Cross Connection Control Program

About Cross Connection Control 

Every drinking water system in Illinois must have a cross connection control program, more commonly known as a backflow prevention program. Backflow prevention is designed to protect the public water supply from contamination from non-drinkable sources. Cross-connection hazards exist in a variety of places, such as factories, processing plants, laundries, dental offices and hair salons. Residential in-ground sprinkler systems are also capable of contaminating the public drinking water if they are not properly protected. 

Backflow prevention devices are required on all commercial and residential properties where contamination hazards exist. These devices must be maintained and tested annually to ensure that they are working properly. The State of Illinois requires that every backflow device be inspected annually by a certified backflow tester, and every city that operates a public water system is responsible for making sure that this is done. 

The City of Naperville has contracted with Backflow Solutions, Inc. (BSI) to manage the City’s backflow inspection program. BSI will serve as the primary point of contact for backflow inspections within the City of Naperville and can be contacted at or by calling (888) 966-6050.

Water customers with previously registered backflow devices will receive a notification and reminder directly from BSI that testing is due. 

As a reminder, you only need to have your assemblies tested once per year. Your testing date remains the same annually. You may hire any licensed plumber with a CCCDI to test your assembly; to find a CCCDI-licensed plumber in the area please visit BSI's website and click on the Water Customer tab. You can contact BSI at any time to verify the date of your last test or if you have any questions about the testing process.

Frequently Asked Questions (FAQs)

How will I know when my device is due for testing?

BSI will send you a letter thirty days before your device is due for its annual test. 

Does BSI perform backflow device testing?

No, BSI is not permitted to do any testing. They are only contracted to accept test results and maintain the City’s database.

Is there a fee for testing my backflow device?

Your licensed testing contractor will charge you a fee for the services that they perform. 

Are there any penalties/fines from the City if the test is not done before the deadline date on the letter?

The Water Utility is authorized to turn off water service to customers who place the public water supply at risk. Customers who fail to comply will receive reminders from BSI and will receive a final notice from the City prior to disconnection. Customers who are disconnected for backflow violations will be charged the same reinstatement fees as customers who are disconnected for non-payment.

Should I tell BSI if my lawn sprinkler is permanently or temporarily disconnected?

The City of Naperville no longer accepts “Inactive Forms” for lawn irrigation systems not in use. It is the customer’s responsibility to have device(s) tested annually by a licensed contractor and documentation submitted directly to BSI. If you choose to permanently shut down/disconnect your system, you are required to have a licensed contractor remove the RPZ, cap off the system and submit documentation directly to BSI.  

Do I send my test report to BSI from now on?

No, your backflow testing contractor will submit your test results online.

How do I know if my test report has been received?

Your test submission status can be viewed under the Water Customer tab on BSI's website. If your test results have not been entered, please remind your contractor to do so.

Can the City or BSI recommend contractors to use for my testing?

BSI maintains an online list of licensed Cross Connection Device Inspectors who operate in Illinois. Each customer is responsible for choosing their own testing contractor and is under no obligation to continue using their previous contractor.