Environmental Permitting

PM-2.5 NAAQS: What’s Next?


Significant sources of pollutants, such as power plants and large industrial facilities, wishing to add or modify sources of pollutants may have to comply with PSD permitting requirements.  Such sources must ensure that the project will not cause or contribute to a violation of any NAAQS or any maximum allowable pollution increase (a.k.a., a PSD increment). 

Sources already in the permitting process would experience significant delays if they were required to now go back and evaluate the project with respect to these recent NAAQS revisions.  As a result, EPA will grandfather such sources with:

  • Permit applications deemed complete by December 14, 2012; or
  • Permit applications for which public notice of a draft permit or preliminary determination is published before March 18, 2013.

Nonattainment Designations

Once a new NAAQS is set, EPA and state agencies work together using monitoring data to determine what areas should be designated nonattainment and establish the area’s boundaries.  The schedule for making such determinations is as follows:

  • December 2013: states make recommendations for area designations to EPA;
  • August 2014: EPA responds to state recommendations, and states will have the opportunity to comment on EPA’s responses; and
  • December 2014: EPA will make final nonattainment designations, which will likely become effective in early 2015.

A preliminary determination by EPA indicates that there are 66 counties nationwide that do not meet the new PM-2.5 NAAQS.


Determinations of attainment and maintenance of the new PM-2.5 standards will be made using data from a national network of approximately 900 PM-2.5 monitors.  The new standards require the relocation of some monitors so that near-roadway monitoring can be conducted in each urban area with a population equal to or greater than 1 million.  The near-roadway monitoring will be phased-in from January 1, 2015, to January 1, 2017, therefore data from these monitors will not be available for the initial nonattainment designations for the new PM-2.5 standard.


States must attain the new PM-2.5 NAAQS “as expeditiously as practicable” but not later than 5 years after the final nonattainment designations are made, which makes the anticipated date in 2020.  An extension to 2025 may be granted depending on the severity of an area’s PM-2.5 pollution problems and the availability of pollution controls.

States with nonattainment areas must develop state implementation plans (SIPs) to demonstrate how air quality will be improved to meet the NAAQS.  All SIPs for the new PM-2.5 standard must be submitted to EPA for approval within 3 years after the final nonattainment designations are made, which makes the anticipated date in 2018.  The SIPs may include federal and local rules that will be implemented in the area to bring it into attainment. 

EPA has already implemented numerous regulations to reduce PM-2.5 pollution.  As a result, most areas of the country will not have to implement local requirements to meet the standard.  EPA estimates only 7 counties will not meet the new PM-2.5 NAAQS in 2020, based on current federal rules and will need to rely local requirements for attainment.

Additional Resources:

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Timothy P. Fagan is a Legal Editor for BLR’s environmental publications, focusing primarily on air quality related topics. Mr. Fagan has covered environmental developments with BLR since 2000. Before joining BLR, he spent 5 years in environmental consulting and was responsible for air quality permitting and compliance for a broad range of industries in both the private and public sector. He received a Bachelor of Science degree in chemical engineering from Villanova University and a Master’s degree in environmental engineering from the Pennsylvania State University.

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