Legionella in drinking water

Whether you take a shower in the morning, at night, or after a workout, it helps to revive our senses and give us a new burst of energy. Hardly anyone would doubt that showering is healthy. But can we always be so sure?

Legionella and E-coli bacteria

30,000 people in Germany are diagnosed each year with legionellosis

Legionella are bacteria that cause both the lethal Legionnaires’ disease (a severe form of pneumonia) and Pontiac fever. Legionella is a tiny bacterium that occurs naturally in soil and surface water and passes into our water pipes through the cold water. They thrive and multiply particularly well in the hot water systems in our homes, in other words, the lines feeding our home showers. And, if you use energy-saving water heating systems, such as those power by solar or heat pump, Legionella thrives particularly well due to the relatively low temperatures of the hot water.

When you inhale the spray and steam coming off your shower head, you run the risk of inhaling bacteria, including Legionella. According to estimates by the Robert Koch Institute, some 30,000 people in Germany come down with legionellosis each year. This is a severe form of pneumonia caused by inhaling Legionella in a shower or in the water vapor coming off HVAC systems.

Heat ineffective at killing Legionella

High temperatures were formerly used to fight Legionella in our water supplies, although only very inadequately. The temperature needed to be kept above 60°C in all segments of the systems. The technical design of the pipelines coupled with calcification, biofilm, and amoebas in the lines keep the higher temperatures from killing the Legionella. Studies at ETH Zurich also show that Legionella can survive for up to 60 minutes a temperatures of 70°C. Long-standing, traditional methods for sanitizing our pipelines are therefore not reliable!

Modern, energy-efficient water heaters such as those powered by geothermal or solar are usually also not able to raise the water temperature sufficiently to ensure that the Legionella is effectively killed.

Legionella limits regularly exceeded

Analyses of tests done by the Bavarian Office for Food Safety and Health between 2003 and 2008 show that in

  • 14% of all apartment buildings,
  • 9% of all single-family homes
  • 27% of all schools
  • 9% of all day-cares

and also hospitals, nursing homes, hotels, and other public facilities significantly exceed the threshold for taking action according set in drinking water regulations (>100 colony-forming units per 100 ml of water).

Frequently asked questions about Legionella

Where do Legionella bacteria come from?

Legionella is naturally found in soil and natural waterways and thus everywhere in the water supply. From there, it gets flushed into the pipelines of our buildings where the bacteria multiply explosively, which is why protecting against Legionella is so important. Legionella live from dead bacteria, so they need a constant supply from the water supply. Most Legionella live in biofilms which provide outstanding protection against heat and disinfectant chemicals. This makes protection against Legionella absolutely necessary.

When do Legionella become dangerous?

Legionella enter the lungs through tiny water droplets that we breathe in while showering or from humidifiers. Infection with Legionella can cause severe pneumonia. According to estimates by the Robert Koch Institute, some 30,000 people in Germany come down with legionellosis each year, and 1,200 die from this pneumonia.

Does chlorine fight Legionella?

Biofilm in the pipe network consists of bacteria, other microorganisms, and a lot of slime produced by the micro-organisms to protect themselves and to enrich their nutrients. Biofilm is found in every niche caused by rust, lime, pipe fittings, or valves, but it can also adhere even to the walls of new pipes. Bacteria can also easily move from one part of the pipeline system to another: they break off from their colony, taking a part of the biofilm with them, and then move to another section of pipe. Often they end up in showerheads.

Chlorine can only penetrate these biofilms if used at very high concentrations. Our old pipelines cannot withstand such high concentrations so the continuous dosage at those levels is not allowed. Low concentrations are ineffective.

How many germs are really in my pipes?

Bacterial smears, a method going back more than a century, are still used to detect microorganisms in drinking water today. A small sample of the water collected is smeared on a culture medium and the number of bacteria colonies that form are counted. Scientists now know that only 0.1 to 1% of all bacteria in water tend to form colonies on laboratory cultures. This means

  • That for each liter of water we draw from the public water supply, 100 million bacteria are coming into the pipes of our buildings.
  • Every day, billions of new bacteria thus infect our pipes.
  • The values ​​for Legionella on which we base our treatments are 100 to 1,000 times below the actual values. So even if no Legionella shows up in the analysis, there is still plenty in the actual supply.

Is heating the water an effective form of disinfection?

Current technical regulations say that the water in your pipes would need to be heated to 70°C in order to kill the Legionella they contain. But scientific studies have shown that Legionella can survive for more than 60 minutes at such temperatures.

Our existing technical standards that advise flow temperatures of at least 60°C and 70°C for thermal disinfection simply no longer meet the needs for modern environmentally-friendly systems. Geothermal heat pumps deliver their highest efficiency at below 50°C, while boilers often run with return temperatures at 30°C.

What can I do for healthy drinking water?

Our Seccua Filtration systems help you purify your drinking water – installed where city water gets into yout home. So you’re having clean drinking water at every faucet in your home – and in the shower as well. That’s for sure!

Get in touch with us:
(844) 533-1305

Showering securely with Seccua filtration

With Seccua Filtration systems you can’t only filtrate Legionalla and bacteria out of your drinking water, but also the chlorine which often is used to remove legionella.

Seccua filtration

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(844) 533-1305