Summary of EPA's Final Revised CSAPR Update for the 2008 Ozone NAAQS

On March 15, 2021, EPA released its final rule, “Revised Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS” (Final Rule). EPA states that this Final Rule is intended to address the D.C. Circuit’s remand of the Cross-State Air Pollution Rule (CSAPR) Update, which finalized FIPs for 22 states to address their interstate transport obligations under the Clean Air Act for the 2008 ozone NAAQS, as well as vacatur of the CSAPR Close-Out, which found that the CSAPR Update was a complete remedy of these obligations.