The Environmental Protection Agency (EPA) proposes to redesignate the Oakridge, Oregon nonattainment area (Oakridge NAA or Oakridge area) to attainment for the 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) National Ambient Air Quality Standard (NAAQS).

The Environmental Protection Agency (EPA) finds that the Chicago-Naperville, IL-IN-WI area (Chicago area) is attaining the 2008 ozone National Ambient Air Quality Standard (NAAQS or standard) and, in response to a request from the Wisconsin Department of Natural Resources (Wisconsin or the State), is redesignating the Wisconsin portion of the area to attainment for the 2008 ozone NAAQS, because the State has met the statutory requirements for redesignation under the Clean Air Act (CAA).

The Environmental Protection Agency (EPA) is proposing to fully approve the Limited Maintenance Plan (LMP) submitted by the State of Montana to EPA on November 4, 2021, for the Thompson Falls Moderate nonattainment area (NAA) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM<INF>10</INF>) and concurrently redesignate the NAA to attainment for the 24-hour PM<INF>10</INF> National Ambient Air Quality Standard (NAAQS).

The Environmental Protection Agency (EPA) is proposing to approve the ``FINAL SIP Revision: Nogales PM<INF>2.5</INF> Maintenance Plan and Redesignation Request (2006 Fine Particulate NAAQS)'' (``Nogales Maintenance Plan'' or ``Plan'') as a revision to the state implementation plan (SIP) for the State of Arizona. The Nogales Maintenance Plan includes, among other elements, an emissions inventory consistent with attainment, a maintenance demonstration, contingency provisions, and a motor vehicle emissions budget for the ten-year maintenance period.