On October 1, 2015, EPA announced a strengthening of the National Ambient Air Quality Standard (NAAQS) for ground-level ozone from a value of 75 ppb to 70 ppb. EPA projections, based on current monitoring networks, are that the majority of the U.S. will meet the revised standard by 2025. States will need to work closely with the EPA to finalize area designations and implement control measures to comply with the lowered standard through rulemaking.
Key highlights associated with the revised ozone NAAQS:
- A memo put forward by the EPA that outlines the agency’s plans for addressing issues related to implementing the revised standard including guidance available to agencies, designating areas, interstate ozone transport, managing monitoring networks, ensuring major source permitting is effective and efficient, and the challenges to reducing ozone in California.
- EPA’s plans with respect to the Exceptional Events rule that allows for exclusion of air quality data (including ozone data) that may be skewed due to events outside of an area’s control (such as wildfires).
- Grandfathering provision for certain pending preconstruction permit applications.
- Modernization of monitoring requirements including streamlining of the Photochemical Assessment Monitoring Stations (PAMS) network and an additional Federal Reference Method for ozone measurement.
- Public engagement including updates to the ozone monitoring season and air quality index.
Potential Implications of the Final Standard
The map below identifies 241 counties in violation of the 2015 revised ozone standard based on 2012-2014 data. Note that EPA will not designate areas as nonattainment based on the 2012-2014 data, but will likely use 2014-2016 data to determine area designations.
Please join Trinity Consultants for a complimentary webinar as we analyze the revised National Ambient Air Quality Standard (NAAQS) for ozone and its impact on stationary sources throughout the U.S.
Please click here to register.