A labor agreement signed by a port district may contain:
(1) Provisions that the employee organization chosen by a majority of the employees in a grouping or unit will be recognized as the representative of all employees in the classification included in such grouping or unit;
(2) Maintenance of membership provisions including dues cross-check arrangements as provided in *RCW 41.56.231; and
(3) Provisions providing for binding arbitration, the expenses being equally borne by the parties, in matters of contract interpretation and the settlement of jurisdictional disputes.