Air Pollution Source Types  

Major and Minor

Different permit classifications are created through the determination of whether or not the given air pollutant source is a major or minor source of air pollutants. A major source of air pollutants is determined by the emissions from one or more stationary sources of the same type located in one or more adjacent properties and or under a common control. The emission thresholds set for air pollutant sources, to be classified as major or minor sources, vary depending on the type of emission of air pollutants. If the following emission thresholds are met, in equivalence or excess, a source air pollutant is classified as a major source, otherwise, the source is considered a minor:   

• Any source that can emit or have the potential to emit (the maximum possible air pollution emissions allowed from a stationary sources physical and operational design, this is altered if limitations are placed on the source) 10 tons per year (TPY) or more of any one hazardous air pollutant (HAP).
• 25 TPY or more of any combination of HAP’s.
• 50 TPY of volatile organic compounds (VOC).

• 100 TPY of any other regulated pollutant.

*These standards/thresholds can be altered depending on location and air pollutant type.

Stationary, Portable, and Area

A stationary source is any building, structure, facility, or installation that emits or may emit any regulated air pollutant or any which is listed within section 112(b) of the clean air act.

A portable Source is an air contaminant source that is specifically designed to be transferred to a new site as need warrant and thus cannot become permanently fixed to a location. If you have inquiries about this please visit the Ohio EPA’s Engineering Guide #44 referring to frequently asked questions pertaining to exemptions, definitions, time limits, and permitting. Available through the Ohio EPA. 

An area source of air pollution is any stationary source of HAP’s that is not a major source as defined in the Code of Federal Regulations (CFR 40 part 63)

Facility Classifications

If a person or facility have sources of air pollutants, a permit to pollute is required. The persons or facilities with these sources are assigned differing categorizations dependent on the size, location, products, emission types, and amounts of air pollutants released, and or created, from their air polluting source and or sources. This categorization, classification, is based off of pre-defined criteria. The classifications are for Title V (largest facilities and heaviest polluters), non-title V (often small businesses), and synthetic minor (restrictions placed on operating air pollutant sources to reduce emissions temporally and the facilities potential to emit. These operational restrictions often allow a facility to be exempt from the requirements for a Title-V permit).

A facility is classified as a Title V facility if any of the following are met (not complete list)

• Any major source is present.
• Any source, including an area source, is subject to a standard or requirement under sec. 111 and 112 of the Clean Air Act (i.e. Hazardous Air Pollutants (HAP’s)).
• Any affected source, defined within Title IV of the Clean Air Act. This refers to requirements necessary to reduce the adverse effects of acid deposition mainly through reductions in annual emissions of sulfur dioxide and nitrogen oxide emissions.
• Any source in a source category designated by the administrator in accordance with the Code of Federal Regulations Title 40 part 70 (40 CFR 70.3) which includes state operating permit programs associated with required permitting.