Two years after a retirement system established by this chapter becomes operative, a safety member except an elective officer, the sheriff and undersheriff, and the marshal appointed to serve the superior court within the county, shall be retired as of the first day of the calendar month next succeeding that in which he or she attains age 60.

This section shall not be operative in any county until such time as the board of supervisors shall, by resolution adopted by a majority vote, make this section applicable in the

county.