Cross-Connection Control & Backflow Prevention Program
The City of Pleasanton is committed to delivering safe, reliable drinking water to our customers. A key part of ensuring the safety of our water is protecting it against cross-connections. The City is required by state and federal law to protect its water supply through a Cross-Connection Control and Backflow Prevention Program, which is overseen by the City’s Environmental Services Division.
Cross-connections are points in the water system where non-potable water sources (such as chemicals or water unsafe for drinking) could come in contact with drinking water, or potable water. As part of this program, a certified backflow prevention assembly, or BPA, is required for all non-residential water service connections, as well as existing residential water service connections where a potential hazard to the water supply has been identified, such as an on-site well, booster pump station, or unprotected fire sprinkler system.
Latest State and Local Mandates Related to Cross-Connections
Following the passage of Assembly Bill 1671 in October 2017, the State Water Resources Control Board (SWRCB) adopted the Cross-Connection Control Policy Handbook (CCCPH), establishing standards for backflow protection and cross-connection controls in public water systems throughout California. The plan went into effect on July 1, 2024, and was subsequently amended in June 2025.
As required by law, in June 2025, the City adopted its own Cross-Connection Control Plan (CCCP), which is subject to state review and approval. The purpose of this CCCP is to protect the health of our water customers by:
- Preventing the occurrence of backflow into the City’s drinking water system.
- Ensuring proper installation and maintenance of backflow protection assemblies on services to premises where actual or potential hazards exist.
- Promoting the elimination of existing or future cross-connections through inspection and regulation of plumbing and water piping within or between a customer’s premises and the City’s water system.
In July 2025, the City adopted Ordinance No. 2296 amending Chapter 14.16 of the Pleasanton Municipal Code to align with the state’s CCCPH guidelines and to provide staff the authority to require water users to protect the City’s water system from contamination.
Key Changes to the City’s Municipal Code:
- Requires properties with fire protection systems to include backflow protection.
- With minor exceptions, all commercial, industrial, dedicated irrigation, and multi-family residential customers with meter service must have appropriate backflow protection in accordance with CCCPH.
- Requires backflow testers to notify the Public Works Department of any suspected incidents of cross connection.
- Provides the authority to require compliance with CCCPH on all currently noncompliant backflows.
- Expands water users’ responsibility to obtain proper backflow protection when notified by the City and establishes timelines for compliance.
What is a Cross-Connection?
A cross-connection is an actual or potential plumbing interconnection between the City’s potable water supply and a non-potable source, which may be unsafe for drinking. Examples of non-potable water sources include washwater in a bucket, private wells, swimming pools, irrigation systems, pesticide and fertilizer sprayers, booster pumps, and other appliances and equipment that use water, such as fire sprinklers.
Backflow
Backflow is the undesired or unintended reversal of the flow of water or other liquids, gases, or substances into the water distribution system. Normally, drinking water flows one way through the City’s system into your property. However, unprotected cross-connections can allow contaminated water from non-potable sources to backflow into the drinking water system, posing a risk to the City’s water system and overall public health.
Backflow can occur in two ways:
Backpressure
Backpressure occurs when the pressure in a customer’s plumbing system exceeds the pressure in the City’s water system, allowing contaminants from non-potable sources to enter the drinking water system. These pressure changes can occur for various reasons, such as elevation changes or the use of an on-site booster pump.
Backsiphonage
Backsiphonage occurs when there is a sudden drop in the pressure of the drinking water system, such as during fire suppression or a water main break. This can create a vacuum or siphoning effect that draws non-potable water or other contaminants into the drinking water system.
Backflow can be prevented by installing, regularly testing, and maintaining an approved backflow prevention assembly (BPA) device after the water meter on applicable premises.
Cross-Connection Control
Examples of where you can find common cross-connections include:
- Hose Bibbs
- Toilet Flush Valves
- Swimming Pool Fill Lines
- Space Heating Boilers
- Recirculation or Booster Pumps
- Landscape Irrigation Systems
- Fire Sprinkler Systems
- Secondary Sources of Water, such as a Private Well or Pond
- Temporary Cross-Connections with your Hose in a Bucket, Pool, or Connected to a Chemical Sprayer
How You Can Help Prevent Backflow
Don’t:
- Submerge hoses in pools, buckets, or other containers.
- Attach chemical dispensers, such as pesticide sprayers, to the hoses.
- Connect your drinking water system to an appliance without proper education on plumbing codes and any potential risks.
Do:
- Store hoses safely and keep them clear of contaminants.
- Inspect your plumbing for potential unprotected cross-connections.
- Use air gaps or approved backflow prevention assemblies to protect against backflow, and schedule inspections and testing as required.
- Contact us if you notice changes in your water quality or suspect contamination of your drinking water.
Backflow Prevention Devices and Program
Unprotected cross-connections with the City’s water distribution system are prohibited. No water service connection to any premises shall be installed or maintained by the City unless the water supply is protected from contamination and pollution. Whenever backflow protection is found to be necessary, the City will require the water customer to install, test, and maintain an approved backflow prevention assembly (BPA) in accordance with the City’s backflow standards for continued water service or before new water service is granted.
