What is a Cross Connection?

• A. A loop between two lines in a single zone
• B. A point of connection between polluted and potable water
• C. An intersection point of a four way system
• D. A threaded connection where the pieces are improperly aligned

Answer: (B)

A cross connection is any physical linkage between the potable water supply and something that could introduce contamination. When backflow occurs—due to a drop in pressure or a higher-pressure polluted source connected to the system—contaminants can be drawn back into the drinking water. This is why cross connections matter and why backflow prevention devices or air gaps are used to keep the clean water supply safe. The other scenarios describe piping arrangements or fittings that don’t inherently create a pathway for contaminated water to flow into the potable system.