Backflow: The Enemy of Your Plumbing System

Backflow is exactly what it sounds like: water or wastewater flowing in reverse. And yes, it’s as bad as it sounds. Backflow can result in everything from mild inconvenience to serious contamination of your clean water supply. The good news? It’s preventable.

In this brief article brought to you by Mr. Rooter Plumbing, we break down what backflow is, why it happens, and what you can - and should - do about it. If you'd rather have a trained plumber investigate, then call or message Mr. Rooter to hire a uniformed professional.

What Is Backflow?

Backflow is when water flows opposite its intended direction. This typically happens when there’s a sudden drop in water pressure (like during a main line break, firefighting activity, or heavy water use in a nearby area). The abrupt change in pressure can cause contaminated water from toilets, garden hoses, or dishwashers to be siphoned back into the clean water supply.

This isn’t just a theoretical plumbing issue. Backflow is real and can actually contaminate your drinking water with anything from pesticides and fertilizers to sewage.

Two Main Types of Backflow

There are two ways backflow can happen. The first is what we mentioned above: backsiphonage. This is the most common and happens when negative pressure in the water supply causes water to be siphoned backward... sort of like when you suck on a straw to create suction.

The other type of backflow is backpressure. This happens when the pressure in your plumbing system is greater than the pressure in the water supply. Backpressure is often due to things like boilers, pumps, or elevated water tanks. Either way, the result is the same: unwanted and potentially hazardous water going where it shouldn’t.

Signs You Might Have a Backflow Problem

Backflow is typically silent, but it can come with a few telltale symptoms. Watch out for:

• Water that looks discolored or cloudy
• A foul or odd smell in your tap water
• Slow or sputtering water flow
• Visible sediment or debris in water
• A noticeable taste difference

There is no good reason to ignore the quality of your drinking water or plumbing system. Call in a plumber who knows how to investigate and address backflow issues before they get worse. The team at Mr. Rooter are always ready to help.

The Role of Backflow Prevention Devices

Backflow is not something you have to live with. Nor is it something that demands a complete repiping. This issue can be tackled with the aptly-named backflow prevention device. There are several types of devices, but the most common include:

• Air Gap Separation (AG): Simply, a physical space between the water supply and the receiving vessel.
• Double Check Valves (DCVs): This valve is commonly used to protect against low to medium hazard installations. They allow water to flow in only one direction and seal off when pressure reverses.
• Reduced Pressure Zone (RPZ) Valves: This valve is commonly used to protect against high hazard installations such irrigation systems that use chemical additives.

We must note that these devices are not set-it-and-forget-it installations. They require periodic testing and maintenance.

How to Protect Your Property from Backflow

Now that you know what backflow is and why it matters, here’s how to stay on top of it. First, install the right backflow prevention device. If you’re unsure what your system needs, a licensed plumber can assess the setup and recommend solutions.

Remember to keep up with the devices. In many municipalities, annual testing of backflow prevention devices is required by law. Even if it’s not mandatory, it’s a smart move for safety and peace of mind. Watch for changes in your water’s color, taste, or smell. 

If something feels off, trust your gut and contact a trusted plumbing company like Mr. Rooter Plumbing. We are proud to offer emergency plumbing repair service when you need it.