Water System Information

Drinking Water Quality
The Department of Health requires the City to provide all water system customers with a report each year about the quality of the water we provide. To ensure tap water is safe to drink, the Environmental Protection Agency and the Washington State Board of Health regulate the amount of certain contaminants in water provided by public water systems. The U.S. Food and Drug Administration and the Washington State Department of Agriculture regulations establish limits for contaminants in bottled water that must provide the same protection for public health. 


To encourage conservation, Duvall offers water efficiency programs through its partnership with Seattle Public Utilities. Conservation programs seek to reduce indoor and outdoor water use by promoting high efficiency plumbing fixtures, appliances, and irrigation technologies, as well as leak detection and repair. Thanks to continuing community support and participation, these programs have been very successful.

Conservation Resources

Annual Water Quality Reports

Cross Connection Control Program

Cross Connection

If you have an irrigation system for your yard, fire suppression sprinkler system, boiler, pool/spa or water feature, state law requires that you get a backflow prevention assembly to prevent contaminated water from flowing back into our drinking water system — a serious health hazard.

Backflow Testing

Backflow assemblies fail for a variety of reasons. That’s why state law requires them to be tested annually by a certified backflow assembly tester (BAT) — to ensure that the assemblies will function if there is a backflow event.
The City maintains a database of assemblies installed throughout the city. We monitor all
testing and send customers an annual reminder notice. Your efforts in performing required testing is essential in protecting your drinking water.
Email  for more information or to submit Test Reports.
City of Duvall Backflow Test Report Form

Cross Connection Control Resources