Legionella in drinking water: causes, risks and protective measures

Legionella in drinking water are a serious health risk that particularly affects homeowners, landlords and operators of public institutions. These bacteria can cause the so -called legionnaire disease, a potentially heavy form of pneumonia. The misunderstanding that legionella becomes dangerous by drinking water is widespread. In fact, people are infected by inhaling the smallest water droplets (aerosols) that contain legionella. A classic scenario is the shower where such aerosols can easily arise.

Health risks through legionella

The legionnaire disease often manifests itself with flu -like symptoms such as fever, cough and muscle pain. It is particularly dangerous for people with a weakened immune system, such as older or toddlers, where she can lead to life -threatening pneumonia. In Germany, an estimated 2,000 people die annually from the consequences of this infection. The actual number of infections is difficult to determine, since the symptoms are often confused with those of flu and not every case is diagnosed.

Legal requirements and prevention measures

Since the end of 2011, the Drinking Water Ordinance in Germany stipulates that landlords have to have an examination on legionella every three years. This regulation aims to identify and prevent legionella outbreaks at an early stage. In the event of positive findings, tenants may even be able to get showering in their apartments until the problem is resolved.

Temperature increase as a short -term measure

A common method to combat legionella in the hot water system is to increase the water temperature to over 60 ° C. This temperature kills legionella, but also carries some risks and disadvantages. First, there is a risk of scalding for the residents. Second, this measure is not always reliable because it requires even heating of the entire water system, which is not always guaranteed. In addition, the higher temperature creates increased energy costs, especially in the case of systems that are operated with solar technology. Here the water, which is usually heated to 40-50 ° C, must be brought to the required 60 ° C with additional energy expenditure.

Chemical disinfection and its limits

Another method is chemical disinfection, in which chlorine or other disinfectants are used. However, this method is controversial because legionella are relatively resistant to many chemicals. In order to kill them effectively, high concentrations are often necessary that can exceed the permissible limit values. In addition, such chemicals can be harmful to health and must be carefully dosed and monitored.

UV-C disinfection: an effective and safe solution

In view of the uncertainties and disadvantages of the above methods, the UV-C disinfection A reliable and environmentally friendly alternative. UV-C light has the ability to destroy the DNA of microorganisms such as legionella, which means that they become inactive and cannot multiply. This method is particularly effective because it is applied directly in the water cycle and does not leave any chemical residues.

How the UV-C disinfection works

In a UV-C disinfection system, the water is continuously directed by a chamber in which it is irradiated with UV-C light. This light destroys the Legionella DNA, making the bacteria harmless. A great advantage of this method is that it works regardless of the water temperature and therefore there is no risk of scalding. In addition, energy consumption is comparatively low, which also makes it economically attractive.

Areas of application and advantages

UV-C disinfection systems are suitable for single-family houses as well as for large residential complexes or public buildings. They are easy to install, require little maintenance and are cost -effective in operation. Another advantage is environmental compatibility because no harmful chemicals get into the environment. This also avoids the problem of chemical residues in the waste water.

Long -term prevention strategies

In addition to installing a UV-C disinfection system, there are further measures that can help prevent legionella in drinking water:

1. Regular maintenance and cleaning : Hot water systems should be maintained and cleaned regularly to avoid deposits and biofilms that can serve as a breeding ground for legionella.

2. Optimization of the water temperature : Even if high temperatures kill legionella, the water temperature in hot water systems should be set so that they inhibit the growth of bacteria without causing scalding. A temperature of about 55 ° C can be a good compromise.

3. Systematic review : Regular microbiological tests of the water can help to recognize legionella early and take appropriate measures.

4. Training and Enlightenment : Creating awareness is an important step towards prevention. Residents and users of buildings should be informed about the risks of legionella and the importance of water hygiene.

Conclusion: security and health through preventive measures

Legionella in drinking water is a serious problem that can be effectively combated by a combination of legal requirements, technical solutions and preventive measures. The UV-C disinfection offers a safe, efficient and environmentally friendly method to minimize the risk of legionella infection. Together with regular maintenance and surveillance, these measures can help ensure the health and safety of the residents.