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  • Cross-State Air Pollution Rule
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Proposed CSAPR Close-Out

On this page:

  • Rule Summary
  • Rule History
  • Additional Resources

Rule Summary

Determination Regarding Good Neighbor Obligations for the 2008 Ozone National Ambient Air Quality Standard

On June 29, 2018, EPA proposed to determine that the CSAPR Update Rule fully addressed 20 states' interstate pollution transport obligations for the 2008 national ambient air quality standards (NAAQS) for ground-level ozone.

EPA held a public hearing on the proposed rule on August 1, 2018, and the public comment period for the proposal ended on August 31, 2018.

Rule History

June 29, 2018 - Proposed Cross-State Air Pollution Rule Close-Out

EPA proposed that the CSAPR Update Rule fully addresses certain states’ interstate pollution transport obligations for the 2008 ozone NAAQS. 

  • Proposed Determination Regarding Good Neighbor Obligations for the 2008 Ozone National Ambient Air Quality Standard
  • Fact Sheet

Technical Support Documents (TSDs)

  • Air Quality Modeling Technical Support Document for the Updated 2023 Projected Ozone Design Values
  • Status of 110(a)(2)(D)(i)(I) SIPs for the 2008 Ozone NAAQS

Previous Actions

  • Memo and Supporting Documentation on Interstate Transport SIPs for the 2008 Ozone NAAQS (Signed October 2017)
  • September 7, 2016 - Final Cross-State Air Pollution Rule Update

Additional Resources

  • Cross-State Air Pollution Rule
  • Interstate Air Pollution Transport
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on March 13, 2022
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