Backflow Assembly Testing

Submitting Test Reports

Backflow test reports are required to be filled out completely, accurately, and legibly. Seattle Public Utilities will currently accept most versions of backflow assembly test reports provided they are completed in accordance with our guidelines and contain all the information required by Washington Administrative Code (WAC) 246-292-036. Download an approved Backflow Test Report Form (pdf). If you have questions about backflow testing, please contact us at or (206) 684-3536.


Testing Compliance Questions & Answers

Why do I have to test my backflow assembly every year?

Backflow prevention assemblies are installed to protect your drinking water from potential sources of contamination. The only way to ensure that they are working properly is to have them tested by a certified Backflow Assembly Tester. It's also Washington State law.

Who can test backflow assemblies?

All backflow prevention assemblies must be tested by a State of Washington Certified Backflow Assembly Tester. There are a large number of certified testers in the area who all required to follow the same testing procedures. Customers are encouraged to contact several testers and find one that meets your pricing and scheduling needs. Certified testers can be found using web searches and by asking friends, neighbors, and family. An official listing of certified testers is kept by Washington Certification Services.

Please note that the tester is responsible for providing SPU with copies of their current state certification and test equipment calibration certificates. We cannot accept test reports from testers that have not provided us with this information.

I have my backflow assembly tested every year as required, but my neighbor says that they have never heard of the testing requirement.

There may be several reasons why your neighbor has not received any test due notices from Seattle Public Utilities. The most common reason is that we do not know about the installation. Sometimes customers make modifications to their water system and do not have them inspected. Your neighbor may also have installed a non-testable device. There are very specific installation requirements that must be met for non-testable devices that make them impractical for many customers to use.

What will happen if I don't test my backflow prevention assembly?

It is important to test your backflow prevention assemblies annually to ensure that they are working properly. Failure to test an assembly increases the risk that the assembly will fail to protect the water supply.

Seattle Public Utilities sends out reminder notifications about backflow assembly testing requirements. However, it is the water service customer that is responsible for ensuring that his or her assemblies are tested on time. If an assembly is not tested, we will take action, starting with assessing fees and leading to termination of water service.

Seattle Public Utilities will make every effort to work with the customer to avoid these actions from being taken, but we must ensure that the drinking water system is protected.