Final Disapproval of “Good Neighbor” State Implementation Plans Addressing Interstate Transport Obligations for the 2015 Ozone National Ambient Air Quality Standards

On this page:

• Action Summary
• Rule History
• Supporting Documents

Action Summary

For the 2015 ozone NAAQS, set at a level of 70 parts per billion, states were required to submit “interstate transport” or “good neighbor” SIP elements by October 1, 2018, that ensure their SIP contains adequate provisions to prohibit emissions that significantly contribute to nonattainment or interfere with maintenance of the NAAQS in other states. The disapprovals are based on an assessment of the information and analyses provided by states in their SIP submissions, comments received, and EPA’s most recent nationwide air quality analysis projecting ozone air quality and contributions in 2023.

• Final Disapprovals

Rule History

Proposed SIP Disapproval Actions

Supporting Documents

• Final Action: 2015 Ozone Transport SIP Disapprovals Fact Sheet (pdf) (190.39 KB, January 31, 2023)
• Final Action: Response to Comment Document (pdf) (4.61 MB, January 31, 2023)
• Final Action Air Quality Modeling Technical Support Document (pdf) (9.89 MB, January 31, 2023)
  • Data File with 2016v3 Ozone Design Values and Contributions (xlsx) (301.18 KB)
  • Supporting Documentation of the 2015 Ozone NAAQS Actions (Power Sector Modeling)
• 2016v3 Emissions Modeling Technical Support Document (pdf) (6.65 MB, January 31, 2023)