40 CFR § 72.81 - Permit modifications.
(a) Permit revisions that shall follow the permit modification procedures are:
(1) Relaxation of an excess emission offset requirement after approval of the offset plan by the Administrator;
(2) Incorporation of a final nitrogen oxides alternative emission limitation following a demonstration period;
(3) Determinations concerning failed repowering projects under § 72.44(g)(1)(i) and (2) of this part.
(b) The following permit revisions shall follow, at the option of the designated representative submitting the permit revision, either the permit modification procedures or the fast-track modification procedures under § 72.82 of this part:
(1) Consistent with paragraph (a) of this section, incorporation of a compliance option that the designated representative did not submit for approval and comment during the permit issuance process; except that incorporation of a reduced utilization plan that was not submitted during the permit issuance process, that does not designate a compensating unit, and that meets the requirements of § 72.43 of this part, may use the administrative permit amendment procedures under § 72.83 of this part;
(2) Changes in a substitution plan or reduced utilization plan that result in the addition of a new substitution unit or a new compensating unit under the plan;
(3) Addition of a nitrogen oxides averaging plan to a permit;
(4) Changes in a Phase I extension plan, repowering plan, nitrogen oxides averaging plan, or nitrogen oxides compliance deadline extension; and
(5) Changes in a thermal energy plan that result in any addition or subtraction of a replacement unit or any change affecting the number of allowances transferred for the replacement of thermal energy.
(c)
(1) Permit modifications shall follow the permit issuance requirements of:
(i) Subparts E, F, and G of this part, where the Administrator is the permitting authority; or
(ii) Subpart G of this part, where the State is the permitting authority.
(2) For purposes of applying paragraph (c)(1) of this section, a requested permit modification shall be treated as a permit application, to the extent consistent with § 72.80 (c) and (d).