The purpose of a backflow preventer is to

• A. Increase Water Pressure
• B. Filter Particulates
• C. Regulate Flow
• D. Prevent Contamination of a Water Supply

Answer: (D)

Backflow prevention is about stopping reverse flow into the clean water supply. When two systems connect, downstream pressure can push non-potable water, chemicals, or other pollutants back into the potable line. A backflow preventer acts as a barrier so that whatever is in the other system can’t contaminate the drinking water. That’s why its purpose is to prevent contamination of a water supply. It isn’t about increasing pressure, filtering particulates, or regulating flow—that’s handled by other devices. By keeping potential contaminants out, it protects health and water quality.