The United States Environmental Protection Agency (USEPA) finalized its reclassification of five (5) “Serious” nonattainment areas that failed to attain the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS) to “Severe” nonattainment for the 2008 ozone NAAQS on November 7, 2022. 

New Regulatory Thresholds 

For areas redesignated as Severe, the more stringent major source threshold of twenty-five (25) tons per year (tpy) applies for reasonably available control technology (RACT), nonattainment new source review (NNSR), Title V, and the more stringent NNSR emissions offset ratio of 1.3:1. The redesignated counties are now subject to the more stringent thresholds and requirements. Some facilities may have new permitting requirements for sources previously excluded from the major source NNSR and Title V permitting programs.

Redesignated Severe Nonattainment Counties

  • California – Morongo Band of Mission Indians
  • Colorado – Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer Counties
  • Connecticut – Fairfield, Middlesex, and New Haven Counties
  • New Jersey – Bergen, Essex, Hudson, Hunterdon, Middlesex, Monmouth, Morris, Passaic, Somerset, Sussex, Union, and Warren Counties
  • New York – Bronx, Kings, Nassau, New York, Queens, Richmond, Rockland, Suffolk, Westchester, Shinnecock Indian Nation
  • Texas – Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant, Wise, Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties

New Permitting Requirements 

If not previously required, facilities in redesignated counties that have the potential to emit (PTE) of twenty-five (25) tons or more of VOC and or NOx may have to apply for Title V permit by November 6, 2023, within one year of the EPA 's reclassification rule becoming final. Other sources may be able to apply for new permits or revise their current permits to limit their emissions below the 25-ton threshold to avoid the more onerous Title V permit monitoring, recordkeeping, and reporting requirements. Connecticut has recently undertaken outreach effort to notify affected facilities.

Please contact Mary Turner at for more information.

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