Section 102431 Of Article 2. Retirement System From California Public Utilities Code >> Division 10. >> Part 14. >> Chapter 6. >> Article 2.

. The board may contract with the board of administration of the Public Employees' Retirement System and enter all or any portion of its employees under such system, provided, that no employees of the district in a bargaining unit which is represented by a labor organization shall be included in such contract except as authorized by a collective bargaining agreement.