What is a cross-connection in a water supply system?

A cross-connection in a water supply system refers to a physical link between potable (drinking) water and non-potable water. This type of connection poses a significant risk because, if the non-potable water were to backflow into the potable system, it could contaminate the safe drinking water supply.

Understanding the implications of cross-connections is crucial for maintaining water safety and public health. Regulations typically require that such connections be monitored and controlled to prevent potential hazards. This involves implementing devices like backflow preventers to ensure that potable water remains uncontaminated.

The other options discuss concepts that do not relate directly to the definition of a cross-connection. For instance, promoting water conservation, controlling water pressure, or treating wastewater do not describe any physical interaction between different water types as a cross-connection does. Thus, the definition provided in the correct choice accurately captures the risk and nature of cross-connections within a water supply system.