Backflow Prevention

Puyallup Water goes to great lengths to ensure delivery of safe and reliable drinking water to your home. Once the water goes past the meter, however, we rely on you to ensure that it remains safe to drink. That may be an issue if you have an irrigation or fire sprinkler system, installed on your water line. Those additions may cause contaminants to flow to your tap.

Properly installed and maintained backflow prevention assemblies will stop contaminated water from reaching your tap or the water system. Learn how to prevent backflow by avoiding contamination through cross connection, which is any connection between the water system and material that could harm the water system.

When Do I Need Backflow Prevention?

Accepted Types of Backflow Prevention

  • Air gaps with premise isolation
  • Reduced pressure backflow assemblies
  • Double check valve assemblies


The potential hazard indicates the appropriate assembly. In general, we accept air gaps and reduced pressure backflow assemblies for high hazards and double check valve assemblies for low hazards.

The chosen backflow prevention assembly must be approved by the Foundation for Cross-Connection Control and Hydraulic Research. Click here for a list of approved backflow prevention assemblies.  Assemblies not currently listed must have been listed at the time of their original installation.

The City inspects assemblies upon installation and conducts periodic re-inspections on all existing assemblies. Assemblies must be tested annually by a certified backflow assembly tester. Assemblies must also be tested after any repair or replacement, with a copy of each test report being submitted to the city. If the chosen assembly tester is not on the city's current approved list, the company must submit a copy of their BAT card and test kit calibration with the test report to Mike Nelson, Cross-Connection Specialist.