🌬️Kentucky SO2 Nonattainment Regulations and Business Compliance
The Environmental Protection Agency (EPA) is proposing to approve two State Implementation Plan (SIP) revisions submitted by the Commonwealth of Kentucky, through the Energy and Environment Cabinet (Cabinet), Division of Air Quality (DAQ) on January 26, 2024, and February 15, 2024, to certify two requirements under the Clean Air Act (CAA or Act). These revisions establish that the Kentucky SIP satisfies the nonattainment new source review (NNSR) and base year emissions inventory requirements for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS) for the Henderson-Webster SO<INF>2</INF> nonattainment area (hereinafter "Henderson-Webster SO<INF>2</INF> Nonattainment Area" or "Area"). These actions are being proposed pursuant to the CAA.
Learn More🌫️EPA Approves Missouri's Sulfur Dioxide Emission Control Revisions
The Environmental Protection Agency (EPA) is taking final action to approve revisions to the Missouri State Implementation Plan (SIP) related to replacing the previous statewide sulfur dioxide (SO<INF>2</INF>) rule with the latest version of a newer SO<INF>2</INF> rule (10 CSR 10-6.261). The SIP revisions include removing outdated requirements and reinstating SO<INF>2</INF> emission limits for the Ameren-Labadie and Evergy-Hawthorn power plants. The revisions do not impact the stringency of the SIP, nor do they impact the state's ability to attain or maintain the National Ambient Air Quality Standards (NAAQS). The EPA is also approving Missouri's negative declaration of sources subject to sulfuric acid production requirements. This final approval action is being done in accordance with the requirements of the Clean Air Act (CAA).
Learn More🌬️EPA Withdraws Nonattainment Designation for Texas Areas
On May 16, 2025, the United States Court of Appeals for the Fifth Circuit (the Court) granted petitions for review of the EPA's nonattainment area designation for the Rusk and Panola Counties area, Texas for the 2010 SO<INF>2</INF> National Ambient Air Quality Standard (NAAQS). Accordingly, that nonattainment designation for the area has been vacated. The vacatur of the nonattainment designation necessarily requires the withdrawal of two contingent actions since the underlying designation is no longer valid: EPA's finding of failure to submit an attainment plan (FFS) issued on August 10, 2020, and EPA's finding of failure to attain the NAAQS by the attainment date (FFA) issued on December 17, 2024. The EPA is withdrawing these two final actions in accordance with the court's decision and finds that any requirements deriving from either the FFS or the FFA are no longer applicable.
Learn More🌬️Texas Air Plan Approval
Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving the portion of the State Implementation Plan (SIP) submittal from the State of Texas demonstrating that the State satisfies the interstate transport requirements of section 110(a)(2)(D)(i)(I), also known as 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.
Learn More🌬️EPA Proposes Redesignation of Muscatine, IA Air Quality Status
The Environmental Protection Agency (EPA) is proposing to redesignate the nonattainment area in Muscatine County, Iowa to attainment for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS). The EPA is also proposing to approve Iowa's maintenance plan for the 2010 1-hour SO<INF>2</INF> NAAQS for the Muscatine nonattainment area and approve modifications to source-specific permits in the Iowa State Implementation Plan (SIP). The EPA's proposed approval of this rule revision is being done in accordance with the requirements of the Clean Air Act (CAA).
Learn More🌬️New EPA Regulations on Sulfur Dioxide Emissions in North Carolina
The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the North Carolina Division of Environmental Quality (NCDEQ), Division of Air Quality (DAQ) on November 28, 2023, for the purpose of revising regulations that establish sulfur dioxide (SO<INF>2</INF>) emission limits and compliance parameters for SO<INF>2</INF>-emitting combustion sources in the State. EPA is proposing to approve these changes pursuant to the Clean Air Act (CAA or Act) and EPA regulations.
Learn More🌫️EPA Proposes Redesignation of Detroit for Sulfur Dioxide Attainment
The Environmental Protection Agency (EPA) is proposing to find that the Detroit, Michigan area is attaining the 2010 sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS) and to act in accordance with a request from Michigan to redesignate the area to attainment for the 2010 SO<INF>2</INF> NAAQS, because the request meets the statutory requirements for redesignation under the Clean Air Act (CAA). EPA is also proposing to approve Michigan's maintenance plan for the Detroit area. Michigan submitted the request for approval of the Detroit nonattainment area's redesignation and maintenance plan on May 5, 2025. EPA approved Michigan's attainment plan for the Detroit area on May 19, 2025.
Learn More🌬️EPA Finds Huntington County Failed Sulfur Dioxide Air Quality Standards
The Environmental Protection Agency (EPA) is determining that the Huntington County, Indiana nonattainment area failed to attain the 2010 Sulfur Dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS) by the applicable attainment date of April 9, 2023. EPA is also approving revisions into the Indiana State Implementation Plan (SIP) intended to provide for attainment of the 2010 SO<INF>2</INF> NAAQS for the Huntington County nonattainment area. These SIP revisions include Indiana's attainment demonstration and other planning elements required under the Clean Air Act (CAA), and an order issued by the Commissioner of the Indiana Department of Environmental Management containing enforceable emission limits. Further, EPA is determining that the provisions of Indiana's SIP submittal adequately provide for attainment of the NAAQS and that the plan meets all other applicable CAA requirements. EPA proposed to approve this action on June 18, 2025, and received no adverse comments.
Learn More🌫️EPA Proposes Municipal Redesignation for Beaver County Air Quality
The Environmental Protection Agency (EPA) is proposing to approve a state implementation plan (SIP) revision and redesignation request submitted on August 12, 2024 by the Pennsylvania Department of Environmental Protection (PADEP). The SIP revision asks the EPA to redesignate the Beaver County, Pennsylvania area from nonattainment to attainment for the 2010 1-hour primary sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS). The revision also asks the EPA to approve into the SIP the Commonwealth's maintenance plan for the 2010 1-hour primary SO<INF>2</INF> NAAQS for the Beaver County area. This action is being taken under the Clean Air Act (CAA).
Learn More🌍EPA Approves Guam Sulfur Dioxide Emissions Inventory Plan
The Environmental Protection Agency (EPA) is taking direct final action to approve a revision to Guam's State Implementation Plan (SIP) under section 110(k)(3) of the Clean Air Act (CAA or "the Act"). This revision concerns the base year emissions inventory for the Piti-Cabras, Guam sulfur dioxide (SO<INF>2</INF>) nonattainment area ("Piti-Cabras area" or NAA) for the 2010 1-hour SO<INF>2</INF> National Ambient Air Quality Standard (NAAQS, "standard," or "2010 SO<INF>2</INF> NAAQS").
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