S.C. Code Ann. § 11-1-50

Such portion of the public monies as may be on deposit in any bank and protected by Federal deposit insurance shall be exempt from the requirement that security be furnished for it by such bank and security shall be required only for such portion of such deposits as shall exceed the amount covered by such insurance. All public officers who have deposited public funds in banks for which security or collateral is required shall obtain it only for the amount by which the particular deposit exceeds the sum protected by Federal deposit insurance. Such portions of trust funds as may be on deposit in any bank and for which security is now required shall be secured only for the amount by which the same exceeds the amount protected by Federal deposit insurance.