WA SB5503

Requires the Public Employment Relations Commission to mandate offers of proof on challenged employees during new organizing petitions for bargaining units of unrepresented workers, whether elections occur by mail ballot or cross-check

Allows the commission to set hearing dates without party consent and draw adverse inferences from subpoena non-compliance, except when unions invoke privilege under RCW 5.60.060(11) and 49.36.040, which triggers in camera review

Permits consolidation of two or more bargaining units into a single larger unit upon petition by an employee organization that already represents both units, if the commission determines consolidation is appropriate

Adds the American Arbitration Association as an alternative source for selecting interest arbitrators in Department of Corrections and ferry system employee collective bargaining disputes, with party consent

Prohibits public employers from requiring workers to waive statutory rights to make claims under state or federal law as a condition of settling a grievance under a collective bargaining agreement