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What is Legionella? 

Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. The risk increases with age but some people are at higher risk including:

  • people over 45 years of age
  • smokers and heavy drinkers
  • people suffering from chronic respiratory or kidney disease
  • diabetes, lung and heart disease
  • anyone with an impaired immune system

The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems such as hot and cold water systems and spa pools.

If conditions are favourable, the bacteria may grow increasing the risks of Legionnaires’ disease and it is therefore important to control the risks by introducing appropriate measures. 


Where does it come from?

Legionella bacteria are widespread in natural water systems, e.g. rivers and ponds. However, the conditions are rarely right for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth, e.g. hot and cold water systems and spa pools used in all sorts of premises (work and domestic).


How do people get it?

People contract Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if:

  • the water temperature in all or some parts of the system may be between 20-45 °C, which is suitable for growth
  • it is possible for breathable water droplets to be created and dispersed e.g. aerosol created by water outlets
  • water is stored and/or re-circulated
  • there are deposits that can support bacterial growth providing a source of nutrients for the organism e.g. rust, sludge, scale, organic matter and biofilms


What is Plymouth Community Homes doing about Legionella?

We are carrying out water hygiene risk assessments as part of our legal obligations. We already regularly monitor and inspect some of our larger buildings to make sure water systems are clean and safe.

You can provide our assessor access to your home for them to check your water. This should take about 30 minutes to one hour, dependent on the type and size of your home.


What Can You Do To Lower The Risk?

  • Clean and disinfect  taps and showers.

Legionella bacteria can multiply on scale, dirt or rust, so clean and disinfect taps and showers every three months or sooner if there is an obvious build-up of debris on the outlet,

  • Setting the right temperature

Legionella bacteria are more likely to grow between 20°C and 45°C, so where possible set hot water thermostats to 60°C. Using cold taps regularly can help temperatures stay below 20°C.

  • Use water taps once a week

All the water taps require use on at least a weekly basis this helps to make sure you don’t have water standing still in pipes. If you’ve been away for more than a week, run all your taps for a few minutes before using the water. You’ll also need to run the water in your shower. Make sure the water doesn’t spray or splash too much as this can create water droplets. If you can’t remove the shower head, cover it with a towel or plastic bag while you run the water.

For further information please email: or call our customer call centre on 0800 694 3101.