What Homeowners Need To Know About Backflow Testing

Modern residential plumbing is designed for maximum convenience, efficiency, and safety. While most American homeowners take the safety of their drinking water for granted, it’s only because of government mandates and behind-the-scenes prevention measures that that is by and large true.

One of these safety measures is backflow prevention. This article will discuss what backflow is, how it is prevented, and why homeowners need backflow testing.

What Is Backflow?

Backflow is when tainted water contaminates potable water (water that is treated and safe to drink). This can have serious health consequences, as wastewater often carries bacteria and other organisms that cause illness. 

The home’s plumbing system uses pipes to deliver clean, treated water from the water main to all the faucets throughout a home. There are separate pipes that drain wastewater away, down to the sewer main beneath the house. Any point where nonpotable water meets clean water is called a cross-connection.

There are two main types of backflow: backpressure backflow and backflow siphonage. Backpressure backflow happens when the downstream pressure increases and forces a reversal in the water flow. Backflow siphonage happens when the water supply pressure drops, creating suction that reverses water flow. Sudden pressure changes may be caused by frozen pipes, a burst water main, the use of fire hydrants, irrigation system failures, thermal expansion, and flooding.

In order to keep the water supply clean and prevent contamination, most homes require some form of backflow prevention.

How Is Backflow Prevented?

Backflow prevention is typically included in residential plumbing systems. These are some of the most common backflow prevention options:

• Air Gap: A physical break in the pipe. Non-mechanical. Usually found at the end of a service line because it causes pressure loss. Effective against backpressure and siphonage backflow.
• Atmospheric Vacuum Breaker: The simplest device for preventing siphonage backflow. A float inside the breaker is lifted by water pressure, which triggers a seal to stop water flow.
• Pressure Vacuum Breaker: Works similarly to the Atmospheric Vacuum Breaker, but may be used in systems with continuous pressure. Not effective against backpressure backflow.
• Double Check Valve: Similar to the Dual Check Valve, but is larger and can handle more pressure. Can also be tested and repaired inline. Effective against siphonage and backpressure backflow, and is the most common device for residential buildings.
• Reduced Pressure Zone Assembly: The most sophisticated backflow prevention device. Consists of two check valves with differing pressure tolerances, and a relief valve. Most effective against high levels of contaminants.

Why Backflow Testing Is Needed

Each state and municipality has its own laws regarding backflow prevention to protect potable water. Most areas require a certain type of backflow prevention device. Homeowners should have their plumbing system tested annually to ensure backflow prevention devices are in excellent working condition.

Backflow testing is critical for the health of the homeowner and of their family. Contaminated water is not always obvious; most pollutants, bacteria, and parasites are invisible to the naked eye. Although their water may look clean, the only way to guarantee its safety is to have it tested by a professional plumber.

Consult Shamrock Plumbing & Drain Cleaning, Inc.

Shamrock Plumbing & Drain Cleaning, Inc. has been providing plumbing services in Orlando, FL and the surrounding area since 2003. Their affordable rates and industry-leading customer service have won them Angie’s List “Super Service Award” six years running.

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