The City of Warrenville completes a Backflow Prevention Survey every three years to help protect our drinking water. The Illinois Environmental Protection Agency and the Illinois Plumbing Code require this survey.
In January 2026, Aqua Backflow will mail a postcard survey to all City water customers.
What is backflow?
Backflow happens when water flows the wrong way, from a private plumbing system back into the public water supply. When this occurs, chemicals or other contaminants can enter drinking water.
Backflow risks can come from connections such as:
- Irrigation systems
- Fire sprinkler systems
- Boilers
- Other equipment connected to the water supply
Why is this survey important?
The survey helps the City identify properties that may have a backflow risk and confirm that the proper prevention devices are in place and working correctly.
Who needs to complete the survey?
All property owners, including residential, commercial, and industrial properties, need to complete the survey. Your responses help determine whether additional backflow protection is needed at your property.
This survey is required by the State of Illinois and plays an important role in keeping Warrenville’s drinking water safe and clean.
Learn more on the City's website at: https://www.warrenville.il.us/869/Lawn-Irrigation-and-Cross-Connection-Con