70.705.  Members deposit fund, source, contributions of members, repayment of withdrawals — transfers from fund — election to eliminate contributions, when. — 1.  The "Members Deposit Fund" is hereby created. It shall be the fund in which shall be accumulated the contributions made by members to the system, and from which shall be made transfers and refunds of members' contributions as provided in sections 70.600 to 70.755.

  2.  Except as provided otherwise in this section, the contributions of a member to the system shall be four percent of his compensations after the date he has completed sufficient employment for six months of credited service.  Such contributions shall be made notwithstanding that the minimum salary or wages provided by law for any member shall thereby be changed.  Each member shall be deemed to consent and agree to the deductions made and provided for herein.  Payment of a member's compensation less such deductions shall be a full and complete discharge and acquittance of all claims and demands whatsoever for services rendered by him to a political subdivision, except as to benefits provided by this system.

  3.  The officer or officers responsible for making up the payrolls for each political subdivision shall cause the contributions provided for in this section to be deducted from the compensation of each member in the employ of the political subdivision, on each and every payroll, for each and every payroll period after the date he has completed sufficient employment for six months of credited service to the date his membership terminates.  When deducted, each of these amounts shall be paid by the political subdivision to the system; the payments shall be made in the manner and shall be accompanied by such supporting data as the board shall from time to time prescribe.  When paid to the system, each of the amounts shall be credited to the members deposit fund account of the member from whose compensations the contributions were deducted.

  4.  In addition to the contributions deducted from the compensations of a member, as heretofore provided, a member shall deposit in the members deposit fund, by a single contribution or by an increased rate of contributions, as approved by the board, the amount or amounts he may have withdrawn therefrom and not repaid thereto, together with regular interest from the date of withdrawal to the date of repayment.  In no case shall a member be given credit for service rendered prior to the date he withdrew his accumulated contributions until he returns to the members deposit fund all amounts due the fund by him.

  5.  Upon the retirement of a member, or upon his death if an allowance becomes payable on account of his death, his accumulated contributions shall be transferred to the benefit reserve fund.

  6.  Each political subdivision, by majority vote of its governing body, may elect with respect to its members an alternate contribution amount of two percent or six percent of compensation or to eliminate future member contributions otherwise provided for in this section.  Should a political subdivision elect one benefit program for members whose political subdivision employment is concurrently covered by federal Social Security and a different benefit program for members whose political subdivision employment is not concurrently covered by federal Social Security, as provided in section 70.655, the political subdivision may also, by majority vote of its governing body, make one election concerning member contributions provided for in this section for members whose political subdivision employment is concurrently covered by federal Social Security and one election concerning member contributions provided for in this section for members whose political subdivision employment is not concurrently covered by federal Social Security.  The clerk or secretary of the political subdivision shall certify the election concerning member contributions to the board within ten days after such vote.  The effective date of the political subdivision's member contribution election is the first day of the calendar month specified by such governing body, or the first day of the calendar month next following receipt by the board of the certification of such election, or the effective date of the political subdivision's becoming an employer, whichever is the latest.  Such election concerning member contributions may be changed from time to time by such vote, but not more often than once in two years.  Except as provided in section 70.707, if such election is to eliminate member contributions, then such election shall apply only to future member compensations and shall not change the status of any member contributions made before such election.  If the effect of such election is to require member contributions, then such election shall apply only to future member compensations and shall not change any member contribution requirements existing before such election.  Should an employer change its member contribution requirements as provided in this section, the employer contribution requirements shall be correspondingly changed effective the same date as the member contribution change.  The limitation on increases in an employer's contribution provided by subsection 6 of section 70.730 shall not apply to any contribution increase resulting from an employer electing to eliminate member contributions.