40 CFR § 72.85 - Permit reopenings.
(a) The permitting authority shall reopen an Acid Rain permit for cause whenever:
(1) Any additional requirement under the Acid Rain Program becomes applicable to any affected unit governed by the permit;
(2) The permitting authority determines that the permit contains a material mistake or that an inaccurate statement was made in establishing the emissions standards or other terms or conditions of the permit, unless the mistake or statement is corrected in accordance with § 72.83; or
(3) The permitting authority determines that the permit must be revised or revoked to assure compliance with Acid Rain Program requirements.
(b) In reopening an Acid Rain permit for cause, the permitting authority shall issue a draft permit changing the provisions, or adding the requirements, for which the reopening was necessary. The draft permit shall be subject to the requirements of subparts E, F, and G of this part.
(c) As provided in §§ 72.73(b)(1) and 72.74(c)(2), the permitting authority shall reopen an Acid Rain permit to incorporate nitrogen oxides requirements, consistent with part 76 of this chapter.
(d) Any reopening of an Acid Rain permit shall not affect the term of the permit.