Who can legally test my backflow assembly in Portland?
Only one kind of person: a Backflow Assembly Tester certified by the Oregon Health Authority (OHA). Not the city, not your water provider, and not a plumber without the certification.
What the certification actually means
OHA certification requires completing an approved training course, passing an exam, and testing with calibrated gauge equipment. The tester's certification number goes on the report they file with your water provider — a report signed by anyone else doesn't count toward your compliance under OAR 333-061.
Common misconceptions
- "The city will send someone." No — the Portland Water Bureau sends the notice and tracks compliance, but you hire the tester yourself.
- "My landscaper handles the sprinklers, so they can test it." Only if they hold the OHA certification. Some irrigation companies do; ask for the certification number.
- "Any plumber can do it." A plumbing license alone isn't enough — the backflow certification is separate.
How to find and verify one
OHA publishes the official list of certified testers. Our directory is built directly from that list for Multnomah, Washington, and Clackamas counties, organized so you can search by city or ZIP and tap to call. When you book, it's fair game to ask for the tester's certification number and confirm their gauge calibration is current.