California Code, Government Code - GOV § 31469.8

(a) In a county of the 18th class, as defined by Sections 28020 and 28039, as amended by Chapter 1204 of the Statutes of 1971, the board of supervisors may meet and confer pursuant to the Meyers-Milias-Brown Act (Chapter 10 (commencing with Section 3500) of Division 4 of Title 1) with a recognized employee organization that represents county employees who are not safety members because the board of supervisors has not made Section 31469.4 applicable in the county, and endeavor to reach agreement on any conditions to be required of employees or an employee organization seeking to have Section 31469.4 made applicable.  The conditions shall include, but not be limited to, whether the employees shall be required to pay all or part of the following:

(b) Any payments made by employees on behalf of the employer to cover the increased cost of safety retirement shall be as determined upon actuarial advice from the retirement board's actuaries, and shall be approved by the board of retirement.

(c) This section shall not be operative in the county until the date on which the board of supervisors, by resolution adopted by a majority vote, makes the provisions of this section applicable in the county.