The Commission may employ technical, administrative, or clerical staff or other aid as may be necessary for its respective departments to carry out the provisions of Chapters 1 to 17, 21, 23, and 33 of this title and may fix the compensation for employment. The Commission may also employ and utilize administrative law judges or hearing officers to preside over rate hearings and other contested matters. The administrative law judge or hearing officer has full authority, subject to being overruled by the Commission, to rule on questions concerning the conduct of the case and the admission of evidence but may not participate in the determination on the merits of any case. The compensation, costs, and expenses incurred incident to utilization of an administrative law judge or hearing officer must be fixed or approved by the Commission and must be included as expenses of the Commission under Section 58-3-100.