Cross Connection Practice Exam

What describes a flow back into the potable water supply due to negative or reduced pressure?

1. Contamination

2. Backflow

3. Backsiphonage

4. Cross connection

The correct answer is: Backsiphonage

The correct choice describes backsiphonage, which specifically refers to the phenomenon where a drop in pressure within a potable water system causes water from a different source to flow back into the drinking water supply. This typically occurs when there is a sudden change in water pressure, like during fire fighting, large water withdrawals, or when a pipe bursts, creating a vacuum that pulls water backward. Backsiphonage is a form of backflow but is distinct due to its reliance on negative pressure dynamics. Understanding this distinction is critical in cross-connection control, as it highlights a specific risk to the drinking water supply. In this context, contamination refers to the introduction of harmful substances into a water system but does not specifically describe the mechanics of how that occurs. Backflow broadly encompasses any reversal of flow, including backsiphonage and backpressure, but does not detail the specific pressure-related mechanism at play. A cross connection involves any actual or potential connection between a potable water supply and a non-potable source, often leading to contamination but does not specify the condition of negative pressure like backsiphonage does.