Backflow Prevention

NOTICE: Work Started Without Permit Fee

No person may commence or proceed with the installation of backflow preventer assemblies without first obtaining a Backflow Permit.  Due to the high volume of work started without permit, in order to offset the cost, the city will implement a double backflow permit fee on each backflow assembly that was installed prior to being issued a backflow permit. Effective January 1, 2017, a $200.00 backflow permit fee will be charged for a backflows installed prior to a permit being issued, required by the Department of Water Management Cross Connection Control (Part 15-116). For additional information, please see the Work Started Without Permit (PDF).

NOTICE: Re-Inspection Fee

Due to the high volume of re-inspections, in order to offset the cost, the city will implement a fee on each additional re-inspection trip required to close out a permit. Effective April 1, 2016, a $100.00 re-inspection fee will be charged for a re-inspection of a Backflow preventer permit, required by the Department of Water Management Cross Connection Control (Part 15-116). For additional information, please see the Re-Inspection Fee Notice (PDF).

Cross-Connection Control

A cross-connection (CCC) 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.

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.


Both new and existing customers of the city's water supply are evaluated by CCC staff to determine which hazards, if any, exist and the type of backflow preventers required. If a backflow preventer assembly is required at a facility, a licensed plumbing contractor must complete, sign, and return the Backflow Preventer Permit Application (PDF). There is a $100 Cross-Connection Control Permit Fee for any new or replacement installation of a backflow preventer.

Outdoor Hoses

It is always important to remember that improperly disconnecting a hose to a hose bib can potentially create a hazardous scenario. Remember to connect an anti-siphon coupler to your hose bib(s) before connecting your hose.
Backflow Prevention Device
Backflow Prevention Device 2
Large Backflow Preventer
Annual Testing Requirements
After an approved backflow prevention (BFP) assembly has been installed and tested, it must be re-tested annually by individuals who have been certified by an approved testing school. The CCC office establishes the annual testing schedule and mails notification to the homeowner or business. The city also maintains a list of qualified testers (PDF) who are approved to conduct testing of devices in Durham.

The owner of the backflow prevention assembly has 15 days to repair or replace the failed assembly if the BFP fails the requirements of the annual test. The 15 day requirement to repair a failed unit is subject to change only upon contact with the City’s Cross Connection Control office to determine replacement/repair due date. Contact the Cross Connection Control office at 919-560-4194 prior to any repair or replacement. In addition, a backflow permit must be submitted with all replacement or new backflow prevention assemblies.

Tester Certification Training
Periodically, Cross-Connection Control staff conducts a state-recognized school for tester certification and recertification. First, a 40 hour, five day backflow tester certification course is offered to individuals who are interested in testing backflows. A 16 hour, two day recertification course is offered to certified testers in order to keep testers skills and regulatory knowledge current. Individuals who are interested in becoming certified testers should review the course packet (PDF)application (PDF), and tester checklist (PDF).

City of Durham Backflow Preventer Permit applications can be completed online using the Land Development Office (LDO). This system will allow you to check on current status of applications and permits. As part of the LDO process, Cross Connection Control (CCC) sign-off is now required for issuance of Certificate of Occupancy.