Washington Revised Code Title 34. Administrative Law § 34.05.437. Pleadings, briefs, motions, service

(1) The presiding officer, at appropriate stages of the proceedings, shall give all parties full opportunity to submit and respond to pleadings, motions, objections, and offers of settlement.

(2) At appropriate stages of the proceedings, the presiding officer may give all parties full opportunity to file briefs, proposed findings of fact and conclusions of law, and proposed initial or final orders.

(3) A party that files a pleading, brief, or other paper with the agency or presiding officer shall serve copies on all other parties, unless a different procedure is specified by agency rule.