EPA’s Proposal to Freeze Ozone National Ambient Air Quality Standards Issued in Anticipation of Criticism

On August 14, the U.S. Environmental Protection Agency (EPA) published its proposal to retain the existing ozone national ambient air quality standards (NAAQS). The proposal sets an October 1 deadline for public comment and schedules two virtual hearings, for August 31 and September 1, 2020. The current ozone NAAQS were established in 2015 and set 70 parts per billion for both primary and secondary standards.

In the proposal and a concurrently published fact sheet, EPA explains that based on the review of its independent science advisers, the Clean Air Scientific Advisory Committee, the 2015 primary standard “protects public health with an adequate margin of safety, including the health of at-risk populations.” The agency finds that the 2015 secondary standard serves its goal of protecting the environment, including vegetation. EPA also identified that the proposal reflected the agency’s consideration of issues raised by the U.S. Court of Appeals for the D.C. Circuit in Murray Energy Corp. v. EPA, No. 15-1385 in remanding the 2015 secondary standard. The case was discussed in greater detail in our previous blog post.