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  2. Air Quality Implementation Plans

PM2.5 Clean Data Policy Clarification Memorandum

This memorandum issued on May 22, 2008, to EPA's Regional Air Division Directors, provides clarification regarding language in the preamble of EPA's particulate matter (PM2.5) implementation rule (April 25, 2007) as it relates to EPA's Clean Data Policy.

  • Sanctions Clocks under the Clean Air Act, As of February 10, 2023 (pdf) (187.9 KB, April 14, 2023)
    Status of active sanctions clock under the CAA

Air Quality Implementation Plans

  • About Air Quality Implementation Plans
  • Approved Air Quality Implementation Plans
  • Develop an Air Quality SIP
  • Find a Regional Contact for Air Quality SIPs/FIPS/TIPs
  • Tools for SIP Status
Contact Us about Air Quality Implementation Plans
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 6, 2025
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