Backflow Testing in Washington (DOH Regulations)

Washington requires annual backflow testing to protect public water systems. Tests must be performed by DOH-certified Backflow Assembly Testers (BATs). Learn the rules, why it matters, and how to find certified testers.

Washington DOH Requirements

Annual testing required for all backflow prevention assemblies

Only DOH-certified Backflow Assembly Testers (BATs) may test

Tests after installation, repair/relocation, and as part of ongoing compliance

Water purveyors may disconnect service if compliance is not met

Why Backflow Testing Matters

Backflow testing prevents contaminants from entering the public water supply, protects public health, and helps property owners avoid penalties or service interruptions.

This page summarizes requirements from the Washington State Department of Health (DOH) regarding backflow prevention and testing. For official regulations, please refer to the Washington DOH Cross-Connection Control Program.

Learn More About Backflow Programs

Washington’s annual testing requirements are part of a larger compliance framework. Explore how state rules connect to national standards and cross-connection programs.

EPA Safe Drinking Water Act

Federal law under the EPA’s Safe Drinking Water Act establishes nationwide protections against contamination. Washington’s backflow requirements align with these federal standards.

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Cross-Connection Control Programs

Washington’s DOH oversees cross-connection control programs, requiring certified Backflow Assembly Testers (BATs) to maintain safe public water systems.

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State Standards

Washington shares PNWS-AWWA certification standards with Oregon and other states, ensuring consistent testing and recognition across the region.

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Important Note

The sole goal of these resources is education. BackFlowRates.com is not associated with the EPA or state authorities, nor does it enforce cross-connection programs.

Explore State Backflow Programs

Washington’s backflow testing standards are part of a larger national effort. Learn how different states approach compliance by visiting our dedicated program pages.

View State Programs

Oregon Backflow Testing

Learn about Oregon’s OHA requirements and annual testing compliance.

Explore Oregon

California Backflow Testing

Discover how Title 17 defines California’s cross-connection standards.

Explore California

Florida Backflow Testing

Understand Florida’s certified tester requirements and enforcement policies.

Explore Florida

Find Certified Backflow Testers Near You

Protect Washington’s drinking water with annual backflow testing. Browse certified testers and book your service directly through our marketplace.

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