1. (a) An increase in emissions from operational or physical changes at an existing facility authorized by a flexible permit is insignificant, for the purposes of minor new source review under this subchapter, if the increase does not exceed either the emission cap or individual emission limitation. This section does not apply to an increase in emissions from a new facility nor to the emission of an air contaminant not previously emitted by an existing facility.

2. (b) For purposes of major new source review, determination of a significant increase in emissions that does not result in an increase to the emission cap includes evaluation of the following:

   1. (1) An increase in emissions from operational or physical changes or series of related changes that would constitute a major modification as defined by §116.12 of this title (relating to Nonattainment and Prevention of Significant Deterioration Review Definitions) must comply with Subchapter B, Division 5 or 6 of this chapter (relating to Nonattainment Review Permits; and Prevention of Significant Deterioration Review, respectively).
   2. (2) Unless a plant-wide applicability limit has been established for the pollutant under Subchapter C of this chapter (relating to Plant-wide Applicability Limits), the permit holder shall document that the change is not a major modification as defined in §116.12 of this title, and maintain the documentation required by Subchapter B, Division 1 of this chapter (relating to New Source Review Permits) concerning actual to projected actual emission increases.
   3. (3) When determining whether a change is a major modification as defined in §116.12 of this title, the project emissions increase and the project net shall be determined as specified as defined in §116.12 of this title, regardless of how the existing facilities are authorized.
   4. (4) For new facilities, or modified facilities under an emission cap for the pollutant where the permit holder elects to use potential to emit rather than projected actual emissions from the facility to determine the project emissions increase, the potential to emit shall be considered as the proposed emissions cap unless an alternate method is demonstrated.
   5. (5) A separate permit limit or physical constraint may be established to limit the facility's potential to emit for facilities that are under a cap or have individual emission limits.
   6. (6) If the project emission increase is such that a de minimis threshold test (netting) is required for a pollutant, the analysis shall be submitted to the commission for review and approval prior to making the change. If netting is not required, the information shall be submitted with the next permit amendment or renewal application.
3. (c) The permit holder shall complete an air quality analysis to demonstrate that the proposed action will not interfere with attainment and maintenance of the National Ambient Air Quality Standards if there may be an increase in emissions from operational or physical changes at any existing facility, group of facilities, or account authorized by a flexible permit and the area is not designated as nonattainment for the pollutant. If the emission increase may result in ambient concentrations greater than de minimis for that pollutant, the air quality analysis shall be submitted to the executive director for review and approval prior to making the change.

Source Note:The provisions of this §116.718 adopted to be effective December 8, 1994, 19 TexReg 9360; amended to be effective January 6, 2011, 35 TexReg 11909.