Skip Navigation
Decrease Normal Increase

Cross Connection FAQs

Backflow Prevention Is Important For Sprinkler Systems

Q: Who can I contact if I have questions?

You can call our offices at (253) 502-8207 or email us at

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

Backflow prevention assemblies protect your drinking water from potential sources of contamination. The only way to ensure they are working properly is to have them tested by a certified backflow assembly tester (BAT). The Uniform Plumbing Code (Section 603) and the Washington Administrative Code (Section 246-290-490) require annual testing of installed backflow prevention assemblies.

Q: Who can test backflow prevention assemblies?

A: All backflow prevention assemblies must be tested by a state of Washington Certified BAT. Tacoma Water provides a list of testers to our customers. This list is not a recommendation - just a list to help you get started. You can find additional testers on the Washington Certification Services website

Q: What is the Authorized Tester Program and what are the benefits of participating?

A: The Authorized Tester Program allows Tacoma Water to send customer test due notices directly to a BAT of the customer's choice. It also allows Tacoma Water to discuss questions and concerns regarding test results directly with the tester instead of requiring the customer to contact the tester and then reply to Tacoma Water. There is no cost associated with the program.

Q: What is the South Tacoma Groundwater Protection District?

The South Tacoma Groundwater Protection District was created to protect an important source of water for Tacoma. Learn more about the ordinance and guidelines that detail the way businesses in this area must manage their hazardous materials.

Q: I have my backflow assembly tested every year as required, but my neighbor says he has never heard of the testing requirement. Why is that?

A: There may be several reasons why your neighbor has not received any test due notices from Tacoma Water, the most likely being that we don't know about the installation. Many times customers make modifications to their water system and do not take out the required permits. Taking out a permit ensures that your work is inspected and installed to code. Most importantly, it ensures that you, your family and, if applicable, your customers are protected.

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.

Q: I am not using my irrigation system anymore. Do I still need to test the backflow assembly?

A: As long as the irrigation system is physically connected to the water system, your backflow prevention assembly must be tested. Tacoma Water will suspend the testing requirement if the customer provides a physical disconnect between the irrigation system and the public water supply by removing the backflow prevention assembly and capping the water supply line. You must contact our Water Quality section at (253) 502-8207 to arrange for a verification inspection once the line has been capped.

Q: What will happen if I choose not to test my backflow prevention assembly?

A: Tacoma Water may take the following enforcement action when backflow prevention assemblies are not tested or maintained as required.

  1. We can assess a $100 fee for each assembly not tested. The fee will be applied directly to your utility account. Additional fees of $100 will be added until testing is satisfactorily completed.
  2. We may install a reduced pressure backflow assembly at your water meter at your expense. 
  3. We may terminate your water service.

For more information, contact us at or (253) 502-8207.