(a) Upon receipt of the recommended decision and transcript and after the 20-day period for receiving written comments on the recommended decision has passed, the Assistant Administrator shall make a final decision on the proposed regulations and waiver, where applicable. The Assistant Administrator's decision may affirm, modify, or set aside, in whole or in part, the recommended findings, conclusions and decision of the presiding officer. The Assistant Administrator may also remand the hearing record to the presiding officer for a fuller development of the record.

(b) The Assistant Administrator's decision shall include:

(1) A statement containing a description of the history of the proceeding;

(2) Findings on the issues of fact with the reasons therefor; and

(3) Rulings on issues of law.

(4) The Assistant Administrator's decision shall be published in the Federal Register. If the waiver is approved, the final adopted regulations shall be promulgated with the decision.