The type of backflow prevention device required under this subchapter shall be commensurate with the degree of hazard which exists:
(A) An approved air gap of at least twice the inside diameter, but not less than one inch, of the incoming supply line measured vertically above the top rim of the vessel, or an approved reduced pressure backflow device assembly shall be installed where the substance which could backflow is hazardous to health, such as but not limited to: sewage treatment plants, sewage pumping stations, chemical manufacturing plants, plating plants, hospitals, mortuaries, car washes and/or medical clinics;
(B) An approved double check valve assembly shall be installed where the substance which could backflow is objectionable but does not pose an unreasonable risk to health; and
(C) An approved double check valve assembly shall be the minimum protection for fire sprinkler systems using piping material that is not approved for potable water use and/or which does not provide for periodic flow through during each 24-hour period, unless a variance has been issued in writing. A reduced pressure assembly must be installed if any solution other than the potable water can be introduced into the sprinkler system.
(Ord. 490, passed 4-11-2005)