Legionella bacteria are found in streams, rivers and lakes. They are also found in soil, compost and mains water and can sometimes enter a home’s water system.
Is Legionella harmful?
Low amounts of Legionella are not harmful. Legionella is only dangerous if conditions are right for the bacteria to grow and if you inhale water droplets from a contaminated water system. The bacteria can cause a number of infections, most of which are not serious. However, Legionnaires’ Disease is fatal in 10% to 12% of cases.
We are legally obliged to check for Legionella in some of our buildings, as part of regular checks to ensure water systems are clean and safe to use.
What you can do
Legionella rarely occurs in homes, as most households do not store large volumes of water, however there are a few tips to make sure your water is safe:
Set the correct water temperature
Legionella grows between 20°C and 50°C, so where possible set hot water cylinders at 60°C or above. Regular use of cold water should ensure temperatures stay below 20°C.
De-scale taps and showers
Legionella can grow and multiply on scale or rust. So de-scale taps and showers every three months or when there is an obvious build-up of scale (in hard water areas, you may need to do this more often). Brush scale off with a nylon brush or wipe with diluted bleach (follow the instructions on the bottle) or a de-scaling solution.
Check the water tank, if you have one
Contact customer services if the lid is missing or damaged.
Use water taps once a week
This will ensure water doesn’t stand in pipes; if you’ve been away for more than a week run all your taps for a few minutes before using the water. Also run the water in the shower – remove the shower head beforehand so water droplets are not created. If you cannot remove it, cover it with a towel while you run the water.
Additional guidance can be found in the Approved Code of Practice and guidance for Legionnaires’ disease on the Health and Safety Executive website.