On October 1, 2015 the United States Environmental Protection Agency (“EPA”) adopted a more stringent air quality standard for ground-level ozone emissions that reduces the national standard from 75 parts per billion (“ppb”) to 70 ppb. By promulgating a new ozone standard, EPA says it aims to reduce smog from ground-level emission sources, including power plants, smoke stacks, and automobiles. In conjunction with the new standard, EPA also issued an “Implementation Memo,” which outlines the agency’s plans for addressing various implementation issues under the new standard.
The new ozone standard was issued as part of EPA’s authority under Sections 108 and 109 of the Clean Air Act (“CAA”) to establish National Ambient Air Quality Standards (also referred to as “NAAQS”). These sections of the CAA require EPA to periodically review its NAAQS. As a result, EPA conducted a review of its ozone NAAQS beginning in 2008, which resulted in the issuance of a proposed rule to change the ozone NAAQS in November of 2014. The draft proposed rule suggested a potential ozone range of 65 ppb to 70 ppb; however, in the final rule, EPA adopted the upper limit of 70 ppb of this range as the new NAAQS for ozone.
EPA also seeks to justify the rule on the grounds that the benefits of the new ozone standard will outweigh the projected $1.4 billion in costs. According to EPA, the public health benefits from the stronger ozone standard account for $2.9 to $5.9 billion of costs. Additionally, EPA believes that most U.S. counties will meet the new ozone standard by 2025 by working within the framework of existing federal and state rules. To facilitate compliance with the new ozone standard, EPA also plans to work closely with states and tribes to develop and implement clean air plans.