; or (ii) if it is the opinion of the head of the Federal agency under subparagraph (A) that a violation has not occurred, an explanation for the basis for the determination by the head of the Federal agency. Informational Requests 439. (a) Notice Required The head of a Federal agency that receives funds under this Act shall respond timely and completely to requests of the Comptroller General of the United States for access to records or interviews with agency employees. Should the head of a Federal agency fail to provide access to records or interviews within 30 days of the request or by such date as is otherwise specified by the Comptroller General, and in such manner as is acceptable to the Comptroller General, the Comptroller General shall provide the appropriate congressional committees and the head of the Federal agency with notice of the undue delay. (b) Agency Responses Required Not later than 30 days after the head of the Federal agency receives a notice under subsection (a), the head of the Federal agency shall respond in writing to the Comptroller General and the appropriate congressional committees with an explanation for the delay and a proposed timetable for providing the requested records or interviews. Not later than 30 days after this response is submitted, and every 30 days thereafter until the Comptroller General informs the appropriate congressional committees that the head of the federal agency has provided access to the requested records or interviews in a manner acceptable to the Comptroller General, the head of the Federal agency shall update the agency’s response in writing. (c) Relationship to Existing Authority Nothing in this section shall be construed to limit, amend, supersede, or restrict in any manner any existing authority of the Comptroller General. FUNDING PROHIBITION ON WATER QUALITY CERTIFICATIONS 440. None of the funds made available by this Act may be used to finalize, implement, or enforce the proposed rule entitled Updating Regulations on Water Quality Certification ,