All new commercial, industrial, multi-family, and potable irrigation water services are required to install a BPA. Single-family residential properties being newly constructed or undergoing renovations that trigger a requirement for a fire sprinkler system will be required to either have a pass-through/purge system or a double check assembly (DC) on the fire service line (note that a DC requires annual backflow testing).
Only approved BPAs shall be allowed for installation by a water customer to protect the City’s water system. Approved BPAs must be fully tested and granted a certificate of approval by a certified laboratory. View a list of approved backflow prevention assemblies, which must be installed in accordance with the City’s Backflow Standards in Section 6.2 of the City’s CCCP.
Annual Backflow Testing Requirements
The City requires all backflow prevention assemblies (BPAs) to be field-tested upon installation, repair, or relocation. Thereafter, all backflow prevention assemblies must be field tested at least once per year by a certified BPA Tester. Customers will receive a notice 45 days prior to their annual test due date.
The City charges an annual administrative fee of $60 per device upon test submittal to maintain this program. If devices are not tested in accordance with State laws and regulations, enforcement action may be taken, and the customer’s water service may be discontinued. The administrative fee is paid to your certified tester, who will forward it to the City’s third-party backflow service provider, Aqua Backflow.
The City maintains a list of approved backflow assembly testers who are authorized to perform backflow-related work within the City. A list of certified testers is provided to assembly owners with the test notification. To be included on the City’s list:
- The tester must hold a valid certification from an accredited State Water Board for backflow prevention assembly testing.
- The tester must provide a yearly copy of the tester gauge calibration report results that include details regarding the test gauge’s make, model, and serial number.
- The tester must hold a valid company contractor’s license and a City of Pleasanton business license.
Backflow testers submit their qualifications and completed test reports through an online portal held by Aqua Backflow.
Additional Resources
- California Urban Water Agencies Pamphlet on Cross-Connection Control
- Cross-Connection Control Policy Handbook (CCCPH) | State Water Resources Control Board
- Pleasanton’s Municipal Code, Chapter 14.16 on Regulations for Protection from Water Contamination
- Approved Backflow Prevention Assemblies
- Backflow Prevention Assembly Standard Details
- Approved Backflow Prevention Assembly Tester List
- Aqua Backflow Testing Portal
FAQs
1. What is a cross-connection?
2. Why is cross-connection control important?
3. How do I know if I have a cross-connection?
Cross-connections can be found in both residential and commercial plumbing systems. Here are examples of where you can look for cross-connections between your drinking water system and non-potable sources on your property: hose bibbs, toilet flush valves, swimming pool fill lines, private groundwater wells, space heating boilers, landscape irrigation systems, recirculation or booster pumps, and fire sprinkler systems.
4. What is backflow, and how does it happen?
Backflow is the reverse flow of non-potable water into the drinking water system. It can occur due to backpressure (higher pressure on the property side) or backsiphonage (a drop in City water pressure).
5. Who is required to install a backflow prevention assembly (BPA)?
All new commercial, industrial, irrigation, and multi-family customers are required to install BPAs. This includes new uses or tenants in existing commercial or industrial buildings, such as a new store or restaurant opening in an existing building or unit in Downtown Pleasanton. Additionally, some existing residential properties—like those with fire sprinkler systems, private wells, or booster pumps—may also need to comply with these requirements. Lastly, a BPA is required for all existing service connections that the City has assessed and identified as having an existing or potential hazard to the City’s water system.
6. Do backflow preventers require testing?
Yes. Backflow preventer assemblies must be tested upon installation, repair, or relocation, and at least once annually by a certified backflow tester. A list of certified testers in our area is available on our website and is sent with customer notices.
7. How will I know if I need to comply?
The City will notify you directly if a backflow preventer assembly is required at your property. You may also be informed during the building permit process, City hazard assessments, or related inspections.
8. How do I find an approved backflow tester?
The City maintains a list of approved certified testers. You will receive this list with your test notification, or you can view it on PleasantonWater.com.
9. What happens if I do not comply?
If you do not install or test your backflow device as required, the City may take enforcement actions, including shutting off water service, until you comply. Notices will be sent to customers at least 45 days prior to the testing deadline and before any further enforcement actions are taken.
10. What if I fail my backflow test? Who is responsible for the repairs?
Customers are responsible for all repairs or replacements needed. A passing test result must be submitted annually to comply with the City’s Cross Connection Control Program. After a failed test, the customer should perform the necessary repairs or replacements needed and have the device retested.
11. Where can I learn more or ask questions?
Visit the Cross-Connection Control section of PleasantonWater.com or contact the City’s Environmental Services Division at (925) 931-5515 or third-party Aqua Backflow at (847) 742-2296.
Administration Hours
Environmental Services Division
For general questions related to cross-connections, backflow prevention, and City requirements, please contact us by telephone or our contact form.
Phone: (925) 931-5515
If you are unsure when your backflow preventer is due for a test, or if you need additional information on test due notice, failed devices, list of approved testers, tester registration, or change of address, please contact:
Aqua Backflow at (847) 742-2296 or [email protected]
Contact us by filling out the form below: