Backflow Tester List

State rules

Washington

The Washington State Department of Health certifies Backflow Assembly Testers and Cross-Connection Control Specialists under the waterworks operator rules. A backflow assembly tester inspects, field-tests, maintains, and repairs backflow prevention assemblies, devices, and air gaps that protect a public water system. The Department’s cross-connection page points to the tester’s duties in WAC 246-292-034 and to a public list and a certification-verification tool. A separate fact sheet says state drinking-water rules require inspection and testing by a Department-certified tester after installation, reinstallation, relocation, or repair. Plumbing and contractor licenses from Labor and Industries can also apply when the work is installation or repair inside a building. Testing and inspection of assemblies, by itself, is marked on that sheet as requiring the Department tester certification and not the plumber certificate.

Checked against official sources on October 11, 2026. Rules and links change; confirm with the office listed before you act.

Try a ZIP like 30303, “Travis County” or “Columbus, OH”
Drinking-water agency
The Washington State Department of Health certifies backflow assembly testers and cross-connection control specialists.
Who may test an assembly
A Department of Health certified Backflow Assembly Tester.
Official program page
Official page →
Tester lookup
Official page →

WAC 246-292-034 says the tester uses a field-test kit meeting the USC Manual of Cross-Connection Control, tenth edition, and keeps laboratory proof of the kit’s accuracy. When the purveyor requires it, the tester submits that proof and the Department validation card. Reports follow the cross-connection rule, and procedures stay consistent with the tester’s last passed practical exam. Replacement parts come from the original manufacturer. If chapter 18.106 RCW requires a plumber certificate, the tester must hold it.

WAC 246-292-033 gives the cross-connection specialist the job of developing and carrying out the water system’s program. That credential is not the same as the field tester, although one person may hold both. The Department page links a county tester list and a verification tool run with Washington Certification Services. Use those tools. The fact sheet says employer-owned premises can change contractor and plumber duties. The Department tester certification remains the testing credential in the table.

No customer test fee is set on these pages. The water purveyor receives the report. The fact sheet says inspection and testing follow installation, reinstallation, relocation, or repair. A specialist credential alone does not replace the tester certification for that field test. Ask the purveyor which report form it requires before the visit, and ask to see the current Department validation card. That card is the tester credential the fact sheet describes.

Official resources in Washington

Department of Health cross-connection control

Links tester and specialist duties, the public tester list, and certification verification.

WAC 246-292-034

States the backflow assembly tester’s inspection, testing, kit, and reporting duties.

Backflow assembly testing requirements

Table of when the Department tester certification, a contractor registration, or a plumber certificate is required.

Key facts for Washington

What to do next

  1. Verify the tester on the Department’s certification tool and ask for the validation card.
  2. If the work includes repair inside a building, ask about the plumber certificate as well.
  3. Do not hire a cross-connection specialist and assume that person can field-test unless the person also holds the tester certification.
  4. Ask the water purveyor where the completed report must be sent.

Looking for your city or county in Washington?

We haven't found official program-level pages for Washington we can verify yet, so we don't show local numbers here rather than guess. Here's what to use instead, in order:

  1. General Start with the statewide information above. It applies across Washington, but cities and counties can add their own steps, fees or deadlines.
  2. Call to confirm Ask the official office. They have the current local rule, fee and form.
    Washington State Department of Health cross-connection control
    Website →
    Phone not shown: use the contact page on the official website above.
    Your city or county office: MRSC Washington city and town profiles →
    Not sure who handles it locally? USAGov's free help line, 1-844-872-4681, or the Washington page on USA.gov can point you to the right office.
  3. Know the current info? Tell us and include a link to the official page. We check every tip before it goes up.

Helpful guides

Backflow tester planner →

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