Proposed rule · 2026-17503

Air Plan Approval; Mississippi; 2010 1-Hour SO2 NAAQS Transport Infrastructure

Pursuant to the Federal Clean Air Act (CAA or the Act), the U.S. Environmental Protection Agency (EPA or Agency) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Mississippi, through the Mississippi Department of Environmental Quality (MDEQ), on January 27, 2022, for the purpose of complying with the "good neighbor" provision of the CAA for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>) primary National Ambient Air Quality Standard (NAAQS). The good neighbor provision requires each State's implementation plan to contain adequate provisions prohibiting the interstate transport of air pollution in amounts that will contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other State. In this proposed rulemaking, the EPA is proposing to determine that Mississippi will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO<INF>2</INF> primary NAAQS in any other State. Therefore, the EPA is proposing to approve the January 27, 2022, SIP revision as meeting the requirements of the good neighbor provision for the 2010 1-hour SO<INF>2</INF> primary NAAQS.