Wash. Rev. Code § 47.52.170
No witness's testimony shall be received unless he or she shall have been duly sworn, and the board may cause all oral testimony to be stenographically reported. Members of the board, its duly authorized representatives, and all persons duly commissioned by it for the purpose of taking depositions, shall have power to administer oaths; to preserve and enforce order during such hearings; to issue subpoenas for, and to compel the attendance and testimony of witnesses, or the production of books, papers, documents and other evidence, or the taking of depositions before any designated individual competent to administer oaths, and it shall be their duty so to do; to examine witnesses; and to do all things conformable to law which may be necessary to enable them, or any of them, effectively to discharge the duties of their office.
RCW 47.52.170