Wash. Admin. Code § 132S-20-065
Discovery, including investigation in adjudicative proceeding, may be permitted at the discretion of the presiding officer. In permitting discovery, the presiding officer shall make reference to the civil rules of procedure. The presiding officer shall have the power to control the frequency and nature of discovery permitted, and to order discovery conferences to discuss discovery issues.
Prehearing conferences. Where an adjudicative procedure includes a hearing, prehearing conferences or other conferences may be held at the discretion of the presiding officer, or pursuant to a motion by either of the parties for a prehearing conference for the settlement or simplification of issues. The prehearing conference may be conducted by telephone, television, or other electronic means, at the discretion of the presiding officer and where the rights of the parties will not be prejudiced. Each participant in the conference shall have an opportunity to participate effectively in, to hear, and if technically and economically feasible, to see the entire proceeding while it is taking place.
Wash. Admin. Code § 132S-20-065