstration begins January 19, 2025, and concludes on February 18, 2025. Comments may be submitted by email to ee.comment@arkansas.gov. The full public notice and complete Exceptional Events Demonstration package being submitted to EPA are available below.

• 2022-2023 PM_2.5 Exceptional Events Demonstrations, Notice of Public Comment Period
• 2022-2023 PM_2.5 Exceptional Events Demonstrations for Arkansas for Public Review

Infrastructure and Transport SIP Updates

Under CAA sections 110(a)(1) and 110(a)(2), each state is required to submit a state implementation plan (SIP) that provides for the implementation, maintenance, and enforcement of a revised primary or secondary NAAQS. CAA section 110(a)(1) and section 110(a)(2) require each state to make this new SIP submission within three years after the EPA promulgates a new or revised NAAQS. After EPA finalizes area designations for Arkansas, DEQ will begin work on the elements required under CAA section 110. EPA has up to three years from promulgation of a new NAAQS to finalize area designations.