What is the purpose of a backflow preventer?

A backflow preventer is a critical device used in plumbing systems to ensure the safety of drinking water. Its primary purpose is to prevent contaminated water from flowing back into the potable water supply. This is crucial because if water from a lower pressure area (such as a drain or a non-potable source) flows back into the clean water supply, it can introduce harmful pathogens and pollutants, posing a health risk to consumers.

Backflow can occur for a variety of reasons, including changes in water pressure due to demand or a break in the water supply line. The backflow preventer is designed to create a barrier that allows water to flow only in one direction—away from the clean water supply. By doing so, it effectively mitigates the risk of contamination.

While options related to increasing water pressure, preventing water from flowing forward, or monitoring water usage touch on other aspects of plumbing, they do not address the critical and specific function of safeguarding drinking water quality, which is the paramount responsibility of a backflow preventer.