(1) Except as provided in subsection (2) of this section, in the discretion of the agency head, the presiding officer in an administrative hearing shall be:
(a) The agency head or one or more members of the agency head;
(b) If the agency has statutory authority to do so, a person other than the agency head or an administrative law judge designated by the agency head to make the final decision and enter the final order;
(c) One or more administrative law judges assigned by the office of administrative hearings in accordance with chapter 34.12 RCW; or
(d) A person or persons designated by the secretary of health pursuant to RCW 43.70.740.
(2) An agency expressly exempted under RCW 34.12.020(4) or other statute from the provisions of chapter 34.12 RCW or an institution of higher education shall designate a presiding officer as provided by rules adopted by the agency.
(3) Any individual serving or designated to serve alone or with others as presiding officer is subject to disqualification for bias, prejudice, interest, or any other cause provided in this chapter or for which a judge is disqualified.
(4) Any party may petition for the disqualification of an individual promptly after receipt of notice indicating that the individual will preside or, if later, promptly upon discovering facts establishing grounds for disqualification.
(5) The individual whose disqualification is requested shall determine whether to grant the petition, stating facts and reasons for the determination.
(6) When the presiding officer is an administrative law judge, the provisions of this section regarding disqualification for cause are in addition to the motion of prejudice available under RCW 34.12.050.
(7) If a substitute is required for an individual who becomes unavailable as a result of disqualification or any other reason, the substitute must be appointed by the appropriate appointing authority.
(8) Any action taken by a duly appointed substitute for an unavailable individual is as effective as if taken by the unavailable individual.