This bill significantly amends Section 401 of the Federal Water Pollution Control Act (FWPCA) to streamline and narrow the scope of water quality certifications. It redefines the criteria for these certifications, focusing specifically on discharges that directly result in violations of certain FWPCA provisions, rather than broader activities or potential impacts. The legislation aims to provide greater clarity and predictability in the certification process for federal licenses and permits by focusing on specific, measurable impacts. Key changes include requiring states, interstate agencies, and the Administrator to publish their certification requirements within 30 days of the Act's enactment. Decisions to grant or deny a certification must be based only on compliance with specific sections of the FWPCA (301, 302, 303, 306, and 307) and must be provided in writing to the applicant. Furthermore, certifying authorities must identify all necessary additional materials or information within 90 days of receiving a certification request. The bill also explicitly defines the applicable provisions of these sections, clarifying that they encompass specific effluent limitations, performance standards, prohibitions, and state law requirements. These state law requirements must implement water quality criteria under Section 303 and be necessary to support the designated use or uses of the receiving navigable waters. This precise definition further restricts the scope of review for water quality certifications.