There shall be no cross-connections in plumbing between safe and potentially unsafe water supplies. Water shall be delivered at least two (2) delivery pipe diameters above the rim or points of overflow to each fixture, equipment, or service unless protected against back-siphonage by approved vacuum breakers or other approved back-flow preventers. A faucet or fixture to which a hose may be attached shall have an approved vacuum breaker or other approved back-flow preventer.
S.C. Code Regs. ch. 61, 61-125, 61-125.2300, 61-125.2302