What is Backflow? How can I prevent it?

SAINT LOUIS, MO (April 21, 2022) – Central States Water Resources (CSWR) is committed to supplying homes and businesses with safe, reliable water every day. But the only way to ensure your water services remain completely free of harmful chemicals or contamination is to protect pipes from backflow.

What is backflow? It’s a plumbing term for when water flows the wrong way through a pipe. (Think of the “back” in backflow as short for backwards.) Pipes use water pressure to send water one direction. When backflow happens, water goes the wrong direction — and brings unhealthy contaminants with it. Those contaminants can include anything you’ve ever tried to send down the drain: from dangerous pesticides and harmful HVAC chemicals, to human waste or your dead pet goldfish.

Still not sure how backflow works? Imagine you’re drinking a milkshake through a straw. As you drink, you create suction that increases pressure on the straw and causes the milkshake to travel up out of the cup and into your mouth. If you reversed the pressure by blowing (or if the cup started sucking back, which would be terrifying but stick with us for the sake of the analogy), the milkshake would travel back through the straw from your mouth into the cup. In this scenario, backflow is what happens when your delicious milkshake flows “backwards” into the cup, and no one wants that.

As your water utility, we do everything we can to make sure your water supply is clean and safe, but once the water travels to your property, the only way to be sure your supply is protected is to install a backflow prevention device. Backflow prevention is so important to clean drinking water that states have their own laws and regulations for it. Our customers are responsible for having a backflow prevention device installed and inspected annually by a certified tester. Without a working backflow prevention device, customers are at risk of contaminating the public water supply, your own drinking water and even your building’s pipes — a serious problem that requires an expensive fix.

Unless you have plumbing and piping experience, it’s best to work with a professional to install a backflow preventer. Installing the device costs about $300 on average, according to an estimate from HomeAdvisor.com, but the price can vary depending on the size and type of system. You can buy backflow prevention supplies at your local hardware store, sprinkler supply store or construction supplier

Backflow prevention devices are critical to keeping water clean. Don’t let your pipes flow backwards onto your property and contaminate the entire system. Homes or businesses that have been closed during the COVID-19 pandemic are particularly vulnerable to backflow when water systems come back online. To learn more about how to prevent backflow, contact Central States Water Resources.