Except as otherwise provided by statute, the department, one or more members of the department, or one or more hearing officers designated and empowered by the department to conduct hearings shall preside as hearing officers. Hearings shall be conducted in an impartial manner. Upon filing in good faith by a party of a timely and sufficient affidavit of personal bias or disqualification of a hearing officer, the department shall determine the matter as part of the record in the case, and its determination shall be a matter subject to judicial review at the conclusion of the adjudicatory proceedings. Whenever a hearing officer is disqualified or it become impractical for him to continue the hearing, another hearing officer may be assigned to continue with the case unless it is shown that substantial prejudice will result therefrom.