California Code, Government Code - GOV § 31812

(b)(1) With respect to persons who become members of a county retirement system after the effective date of the amendments to this section enacted at the 1979-80 Regular Session, each member shall contribute as provided for in Article 6 (commencing with Section 31620) or (in case of those members defined in Sections 31470.2, 31470.4, and 31470.6) Article 6.8 (commencing with Section 31639) of this chapter less an amount equal to one-third of that portion of such contribution which is payable with respect to the first one thousand fifty dollars ($1,050) monthly wage, or in counties where the board of supervisors pursuant to subdivision (b) of Section 31808.6 elects to compute the retirement allowance of safety members according to the provisions of Section 31664, each safety member shall make contributions as provided for in Article 6.8 of this chapter with respect to all of his or her monthly wage.

(2) This subdivision may be made applicable in any county of over six million population on the first day of the month after the board of supervisors of such county adopts by majority vote a resolution providing that this subdivision shall become applicable in such county.