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Legionnaires' Disease: Risks of COVID19 and re-opening safely

Legionnaires' Disease: Risks of COVID19 and re-opening safely

17 September 2020

As buildings are slowly reopening post-lockdown, it is essential that water systems are not put back into use without considering the risks of Legionnaires’ disease. There is an increased risk of waterborne pathogens, such as Legionella, being present as a consequence of the conditions that lockdown created.

Many buildings have been left empty for several weeks, and even months, due to the global COVID19 pandemic. This coupled with the warm summer months could result in the ideal breeding ground for Legionella bacteria to grow in building water systems.

Six in hospital with suspected Legionnaires' disease in West Bromwich

There have already been a number of stories in the news about hospitalisations due to Legionnaires' Disease, one of which has left 6 people in West Bromwich in a serious condition in recent days. The Health and Safety Executive is investigating this particular outbreak, along with Sandwell Council and Public Health England (PHE). Full story available here.

Managing the risks

Ideally, changes in Legionella risk will have been considered at an early point in planning lockdown arrangements. However, if not, Estates & Facilities Managers must consider that risk now, particularly if it is foreseeable that buildings and water systems may remain shut down or subject to low usage - especially as a second Winter spike in COVID19 cases is on the horizon.

There is always an opportunity to put measures into place to reduce the risk of conditions for Legionella bacteria growth occurring. This is where Develop can help - we offer a range of courses to help manage the risks and put control measures in place including:


What is Legionnaires' Disease?

Legionnaires’ disease is a type of pneumonia which can cause serious respiratory illness. It can occur when tiny droplets of water containing Legionella bacteria are breathed into the lungs of susceptible people.

All hot and cold water systems are susceptible to bacteria growth including those at hospitals, retail outlets, beauty salons, offices, leisure centres, hotels, sports clubs, hotels, restaurants and camp sites. In short, anywhere that has a water supply is at risk.

There is also the potential for an increased number of people to be susceptible to Legionnaires’ disease due to a compromised respiratory system during or after infection with COVID19.

Legionnaires' Disease risks - water temperature and the time to stagnate

Legionella bacteria thrive at temperatures between 20°C and 50°C so one of the key control measures for minimising the risk is to ensure that cold water is below 20°C and hot water is above 50°C. When water is below or above these temperatures Legionella bacteria will not grow. Water between these temperatures presents a greater degree of risk, particularly where it is left to stagnate. Water left within a system without movement for more than a week increases the risk of bacteria growth.

Legal Guidance

Under UK health and safety law, owners and operators of water systems have a duty to keep them safe in order to protect the health and safety of employees and visitors. This is true at all times but especially important in recent times where buildings have been closed for sustained periods and/or subject to low use. Guidance on how assess the risks and to implement control measures is provided by the Health and Safety Executive (HSE) in the following documents: L8 Approved Code of Practice and HSG274 Part 2 – The Control of Legionella Bacteria in Hot and Cold Water Systems.

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