Backflow Prevention

Cross-Connection Control & Backflow Prevention

Cross-Connection Control is the prevention of actual or potential connections between the public water supply and a source of contamination or pollution. Backflow prevention devices prevent the unwanted reversal of flow from an end user’s water system back into the public water supply. 

The Cross-Connection Control Program serves as a technical reference for policy requirements and industry standards.
View the official policy online
Cross-Connection Control Program Policy, revised Nov. 2020 (PDF)

Cross-Connection Control staff provide consultation for installation of backflow prevention devices in industrial, commercial and residential applications for domestic, fire protection and irrigation systems. Water connections are assessed for the degree of hazard they present and our personnel determine if a device is required on new or existing water lines serving structures. They also decide which containment type of backflow preventer must be installed.

Customers must then apply for an installation permit from the Inspections Division of the Planning and Development Services Department. The installation must be performed by an NC Licensed Plumber Contractor or Licensed Utility Contractor. Initial and annual testing of backflow prevention assemblies must be conducted by one of the approved and registered testing companies linked below. They will submit your test report to ensure compliance with state regulations. Continue reading for details on testing requirements.

Annual Backflow Assembly Testing Notifications

The State of North Carolina requires backflow prevention assemblies be installed on all cross-connections to help keep our water supply safe. These assemblies must be tested and certified every year to ensure that they are working properly.

Property owners are responsible for the installation, operation, testing and maintenance of required backflow prevention devices.

As of January 1, 2020, new state record-keeping guidelines went into effect that require public water systems to enforce the existing law, maintain a database of all cross-connections and report the annual test results within our water system. 

Winston-Salem/Forsyth County Utilities has hired BSI Online to assist in administering the backflow test reporting program for our system. BSI Online sends out notification letters to customers listed in our records as having backflow prevention assemblies. The letters are sent 30 days prior to the assembly testing due date.

Please note that letters display a Worth, Illinois return address. BSI Online is our authorized service provider and is located in the state of Illinois.

Important information included in the letter:

  • Customer name on water billing account
  • Physical address of property where backflow assembly is listed
  • Customer Confirmation Number (CNN) the backflow testing company uses to upload test reports for the property
  • Test due date
  • Information concerning assemblies that require testing

Visit and enter your CCN to check your test status, locate a list of testing companies in your area and learn more about backflow prevention.

  • All failed assemblies must be repaired or replaced at the owner’s expense
  • An initial test report with passing results is required for all new or replaced assemblies

BSI Online provides customer service concerning backflow prevention for Winston-Salem/Forsyth County Utilities customers. Water customers can call 888-966-6050 Monday- Friday 8:00am - 5:00pm or email

Test Report Submissions-Contractor Information

Test reports are only accepted from testing companies approved by WSFC Utilities. To apply, testing companies must email the following to Cross-Connection Control Supervisor Tom McEwen:

  • Testing Company Application eff. July 2019 (PDF)
  • Copies of each tester’s certification for any staff performing backflow assembly tests within the WSFC Utilities system
  • Copies of Test Kit Calibrations for all testing kits that will be used for testing backflow prevention assemblies within the WSFC Utilities system

After approval has been granted by WSFC Utilities:
To register as a testing company with BSI Online, email documentation, including Tester Certification and Test Kit Calibrations to or fax to 888-414-4990. 

All test reports must be sent to BSI Online. If you have any questions, please contact BSI Online testing company support at 800-414-4990.

*If setting up a new installation, the Test and Maintenance Report should be email to Cross-Connection Control Supervisor Tom McEwen.