Notice: If you have recently been notified that you are required to install a backflow prevention device, click here for instructions and other information to help you through the process! Special information for private well owners is also included.
Backflow Prevention Device and Who Needs One
Backflow devices are an integral part of the City’s Cross Connection Control Program. They help to ensure that no contaminants of any kind (chemicals, debris, reclaimed water, etc.) enter the potable water system.
Backflow devices are owned by the customer and regulated by the State through the City of Palo Alto. While it is primarily business customers who are required to have these devices, some residential properties need them, also.
The State of California Department of Health Services provides regulations for the City and our customers through California Code of Regulations, Title 17. These regulations spell out the types of services that require backflow devices.
For a general guide to understanding and installing backflow prevention devices, click here.
Thinking of going green? To understand important backflow issues related to using stormwater "rain barrels", recycled "gray water" and solar water heaters, click here. Backflow Device Testing Procedures
Once backflow devices are installed, the devices must be tested on an annual basis and test results must be submitted to the City. Your City approved tester will place a serialized, color-coded, metal tag on your device that will be changed out each year.
The City will only accept test reports from testers who have registered with the City of Palo Alto and have provided the Cross Connection Control Program with copies of their State certification and calibration reports. The list of registered testers may be found here.
Testers wishing to register with the City may contact the Cross Connection Control Program office at (650) 496-5926 or via e-mail by clicking here.
All tests results must be submitted on a City of Palo Alto test formwhich can be downloaded here.
Questions about the backflow prevention device survey, testing, or test reporting? Please contact the City's Cross-Connection Control Office at (650) 496-5926.
Trying to install a backflow prevention device?
If you have already looked for the correct location for your device but still need further assistance, our Building Department can assist you. Please contact one of our two inspectors (but not both!) with your specific questions:
Please do not ask plumbers bidding on your job to contact the inspectors. Only you or a plumber who is already contracted for the work should be in contact with the inspectors. This eliminates confusion and allows our staff to give you more efficient service.
The City’s Backflow Rules and Regulationscan be found here.
Utilities Operations Office Municipal Service Center 3201 East Bayshore Rd. Palo Alto, CA 94303 Electric Phone: 650-496-6934 Fax: 650-493-8427 Water, Gas, Wastewater Phone: 650-496-6982 Fax: 650-496-6924 Hours: Mon-Fri 7:00-3:30pm