In plumbing systems, what is the term for an unintended flow of water back into the potable water supply?

The term for an unintended flow of water back into the potable water supply is backflow. This phenomenon can occur when there is a change in pressure within the plumbing system, which can cause contaminants from non-potable water sources to flow backward into the clean drinking water supply. Backflow poses significant health risks, as it can introduce pollutants and microorganisms into the water supply, undermining its safety and quality.

Preventing backflow is crucial in plumbing design and maintenance. Measures such as backflow preventers are employed to safeguard against this hazard. Understanding the implications of backflow is essential for plumbers to protect public health and comply with plumbing codes and regulations.

In contrast, cross-connection refers specifically to the actual physical link between potable and non-potable water systems, which can create a risk for backflow but is not synonymous with it. Water hammer describes the noise and movement in pipes caused by sudden changes in water flow, and a pressure drop refers to a decrease in water pressure that can affect system performance but does not directly relate to the backward flow of water into the supply.