Air Plan Approval; Kentucky; Louisville Area Limited Maintenance Plan for the 1997 8-Hour Ozone NAAQS
Key claim: EPA is proposing to approve Kentucky’s plan to keep ozone pollution in the Louisville-area counties within the 1997 federal standard, which would make those local air-quality commitments federally enforceable.
Abstract
(Proposed Rule · Environmental Protection Agency) The U.S. Environmental Protection Agency (EPA or Agency) is proposing to approve a State Implementation Plan (SIP) revision submitted by the Commonwealth of Kentucky through the Energy and Environment Cabinet (Cabinet) on behalf of the Louisville Metro Air Pollution Control District (District) via a letter dated June 3, 2024. The SIP revision consists of a Limited Maintenance Plan (LMP) for the Kentucky portion of the bi-state Louisville, Kentucky-Indiana 1997 8- hour ozone maintenance area (the “bi-state Louisville Area”). The Kentucky portion of the bi-state Louisville Area includes the Bullitt, Jefferson, and Oldham Counties of Kentucky (the “Louisville Area”). The EPA is proposing to approve the Louisville Area’s LMP because it provides for the maintenance of the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS) within the bi-state Louisville Area through the end of the second 10-year portion of the maintenance period. The effect of this proposed action would be to make certain commitments related to maintenance of the 1997 8-hour ozone NAAQS in the Louisville Area federally enforceable as part of the Kentucky SIP.
Why this matters
Limited maintenance plans lock in state-level ozone controls as federally enforceable commitments even for a superseded standard, preserving anti-backsliding protections while relieving the area of certain nonattainment-related permitting burdens. The Louisville action is part of a broader wave of EPA housekeeping on the 1997 ozone NAAQS, incrementally closing out legacy Clean Air Act obligations across Kentucky and neighboring states.