The Environmental Protection Agency (EPA) is proposing to strengthen air quality standards to within a range of 65 to 70 parts per billion (ppb), while taking comment on a level as low as 60 ppb. EPA last updated these standards in 2008, setting them at 75 ppb.
Specifically in regards to the EPA proposal the EPA is proposing to revise the primary standard to a level within the range of 0.065 to 0.070 parts per million (ppm), and to revise the secondary standard to within the range of 0.065 to 0.070 ppm, which air quality analyses indicate would provide air quality, in terms of 3-year average W126 index values, at or below a range of 13-17 ppm-hours. The EPA proposes to make corresponding revisions in data handling conventions for O3 and conforming changes to the Air Quality Index (AQI); to revise regulations for the prevention of significant deterioration (PSD) program to add a transition provision for certain applications; and to propose schedules and convey information related to implementing any revised standards.
EPA will seek public comment on the proposal for 90 days following publication in the Federal Register, and the agency plans to hold three public hearings. EPA will issue final ozone standards by October 1, 2015.
EPA proposal and other corresponding documents will provide additional details in including the regulatory impact analysis and how to submit comments.