Cross Connection Practice Exam

What is the primary function of a backflow preventer?

1. To save water

2. To prevent contamination of potable water

3. To regulate water temperature

4. To filter impurities in water

The correct answer is: To prevent contamination of potable water

The primary function of a backflow preventer is to prevent contamination of potable water. This is crucial in maintaining the safety and integrity of drinking water supplies. Backflow can occur when there is a change in pressure within a plumbing system, which can lead to the reverse flow of water. This reversal can draw potentially contaminated water from non-potable sources back into the clean drinking water supply. Backflow preventers are specifically designed to stop this reverse flow by creating a barrier between the potable water supply and any sources of contamination. They act as a safeguard against harmful substances, ensuring that the water consumed by the public remains safe and free from pollutants. This critical function is why backflow preventers are a required feature in many plumbing codes, especially in areas where there is a higher risk of contamination. The other options, while potentially relevant in a broader context, do not accurately represent the core purpose of a backflow preventer. Saving water, regulating water temperature, and filtering impurities are not direct functions of backflow prevention devices, making them less relevant in the context of the question.