(1) “Airbreak” is a physical separation which may be a low inlet into the indirect waste receptor from the fixture, appliance or device indirectly connected.

(2) “Airgap” is the unobstructed vertical distance through the free atmosphere between a supply line outlet and overflow rim of a receiving vessel. This separation must be at least twice the inside diameter of the supply line, but never less than one inch.

(3) “Backflow” is the flow of water or other liquids, mixtures or substances into the distributing pipes of a potable supply of water from any source or sources other than its intended source (see “Back-siphonage”).

(4) “Backflow connection or condition” is any arrangement whereby backflow can occur.

(5) “Backflow preventer” is a device or means to prevent backflow into the potable water system.

(6) “Back-siphonage” is the flowing back of used, contaminated, or polluted water from a plumbing fixture or vessel into a water supply pipe due to a negative pressure in such pipe (see “Backflow”).

(7) “Cross-connection” is any connection or arrangement, physical or otherwise, between a potable water supply system and any plumbing fixture or any tank, receptacle, equipment or device, through which it may be possible for nonpotable, used, unclean, polluted and contaminated water, or other substances, to enter into any part of such potable water system under any condition. (Ord. 1405 § 1 (Exh. 1), 2015; Ord. 721 § 2, 1987).