Wash. Rev. Code § 49.08.010
It shall be the duty of the chair of the public employment relations commission upon application of any employer or employee having differences, as soon as practicable, to visit the location of such differences and to make a careful inquiry into the cause thereof and to advise the respective parties, what, if anything, ought to be done or submitted to by both to adjust said dispute and should said parties then still fail to agree to a settlement through said chair, then said chair shall endeavor to have said parties consent in writing to submit their differences to a board of arbitrations to be chosen from citizens of the state as follows, to wit: Said employer shall appoint one and said employees acting through a majority, one, and these two shall select a third, these three to constitute the board of arbitration and the findings of said board of arbitration to be final.
RCW 49.08.010
Public employment relations commission: Chapter 41.58 RCW.