The U.S. Environmental Protection Agency today lowered the annual National Ambient Air Quality Standard (NAAQS) for Particulate Matter smaller than 2.5 microns from 12 to 9 micrograms per cubic meter. EPA establishes NAAQS for outdoor, publicly-accessible air to “provide public health protection, including protecting the health of “sensitive” populations such as asthmatics, children, and the elderly.” EPA reviews the standards periodically.

View the EPA announcement here: Final Reconsideration of the National Ambient Air Quality Standards for Particulate Matter (PM) | US EPA

This will mean two things:

  • Facilities that need to get air permits, and need to conduct air quality dispersion modeling to document compliance with the NAAQS, will eventually need to use the lowered standard in their analysis. High-profile projects will likely need to document compliance with the new standard immediately. From a brief review of past Epsilon air permitting projects, the new standard should be achievable by most projects in the eastern U.S. (where background particulate levels are lower).
  • States where the background level is above the new standard (generally in the western U.S.) will need to be redesignated as being in nonattainment. That process takes a few years, but air permits for new & modified facilities in those states will eventually need to meet tighter emission limits (Lowest Achievable Emission Rate) and get emissions offsets.

Epsilon Associates obtains air permits for clients nationwide, and can assist with any questions regarding the new standards and how they affect permitting.

Related Epsilon Knowledge Center articles: EPA Proposes Revisions to the Air Quality Standard for Particulate Matter.