Section 121.16 - When the Administrator certifies(a) Certification or waiver by the Administrator is required where no state, Tribe, or interstate agency has authority to give such a certification.(b) When acting pursuant to this section, the Administrator shall comply with the requirements of Clean Water Act section 401 and this part. 85 FR 42284 , 9/11/2020; 88 FR 66661 , 11/27/2023