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Clarifications Regarding Regional Haze State Implementation Plans for the Second Implementation Period

July 8, 2021 -- EPA is issuing a memorandum providing information regarding development of State Implementation Plans (SIPs) for all states for the regional haze second planning period in response to questions and information EPA is receiving from states and stakeholders. The memorandum supports EPA’s efforts to work in partnership with states to ensure that the second planning period of the regional haze program secures meaningful reductions in visibility impairing pollutants that build on the significant progress states have already achieved. By clarifying and providing information on existing statutory and regulatory requirements, the memorandum provides a good balance of flexibility and accountability for states and sources to ensure that the regional haze program will continue to improve visibility in our national parks and wilderness areas. EPA is committed to working collaboratively with states and other stakeholders to support development of SIPs that are consistent with the Clean Air Act and the Regional Haze Rule.

  • Clarifications Regarding Regional Haze State Implementation Plans for the Second Implementation Period (pdf) (248.88 KB)

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Last updated on May 12, 2025
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