If, after considering the complete description, the record of a hearing, if any, held pursuant to §121.23, and such other information and data as the Regional Administrator deems relevant, the Regional Administrator determines that there is reasonable assurance that the proposed activity will not result in a violation of applicable water quality standards, he shall so certify. If the Regional Administrator determines that no water quality standards are applicable to the waters which might be affected by the proposed activity, he shall so notify the applicant and the licensing or permitting agency in writing and shall provide the licensing or permitting agency with advice, suggestions, and recommendations with respect to conditions to be incorporated in any license or permit to achieve compliance with the purpose of this Act. In such case, no certification shall be required.