Cal. Health & Saf. Code § 18946
Except as provided in Section 18947, the commission may hear the appeal itself, or by designating a member of the commission to be a hearing officer, or may refer the appealing parties to an advisory panel, a committee, or to a hearing officer appointed by the Office of Administrative Hearings, wherein the hearing officer designated by the commission or appointed by the Office of Administrative Hearings, should, where possible, possess some expertise in the technical aspects of the appeal. If a referral is made, the panel, committee, or hearing officer may make an investigation and conduct hearings as they deem appropriate, provided that all interested agencies or parties shall have a full and fair opportunity to be heard. A proposed written decision shall be submitted to the commission which the commission may adopt, adopt as modified, or reject. The commission shall render its decision or interpretation in writing.
Ca. Health and Saf. Code § 18946