FAQ Category: Backflow / Cross-Connection

Backflow prevention assemblies should be protected from freezing, physical damage, and tampering. Proper installation, routine maintenance, and timely testing help ensure long-term performance.

Most backflow prevention assemblies must be tested annually or as required by state regulations and NBU policies.

Backflow prevention devices contain moving parts that can wear out or fail over time. Periodic testing ensures that the device is functioning correctly and continues to protect the water supply.

A backflow preventer is a mechanical device installed on a plumbing system to prevent contaminated water from flowing backward into the public water supply.

Backflow is prevented by installing approved backflow prevention devices or maintaining proper air gaps between potable water and potential contaminants. These safeguards stop contaminated water from flowing backward into the public system.

Back-siphonage happens when there is a sudden drop in pressure in the public water system, such as during a water main break or heavy firefighting demand. This pressure drop can pull contaminated water from private systems into the public supply.

Backpressure backflow occurs when pressure in a private plumbing system becomes greater than the pressure in the public water system, forcing contaminated water backward into the public supply.

NBU’s Cross-Connection Control and Backflow Prevention Program is required to protect the public drinking water system from contamination. These programs ensure that pollutants, chemicals, or bacteria from private plumbing systems cannot flow backward into the public water supply.