What is Legionella?

Legionella bacterium is a natural inhabitant of water and can be found in both in the environment (rivers, lakes and streams) and man-made sources but usually in low numbers. It has been found in water at temperatures between 6°C and 60°C but favours growth between 20-45°C. It also needs organic nutrients to grow such as slime, sludge and bio-film and these are abundant in the natural environment. It can also be found in domestic water systems and pipework and is especially prevalent if the water is infrequently used or at the end of pipe runs.

What is Legionnaires’ Disease?

It’s an illness characterised by pneumonia normally caused by inhaling the legionella bacterium contained within either tiny droplets of water (aerosols) or evaporated droplets.

It is contracted by inhaling these droplets deep into the lungs. It is not usually associated with drinking contaminated water.

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.

What are the symptoms?

The symptoms of Legionnaires' disease are similar to the symptoms of the flu:

  • High temperature, feverishness and chills.
  • Cough.
  • Muscle pains.
  • Headache; and leading on to pneumonia, very occasionally.
  • Diarrhoea and signs of mental confusion.

Legionnaires’ disease is not known to spread from person to person.

The incubation period is between 2-10 days, however not everyone exposed will develop full symptoms and may only suffer a mild flu like infection.

Who manages the risk on my behalf?

DIO (A) - All water systems are included in our Legionella Management Plan.

This means specific maintenance issues and other checks are undertaken by our specialist contractor to ensure your water systems are maintained to an optimum standard and to prevent legionella bacteria proliferation.

Boilers and heating systems are maintained. Water sampling and testing is regularly carried out. All in line with current legislation.

What can you do?

Do not adjust the domestic hot water storage tank temperature.

  • Keep it above 60°C.
  • Contact your HEM for advice on how to operate your hot water boiler.

Remove and clean shower heads and tap diffusers/inserts approximately every 3 months with boiling water and/or mild disinfectant.

Report faults in your water systems to the Babcock Help desk on 0800 8884 242 (boiler failures, broken taps, shower heads, leaking pipes etc.)

The simple rules to remember are: Flush, Clean and maintain Temperature.

On move in - It is a good practice to run the bath and hand basin taps continuously for at least five minutes.

Showers - If your shower has not been used for:

  • A week - Run water from both hot and cold supplies through the shower hose and shower head for 3 minutes. To ensure no spray escapes from the shower head, run it through a bucket of water or full bath.
  • Two weeks or more - Disinfect the shower head. The shower head should be removed and the shower, run for 3 minutes. The shower head should be disinfected before being refitted by immersing for at least an hour in any solution designed for cleaning baby feeding bottles (e.g. Milton).

We recommend that shower heads should be regularly disinfected about four times a year.

After holiday action - Flush the whole water system for two minutes or more.

  • First flush your toilets,
  • Then let the kitchen taps and the hand basin taps run for 3 minutes.
  • Next, flush the shower through as described above.
  • Finally, let any other taps (garden taps etc.) run for 3 minutes.

SFA Checklist

  • Prevent and remove any scaling of shower heads and tap outlets.
  • Place the shower head in the bath/shower tray so that the water drains from the shower hose when the shower is not likely to be used for 3 days or more.
  • Flush taps and showers prior to any use if they have not been in use for more than 3 days, e.g. after returning from holiday or deployments.
  • Don’t leave garden hoses connected to the outside tap for prolonged periods during the summer when the sun can generate water temperatures in the hose can encourage the growth of bacteria.
  • Check the temperature of the stored domestic hot water in your SFA is set to 60 degrees.
  • If your SFA is fitted with a water filter make sure you flush and clean it on a regular basis – ask your local HEM for support if you are unsure how to do this.


SFA occupants are encouraged to be vigilant in ensuring any unused tap in your SFA is flushed through on a regular basis.

Especially in rooms that may be used infrequently or not used for prolonged periods e.g. guest bedrooms or rooms occupied by children who are attending boarding school.