The potentially dangerous reversal of the flow of water from its intended direction in any pipeline or plumbing system. A cross-connection is a physical connection between two separate piping systems; one containing potable water and the other containing water of questionable safety. Backflow can allow drinking water in plumbing systems to become contaminated and unusable.
What are backflow preventers?
Backflow preventers are mechanical plumbing devices and assemblies installed in plumbing systems to prevent water from flowing backward in the system. A properly tested and maintained backflow preventer can reliably prevent water of an unknown quality from contaminating a community’s water system.