A water main break drops city pressure to zero while a garden hose is left submerged in a bucket of fertilizer. Contaminated water is drawn back into the potable system. What is this type of backflow called?

Giải thích

Backsiphonage occurs when a drop in supply pressure (from a main break, firefighting, or heavy demand) creates a vacuum that siphons contaminated water back through a submerged connection into the potable system. It differs from backpressure, where a downstream pump or pressurized source pushes water backward. A simple hose bibb vacuum breaker prevents backsiphonage at outdoor faucets.