To limit pollution air permits have been issued for construction and use of equipment and operations found to release air contaminates. There are both state and federal clean air permit programs. Two programs discussed further in this section are
New Source Review (NSR) permits, and Clean Air Act Amendments,
Title V operating permits
New Source Review
New major stationary sources or major modifications of existing major sources which would emit a nonattainment pollutant must obtain a nonattainment permit before construction begins. This permit will include requirements to: 1) offset projected emissions of the specific pollutants which do not meet the NAAQS with emission reductions of the pollutants at existing facilities, and 2) install pollution control technology to achieve the lowest achievable emission rate.
A "major" source is generally one with the potential to emit more than 100 tons per year (tpy) or more of a nonattainment pollutant. In ozone nonattainment areas, this level is reduced to to 10 - 50 tpy depending on the severity of the ozone nonattainment area. For serious carbon monoxide nonattainment areas, any source with the potential to emit 50 tpy or more would need a nonattainment permit. For serious particulate matter nonattainment areas, a major source is one with emissions of 70 tpy or more.
In a parallel track, new sources in areas that attain the NAAQS must obtain a Prevention of Significant Degradation (PSD) preconstruction permit. The PSD permit includes a requirement to comply with ambient air quality levels and to install "best available control technology" (BACT) for criteria pollutants emitted in "significant" levels. (Note that some states extend BACT coverage to air toxics as well.) A "new" source for PSD purposes, is one of 28 listed sources in sec. 169 of the CAA with the potential to emit 100 tpy or more of any air pollutant subject to regulation under the CAA or any other source with the potential to emit 250 tpy of any air pollutant subject to regulation under the CAA.
For both nonattainment and PSD new source review, a modified source is "any physical change in, or change in the method of operation of, a stationary source which increases the amount of any air pollutant emitted by such source or which results in the emission of any air pollutant not previously emitted". However, in its implementing regulations, EPA has limited application of PSD and nonattainment permit requirements to those major modifications that constitute a nonroutine physical or operational change and which result in a significant net increase in emissions.
The PSD and nonattainment regulations are quite complicated; the actual regulations, EPA interpretation and guidance documents, and relevant court decisions need to be closely studied for details that may be applicable to a particular fact situation.
Title V
EPA’s operating permit rule implements Title V of the 1990 CAA Amendments. The Title V operating permit requirements are primarily procedural and were not intended by Congress to create new substantive requirements. The Title V requirements do not change the review process for new or modified sources of air pollutants. Congress intended that the states administer the operating permit program. States retain the right to impose more stringent operating permit requirements.