Cal. Gov. Code § 31801
It is the intent of the Legislature that the enactment of this article shall authorize persons in positions covered by a retirement system pursuant to this chapter to participate in the federal old age and survivors insurance provisions of the Social Security Act without jeopardizing the continued maintenance of their local system.
To this end and notwithstanding any other provisions of this chapter, the provisions of this article, when made applicable by resolution of the governing board, shall supersede or modify any inconsistent provision in this chapter in its application to every member whose position is included in an agreement between the state and federal government for coverage under the old age and survivors insurance provisions of the Social Security Act.
The provisions of this chapter are not repealed by this article, however, and except as superseded or modified by this article in their application to members who are covered by old age and survivors insurance, they shall continue to be fully effective and operative.
Nothing in this article shall authorize the extension of the federal system to service in any policeman's or fireman's position covered by a separate retirement system unless all of the policemen or firemen are included as a unit without any division of their separate retirement system.
When federal benefits are to be extended to any fireman's or policeman's position pursuant to this part they shall vote separately from other members of such system in all cases without regard to their classification as miscellaneous members or otherwise, and notwithstanding Section 22009.1, such system shall constitute a separate retirement system with respect to the positions of policemen or firemen, or both, covered by the system.
Ca. Gov. Code § 31801