Do I Need a Backflow Preventer for My Property?
As a property owner, you're likely familiar with the importance of maintaining your plumbing system. One aspect that often gets overlooked is backflow prevention — a device that stops contaminated water from entering your clean water supply. But do you actually need one?
What is a backflow preventer?
A backflow preventer is a device that stops water from flowing backward into your potable supply, which can happen when pressure drops or reverses. It's the barrier between your drinking water and whatever else is connected to your plumbing — irrigation, boilers, pools, or process equipment.
Who needs one?
Requirements vary by jurisdiction, but backflow preventers are commonly required for:
Properties with irrigation systems
Commercial and industrial buildings
Properties with fire sprinkler systems
Buildings with boilers, cooling towers, or chemical injection
Properties with private wells connected to municipal supply
Swimming pools and water features
Types of backflow preventers
Reduced Pressure Zone (RPZ/RP): The highest level of protection, required for high-hazard applications. Uses two check valves plus a relief valve that vents to atmosphere.
Double Check Valve Assembly (DCVA): Two check valves in series. Used for lower-hazard applications.
Pressure Vacuum Breaker (PVB): Common on irrigation systems. Uses an air inlet valve and check valve.
Spill-Resistant Vacuum Breaker (SVB): Similar to a PVB but designed to prevent spillage during operation.
The right device depends on your hazard level, which your water authority determines — not something to guess at.
How to find out if you need one
Contact your water purveyor. They set the requirements for your service area and can tell you definitively what applies to your property.
Check your local plumbing code. Requirements are often written into municipal code and available on your city or county website.
Have a cross-connection survey done. A certified specialist inspects your property and identifies every connection that could allow contamination.
Benefits of proper backflow prevention
Protection of your water supply from contamination
Compliance with local health and safety regulations
Reduced liability if a contamination incident occurs
Avoiding fines and potential service disconnection
Conclusion
Whether you need a backflow preventer comes down to what's connected to your plumbing and what your water authority requires. If you're unsure, a cross-connection survey answers the question definitively — and it's far cheaper than a contamination incident or a compliance violation.