What is a "cross-connection" in plumbing?

A cross-connection in plumbing specifically refers to a physical connection between a potable (drinking water) source and a non-potable (potentially contaminated) water source. This connection poses a significant risk to public health, as it can allow contaminants to flow back into the potable water supply, leading to contamination.

The importance of understanding cross-connections lies in the necessity to maintain the integrity of the drinking water system. Regulations and guidelines often focus on preventing such cross-connections to ensure that safe drinking water is not compromised. The potential scenarios in which a cross-connection might occur include when a hose is submerged in a bucket of soapy water or when irrigation systems use non-potable water without proper backflow prevention.

While other options discuss related topics, they do not capture the precise definition of a cross-connection. A connection to a secondary water supply could refer to various setups that are not necessarily related to contamination, and methods of testing water quality focus on ensuring safety rather than defining interconnections. Likewise, a type of plumbing joint describes physical construction techniques rather than the critical issue of potential contamination inherent in cross-connections.