Legionella in Water

In Germany and many other parts of the world. there are usually no legionella bacteria in the drinking water, at least if the water is coming from a public supplier.

The authorties control strictly the water suppliers and ensure they provide water of high quality. In general there is nothing to worry about.

Why one has to be careful about legionella?

Legionella in the water might cause the so called legionella pneumophila infection, also known as the Pontiac Fever. This infection, if not recognized in an early stage or not treated in time, might cause pneumonia. Around the world there are again and again cases, where people died, because of legionnaires‘ disease.
That’s why the authorities reacted. Today the possible ways to get infected are identified. And rules established how to minimize the risk to get legionellosis. Public places, such as schools, sports centers or hospitals are checked regularly for legionella. Authorities close whole buildings or showers in schools or hospitals. And the necesarry actions to bring legionella under control are described and followed.

Despite all the care and good water practice, it cant be avoided there are cases where bacteria grow in the water. In boilers operated at lower temperatures for saving energy are an excellent habitat for microorganisms. Or distribution networks, where stagnant water cooles down after a time, are typrical places where legionella grow.
If legionella pneumophila enter a water system, it is difficult to get rid of them again. They live in incrustations or biofilm on the pipe walls, which also can protect the legionella from heat or other harmful factors.

There are several methods to fight legionella. The most common ones are thermal disinfection, UV light and chemical treatment. For thermal disinfection the water is brought and held at a very high temperature to kill the bacteria. Sometimes this is done regularly which is expensive and difficult. While the water is heated up no one in the building can take out water due to the risk of burning oneself.

UV treatment works where water flows through the device. Every bacteria in the water is killed. The problem is that huge water systems often have so called dead legs where water is stagnating. These spots would not be reached by the common treatment methods. Ergo bacteria can grow here and spread in the system.

Fighting legionella without chemicals

Against these microbiological problems we developed a special device. Our Merus Ring Bio is responsible for many good results against legionella and other bacteria. In the first weeks after the installation the amount of microorganisms in the water goes down about 80%. Afterwards this development is slowed down but goes on continuously. Depending on the complexity of the system it can take some months until there are no microorganisms in the pipe anymore. But the solution is sustainable – the success stays stable.

Please note: for this application we always start with a trial phase where the water needs to be monitored by a unbiased laboratory. Working with bacteria and the human health is a sensitive issue, therefore we need to ensure the success of the method in every individual case.

Two effects of the Merus technology are needed to achieve good results. First of all the special Bio Rings emit an oscillation which reduce bacteria growth directly. Additionally incrustations and deposits in the pipe are removed and thus the habitat of the microorganisms destroyed.

The effect is transported with the direction of flow. Therefore also dead legs are reached which is a big advantage of the method.

What is important is that we always offer the solution, not the device. This means we guarantee contractually that in a documented time the amount of microorganisms in the water is below the required values. In most buildings this is less than 100 cfu/ml at a temperature of 22°C. As no bacteria is killed but their habitat is taken there is no sudden result expected but success in the long run.

To achieve the results described above our special Merus Ring Bio is needed. The standard rings have only minor effect on bacteria in the water.

We are not able to kill bacteria in the water and regain water quality right after the installation. To achieve this filters or similar methods are needed.



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