Wash. Rev. Code § 41.80.001
Collective bargaining negotiations under this chapter shall commence no later than July 1, 2004. A collective bargaining agreement entered into under this chapter shall not be effective prior to July 1, 2005. However, any collective bargaining agreement entered into before July 1, 2004, covering employees affected by this section and RCW 41.80.010 through 41.80.130, that expires after July 1, 2004, shall, unless a superseding agreement complying with this section and RCW 41.80.010 through 41.80.130 is negotiated by the parties, remain in full force during its duration, but the agreement may not be renewed or extended beyond July 1, 2005, or until superseded by a collective bargaining agreement entered into under this section and RCW 41.80.010 through 41.80.130, whichever is later. The duration of any collective bargaining agreement under this chapter shall not exceed one fiscal biennium.
RCW 41.80.001