Provides that beginning July 1, 2008, and ending September 30, 2008, an eligible member of plan 1 of the teachers' retirement system may make a one-time irrevocable election, filed in writing with the department, to leave any service credit earned as a member of plan 1 of the teachers' retirement system in that system and join plan 1 of the public employees' retirement system. An eligible member who makes this election may, upon satisfying the requirements of chapter 41.54 RCW, become a dual member of the two systems in order to combine service in each system for the purpose of determining benefit eligibility.