Backflow testing requirements help ensure that contaminated water doesn’t enter your clean water supply. For commercial properties, this testing confirms that backflow prevention devices are working as intended, protecting people from serious health risks.
When water flow is disrupted, due to pressure drops or valve failures, there’s a chance that dirty water can reverse direction and mix with potable water. Backflow testing checks for this risk and verifies that safeguards are holding up.
Certified testers evaluate pressure levels and device function, usually completing the test in under an hour. Annual testing is often required by law and helps maintain both safety and compliance.
In this article, we’ll break down when testing is needed, what’s involved in the process, and how to stay up to date with regulations through the topics below:
- Understanding backflow and its risks
- Backflow prevention devices
- Local backflow testing requirements for San Diego commercial properties
- Testing procedures and compliance
- Dealing with backflow incidents
Let's dive in!
Understanding backflow and its risks
Backflow is a significant threat to public water systems by allowing contaminated water to enter clean drinking water supplies. When this happens, harmful substances can mix with your property’s drinking water and create serious health hazards.
What is backflow?
Backflow happens when water flows opposite its normal path in plumbing systems. This occurs in two main ways:
Back-siphonage:
- Caused by a drop in water pressure
- Similar to drinking through a straw
- Can pull contaminated water into clean pipes
Back pressure:
- This happens when downstream pressure exceeds supply pressure
- Common in tall buildings and industrial systems
- Forces contaminated water backward through pipes
Health risks and contamination
Contaminated backflow water can contain many dangerous substances, such as:
- Chemicals: Pesticides, cleaning products, industrial fluids
- Biological: Bacteria, viruses, sewage
- Physical: Dirt, debris, rust particles
The health impacts can be severe, and people who drink contaminated water may experience:
- Immediate illness like nausea and fever
- Long-term health problems
- Infections from waterborne diseases
Water contamination through backflow can affect entire neighborhoods or buildings. A single incident can expose hundreds of people to unsafe drinking water.
Backflow prevention devices
Backflow preventers play a vital role in protecting your drinking water from contamination. These devices use mechanical valves and pressure differentials to stop contaminated water from flowing backward into clean water supplies.
Types of backflow preventers
Reduced Pressure Principle (RP) Devices: These create a physical barrier between potable and non-potable water using multiple check valves. They are the most reliable type for high-hazard applications.
Double Check Valve Assemblies: Contain two spring-loaded check valves that work together. They're ideal for low-hazard situations like irrigation systems.
Pressure Vacuum Breakers: This system uses air pressure to prevent backflow. We commonly install these on outdoor spigots and sprinkler systems.
- Air Gap Devices: A simple mechanism that creates a physical separation between the water supply and any potential contaminants. It’s effective and meets most safety standards.
Installation and maintenance
You must install backflow preventers in easily accessible locations for testing and repairs. The device should be placed above ground level and protected from freezing. Annual testing by certified professionals ensures proper function and typical tests assess:
- Valve seals and springs
- Pressure readings
- Relief valve operation
- Internal parts for wear
Regular maintenance includes:
- Cleaning internal components
- Replacing worn parts
- Checking for leaks
- Protecting from weather damage
Professional installation is required by most local codes, and we recommend keeping detailed records of all tests and repairs for compliance purposes.
Local backflow testing requirements for San Diego commercial properties
For businesses operating in San Diego, understanding backflow testing requirements is essential for both compliance and public safety.
The city enforces specific regulations to ensure that backflow prevention devices are installed, maintained, and tested regularly, especially in commercial settings where the risk of contamination is higher.
Installation requirements
According to the City of San Diego Public Utilities Department, all commercial properties with water meters 1.5 inches or larger, along with dedicated irrigation systems, are required to install a backflow prevention assembly immediately downstream of the water meter.
This ensures that any cross-connections or changes in water pressure do not introduce contaminants into the public water supply.
Annual resting and certification
Backflow devices must be tested once per year by a certified backflow tester. Beginning July 1, 2025, all testers must hold certification from an approved organization, such as:
- American Water Works Association (AWWA)
- American Backflow Prevention Association (ABPA)
- American Society of Sanitary Engineering (ASSE)
These professionals are authorized to perform inspections, submit test results, and ensure your system remains compliant with city code.
Non-compliance consequences
If backflow prevention assemblies are not installed, tested, or maintained properly, the City of San Diego may issue code enforcement actions. These can include fines or water service interruption until full compliance is restored.
Testing procedures and compliance
Backflow testing requires specific steps and must follow strict regulatory guidelines set by local water authorities.
Standard testing process
A certified backflow tester starts by notifying the property owner about temporary water service interruption. The tester then inspects the device for proper installation and any visible damage.
The test involves checking multiple components, including:
- Two check valves
- Two shutoff valves
- Four test cocks
Each test cock must be flushed before testing begins, and the make, model, and serial number of the device will be recorded for documentation purposes. The tester will also measure pressure differentials across the device at different flow rates. This confirms the backflow preventer stops contaminated water from entering the clean water supply.
Frequency and regulatory requirements
Most water districts require yearly backflow testing by certified professionals, but some high-risk facilities need more frequent testing.
Local water authorities set specific rules about:
- Testing schedules
- Required Documentation
- Tester qualifications
- Device maintenance
Failing to complete mandatory tests can result in fines or water service disconnection. Property owners must keep test records for at least 3 years and commercial buildings often face stricter requirements than residential properties. We recommend setting up automatic renewal reminders to stay compliant with local regulations.
Dealing with backflow incidents
Swift action and proper prevention are essential when facing backflow issues in plumbing systems. You must act quickly to protect your water supply and implement strong safeguards.
Immediate steps and plumbing repairs
If you notice changes in water color, taste, or pressure, shut off your main water valve immediately and contact a licensed plumber for an emergency service. The plumber will conduct pressure tests to find the exact location of the backflow problem. This helps identify if it's happening due to a faulty valve or broken pipe.
Common repairs include:
- Replacing damaged backflow preventers
- Fixing broken check valves
- Repairing pipe connections
- Adjusting water pressure regulators
Preventive measures and best practices
It’s a good idea to schedule backflow tests during spring as part of an annual maintenance plan. You should also keep detailed maintenance records of:
- Test dates and results
- Equipment inspections
- Repair history
- Pressure readings
Key Prevention Steps:
- Install high-quality backflow prevention devices
- Maintain proper water pressure levels
- Check valve seals regularly
- Clean strainers and filters monthly
Conclusion
Staying compliant with backflow testing requirements isn’t just about following regulations, it’s about protecting your business, your customers, and your community.
With updates taking effect in 2025, now is the time to ensure your backflow prevention systems are up to date and functioning properly. Reliable devices and regular testing reduce the risk of contamination, costly repairs, and service disruptions.
If something does go wrong, having the right measures in place can make all the difference. Taking a proactive approach now helps avoid bigger problems later. Prioritize your water safety, it’s a smart move for any commercial property.
Get in touch to arrange your next backflow test to avoid compliance issues.
