1408.1 A plumbing system shall be installed to preclude backflow of a solid, liquid, or gas contaminant into the water supply system at each point of use at the food processing operation, including on a hose bibb if a hose is attached or on a hose bibb if a hose is not attached and backflow prevention is required by the Plumbing Code by:

1. (a) Providing an air gap as specified in section 1405; or
2. (b) Installing an approved backflow prevention device as specified in section 1406.

SOURCE: Final Rulemaking published at 56 DCR 5245 (July 3, 2009).