Water systems and legionella

As lockdown eases, all businesses and building owners are reminded to check the water systems in their premises as they reopen. There may be an increased risk of Legionella bacteria being present as a result of water systems not being used during the lockdown period.

The health risk

Legionella bacteria can cause illness by breathing in small droplets of water suspended in the air containing this bacteria. It causes serious illness such as Legionnaires’ disease, which is a type of pneumonia and also flu-like illnesses such as Pontiac fever.

Legionella bacteria can be found naturally in rivers and ponds where it is not an issue, however under the wrong conditions it can become a serious health risk in man-made water systems. This is particularly the case for hot and cold water systems that supply sinks, showers, washing machines and other equipment in anywhere that has been closed, partially closed or restricted in use at some point during lockdown.

Here are some examples:

  • hotels, B&Bs
  • retail outlets (including hairdressers), restaurants, pubs
  • dental practices
  • schools, colleges and universities
  • office buildings
  • residential accommodation (for example second homes and student flats)
  • places of worship, community halls, sports and fitness clubs
  • cooling towers
  • evaporative condensers
  • spa pools

If you manage your water systems well and have the right controls in place you will be able to keep them safe.

What you need to do

If you're an employer, or someone in control of premises, for example a landlord, you have a duty under health and safety law to understand and manage legionella risks. All systems need a risk assessment but not all systems will need elaborate control measures. 

More guidance can be found on the Health and Safty Executive (HSE) website:

You may also find secondary guidance produced by your industry or trade sector.

Any questions

Please contact the Food and Safety Team at foodandsafety@medway.gov.uk.