What is the term for the flow of water or other liquids into the distributing pipes of a potable supply from an unintended source?

The term for the flow of water or other liquids into the distributing pipes of a potable supply from an unintended source is indeed backflow. Backflow occurs when there is a reversal of flow in the plumbing system, allowing non-potable or contaminated water to enter the potable water supply. This situation poses a significant health risk, as it can introduce harmful contaminants or pollutants into the drinking water system.

Understanding the mechanisms that lead to backflow is crucial for maintaining water safety. It can happen due to a variety of factors, such as changes in pressure within the system, including when water is withdrawn for firefighting, or during a sudden drop in pressure. To prevent backflow, it's essential to install devices like backflow preventers, which act as a safeguard against the unintended reversal of flow.

The other terms mentioned are relevant to plumbing but serve different contexts. Cross-connection refers to a connection between potable and non-potable water systems, creating a potential path for backflow. Contamination is a broader term that encompasses any adverse alteration of water quality, and back-pressure is a specific form of backflow that occurs when the pressure in the non-potable system exceeds that in the potable system. Recognizing the distinction between these terms helps in applying preventative measures effectively