(a) Upon request of either party the presiding officer may render an oral initial decision at the close of the hearing when the nature of the case and the public interest warrant. If a party desires an oral initial decision he or she shall notify the presiding officer and the opposing party at least 5 days prior to the date set for hearing. Parties may then submit proposed findings and conclusions orally or in writing at the conclusion of the hearing.

(b) If an oral initial decision is not rendered, the presiding officer shall render a written initial decision with all due speed after the parties have submitted all posthearing material. The initial decision shall become the final agency decision unless it is appealed.

(c) The initial decision shall include findings upon all material issues of fact and law presented on the record and the reasons for those findings.