Backflow Testing in Durham, NC

How Durham's program works

The Department of Water Management runs a Cross Connection Control program to stop water from private plumbing from being pulled back into public mains. Backflow can happen when pressure drops in the main, for example during a break or heavy hydrant use, and a hose or irrigation line sitting in fertilizer or standing water becomes a path for contamination.

• Installed assemblies are tested at install and then every year after.
• The tester must be certified by the City.
• Results go to the City through the Backflow Solutions Inc. (BSI) online portal.
• The City's opt-in testing program ended at the close of 2024, so owners now arrange their own tests.

Irrigation systems

Any irrigation system tied to City water needs an RP-type assembly (ASSE 1013). Running sprinklers off an unprotected hose bibb is not allowed. The City has also imposed water-use restrictions on irrigation during drought, so check its current status before you plan any watering after a test or repair.

What happens if a test is late

Durham can lock the water meter when a required test is overdue, and the City's FAQ lists a $250 unlock fee per device. Booking the test before the deadline is far simpler than getting service restored. Keep a copy of each passing report, note the month it was done, and set a reminder for the same month next year so the annual cycle does not slip.

Installs, replacements and removals

Putting in a new assembly, replacing an old one, moving one or taking one out all require a backflow permit from the Cross Connection Control program. That permit is separate from a plumbing permit issued by City-County Building & Safety. A plumber can tell you which permits a job needs.

During the test

The tester briefly shuts the water off at the assembly, connects a gauge kit to its test cocks and checks that the check valves hold and the relief valve opens at the correct point. A failed device usually needs cleaning, new rubber parts or replacement, then a retest.

What affects cost

Price depends on the number and type of assemblies, their size, how easy they are to reach, and whether a failed device needs a repair kit or a full replacement and permit.