Legionella is a type of bacteria which occurs naturally in water sources but can multiply and colonise artificial water systems, e.g. cooling towers, evaporative condensers, hot and cold water systems, spa pools.
If the Legionella bacteria are expelled out of these water systems through taps or showers and then ingested they can cause illness, e.g. Legionnaire’s disease.
What is Legionnaire's disease?
Legionnaires' disease is a type of pneumonia which can cause serious illness and death when harmful bacteria are inhaled.
Whilst the risk of contracting the Legionella bacteria is rare, some people are at higher risk, such as those who are over 50 years, smokers, and those with underlying health conditions.
Where can Legionella be found?
Legionella bacteria can be found in natural water sources like rivers, lakes and ponds. They can also be present in the artificial water systems in our homes and gardens such as:
- Hot and cold-water systems and drinking water systems
- Storage tanks
- Baths, taps and showers
- Firefighting sprinklers and hoses
- Garden hosepipes
- Lawn sprinklers or watering systems.
Why has lockdown increased the risk?
In the current coronavirus crisis, it is imperative that our health service is not put under any additional strain.
The closure of buildings, parts of buildings or their restricted use, can increase the risk for Legionella growth in water systems and associated equipment including the above if they are not managed adequately.
The bacteria grow in warm conditions and can multiply to a dangerous level if water in buildings has not been used for some time.
What you can do to manage the risk during closure
It is very important that while many buildings and offices are shut down due to the pandemic, that water systems are still well maintained to prevent future health issues like Legionella outbreaks.
To manage the risks during a period of closure:
- Start a flushing regime or other measures such as draining the system if the water system is to remain out of use for long periods
- As a general principle, outlets on hot and cold-water systems should be used at least once a week to maintain a degree of water flow and to minimise the chances of stagnation
- Low risk premises such as offices that just have water supplied to kitchens and toilets can help prevent the build-up of Legionella by flushing through simple hot and cold-water systems with fresh mains water for several minutes.
How to reopen safely
For general information on reopening businesses safely please refer to the Chartered Institute of Environmental Health (CIEH) guidance:
If you are an employer you have responsibilities to protect your employees, visitors and customers from the risk posed by Legionella bacteria.
As an employer or person in control of premises you must understand how to:
- Identify and assess sources of risk
- Manage any risks
- Prevent or control any risks
- Keep and maintain the correct records
- Carry out any other duties you may have.