What Are These Pipes Sticking Out Of The Ground?

They are in front of every school, shopping center, and hospital in America. They are even connected to our irrigation systems. You have probably seen hundreds of them and have not even noticed. What are these pipes with all these handles and valves that come out of the ground and immediately go back into the ground? Why do they populate parking lots and business fronts all around us? What is their purpose and who is responsible for making sure they are installed in the right places and are working probably? We here at Water Nuggets have the answers.

More Than Just Pipes

These pipes coming out of the ground are called Backflow Assemblies (not devices!) In simple terms they keep water from city water mains flowing in one direction. These assemblies are critical in keeping the public safe by not allowing contaminated water to enter the drinking water system. Once drinking water flows from the city’s water main and into a private residence or business, the city loses the ability to ensure the quality and safety of the drinking water. Backflow assemblies keep the water from re-entering or back flowing back into the city’s drinking water main. Backflow can occur in two ways, back pressure or back siphoning. Back pressure can occur if a water user has something like a water pump on site for boosting the water pressure on the private property in places like high rise apartments buildings or apartment complexes. If the pump on the private property increases the water pressure to a higher point than the city’s water system is delivering, then water from the private property may flow back into the city’s drinking water system. Back siphoning occurs when the pressure in the city’s water main suddenly drops and a vacuum is created. Water may be siphoned from private property into the drinking water system. Pressure drops may occur if a car hits a fire hydrant or there is a large water main break. Backflow assemblies prevent water flowing back into the city’s water system with the use of internal components such as springs and check valves. So why are backflow assemblies located all over commercial areas and even our homes?

Backflow Assembly on a Business Fire Line

Why You See So Many Backflow Assemblies

The reason you see so many backlfow assemblies installed around your town is because there are many possible pollutants and contaminates that may degrade the quality of the drinking water. Picture a large fire line for an office building. Water enters that water line and sits there unless it is used. Over time the quality of that water will deteriorate and make in unsafe to drink Also, certain chemicals may be added to in fire line pipes to prevent corrosion. The backflow assembly installed in the front of the building will keep that ucky water (technical term) from entering your drinking water. Other examples of things that can have an adverse effect on water quality are things like boilers, private water wells, sewage treatment plants, swimming pools, and irrigation systems. Anything that you can connect a water pipe to or drop a hose into can cause a cross-connection and adversely effect the public’s drinking water. The next question you have is probably, who is making sure all these hazards to the drinking water system have backflow assemblies installed to keep us safe? Who is making sure the backflow assemblies are working properly?

Backflow Assembly Protecting the City Water System from a Private Well

Who is Responsible for Making Sure Backflow Assemblies are Installed Correctly

Many States such as California require that each water purveyor have a certified Cross-Connection Specialist on staff. A Cross-Connection Specialist is trained to identify hazards to the drinking water and know the exact type of backflow preventer to install to mitigate the hazard. After a Cross-Connection Specialist identifies a possible hazard to the drinking water system he/she uses plumbing code along with State and local laws to enforce the immediate mitigation of that hazard. If a hazard is found on private property, the Cross-Connection Specialist notifies the property owner on how to mitigate that hazard. By doing this, the Cross-Connection Specialist not only protects the city’s water system, but also protects the private drinking water system. If the private property owner does not mitigate the hazard, the water purveyor will disconnect the drinking water service until the mitigation is made to prevent possible drinking water contamination. Since backflow assemblies are mechanical they do experience normal wear and tear. Backflow assemblies are required to be tested annually by a certified backflow assembly tester and a passing test report must be submitted to the local water purveyor.

AVB Backflow Preventer on a Home Irrigation System

Now you know why you see those pipes sticking out of the ground in every mall parking lot and business center. You know that backflow assemblies are an essential part of ensuring the safety and quality of your drinking water. Remember to check your home for any possible cross connections that may pose a risk to your health. Things like hose bibs, swimming pools, and irrigation systems all require some type of backflow preventer. If you have more questions, you can always contact your local water district and request a Cross-Connection Survey to ensure you and your family have the best water quality possible.

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