What is Backflow?

Water distribution systems are designed with the intention of the water flowing in a certain direction – from the distribution system to the consumer. However, hydraulic conditions with in the system may deviate from the “normal” conditions, causing the water to flow in the opposite direction. Therefore, it is possible and common for the water to flow in the opposite direction in unprotected systems. This is called backflow. When this happens the water system can become contaminated with pollutants that could be harmful to water users.

What causes Backflow?

Backflow is defined as the undesirable reversal of flow of water or mixture of water and other liquids, gases or other substances into the distribution pipes of the potable (drinkable) supply of water from any source or sources.Hazards 3

Backflow is caused by cross-connection that have the potential of allowing contaminants into the drinking water system. Back-siphonage can occur when the water pressure in the distribution system becomes sub-atmospheric. This could allow the influx, or pulling, of contaminated water into the system. Another cause of backflow is back-pressure. Back- pressure occurs when there is higher pressure in the down-stream piping that can force contaminated water into the public water system.

Now it is important that we protect our water system from this condition known as backflow, and one way to do this is to install, test/certify and maintain backflow prevention assemblies.

Hazards 12Backflow prevention programs have proven to help reduce the potential of backflow contamination in water systems.


Images of hazards

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