(a) Only approved cross-connection control devices or methods can be used to satisfy the requirements of this article.
(b) The type of protection required shall depend on the degree of hazard that exists as follows.
(1) An approved fixed air gap separation shall be installed where the waterworks system may be contaminated with substances that could cause a severe health hazard.
(2) An approved fixed air gap separation or an approved reduced pressure principle backflow prevention device shall be installed where the waterworks system may be contaminated with a substance that could cause a system or health hazard.
(3) An approved fixed air gap separation or an approved reduced pressure principle backflow prevention device or a double check valve assembly shall be installed where the waterworks system may be polluted with substances that could cause a pollution hazard not dangerous to health.
(4) An approved fixed proper air gap separation or an approved reduced pressure principle backflow prevention device shall be installed on premises where it is impractical to determine whether cross-connections exist or is impossible to make a complete cross-connection survey or on premises having a repeated history of cross-connections being established or re-established.
(c) Reduced pressure principle backflow prevention devices shall be installed on fire safety systems connected to the waterworks system when:
(1) The fire safety system contains anti-freeze, fire retardant or other chemicals;
(2) Water is pumped into the system from a source other than the waterworks system;
(3) Water flows by gravity from a non-potable source of water can be pumped into the fire safety system from any source other than the waterworks system; or
(4) There is a connection whereby a source other than the waterworks system can be introduced into the fire safety system.
(d) All other fire safety systems connected to the waterworks system shall be protected by a double check valve assembly on metered service lines and a double detector check valve assembly on unmetered service lines.
(e) The type of cross-connection control devices required for any other potable water supply system shall be equivalent to the devices used to protect the waterworks system from similar hazards, unless the superintendent of water permits otherwise.
(f) Cross-connection control devices shall be accessibly located for observation, maintenance and replacement services.