Reversal of Flow
Backflow is the undesirable reversal of the flow of water from its intended direction in any pipeline or plumbing system. Backflow is dangerous because it can allow drinking water in plumbing systems to become contaminated and unusable.
Causes of Backflow
Backflow occurs as a result of a “cross-connection” within the water system, which exists when there is any actual or potential connection between a potable water system and any other source or system through which it is possible to introduce into the potable system any used water or substance.