Flush out water supply before reopening buildings to avoid potentially deadly legionella bacteria

Flush out water supply before reopening buildings to avoid potentially deadly legionella bacteria

PHE guidance says there should be "regular flushing" of the water system at the likes of dental practices, hairdressers, gyms and hotels, as well as office buildings, to stop bacterial growth. This is far from an exhaustive list and all businesses and property owners of previously unoccupied buildings should carry out a risk assessment as whether this is an action, they should take to protect the welfare of their employees and the general public.

Premises are also required to undertake a detailed review of all aspects of their water management system before reopening amid the continuing coronavirus lockdown.

Legionella is bacteria naturally present in water systems and causes Legionnaires' disease, a lung infection which is caused by inhaling droplets of water, mist or vapour that can be present in taps, spa pools, showers and air conditioning units in large buildings.

Legionnaires' disease is not contagious. The disease is transmitted via drinking or breathing in the bacteria and is not transmitted by an infected person.

Although the disease is rare, it can be fatal (in around 10% of cases), and it’s usually caught in places like hotels, hospitals or offices where the bacteria have got into the water supply. It can lead to serious illnesses in people aged over 50, smokers and those with underlying health conditions. When the temperature of water is between 25°C and 45°C, the bacteria multiply. Poor or no flow into the system can also have that effect.

Because many hot and cold-water systems will not be running during the lockdown, the chances of the bacteria forming will increase if no action is taken, particularly given summer is approaching, and heating systems may have been running prior to lockdown.

The PHE guidance says: "Regular flushing out of the premises' water system throughout the shutdown period is required. However, all aspects of the water management system need to be reviewed before reopening the business, and necessary action will be dependent on the complexities of the system. This may be done by a combination of workers employed by the organisation if they have the necessary skills and knowledge. If a water system requires disinfection, then a water consultant will be needed."

Property owners and businesses alike can take the following simple steps to reduce the risk, while buildings stand idle:

  • Use hot and cold-water systems at least once a week. This will maintain a degree of water flow and minimise the chances of stagnation.
  • Drain water systems fully if buildings remain vacant for long periods.
  • Clean and descale shower heads and hoses.
  • Remove dead legs/dead ends in pipework.
  • Run shower heads and taps frequently, at least weekly.
  • Ensure hot water storage cylinders store water at 60C or higher.
  • Hot water should be distributed at 50C or higher with thermostatic mixer valves fitted as closely as possible to outlets where a scald risk is identified.
  • Ensure cold water is stored and distributed below 20C

It is also recommended that these steps being taken are recorded as part of any ongoing maintenance program. Also, it is your duty under general health and safety law that you have considered the risks from legionella that may affect your staff and members of the public and therefore make sure you take suitable precautions and introduce the necessary controls by carrying out a risk assessment.

View a brief guide on Legionnaires disease.

HSE Legionnaires guidance.

People who think they may have Legionnaires' disease are advised to visit www.nhs.uk/conditions/legionnaires-disease or to call 111.

*Source: https://news.sky.com/story/coronavirus-businesses-told-to-flush-out-water-supply-before-reopening-to-avoid-potentially-deadly-legionella-bacteria-11990957

The information contained in this bulletin is based on sources that we believe are reliable and should be understood as general risk management and insurance information only. It is not intended to be taken as advice with respect to any specific or individual situation and cannot be relied upon as such. If you wish to discuss your specific requirements, please do not hesitate to contact your usual Towergate Insurance Brokers adviser.

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