Sulfur Dioxide Designations
Guidance and Data
Status and Next Steps: Area Designations for the National Air Quality Standard for Sulfur Dioxide Established in 2010
March 20, 2015 - EPA informed environmental commissioners of 28 states that they have areas that will be addressed in the next round of designations under the one-hour healthâbased national air quality standard for sulfur dioxide (SO2). Air quality in parts of these states may be impacted by large sources of SO2 emissions. In addition, air quality monitors in some of these states are measuring preliminary violations of the standard. EPA is also informing seven tribes that they may be impacted by nearby sources of SO2 emissions.
- Fact Sheet - Status and Next Steps: Area Designations for the SO2 2010 Standard (PDF) (3pp, 77k)
- Remaining SO2 Designations Schedule (PDF) (1pg, 217k)
- Final Court Order for Remainder of 2010 SO2 Standard Designations (PDF) (10pp, 440k)
- Electric Power Plant Sources Exceeding the Emissions Thresholds Established by Court Order (PDF) (4pp, 313k)
- Ambient Air Quality Monitors for SO2 Recording Preliminary Violations of the 2010 Primary Standard (PDF) (1pg, 39k)
- States and Tribes Without Violating Monitors or Electric Power Plant Sources Exceeding the Emissions Thresholds Established by the Court Order but that Have a Border Located within 20 Kilometers of a Source in a Neighboring State that Exceeds those Emissions Thresholds (PDF) (1p, 84k)
- Updated Guidance for Sulfur Dioxide Area Designations (PDF) (11pp, 1.2MB)
- Technical Assistance Document: SO2 NAAQS Designations Modeling (PDF) (71pp, 1.6MB)
- Technical Assistance Document: SO2 NAAQS Designations Source-Oriented Monitoring (PDF) (30pp, 3.1MB)