40 CFR §62.15040

1. (a)Class I units. If you plan to achieve compliance more than 1 year following the effective date of this subpart and a permit modification is not required, or more than 1 year following the date of issuance of a revised construction or operation permit if a permit modification is required, you must meet five increments of progress:
   1. (1)Submit a final control plan.
   2. (2)Submit a notification of retrofit contract award.
   3. (3)Initiate onsite construction.
   4. (4)Complete onsite construction.
   5. (5)Achieve final compliance.
2. (b)Class II units. If you plan to achieve compliance more than 1 year following the effective date of this subpart and a permit modification is not required, or more than 1 year following the date of issuance of a revised construction or operation permit if a permit modification is required, you must meet two increments of progress:
   1. (1)Submit a final control plan.
   2. (2)Achieve final compliance.