Lots of people know about waterborne Legionella and how dangerous it can be, but few realise how prevalent it is

Legionella is a pathogenic group of bacteria that cause pneumonia-type illnesses, with the most serious being Legionnaires’ disease.  You usually get it by breathing in mist from water that contains Legionella. The mist may come from hot tubs, showers, or taps in large buildings.

While most of those who are exposed to Legionella will not become ill, it’s still vital to ensure water systems and their constituent parts are properly maintained. To remain compliant, businesses need to assess risks in their networks, manage any identified issues, and then prevent the possibility of an outbreak. All of this work requires documentation to remain on the right side of the law.

How is it controlled?

To control Legionella, the temperature of a plumbing system can be maintained so as to prevent growth. The ideal temperature for Legionella is between 25-42°C, but when water is heated above 50°C, 90% of strains die. It is therefore imperative to keep the temperature above this threshold.

A heating loop is used to circulate hot water around a building and keep the temperature constant, however there are “legs” which must branch off in order to supply mixers to taps and showers. When these outlets have not been used for a while, the water in these legs converges to ambient temperature where Legionella thrives.

The potentially fatal consequences of serious contamination mean routine monitoring and inspection of at-risk areas is critical for those in charge of buildings. In no other environment is this more important than public washrooms, where complex circulating hot water systems are commonplace.

For some time, it has been recognised that failings in these environments often result from sub-standard risk assessments that overlook the different parts of a plumbing network. In response, Health and Safety Executive (HSE) has revised its own technical guidance document (HSG274 Part 2) to combat avoidable failings in Legionella control. Keeping compliant and free from bacteria will keep staff and customers safe from contaminated water. Legionella outbreaks can never be fully eliminated but they can be mitigated with the right procedures in place.

Eliminate manual procedures with FlushSafe

To restrict Legionella growth, we monitor the temperature of each leg 24/7 and automatically purge the outlet when the temperature drops below (or above) the temperature threshold.

We also install sub meters on each outlet so we can document the exact time and amount of water consumed on each purge.

In this way, we reduce time spent on legionella compliance by over 80% and save up to £20 per tap annually on water and energy wastage.

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