Wash. Rev. Code § 43.21B.160
In all appeals, the hearings board shall have all powers relating to administration of oaths, issuance of subpoenas, and taking of depositions as are granted to agencies in chapter 34.05 RCW, the Administrative Procedure Act. The hearings board, and each member thereof, shall be subject to all duties imposed upon, and shall have all powers granted to, an agency by those provisions of chapter 34.05 RCW relating to adjudicative proceedings. In the case of appeals within the jurisdiction of the hearings board, the hearings board, or any member thereof, may obtain such assistance, including the making of field investigations, from the staff of the director as the hearings board, or any member thereof, may deem necessary or appropriate. Any communication, oral or written, from the staff of the director to the hearings board shall be presented only in an open hearing.
RCW 43.21B.160
Effective date-1989 c 175: See note following RCW 34.05.010.