Water safety


Most of us jump in the shower or turn on the taps without a second thought. We expect the water that flows in our homes to be clean and fresh – and it nearly always is. But our hot and cold water systems can become breeding grounds for harmful bacteria.

What is Legionella?

The Legionella bacteria can grow in our water systems, particularly where there is stagnant water or where water temperature is set between 20-45°C (68-104°F). Legionella can stick to limescale and rust and feed on debris built up around taps and shower heads. It is most dangerous when spread in aerosol form – that’s the fine spray produced by showers and modern mixer taps.

What is Legionnaires’ Disease?

If inhaled, Legionella can cause Legionnaires’ Disease – a severe form of pneumonia with flu-like symptoms. It most commonly affects older people, those with chest or lung conditions and people with weakened immune systems, but it is not contagious.

What do we do to reduce the risk of Legionella?

  • Identify and then prevent or control risks to your water supply
  • Analyse water samples, where necessary
  • Record and periodically review risks and action taken
  • Carry out regular risk assessments of equipment supplying water to homes not served directly by the water mains and ensure water is delivered at a safe temperature.

What can you do to reduce the risk of Legionella?

  • Run taps and showers for ten minutes, if they haven’t been used for a while, to flush out stagnant water
  • Keep shower heads and taps clean and descaled. Regularly bleach or apply anti-bacterial product to help kill any bacteria
  • Set your boiler temperature to 60°C (140°F), but be aware that hot water can scald. Call us for advice or if you are unsure how to change your boiler temperature.
  • If at any point you are concerned with the quality of your water supply, please call us on 0300 123 9966 or email ask@onehousing.co.uk