How quiet is a sewage treatment plant?

29 Nov 2018


How quiet is a sewage treatment plant? It’s important to consider the impact that a wastewater system will have on all aspects of your quality of life. We get many questions from homeowners about how their sewage treatment plant will look in their garden, and rightfully so, aesthetics are an important consideration when choosing the right treatment plant. However, the noise that a treatment plant makes is often overlooked.

The first question to ask yourself is: ‘does it matter?’ If you plan to install the treatment plant a long way away from the house, and perhaps behind a garage then the sound that a treatment plant makes doesn’t matter so much. If on the other hand you enjoy your garden and the treatment plant will be close (within 15 metres from the house), then the noise will be important.

So, what creates noise? A sewage treatment plant requires oxygen to be added to the water. This is done using an Air blower (or air compressor). these air blowers use a piston or diaphragm, rapidly moving back and forth to push air into the water. It is this rapid movement that creates a hum or buzzing sound. The quality of the air blower, will have an impact on the sound it creates but also its housing, which we will discuss later in this article.

Air blower Quality:

Top end treatment plants will use air blowers from manufacturers like Hiblow or Nitto. Charles Austin also do good quality air blowers which are cheaper than Hiblow or Nitto. Some treatment plants will however use unbranded air blowers and it is important to find out which is supplied with the system. Unbranded air blowers, often Chinese in origin will work, but it is often hard to get replacement diaphragms for them and we find them to be noisier, especially as time goes on.

Air blower Housing:

This is a very important point. Many sewage treatment plants house their blowers in a small GRP box. Either attached to the top of the treatment plant or to the side. These will often resonate the noise from the blower and act like a speaker. Which is fine if the system is to be installed away from the property, but no so much if it is to be installed within 15-20m away. Some manufactures have opted to install the blower under the lid of the tank. So far, only the SOLIDO and SOLIDO smart from premier tech do this well. The Solido and Soldio smart house the blower in a sealed container to prevent moisture getting to it. Our experience over the last 5 years with this method has proved that it is very successful. Noise is illuminated and the blowers are kept bone dry, prolonging their lifespan greatly.

This video shows you how silent a solido system is:

Take Home Message:

In our experience, noise is just as much of a concern to home owners as aesthetic appearance it. Choosing the right treatment plant for the environment isn’t always as easy as it seems. always ask the suppler about noise levels and what type of blower is used as well as how it’s housed. This will give you a good feeling as to how experienced and confident the supplier is about the product they are supplying.

We found a very interesting discussion on a build forum where homeowners discuss the noise levels of their treatment plants. I would highly recommend having a read through, it gives some real insight from homeowners about what the noise of their treatment plants is like and what they have done to try and help. You can read the discussion by clicking this link.

Feel free to speak to us on: 01844 877030 to discuss noise levels in a treatment plant

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