Backflow is prevented either by complete physical separation of piping systems or through the use of an approved backflow prevention device. Backflow prevention devices are required to isolate a private water system, such as water lines within a commercial site, at the point of connection with the City's public potable water system. With the use of an approved backflow prevention device water can flow from the City's public water system into the private water system, but water from the private water system cannot flow back into the City's public water system. Backflow prevention devices are also used to isolate fire lines, residential irrigations systems, and reclaimed water systems from the City's potable water system.
For detailed information on the installation, inspection, repair and maintenance of backflow prevention devices or for more information on Cross Connection Control, please refer to our Cross Connection Control Manual (PDF).