(a) For a proposed NSR major modification, BACT is required for each emission source that is part of the proposed modification, for all regulated NSR contaminants to be emitted by the proposed modification which equal or exceed the applicable significant net emission increase threshold listed in table 6 of Subpart 231-13 of this Part or, in the case of GHGs, the applicable significant project threshold in table 6 of Subpart 231-13 of this Part.

(b) For phased construction projects, the determination of BACT must be reviewed and modified as appropriate at the latest reasonable time which occurs no later than 18 months prior to commencement of construction of each independent phase of the project. At such time, the applicant may be required to demonstrate the adequacy of any previous determination of BACT for the modification.

(c) In establishing the final BACT limit, the department may consider any new information, including recent permit decisions, or public comment received, subsequent to the submittal of a complete application.

(d) BACT will not be established in final form until the final permit is issued.