(a) Flexible permit amendments. All representations with regard to construction plans and operation procedures in an application for a flexible permit or flexible permit amendment, as well as any general and special conditions, become conditions upon which the subsequent flexible permit is issued. Except as provided in §116.118 of this title (relating to Construction While Permit Amendment Application Pending), it shall be unlawful for any person to vary from such representation or flexible permit provision if the change will cause a change in the method of control of emissions or the character of the emissions, will relax emission controls, or will result in a significant increase in emissions unless application is made to the executive director to amend the flexible permit in that regard and such amendment is approved by the executive director or commission. Applications to amend a flexible permit shall be submitted with a completed Form PI-1 and are subject to the requirements of §116.711 of this title (relating to Flexible Permit Application).
(b) Flexible permit alterations.
  (1) A flexible permit alteration is for any variation from a representation in a flexible permit application or a general or special provision of a flexible permit that does not require a flexible permit amendment.
  (2) All flexible permit alterations which may involve a change in a general or special condition contained in the flexible permit, or affect control equipment performance must receive prior approval by the executive director. The executive director shall be notified in writing of all other flexible permit alterations within ten days of implementing the change, unless the permit provides for a different method of notification. Any flexible permit alteration request or notification shall include information sufficient to demonstrate that the change does not interfere with the owner or operator's previous demonstrations of compliance with the requirements of §116.711 of this title, including the protection of public health and welfare. The appropriate commission regional office and any local air pollution program having jurisdiction shall be provided copies of all flexible permit alteration documents.
  (3) Flexible permit alterations shall not be subject to the requirements of best available control technology identified in §116.711(2) of this title.
(c) Changes not requiring an amendment or alteration. The following changes do not require an amendment or alteration, except that an amendment is required if the change will cause a change in the method of control of emissions or the character of the emissions, will relax emission controls, will result in a significant increase in emissions as determined under §116.718 of this title (relating to Significant Emission Increase), or conflicts with an existing permit condition:
  (1) a change in throughput; or
  (2) a change in feedstock.
(d) Permit by rule under Chapter 106 of this title (relating to Permits by Rule) in lieu of permit amendment or alteration.
  (1) Regardless of subsection (a) or (b) of this section, no permit amendment or alteration is required if the changes to the permitted facility qualify for a permit by rule under Chapter 106 of this title unless prohibited by permit provision as provided in §116.715 of this title (relating to General and Special Conditions). All such changes permitted by rule to a permitted facility shall be incorporated into that facility's permit at such time as the permit is amended or renewed.
  (2) Emission increases authorized by Chapter 106 of this title at an existing facility authorized by a flexible permit shall not cause an exceedance of the emissions cap or individual emission limitation.

Source Note: The provisions of this §116.721 adopted to be effective December 8, 1994, 19 TexReg 9360; amended to be effective July 8, 1998, 23 TexReg 6973; amended to be effective September 4, 2000, 25 TexReg 8668; amended to be effective January 6, 2011, 35 TexReg 11909; amended to be effective July 31, 2014, 39 TexReg 5777; amended to be effective August 6, 2020, 45 TexReg 5351