Backflow Prevention Practice Exam

Which of the following is a common purpose of an air gap in plumbing?

1. Preventing backpressure

2. Controlling water flow

3. Avoiding contamination of drinking water

4. Facilitating drainage

The correct answer is: Avoiding contamination of drinking water

An air gap serves a crucial role in plumbing systems, primarily designed to avoid contamination of drinking water. It acts as a physical separation between the potable water supply and any potential contaminants that could be present in non-potable sources. By creating this gap, there is no direct pathway for contaminants to flow back into the clean water supply, which is essential for maintaining water quality and safety. This design is particularly important in preventing backflow, as it safeguards against pollutants entering the potable water system, especially in situations where backpressure or back-siphonage could occur. Because of the air gap's effective protection against contamination, it is widely recognized and required in various plumbing codes and standards for safe installation practices. While other options, such as preventing backpressure or controlling water flow, may relate to plumbing functions, they do not encapsulate the primary intent of an air gap. Instead, the definitive purpose of an air gap is fundamentally linked to maintaining the integrity and safety of drinking water.