In any county the board of supervisors may provide by ordinance that members specified in the ordinance shall be credited, for up to 100 percent of sick leave accumulated as of the date of their retirement, and that sick leave credit shall be in addition to service credit. The additional cost to the retirement system shall be borne by the county or district.

This section shall not apply to members who are employed by a district unless the governing board of the district provides by resolution for its application to such members.