D.C. Mun. Regs. tit. 25, r. 25-B1501
Except as specified in this section, a direct connection shall not exist between the sewage system and a drain originating from equipment in which food, potable water, portable equipment, utensils, or food packaging materials are placed.
Section 1501.1 shall not apply to floor drains that originate in refrigerated spaces that are constructed as an integral part of the building.
If allowed by the Plumbing Code, a warewashing machine may have a direct connection between its waste outlet and a floor drain when the machine is located within one and one-half meters (1.5m) or five feet (5 ft.) of a trapped floor drain and the machine outlet is connected to the inlet side of a properly vented floor drain trap.
If allowed by the Plumbing Code, a warewashing or culinary sink may have a direct connection.
D.C. Mun. Regs. tit. 25, r. 25-B1501