Cross Connection Practice Exam

What is a common indicator that a backflow preventer is functioning correctly?

1. Water flow is constant

2. There is no pressure drop

3. Testing results show no backflow

4. It makes no noise

The correct answer is: Testing results show no backflow

A common indicator that a backflow preventer is functioning correctly is that testing results show no backflow. Backflow preventers are designed to allow water to flow only in one direction, preventing contaminants from entering the potable water supply. Regular testing of these devices ensures they are performing their function effectively. When testing reveals no backflow, it confirms that the device is successfully preventing reverse flow, thereby protecting the water supply. Looking at the other choices, while constant water flow, absence of pressure drops, and a lack of noise might suggest normal operation, they do not specifically verify that a backflow preventer is effectively preventing backflow. These indicators may not directly correlate to the preventer's performance in isolating contaminated water from the clean supply. Hence, the best measure of a backflow preventer's correct functioning is derived from testing that verifies no backflow is occurring.