What is backsiphonage?

Backsiphonage is a specific type of backflow that occurs when there is a negative pressure or vacuum in the water supply system, leading to the reversal of water flow. This phenomenon can happen when there is a sudden drop in water pressure, such as during a plumbing event like a mainline break or heavy water consumption in the area. When this drop in pressure occurs, water can be drawn from the potable water system back into the system, potentially contaminating it with non-potable substances from other sources like drainage systems or open water bodies.

Understanding this concept is crucial for plumbing professionals because backsiphonage can pose significant health risks, leading to potential contamination of drinking water supplies. This is distinct from backflow caused by gravity or pressure differences, making it important for plumbers to recognize and address the conditions leading to backsiphonage. Proper preventive measures, such as ensuring pressure is maintained and installing backflow prevention devices, are essential to safeguard against this risk.