Covid-19 and the increased risk of Legionella

Covid-19 and the increased risk of Legionella

June 17, 2020

Landlords, employers, the self-employed or anyone in control of premises are responsible for assessing and controlling risks associated to legionella.

The persons responsible for these premises need to understand and consider the impact on their water systems due to closure or reduced occupancy of buildings such as:

  • Poor turnover of cold water storage cisterns resulting in stagnation
  • Elevated cold water storage cistern temperatures increasing the risk of bacterial growth
  • Mains cold water supply pipework becoming stagnant due to decrease usage resulting in temperature increase and potential bacterial growth
  • Stagnant water within point of use water heaters and expansion vessels and potential bacterial growth
  • Cleaning of filters and strainers
  • Vending machines and point of use water dispensers not binge utilised as often, resulting in water supplies becoming stagnant which could result in the water temperature increasing

One of the key risks that people forget is stagnation causes bacteria growth, this may then cause a biofilm that can be very difficult to remove and can harbour bacteria which then becomes difficult to eliminate.

Many buildings when not in full use can experience significant thermal gains depending on the structure of the building. This further assists with bacteria growth due to the cold water systems also becoming warmer.

It is very important that the risks should be analysed and considered prior to the re-opening of any buildings and also that Covid-19 increases the risk of legionella as a secondary infection and could be fatal.

If you are unsure about the risks to your premises please do not hesitate to get in touch with us or another suitably qualified professional who will be able to give advice.

How can we help?

We can help to minimise the risks to all occupants by:

  • Implementing measures during periods of shutdown ensuring buildings are safe upon reopening
  • Assisting where buildings are due to be reopened and have either not been shut down correctly or adequately maintained during shutdown

As a company we can offer some control measures such as:

  • System Flushing
  • Disinfection
  • Sampling
  • Providing a long term solution via a legionella Risk Assessment

We strongly recommend that every written scheme for the control of legionella includes a start-up and shut down procedure for water systems and it is evident since Covid-19 that many have fallen short of providing a scheme that is suitable.

More information on the risk of legionella during the Covid-19 Outbreak is available from the HSE’s website.

If you would like more information on how we can help you to manage your property during or after shutdown please do not hesitate to get in touch – on 0345 600 7 800 or via email on or by using our Contact Form.