Chapter 12.14 CONTROL OF BACKFLOW AND CROSS-CONNECTIONS


Section 12.14.050 Type of protection required.

    1. The type of protection required under Sections 12.14.040-1 and 12.14.040-2 of this ordinance shall depend on the degree of hazard that exists as follows:
        a. An approved air gap separation or an approved reduced pressure principle backflow prevention device shall be installed for both high- and low-hazard applications   where a public water supply system may be contaminated with any substance that could cause a system hazard or health hazard;
        b. An approved double check valve backflow-prevention   assembly shall be installed only for low-hazard applications   where a public water supply system may be contaminated with any substance that could cause a pollution hazard;
        c. An approved reduced pressure principle backflow prevention device shall be installed at the service connection where there exists a plumbing hazard;
        d. A dual check does not meet the requirements of a backflow-prevention assembly;
        e. In the case of any premises where, because of security requirements or other prohibitions it is impossible or impractical to make a complete cross-connection survey of the consumers potable water system, a reduced pressure principle backflow prevention device shall be installed at the service connection.
    2. The following assemblies shall only be used to prevent backflow from backsiphonage.   
         a. An approved pressure vacuum-breaker assembly (PVB) can be used for both high- and low-hazard applications for internal protection only.  It does not protect against backpressure, but may be used in a dedicated single use service, such as an irrigation system.  This device shall be installed a minimum of 12” above the highest point of use and any downstream piping supplied from the assembly.
         b. An approved atmospheric vacuum breaker (AVB) can be used to protect both high- and low-hazard applications for internal protection only.  This device shall be installed to prevent backflow from backsiphonage only for specific installations, such as lab faucets or other types of equipment that use built-in AVBs. This device shall be installed a minimum of 6” above the highest point of use and any downstream piping coming from the device and shall not be subjected to continuous use and shall not be pressurized more than 12 hours in a 24-hour period. (Ord. 2006-0369;93/U-954)