Water systems for fighting fire, derived from a supply not approved as safe for potable use shall be kept wholly separate from the potable system. In cases where the domestic water system is used for both drinking and firefighting purposes, approved backflow prevention devices shall be installed to protect the domestic system. Fire protection classes and required devices are as follows:
(a) Classes I and II. Direct connections from the public water mains only; no tanks, reservoirs, or physical connection from other water supplies, no anti-freeze or, other additives, no booster pumps creating less than a positive ten (10) psi suction pressure; all outlets discharging to atmosphere. Generally, Classes I and II do not require backflow prevention devices (i.e., at fire hydrants connected to public main).
(b) Class III. Direct connection from public water system plus either elevated storage tank, fire pumps taking suction from such tanks/reservoirs, or pressure tanks. The water in the storage tanks shall be potable. Generally, Class III requires only double check valves to prevent stagnant waters from backflowing into the potable system.
(c) Classes IV, V and VI. Like Class I and II, but with an auxiliary water supply within one thousand two hundred (1,200') feet of the pumper connection. This class requires a reduced pressure device or double check valve depending upon the quality of the auxiliary water supply. If auxiliary supply is nonpotable source such as contaminated water, industrial water systems or contains chemical additives, an air gap may be required.
(Ord. 1516-NS, eff. June 5, 2009)