Minor Sources

Smaller facilities usually fall under a minor source or general permit. These facilities will have PTEs above the exempt thresholds but below the major source thresholds. As with Title V permits, minor source permitting must be initiated prior to construction.


For example, in NY, if a facility emits between 12.5 and 25 tpy of NOx they would be classified with an Air State Facility Permit. This permitting level is much less strenuous, requiring only one annual capping report to confirm that facility emissions fell below the 25 tpy permitted cap, based on a 12-month rolling total.  Due to this lower reporting level, many facilities will often accept fuel limitations of operating restrictions to qualify for an ASF permit as a synthetic minor.


Up until recently, ASF permits never expired and often have testing and reporting requirements “only upon request”. The NYSDEC modified 201-5.3 to limit ASF permit terms to ten years for all new and modified facilities. ASF permits modifications must be submitted at least 30 days prior to the previous permit expiration date.  


Very small facilities may fall under the 12.5 tpy threshold for NOx and be able to file an Air Registration. This permit level has no reporting or testing requirements and never expires as long as emissions remain below the threshold. Other states, like New Jersey, offer various permitting options under Subchapter 8 for these smaller or exempt sources.


In the event that operations mandate ramping up existing emission units or installing new units, a netting analysis would be completed to determine if the proposed project triggers New Source Review (NSR) or Prevention of Significant Deterioration (PSD). This analysis can be performed up to five years prior to a projected construction start date. 


Minor sources are more likely to not have environmental professionals on staff, and more likely to have frequent managerial changes. Reliable assistance from practiced professionals can go a long way to ease these potential disruptions. 


Contact a Cemtek representative to discuss how we can help your company plan and permit for upcoming projects as well as develop an environmental conducive to compliance going forward.

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Randy Thompson

Useful Information


Example (NY): Air State Facility Permit/Minor Source Permit (Annual Facility PTE of less than 50% of the major source threshold)

  • Permit Application with public notice 
  • One Annual Emissions Capping Certification report
  • Occasionally quarterly or semi-annual compliance reporting
  • Testing required only upon request
  • Renewal every ten years for new or modified facilities
  • Some states such as NJ require that minor sources submit an annual emission statement. 

Air Registration (Annual Facility Potential to Emit of less than 12.5 tons of NOx)

  • Permit Application
  • No Annual reporting