Backflow Prevention Practice Exam

What does the design of a pressure vacuum breaker inherently protect against?

1. Flooding in irrigation systems

2. Contamination of potable water supplies

3. Over-pressurization of pipelines

4. Corrosion in water lines

The correct answer is: Contamination of potable water supplies

The design of a pressure vacuum breaker inherently protects against the contamination of potable water supplies. This device is specifically created to prevent backflow, which occurs when water flows in the reverse direction, potentially allowing pollutants or contaminants to enter the clean water supply. The vacuum breaker accomplishes this by using a valve and an air inlet that opens when there is a drop in pressure, allowing air to enter the system and breaking the siphon effect that can lead to backflow. This function is particularly important in systems where there is a risk of connection to non-potable water sources, such as irrigation systems or sprinkler systems that may inadvertently draw contaminated water back into the clean water supply. By effectively mitigating this risk, the pressure vacuum breaker plays a vital role in maintaining the safety and integrity of drinking water sources. Other factors such as flooding in irrigation systems, over-pressurization of pipelines, and corrosion in water lines are important considerations in water system management, but those are not directly addressed by a pressure vacuum breaker.