S.C. Code Ann. § 9-1-1090

The accrued liability contribution shall be discontinued as soon as the accumulated reserve in the employer annuity accumulation fund shall equal the present value, as actuarially computed and approved by the Board, of the total liability of such fund less the present value, computed on the basis of the normal contribution rate then in force, of the prospective normal contributions to be received on account of all persons who are at the time members.