(a) The annuity savings fund shall be the fund in which shall be accumulated the contributions deducted from the compensation of members in order to provide for their annuities. Contributions to and payments from the annuity savings fund shall be made as follows:

(1) Each employer shall cause 5 percent of the earnable compensation to be deducted from the salary of each member for each and every payroll period; but the employer shall not have any such deduction taken from the compensation of a member who elects not to contribute if he has attained 65 years of age or has completed 35 or more years of service. In determining the amount earnable by a member in a payroll period, the employer may consider the annual rate of compensation payable to such member on the first day of the payroll period as continuing throughout such payroll period, and it may omit the deduction from compensation for any period less than a full payroll period if the employee was not a member on the first or last day of the payroll period. In order to facilitate the making of deductions, the employer may modify the deductions required of any member but not by more than one-tenth of 1 percent of the annual compensation from which such deductions are to be made. Each employer shall immediately pay amounts deducted to the board of trustees, in such manner as the board of trustees shall prescribe, which amounts shall be credited by the board of trustees to the member's account in the annuity savings fund. Beginning July 1, 1980, the employee contributions required under this chapter shall be paid as provided in Code Section 47-2-54;

(2) The deductions under paragraph (1) of this subsection shall be made notwithstanding that the minimum compensation provided for by law for any member shall be reduced thereby. Every member shall be deemed to consent and agree to the deductions made under paragraph (1) of this subsection; and payment of salary or compensation less such deductions shall be a full and complete discharge and acquittance of all claims and demands whatsoever for the services rendered by such person during the period covered by such payment, except as to the benefits provided under this chapter;

(3) In addition to the contributions deducted from the compensation of members under paragraph (1) of this subsection and subject to the approval of the board of trustees and such conditions as it may prescribe, any member may redeposit in the annuity savings fund, by a single payment or by an increased rate of contribution, all or any part of amounts that he previously withdrew from it under this chapter; or, subject to such approval and conditions, any member may deposit therein, by a single payment or by an increased rate of contribution, an amount computed to be sufficient to purchase an additional annuity which, together with his prospective retirement allowance, will provide for him a total retirement allowance of not more than one-half of his average final compensation, provided that for this purpose a member shall be deemed to have retired at age 65 and amounts earned after reaching that age shall not be included in average final compensation. Such additional amounts so deposited shall become a part of the member's accumulated contributions, provided that upon retirement they shall be treated as excess contributions returnable to the member as an annuity of equivalent actuarial value and shall not be considered in computing the pension; and

(4) Notwithstanding paragraphs (1) through (3) of this subsection, no deductions shall be made from a member's salary if the employer's contribution as to such member is in default.

(b) The accumulated contributions of a member, which contributions are withdrawn by him or are payable in the event of his death, shall be paid from the annuity savings fund. Upon the retirement of a member, his accumulated contributions shall be transferred from the annuity savings fund to the pension accumulation fund.