What condition defines back-flow in a water system?

Back-flow in a water system is defined by a reverse flow due to pressure differences. This phenomenon occurs when the normal direction of water flow in a plumbing system is disrupted, typically because of a decrease in pressure on the supply side or an increase in pressure on the consumer side. Such situations can lead to water flowing backward, potentially causing contaminated water from the end-user’s side to enter the clean water supply, which poses a significant health risk.

Understanding this definition is crucial for water operators, as back-flow can lead to unsafe drinking water conditions if not managed properly. To prevent back-flow, various methods and devices, such as check valves or back-flow preventers, are implemented in drinking water systems. This aspect of back-flow is essential for maintaining the safety and quality of water supplies, highlighting its importance in water system management.