A backflow device is a vital component in your plumbing infrastructure and a failing backflow can become a major issue. Not only does a failed backflow pose potential health risks, but it can also cause costly repairs if water flow causes damage to the pipes in your residential or commercial building. Before you contact a plumbing company, learn everything you need to know about backflow testing, such as how testing works, how often you should have these tests, and the specific concerns associated with backflow issues.

What Is Backflow Testing?

Backflow testing is a preventative test conducted by plumbers to assess your piping infrastructure for backflow issues. This testing specifically checks if there is any water flow reversal in the pipes of a building or if there is any indication of backflow siphonage from a septic system. The testing often assesses the water pressure in the building and checks any backflow prevention devices that are installed in the plumbing infrastructure.
A backflow prevention device can either be a mechanical device that creates a physical barrier to prevent backflow or a software-run device that detects reduced water pressure and water valves to identify backflow issues. Both of these devices can quickly detect backflow problems, which will help you avoid the concerns associated with backflow malfunctions. These devices should already be installed as part of your basic plumbing infrastructure.

How Often Should Testing Be Done?

Generally, a backflow inspection should be done once a year to ensure the backflow prevention devices are operating in peak condition. For buildings that have certain plumbing infrastructure, such as sprinkler systems, this testing may be mandated by the local government. Residential buildings should also have backflow devices tested annually, preferably during the same calendar month each year.

What Is the Difference Between Back Pressure and Back Siphonage?

There are two types of backflow issues, and both are potentially hazardous. Back pressure backflow happens when the downstream pipes for the non-potable water are stronger than the potable water pipes, which leads to low water pressure when sinks, showers, and other fixtures are used.
Back siphonage backflow can cause unclean water to contaminate clean water. This is because backflow siphonage causes the downstream water pipe to draw unclean water into the clean water pipe, which ultimately contaminates the water source used for indoor plumbing. Because downstream water pipes may be connected to a septic system, this can be a very concerning problem.

Why Is Backflow Concerning?

Backflow issues can cause some significant concerns, which is why regular inspections are mandated so frequently. The goal of plumbing infrastructure is to keep clean water uncontaminated, so backflow problems can present health risks to individuals, communities, and the environment.


The primary health concern associated with backflow problems is the consumption or use of contaminated water. Backflow water can carry bacteria, pesticides, and other contaminants that can cause significant illness in individuals. Many of these illnesses can be potentially life-threatening or cause hospitalization. Sometimes, if backflow problems affect a larger portion of the water supply for a community, many people can become sick at one time.


Backflow problems can also pose a risk to the environment. When contaminated water flows back into the environment, it can spread pollution to other water sources, such as groundwater, rivers, lakes, and oceans. Contaminated water can also affect the water used for farming, which can spread disease among humans.

Building Damage

Sometimes, backflow problems can also cause damage to buildings. When water flows backward through pipes, it can increase pressure and cause corrosion over time. Eventually, this can lead to pipes bursting or leaking, which can then damage walls and the infrastructure of the building. Damage to pipes and other building infrastructure can mean costly repairs, and you may even have to spend time out of your home while these repairs are being completed.

What Should You Do If You Suspect Backflow Problems?

If you notice any significant changes in the pressure, taste, or smell of the water coming from your shower or sink, you should contact a plumber right away. The clean water in your home should be clear, free of rust or other sediment, and not have a sulfuric scent or a bad taste. These problems should not be consistent, either, and they should not get worse over time. If they do, you likely have a backflow problem.
That said, there may be times when you can expect a temporary change in the appearance or taste of your building’s water. If you had to turn off the pipes in your home for any reason, running faucets after the water is turned back on may result in water that is temporarily rust-colored. If the city changes the level of minerals in tap water, you may also notice a change in the way the water tastes, which should reduce as the minerals or cleansing chemicals stabilize.

What Causes Backflow Problems?

The causes of backflow problems will depend on the piping infrastructure in the building, as well as the specific type of backflow problem you are facing. For back pressure backflow, uneven downstream pressure can be caused by power washing tools, water boilers, sprinkler systems, and washing machines. A break in the main water line can also cause this type of backflow issue.
For back siphonage backflow, the main cause of this issue is damage to the main water line, as well as damage to the pipes. Sometimes, extreme negative pressure associated with reduced water availability because of firefighting or construction can also cause back siphonage backflow. A clogged drain or issues with the septic tank may also cause this issue.

When Should You Contact a Plumbing Company for Backflow Issues?

In addition to annual inspections, it’s a good idea to contact a plumbing company if you suspect there are any backflow problems in your building. If you detect unstable water pressure or if water from faucets and showers has an odd odor or taste, it’s best to call a plumber for an inspection. Water moving back toward the drain can also be a sign that there are backflow problems in a building.

What Happens During Backflow Inspection?

During a backflow inspection, a plumber will first turn off the downstream water valve and wait for several minutes until the pipe has cleared. Then, a plumber will use special hoses to test the water pressure in the plumbing infrastructure to assess the water pressure in each pipe. If the water pressure is unusual in any area, that may indicate that the pipes have a backflow issue.

What Are Backflow Prevention Solutions?

Aside from installing backflow prevention devices, a plumbing company can address backflow prevention in other ways. Air gaps are commonly used to prevent backflow because air gaps between plumbing connections can stabilize water pressure to prevent backflow. However, because air gaps are not possible for all plumbing infrastructure, a plumber may recommend a specialized double valve to regulate wastewater and keep the clean water pipes free from contamination.
Backflow problems with your plumbing infrastructure can cause significant health, community, and environmental concerns. Whether you are dealing with back pressure backflow or back siphonage backflow, it’s important to contact plumbing experts as soon as possible so you can restore the clean water flow in your building. Contact All Phase Plumbing Services to book a backflow test appointment today.