Backflow Assembly Testing

The City has implemented new tracking software for backflow assemblies and the annual test reports of these assemblies. We will be using this software to send notices for assemblies that are out of compliance with annual testing requirements. We plan to start sending notices by early spring of 2022.

We will send out four notices: the first will be 60 days prior to test due date, the second 30 days prior to test due date, the third will be hand delivered 15 days after test was due, and the fourth 30 days after the test was due, with the meter locked off. At the time of the third notice, we will suspend water service until the assembly is brought into compliance.

Backflow Assembly Testers

This annual testing is required by the Washington State Department of Health through WAC 246-290-490. The tests must be performed annually and any identified problems must be corrected immediately. We have a list of Backflow Assembly Testers (BATs). These testers have requested that their company names appear on our current list. This list does not include all certified BATs and is not a recommendation to hire. If you wish to hire an individual whose name does not appear on this list, contact Washington Certification Services to confirm their certification.

About Backflow Assemblies

A backflow assembly is a device incorporated into your plumbing system with one-way valves that prevent potentially contaminated water from entering the drinking water system of a dwelling or the City water supply. The one-way check valve assemblies allow the water to only move forward into the system and not backwards into the water supply pipes that supply fresh water to homes and businesses. This is how backflow assemblies protect our water supply. 

Backflow assemblies are commonly associated with fire sprinkler and irrigation systems. Other applications seen throughout the City include boilers, pools, and even some humidifiers. These assemblies help us ensure the drinking water in Snoqualmie is safe and pleasant for all residents. All irrigation systems MUST have a backflow assembly installed.

More Information

Please send any questions about test due dates, assembly locations, or backflow assemblies to