Backflow

Backflow devices can include air-gaps, reduced-pressure assemblies, or double-check assemblies. They prevent a cross-connection or reduce the risk of potential contamination. The one-way valves acceptable in the SJW service area are Lead-Free Reduced Principle or in a few cases, Lead-Free Double Checks. An air-gap is a physical separation between the water filling a tank and the water inside the tank. These are usually placed just before a pump in a lower pressure situation.

Backflow devices are owned and maintained by our customers, when required.

Backflow prevention devices are required on fire services and some domestic services to protect the public water supply from actual or potential contamination from cross-connection and backflow. In addition, by law, testing and recordkeeping are required on all backflow preventers at least once a year. SJW performs complimentary testing for all customers. All new assemblies were required to be lead-free as of Sept. 1, 2016.

If you have been contacted by our Cross-Connection and Backflow Program, it is because you were identified following a survey, observation or list-examination. When the program began, SJW developed a list of locations with the greatest need for backflow devices. The list is routinely updated and evaluated. Newly identified addresses are contacted each year.

Cross-connections can allow non-potable water to flow backward into the drinking water system, a process known as backflow. This can occur due to changes in water pressure and could introduce contaminants into your home’s plumbing or the broader water supply. Preventing backflow is essential to protecting public health and maintaining water quality.

In December 2023, the State Water Resources Control Board adopted updated regulations through the Cross-Connection Control Policy Handbook (CCCPH), which took effect on July 1, 2024. These updates require water systems like SJW to enhance public education, conduct hazard assessments, and ensure proper backflow protection is in place.

Our Cross-Connection Control Program has been updated to comply with the CCCPH. Our program includes:

• Conducting and reviewing hazard assessments for new and existing customers.
• Offering backflow testing services for both commercial and residential customers.
• Verifying that required backflow prevention assemblies are installed and functioning.
• Providing public outreach and education on cross-connection control and backflow prevention.
• Coordinating with certified specialists for full cross-connection control surveys when required.

Yes. Property owners are responsible for ensuring that backflow prevention assemblies and air-gaps are properly installed, maintained and tested annually. These inspections must be performed by certified backflow prevention assembly testers or cross-connection control specialists. We will notify you if any action is required on your part.

A cross-connection is any actual or potential link between your drinking water and a source of contamination. These are common in both residential and commercial settings. You may have a cross-connection if your property includes any of the following:

• Hose bibbs without backflow protection (e.g., vacuum breakers)
• Toilet flush valves that are not properly air-gapped
• Swimming pool fill lines
• Boilers or water heaters with makeup water connections
• Landscape irrigation systems
• Fire sprinkler systems
• Private wells or alternate water supplies

To protect your water quality and comply with local regulations, we recommend reviewing your plumbing system or consulting with a certified backflow professional.

Under most conditions a lead-free, reduced-pressure assembly is required. A few conditions allow a double-check or air-gap. These are generally related to service-type or zone pressure conditions. We maintain a list of approved backflow prevention assemblies. Please contact our Backflow Department or visit our website for the most current list and guidance on selecting an appropriate device for your property.

We realize that installing a new device can be challenging to coordinate for a variety of reasons. We will evaluate requests for extensions on a case-by-case basis.

We have a list of approved testers that service these devices. Most, if not all, can test and install backflows when required.

Yes. SJW conducts hazard assessments and offers backflow testing services for both commercial and residential customers as part of our Cross-Connection Control Program. However, full cross-connection control surveys of properties must be conducted by certified outside specialists. Annual testing of backflow prevention assemblies must also be performed by certified testers. We can provide a list of approved testers upon request.

Visit the Cross-Connection Control section of our website or contact our Backflow Department at (408) 279-7872 for more details, including:

• Educational materials
• Water Usage/Hazard Assessment Questionnaires
• Lists of approved devices and testers
• Guidance on compliance with the CCCPH