As people work from home and travel is reduced, we are seeing many buildings such as hotels, commercial properties and schools with reduced or fluctuating occupancy, whose water systems are stagnating. As dates have been provided to ease the country out of lockdown, these water systems will need to be carefully managed to reduce the risk of legionella.
Increased Risk of Legionella
Hot and cold water systems are designed to be used in a specific way, and reduced usage puts them at high risk of legionella developing. However, the Health and Safety at Work act still applies, and care must be taken to identify and control this risk. The Legionella Control Association has stated that dutyholders will not be exempt from prosecution, despite the pandemic.

Manage your Water Safely
If you are responsible for water safety in your building, there are a few steps we’d recommend taking:
Additional Water Sampling
Additional sampling will ensure that you are aware of the status of the system at all times.
Risk Assessment Reviewing
We recommend reviewing your risk assessments regularly. Operational circumstances are likely to have fluctuated throughout the pandemic and the risk assessment in place could be outdated.
Cleaning and Disinfection of Systems
Another water safety service which should be carried out regularly. With warm external temperatures and reduced usage, systems are more susceptible to developing legionella bacteria and should be treated to control this risk.
Further Training
Ensure that on-site staff are competent, know how to monitor changes and understand when flushing is required and why this has increased.
These steps will all ensure that you control legionella within your water system and are operating within the law.
Recommissioning your Water System
We strongly advise developing a recommissioning plan before putting a system back into use after a period of reduced usage or shutdown. The Chartered Institute of Environmental Health has a useful guide to Legionnaire’s Disease – lockdown risks and reopening safely and advise that water systems should not be put back into use without considering the risk. Not only is the possibility of legionella higher, people who have had Covid-19 are more susceptible to the pathogens.
The Health and Safety Executive advises that you must “appoint someone with the appropriate authority and competence to oversee the risk controls of your water systems”, and if you are unable to do so, you must consider stopping operation.