15-23-6 Backflow Prevention Methods Required.
A. A backflow prevention assembly shall be installed on each service line to a customer’s water system at or near the property line on private property or immediately inside the building being served; but in all cases, before the first branch line leading off the service line wherever the following conditions exist:
1. In the case of premises having an auxiliary water supply, the public water system shall be protected against backflow from the premises by installing an AG or RPA.
2. In the case of premises on which any industrial fluids or any other objectionable substances are handled in such a fashion as to create an actual or potential hazard to the public water system, the public system shall be protected against backflow from the premises by installing a backflow prevention assembly in the service line, appropriate to the degree of hazard. This shall include the handling of process waters and waters originating from the Utility system that have been subject to deterioration in quality. AG, RPA, or DC.
3. In the case of premises having (a) internal cross-connections that cannot be permanently corrected and controlled, or (b) intricate plumbing and piping arrangements or where entry to all portions of the premises is not readily accessible for inspection purposes, making it impracticable or impossible to ascertain whether or not cross-connections exist, the public water system shall be protected against backflow from the premises by installing an AG or RPA.
4. In the case of any premises where there is the potential for pollution, the public water system shall be protected by an approved DC, PVB, or SVB.
5. Temporary potable water connection for any use, including construction sites and jumpers, shall require an RPA provided and maintained by the Utility.
B. When two (2) or more of the aforementioned conditions exist on the same premises and are served by the same service connection, the most restrictive backflow protection required for any of the conditions shall be required to be installed at the service connection. The order of most restrictive to least restrictive backflow protection shall be as follows:
1. Air gap (AG).
2. Reduced pressure principle assembly (RPA).
3. Reduced pressure principle detector assembly (RPDA).
4. Double check valve assembly (DC).
5. Double check detector assembly (DCDA).
6. Pressure vacuum breaker assembly (PVB).
7. Spill-resistant pressure vacuum breaker (SVB). ((O)07-21, 03/21/2007; (O)98-03, 01/07/1998. Formerly 15-23-5)