(A) The type of protection required under § 51.45(B)(1), (B)(2) and (B)(3) shall depend on the degree of hazard which exists as follows:
(1) An approved fixed proper air gap separation shall be installed where the public water supply system may be contaminated with substances that could cause a severe health hazard;
(2) An approved fixed proper air gap separation or an approved reduced pressure principal backflow prevention assembly shall be installed where the public water supply system may be contaminated with a substance that could cause a system or health hazard; or
(3) An approved fixed proper air gap separation or an approved reduced pressure principle backflow prevention assembly or a double check valve assembly shall be installed where the public water supply system maybe polluted with substances that could cause a pollution hazard not dangerous to health.
(B) The type of protection required under § 51.45(B)(4) and (B)(5) shall be an approved fixed proper air gap separation or an approved reduced pressure principal backflow prevention device.
(C) Where a public water supply or an auxiliary water supply is used for a fire protection system, reduced pressure principle backflow preventers shall be installed on fire safety system connected to the public water supply when:
(1) The fire system contains antifreeze, fire retardant or other chemicals;
(2) Water is pumped into the system from another source;
(3) Water flows by gravity from a non-potable source; or water can be pumped into the fire safety system from any other source; or
(4) There is a connection whereby another source can be introduced into the fire safety system.
(D) All other fire safety systems connected to the potable water supply shall be protected by a double check valve assembly on metered service lines and a double detector check valve assembly on unmetered service lines.
(Prior Code, § 18-5-7)