Cross Connection Control  and Backflow Prevention

Cross Connection Control


A cross connection is a link between a potable (drinking) water system and a non-potable water system. Contamination can occur when a water supply line to a customer is connected to equipment containing a substance not fit for drinking,creating back-flow (reversal of normal flow of a liquid solid or gas). Installation and maintenance of appropriate backflow prevention assemblies or devices prevents contamination of supply lines from cross connections.

Failing to adequately prevent or control backflow events could have significant negative health and economic impacts.

Effective August 1, 2019: City of Durham to contract with BSI (Backflow Solutions Inc.) as third party vendor for backflow test report submittals



On August. 1, 2019 BSI will begin accepting all City of Durham containment and isolation assembly backflow test reports. If you are a City of Durham water customer with a testable backflow assembly, here is what you need to know:

  • Residential Customers with an irrigation backflow assembly are required to test their backflow preventer assembly annually. If you would like to verify your next test due date, contact BSI at 800-414-4990 or the City of Durham's Cross Connection Program at 919-560-4194
  • Water Customers with a testable backflow assembly(s) will receive an initial testing notice two months prior to the test due date.
  • Your testing notice will have a CCN (Customer Contact Number) listed on each letter in the upper right hand corner. The City of Durham Certified Tester you have hired will need this information in order to properly submit your test report online to BSI.
If you are a Certified Tester, here is what you need to know during this transition period:
  • On Aug. 1, 2019, notices will be sent to the customers whose backflow testing date is due by September 30, 2019.
  • Each notice contains a CCN (Customer Contact Number). City of Durham Certified Testers must have this number in order to properly submit containment backflow test reports online to BSI. If your customer does not have a CCN, please contact BSI at 800-414-4990.
  • From August 1, 2019 to August 31, 2019 you can submit test reports with no filing fee.  
  • On September 1, 2019 the filing fee will be $9.95 per test report submitted is applied.
Notice: CCC One-Time Payment – Online PAYMENTUS:  The City of Durham Cross Connection Control workgroup is pleased to offer you an easier way to pay your associated backflow and cross connection payments online using our CCC One-Time Payment – Online PAYMENTUS option.  Please go to https://ipn2.paymentus.com/rotp/dhcc to make a CCC online payment.  When making a payment please select the appropriate payment type and enter either your backflow permit number, building permit number for plan review, or the students name for class enrollment. Once payment has been approved you will receive a confirmation email and a copy will be sent to CCCProgram@durhamnc.gov. Your payment will be applied appropriately. 

All newly installed and permitted test and maintenance reports are to be submitted to the City of Durham electronically by email to cccprogram@durhamnc.gov.


City Programs


CCC programs are required by the state and federal government to protect water systems from potential contamination or pollution. Staff in the CCC program implements the city’s ordinance which requires all industrial, commercial, and irrigation customers to obtain a backflow permit and install backflow prevention assemblies. These assemblies must be installed on the customer's property before any branching of the private system.
Backflow Prevention Device
Backflow Prevention Device 2
Large Backflow Preventer