What device is required by law when drawing water for tank fills from public water sources?

What device is required by law when drawing water for tank fills from public water sources?

• A. Backflow preventers
• B. Float valves
• C. Check valves only for private wells
• D. None

Answer: (A)

The essential idea is protecting the public water supply from contamination by preventing backflow when connecting anything to a public water line. When you draw water for tank fills from public sources, laws require a backflow preventer to stop water from flowing back into the system if pressure changes or a reverse flow could occur. This device acts as a one-way barrier, letting water flow to the tank but preventing potentially contaminated water from re-entering the drinking water supply. Float valves only control how full a tank becomes and don’t guard against backflow into the public line. A check valve by itself can stop reverse flow in some situations, but it doesn’t reliably protect against backsiphonage or cross-connections in all cases, and many codes require a proper backflow prevention assembly instead. So the mandated device is a backflow preventer, not the other options.

The essential idea is protecting the public water supply from contamination by preventing backflow when connecting anything to a public water line. When you draw water for tank fills from public sources, laws require a backflow preventer to stop water from flowing back into the system if pressure changes or a reverse flow could occur. This device acts as a one-way barrier, letting water flow to the tank but preventing potentially contaminated water from re-entering the drinking water supply.

Float valves only control how full a tank becomes and don’t guard against backflow into the public line. A check valve by itself can stop reverse flow in some situations, but it doesn’t reliably protect against backsiphonage or cross-connections in all cases, and many codes require a proper backflow prevention assembly instead. So the mandated device is a backflow preventer, not the other options.