Test your backflow prevention assembly to protect drinking water

Make sure San Francisco’s water supply stays clean and does not get contaminated.

Protecting city water

The Cross-Connection Control Program protects the City’s drinking water. We check connections between the drinking water system and other water sources. 

Test your backflow assembly every year

Backflow prevention assemblies keep fertilizers and chemicals from getting into the drinking water. There are many backflow prevention assemblies across the city.

If you have a backflow assembly, an authorized tester needs to check it every year. 

We will send you a notice every year reminding you to test your assembly. The notice will include forms and your test due date. You will need to:

  1. Give your forms to the tester
  2. Get your backflow assembly tested
  3. Submit proof you got the test

If you don’t submit your test results by your due date, we may fine you.

We keep a list of companies with authorized backflow assembly testers. To get added to our list, learn more about becoming a certified backflow tester.

Get help

If you don’t get your a notice reminding you to test your backflow assembly, let us know. Or if you need your PIC number, annual notice, or test forms, contact us:

If you need to change your mailing address or contact information for notices:

Note: Your contact information is tied to your SF Public Utilities Water Service account. This update will also change your contact for water service billing.

If you have questions about plumbing permits for backflow assemblies, contact SF Department of Building Inspection Services:

If you have questions about a Notice of Violation or other questions about backflow assemblies:

Last updated May 22, 2024