What is backflow? Why is backflow protection necessary?

Drinking water normally flows in one direction (from the meter to the house), although under certain circumstances it can flow in the opposite direction, or ‘backflow’. A backflow incident can happen at any time. All that is needed is a water pressure drop in the public water system main line, most commonly caused by fire fighting, hydrant flushing, flow testing, a water main break, or extreme high usage on the water system. Any connection to a non-potable source not protected could be siphoned back into the public water system, which can pollute or contaminate the water system.

Backflow protection is necessary because we assume that when we turn on the water tap, we have safe drinking water. This is a luxury we enjoy, but not without very strong regulations and considerable expense. Our drinking water is among the safest in the world. Water protection and conservation requires the effort and cooperation of everyone. 

Show All Answers

1. What is a cross connection?
2. How do I know when my assembly needs to be tested?
3. How often do backflow assemblies need to be tested?
4. Do I currently have adequate backflow protection? How can I find out?
5. What is the legal basis for a cross connection control program?
6. What is the responsibility of a building owner, property manager and water supplier?
7. What are some common examples of residential cross connections?
8. What is backflow? Why is backflow protection necessary?
9. What is a backflow assembly?