Originally posted by Holland & Hart.

“On October 1, 2015, EPA finalized the new primary National Ambient Air Quality Standard (NAAQS) for Ozone at 70 parts per billion (ppb); the new standard is more stringent than the current 2008 Ozone NAAQS, which was 75 ppb. At 70 ppb, approximately 32 of 63 counties in the Intermountain West would currently fail to meet the new standard, including counties in Utah, New Mexico, Colorado, and Nevada. The lower Ozone NAAQS is of particular concern to western states, communities, and businesses – where it will be difficult to attain the lower standard due to high levels of “background ozone,” which in some places approaches the 70 ppb standard.

Background ozone can be caused by elevation, types of vegetation, wildfire, international transport, or when atmospheric ozone is pushed to ground level through weather events, a phenomena known as “intrusion.” The Intermountain West is also home to large, sparsely populated counties with few sources of emissions that can be controlled through state permits or rules. While EPA acknowledges that the high background levels of ozone in the Intermountain West pose unique problems for compliance with the new standard, the final rule offers few meaningful options to address the impacts of background ozone.”

Find the whole piece here: https://www.hollandhart.com/new-ozone-impact-west