Whenever the Plumbing Inspector determines that it is not practical
to protect drinking water systems on premises against entry of water from
a source or piping system or equipment that cannot be approved as safe or
potable for human use, an entirely separate drinking water system shall be
installed to supply water at points convenient for consumers.
Sewage pumps shall not have priming connections directly off any drinking
water systems. No connections shall exist between the drinking water system
and any other piping, equipment, or tank in any sewage treatment plant or
sewage pumping station.
Backflow protection by a suitable backflow prevention device shall be
provided on each drinking water pier head outlet used for supplying vessels
at piers or waterfronts. These assemblies must be located where they will
prevent the return of any water from the vessel into the drinking water pipeline
or into another adjacent vessel. This will prevent such practices as connecting
the ship fire-pumping or sanitary pumping system with a dock hydrant and thereby
pumping contaminated water into the drinking water system, and thence to adjacent
vessels or back into the public mains.