Air gaps provide maximum protection from backflow hazards and should be utilized at all locations where "high" hazardous substances are at risk of entering potable water system.
(a) An air gap separation shall be at least twice the diameter of the supply pipeline measured vertically above the top rim of the receiving vessel and in no case less than one (1) inch. If splashing is a problem, tubular screens may be attached or the supply line may be cut at a forty-five (45) degree angle. The air gap distance is measured from the bottom of the angle. Hoses are not allowed.
(b) Air gap separations shall not be altered in any way without prior approval from the regulatory authority and must be available for inspection at all reasonable times.
(c) Side walls, ribs, or similar obstructions do not affect air gaps when spaced from the inside edge of the spout opening a distance greater than three (3) times the diameter of the effective opening for a single, or a distance greater than four (4) times the effective opening for two (2) intersecting walls.
(Ord. 7-15-03-1, passed 7-15-03)