DEQ tells committee it updated Idaho air rules to match federal changes; committee approves incorporation docket

Tiffany Floyd, Air Quality Division Administrator at the Idaho Department of Environmental Quality (DEQ), presented rule docket 58‑01012401, DEQ’s annual incorporation by reference of federal air quality regulations through July 1, 2024. Floyd said incorporation is necessary to maintain state program primacy so DEQ, rather than the U.S. Environmental Protection Agency, implements federal air regulations in Idaho.

Floyd highlighted several federal changes incorporated into Idaho rules. She said EPA approved Idaho’s removal of a vehicle inspection and maintenance program in Northern Ada County’s carbon monoxide nonattainment plan, and that EPA removed a Clean Air Act “emergency defense” provision from Title V permitting (leaving enforcement discretion to states rather than a blanket exemption). Floyd also noted EPA tightened the annual PM2.5 standard from 12 µg/m3 to 9 µg/m3 effective May 6, 2024; she said Idaho anticipates statewide compliance but flagged communities near the standard — Pinehurst, St. Mary’s and Salmon — where DEQ is conducting outreach. Floyd described additional federal updates on lead smelter operations, refrigerant lists, and removal of major source permitting for certain air curtain incinerators that burn clean wood waste.

Floyd explained DEQ also corrected an earlier omission by reinserting long‑standing definitions (such as toxic air pollutant, carcinogenic and non‑carcinogenic increments, Chemical Abstracts Service) to the appropriate chapter for clarity. She said DEQ received one comment from the Idaho Conservation League during public comment and declined to change the proposal, because the reinstated definitions were not new. After the presentation the committee approved docket 58‑01012401 on a voice vote.