When used in this Chapter, the following words and phrases shall have the meanings ascribed to them in this Section:
BACKFLOW: Water of questionable quality, wastes or other contaminants entering a public water supply system due to a reversal of flow. "Back siphonage" is one type of backflow.
CROSS-CONNECTION: A connection or arrangement of piping or appurtenance from which a backflow could occur.
SAFE AIR GAP: The minimum distance of a water inlet or opening above the maximum high water level or overflow rim in a fixture, device or container to which public water is furnished which shall be at least two (2) times the inside diameter of the water inlet pipe but shall not be less than one inch (1") and need not be more than twelve inches (12").
SECONDARY WATER SUPPLY: A water supply system maintained in addition to a public water supply which in any way has been treated, processed or exposed to any possible contaminant or stored in other than an approved storage facility.
SUBMERGED INLET: A water pipe or extension thereto from a public water supply terminating in a tank, vessel, fixture or appliance which may contain water of questionable quality, waste or other contaminant and which is unprotected against backflow.
WATER UTILITY: The City Water Department. (1988 Code §20.107)