What term describes a connection between non-potable and potable water supplies?

The term that describes a connection between non-potable (unsafe for drinking) and potable (safe for drinking) water supplies is known as a cross connection. This is a critical concept in water supply and public health because a cross connection can allow contaminants from non-potable sources to flow into the potable water system, potentially causing harmful health effects.

Understanding cross connections is essential for water operators, as they must implement measures to prevent such connections to ensure the safety of drinking water. Proper backflow prevention devices and techniques are commonly employed to protect potable water systems from contamination.

Other terms mentioned in the question do not accurately capture this connection. For instance, while backflow is related to the movement of water in the opposite direction, it is the result of a cross connection. Water boundary and water link are not standard terms used in the context of water systems and do not relate to the specific issue of contamination risks between potable and non-potable water sources.