What does the term "cross-connection" mean in plumbing?

The term "cross-connection" in plumbing refers to an actual or potential connection between a potable water supply and a non-potable source. This definition emphasizes the risk of contamination to the safe drinking water supply, which can occur if non-potable substances, including chemicals or waste, are allowed to flow into the potable water system.

Understanding cross-connections is vital for ensuring public health and safety, as they can lead to backflow situations where contaminated water can inadvertently enter the drinking water supply. Cross-connection control measures are a key part of plumbing codes and regulations aimed at preventing such occurrences.

The other options do not accurately describe what a cross-connection is. A safe connection between two pipes implies a condition that does not pose a risk, which contradicts the definition of a cross-connection. Similarly, a type of plumbing joint focuses on the physical connections used in piping systems, rather than the risk of contamination associated with cross-connections. A method for preventing backflow, while related, does not define what a cross-connection is but rather addresses one possible consequence of having such connections in place.