What is a cross-connection?

A cross-connection refers specifically to a connection between potable (drinking) water and non-potable water sources. This type of connection can pose significant health risks, as it creates a potential pathway for contaminants from non-potable sources to enter the potable water supply. Regulatory frameworks, such as plumbing codes and public health guidelines, are in place to prevent cross-connections and ensure safe drinking water.

Understanding cross-connections is essential because they can result in instances of backflow, where water flows in the opposite direction due to pressure changes. This backflow can introduce harmful substances, chemicals, or biological agents into the drinking water system, leading to serious health concerns.

In contrast, the other options do not accurately define cross-connections. Identical pipes may be part of a plumbing system but do not create a cross-connection. Connections within stormwater systems or any connection that simply uses a valve do not inherently create a risk between potable and non-potable supplies.