If this article is effective subsequent to the effective date of the coverage of members under the federal system the employees' federal contributions required of members with respect to salary and wages paid for service rendered after the effective date of coverage of such member under the federal system and prior to the time that federal contributions are first deducted from the salary or wage of such members, shall be paid to the county or district by the member in such manner as may be determined by the Retirement Board.
Ca. Gov. Code § 31814