27 CFR § 19.679
Duration of permit
April 24, 2020
The proprietor of an alcohol fuel plant may conduct the operations authorized by the permit on a continuing basis unless:
(a) The proprietor voluntarily surrenders the permit;
(b) TTB suspends or revokes the permit pursuant to §19.697; or
(c) The permit is automatically terminated under its own terms or in accordance with §19.684.