Backflow is the unwanted reversal of flow in a water distribution system. Backflow occurs due to backpressure or back-siphonage and allows non-potable substances to enter a public water system through an unprotected cross-connection.
Backpressure occurs when the pressure in a building’s plumbing exceeds the pressure in the water distribution system.
Backsiphonage occurs when there is a partial vacuum (negative pressure) in a water supply system, drawing liquid from the non-potable source into the water distribution system.
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