What is back-siphonage?

Back-siphonage refers to a situation where clean water is unintentionally drawn back into a supply line due to a pressure drop. This phenomenon often occurs when there is a negative pressure in a piping system, which can happen during events like water main breaks or when heavy water is withdrawn from the system, such as during firefighting or street flushings. In these instances, if there's a connection between the clean water supply and a source of contamination, the contaminated water can be sucked back into the clean water supply, potentially leading to health hazards.

Understanding back-siphonage is crucial in sanitation and safety practices as it highlights the importance of proper plumbing design, including the implementation of backflow preventers and maintaining adequate pressure in water supply systems. This helps in safeguarding water quality by preventing the mixing of contaminated and potable water.