Why Backflow Testing Is Required
What Is Backflow and Why Is It Dangerous?
Backflow occurs when water flows in the opposite direction through your plumbing, potentially pulling contaminants from irrigation systems, boilers, chemical storage, or other non-potable sources into the public drinking water supply. This can happen when there's a sudden drop in water pressure — from a water main break, heavy fire hydrant use, or system maintenance.
The health risks are serious. Backflow incidents have caused real outbreaks of illness from bacteria, pesticides, fertilizers, and industrial chemicals entering drinking water. This is why every state and most municipalities require properties with cross-connections to install and maintain backflow prevention devices.
Cross-Connection Control Programs
Local water utilities run cross-connection control programs as mandated by the EPA's Safe Drinking Water Act. These programs identify properties with cross-connections — any point where a potable water line connects to a non-potable source — and require the installation and annual testing of backflow prevention devices.
Common cross-connections include irrigation and lawn sprinkler systems, fire suppression systems, swimming pools, boilers, dental and medical equipment, and commercial kitchen equipment. If your property has any of these, you almost certainly need a backflow preventer installed and tested annually.
Annual Backflow Testing Requirements
Most jurisdictions require annual backflow testing — a certified backflow tester must inspect your RPZ valve, DCVA, PVB, or other backflow prevention device once a year to verify it's working correctly. The tester uses calibrated test gauges to check internal valve operation, pressure differentials, and relief valve discharge.
After the test, the certified tester files a report with your local water authority documenting the results. If the device passes, you're compliant until the next annual test. If it fails, repairs must be made and the device retested before the deadline — otherwise you risk fines or water service interruption.
Types of Backflow Prevention Devices
The type of device required depends on the hazard level of the cross-connection:
- RPZ (Reduced Pressure Zone) valves — required for high-hazard applications. Considered the gold standard with two check valves and a relief valve. Common in commercial and irrigation systems.
- DCVA (Double Check Valve Assembly) — used for low-to-moderate hazard applications like fire sprinklers. Two independent check valves without a relief valve.
- PVB (Pressure Vacuum Breaker) — protects against backsiphonage only. Commonly used in residential irrigation. Must be installed above the highest downstream point.
Each device type requires specific testing procedures and expertise. When choosing a certified backflow tester, make sure they have experience with your particular device type.
What Happens If You Skip Testing?
The consequences of non-compliance vary by jurisdiction but typically include:
- Violation notices and fines (often $50–$500+ per month)
- Water service shutoff until the device is tested and certified
- Liability for any contamination that results from a failed device
- Increased insurance costs or denial of coverage
The cost of an annual backflow test ($50–$200) is a fraction of what you'd pay in fines, legal liability, or the consequences of contaminated water. Don't wait for a violation notice — schedule your annual backflow prevention device inspection on time.
Find a Backflow Tester Near You
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