Water contamination is a serious issue that homeowners and businesses must address to ensure a safe and clean water supply. One of the most significant risks to water safety is backflow, a problem that can cause contaminated water to flow back into your potable (drinkable) water supply.
Various plumbing devices are designed to stop backflow before it becomes a health hazard. In this guide, we will explain what backflow is, why it happens, and which plumbing devices help prevent it, ensuring your water supply remains safe.
What is Backflow?
Backflow occurs when water flows reversely within a plumbing system, potentially allowing contaminants like pesticides, chemicals, bacteria, and sewage to enter your drinking water. This happens when there’s a sudden change in water pressure, often caused by events such as:
- A broken water main
- A drop in city water pressure due to high demand
- A hose submerged in contaminated water
- A malfunctioning irrigation system
There are two main types of backflow:
- Backpressure Backflow occurs when water pressure within a building or appliance exceeds the pressure of the clean water supply, forcing dirty water back into the system.
- Backsiphonage Backflow occurs when negative pressure (a vacuum effect) pulls contaminated water backwards into the potable supply, often due to a burst pipe or firefighting efforts.
Why is Backflow Dangerous?
If backflow occurs, it can introduce harmful substances into your drinking water, including:
- Fertilizers and pesticides from irrigation systems
- Chemicals from industrial processes
- Bacteria and viruses from sewage or stagnant water
- Soap and cleaning agents from dishwashers and washing machines
Drinking or using contaminated water can lead to serious health risks, including gastrointestinal illnesses, infections, and poisoning. This is why installing the proper backflow prevention devices in your plumbing system is crucial.
Which Plumbing Devices Help Prevent Backflow?
Several backflow prevention devices are available, each designed for specific situations and plumbing systems. Below are the most common types and how they work.
1. Air Gap (Best for Household Protection)
An air gap is the simplest and most effective backflow prevention method. It is a physical space or gap between a water outlet (such as a faucet) and a connected system’s highest possible water level.
Example:
- The space between a sink faucet and the top of the sink basin
- The gap between a dishwasher’s drain hose and the sink drain
Since air cannot conduct water, backflow cannot occur through an air gap. This method is widely used in homes, dishwashers, and food service equipment.
2. Pressure Vacuum Breaker (PVB) (Ideal for Lawn Irrigation Systems)
A pressure vacuum breaker (PVB) is a mechanical backflow prevention device used in sprinkler systems and irrigation setups. It consists of:
- A check valve that prevents backward water movement
- An air inlet valve that opens if the pressure drops
When water pressure drops unexpectedly, the device allows air to enter, breaking the siphoning effect and preventing contaminated water from flowing backwards.
3. Double Check Valve Assembly (DCVA) (For Low-Risk Commercial and Residential Use)
The Double Check Valve Assembly (DCVA) consists of two independent check valves. If one valve fails, the other provides additional protection.
Used In:
- Fire sprinkler systems
- Low-risk industrial and commercial settings
- Some residential systems
While effective, DCVAs do not protect against highly hazardous substances, making them unsuitable for high-risk applications like wastewater handling.
4. Reduced Pressure Zone (RPZ) Valve (For High-Risk Contaminants)
The Reduced Pressure Zone (RPZ) Valve is the most secure type of backflow prevention device. It consists of:
- Two check valves
- A pressure relief valve between them
If either check valve fails, the pressure relief valve opens, preventing contaminated water from entering the clean water supply.
Best for:
- Hospitals and laboratories
- Chemical processing plants
- High-risk water systems
Most municipalities require annual testing of RPZ valves to ensure they function correctly.
Signs That You Have a Backflow Problem
Even with a backflow preventer, plumbing issues can still arise. Here are common signs of a backflow issue:
✅ Water Discoloration – Brown, yellow, or cloudy water indicates contamination.
✅ Unusual Taste or Smell – A metallic, chlorine, or sewage-like odor may be present.
✅ Slow Water Flow – Reduced pressure can indicate backflow problems.
✅ Frequent Plumbing Issues – If you experience sudden drops in water pressure, check for a backflow issue.
Call a licensed plumber immediately to inspect your system if you notice any of these signs.
How to Ensure Your Home or Business is Protected
To prevent backflow issues, follow these steps:
Install the correct backflow prevention device for your plumbing system.
Have your backflow preventer tested annually by a licensed plumber.
Never submerge hoses or faucets in contaminated water.
Watch for changes in water color, taste, or pressure.
Trust Top Shelf Plumbing for Backflow Prevention in Muskogee and Owasso
At Top Shelf Plumbing, we specialize in:
🔹 Backflow prevention device installation
🔹 Routine maintenance and inspections
🔹 Emergency backflow repair services
Whether you need a simple air gap installation or a complex RPZ valve setup, our team ensures your water supply stays safe and clean.
📞 Contact us today for expert backflow prevention solutions in Muskogee, Owasso, and surrounding areas.
