Cross Connection Practice Exam

A water main break will most likely lead to which condition?

1. Backpressure

2. Backsiphonage

3. Contamination

4. Permanently reduced pressure

The correct answer is: Backsiphonage

A water main break typically results in backsiphonage. This condition occurs when there is a sudden drop in water pressure within the distribution system, causing a reversal of flow. When a break happens, water can rush into the break site, creating a vacuum or negative pressure downstream. This vacuum can draw water from nearby sources, including potentially contaminated water, into the clean water supply. In the context of a water main break, backsiphonage poses a significant risk because it can facilitate the introduction of contaminants from soil, cross-connections, or other sources into the potable water system. Understanding this phenomenon is essential for implementing appropriate safety measures to protect the integrity of the water supply. While contamination may occur as a result of backsiphonage, it is the backsiphonage itself that directly leads to the contamination by reversing the expected flow of clean water. The other conditions mentioned—backpressure and permanently reduced pressure—are not the most immediate results of a water main break.