"True minor source" means a source that emits, or has the potential to emit, regulated New Source Review (NSR) pollutants in amounts that are less than the major source thresholds under either the Prevention of Significant Deterioration (PSD) program at 40 CFR 52.21, or the Major NSR program for Nonattainment Areas in Indian Country at 40 CFR 49.166 through 49.173, but equal to or greater than the minor NSR thresholds in § 49.153, without the need to take an enforceable restriction to reduce its Potential to Emit (PTE) to such levels. The PTE includes fugitive emissions, to the extent that they are quantifiable, only if the source belongs to one of the 28 source categories listed in part 51, Appendix S, paragraph II.A.4(iii) or § 52.21(b)(1)(iii) of 40 CFR, as applicable.

"Synthetic minor source" means a source that otherwise has the potential to emit regulated NSR pollutants in amounts that are at or above the thresholds for major sources in 40 CFR 49.167, 40 CFR 52.21 or 40 CFR 71.2, as applicable, but has taken a restriction so that its PTE is less than such amounts for major sources. Such restrictions must be enforceable as a practical matter (as defined in 40 CFR 49.152).

“Synthetic minor Hazardous Air Pollutant (HAP) source” means a source that otherwise has the potential to emit HAPs in amounts that are at or above those for major sources of HAP in 40 CFR 63.2, but that have taken a restriction so that its PTE is less than such amounts for major sources. Such restrictions must be enforceable as a practical matter.

The designation of synthetic minor source is allowed for both regulated NSR pollutants and HAPs and although you may choose to obtain such emission limitations at your own discretion, once you have accepted an enforceable emission limitation, you must comply with that limitation. This is necessary to ensure that you are legally prohibited from operating as a major source. In addition, if you apply for a synthetic minor source or synthetic minor HAP source, you must comply with the same public participation requirements and the same procedures for final permit issuance and administrative and judicial review found at 40 CFR 49.157 and 40 CFR 49.159, respectively.

Any synthetic minor permit will be granted or denied no later than 1 year after the date the application is deemed complete and all additional information necessary to make an informed decision has been provided.

To Apply

To apply for a synthetic minor permit, complete the following forms and send them to your Reviewing Authority:

• New Source General Application (PDF)(15 pp, 76 K)
• Synthetic Minor Limit Application (PDF)(4 pp, 34 K)