What is backflow?

Backflow is a term used to describe a condition where water flows through a water line in the opposite direction from which it was intended to flow. Numerous conditions can cause this to occur – a broken water main near your house, firefighters using a fire hydrant in your area, or incorrectly connected pumps. These conditions can cause contaminated water to flow back into the water main in front of your house.
 

Is this a hazardous situation?
Definitely.  One of the more common hazards is the unprotected lawn irrigation system. If the water pressure in the water main in front of your house decreases, fertilizer and pesticides can be drawn back into the water main via the lawn irrigation system. If this happens, there is a high probability that this water will end up in your household plumbing. Anyone drinking water from your household plumbing could become very ill.
 

Can this be prevented?
By installing an approved backflow prevention assembly, you can rest assured that you, your family, and your neighbors are protected from contamination from your sprinkler system.
 

Is a backflow prevention assembly required?
The Missouri Department of Natural Resources (DNR) requires all lawn irrigation systems to have an approved backflow prevention assembly.
 

 
Does the backflow prevention assembly have to be tested?
DNR requires the backflow prevention assembly to be tested annually to make sure the device is working properly.
 

Who performs the test?
The testing must be done by individuals approved by DNR for backflow prevention assembly testing. A list of certified testers is available by calling City Utilities’ water cross-connection program at 831-8399 or 831-8551.
 

What is the cost for testing?
The cost of testing varies. The person or company who prepares your irrigation system for use each summer may be certified to perform the testing and may include this cost in your annual service contracts. City Utilities does not test backflow prevention assemblies.
 

Do I have to have my backflow preventer tested if I’m not going to use my lawn irrigation system this season?
Testing is not required if you don’t plan to use your system. City Utilities will seal the backflow assembly for everyone’s protection and there is no cost for this service. When you are ready to resume use of your irrigation system, contact City Utilities at 831-8399 or 831-8551 to remove the seal. The backflow prevention assembly must then be tested by a state certified backflow prevention assembly tester within 14 (fourteen) days after the seal has been removed by City Utilities.