California Code, Government Code - GOV § 31648.55

(a) The member serves in the same office.

(b) The service is not a basis for any other present or future public retirement benefits.

(c) The member, prior to the effective date of retirement, by lump-sum payment or by installment over a period not to exceed five years, (1) contributes an amount equal to twice the contributions the members would have made to the retirement fund if the member had been a member during the same length of time as that for which the member has elected to receive credit as service, computed by applying the rate of contribution first applicable to the member upon commencement of membership and (2) pays any interest that would have accrued to that amount.

This section shall not be operative in any county, until adopted by resolution of the board of supervisors.