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What is a backflow preventer and does my Greenwood home need one?

Apr 12, 2024

You’d probably never think of your Greenwood-area home’s backflow preventer as its most glamorous feature of its design and appearance, but it keeps all your home’s assets and structure — along with your family — significantly safer. That’s why it’s important to develop a basic understanding of what a backflow preventer is and how it protects you and your home by making sure your water is safe.

What is a Backflow Preventer?

In simple terms, a backflow preventer is a mechanical device installed as part of your home’s plumbing to protect again unexpected reversals of your home’s water flow. What’s known as backflow can happen when there’s a sudden drop in your home’s water pressure, or when something like a flash flood overwhelms your home’s sewer or septic system. Backflow refers to dirty, non-drinkable water flowing back through your drains and contaminating the fresh water in your lines.

Why Would I Need Backflow Prevention?

Without something to stop the backflow, everything from industrial chemicals to agricultural pesticides to bacteria-filled sewage might enter your home’s drinking water supply. Backflow preventers are designed and installed to protect your home’s water supply in three ways.

Protection Against Contamination

As mentioned, protecting your home’s water supply from contamination is one of the primary purposes of backflow preventers. The term for water that’s safe to drink is “potable,” so “non-potable” water is unsafe for any number of reasons. For example, it might be runoff from a nearby farm field, where rainwater washed pesticides off the soil. Or it might be wastewater discharged back into the soil from a local industrial facility. Could even have been exposed to what you flush down the toilet every day. No matter the reason, non-potable water is simply unsafe — and if even a drop reaches your water supply, would you want your family to drink it? When non-potable water tries to reach your water supply, the preventer keeps it from getting in.

Protection During Water Main Breaks

Municipal water systems are generally very safe and well-maintained. Unfortunately, things break now and then. The contractor widening that road accidently dug right through the water line that feeds your neighborhood, and they’re saying your service should be restored before midnight, assuming all goes well. A sudden drop in pressure in the municipal water supply system like a water main break could cause contaminated water to be drawn back into your home’s plumbing. The backflow preventer automatically makes sure that doesn’t happen.

Prevention of Cross-Connections

Sometimes, home and business owners may have water systems that involve both potable and non-potable water sources. For example, you might have a swimming pool or irrigation system that draws water from a non-potable source. A warehouse might have a fire sprinkler system that draws water from a nearby retention pond. The separate water systems may share drains or operate in close proximity. In cases like these, backflow preventers create a secure physical barrier to prevent the backflow of contaminated water into the clean water supply.

Backflow Prevention & Building Codes

Many zoning authorities and municipalities require backflow preventer installation as part of their plumbing codes and regulations. Homeowners may be legally obligated to install and maintain backflow preventers to ensure the safety and integrity of the public water supply.

Types of Backflow Preventers

Homeowners can choose among several types of backflow preventers:
• Double Check Valve Assembly backflow preventers use two independently operated check valves with a shut-off valve between them.
• Reduced Pressure Zone assemblies incorporate two check valves and a relief valve, offering a higher level of protection that’s often required for commercial and industrial applications.
• Pressure Vacuum Breaker backflow preventers that are typically used for outdoor irrigation systems and other non-health hazard applications.

We’re backflow preventer experts

Clean water is critical to keeping your family healthy. If you’re concerned about the effect outside contaminants could have on what you use to cook and drink, contact the backflow preventer experts from Johnson Heating Cooling & Plumbing. They’ll examine your home’s plumbing and identify the best ways to protect your water supply, whether that’s a backflow preventer or something like a purifier. No matter what the best option for you home, they’ll help you rest easier.

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