Legionella and Legionnaires’ Disease – What is it?

Preventing legionella (Legionnaires’ disease) is a necessity for those who own premises which are used for business or trade, or rented for residential or business purposes; any commercial premises that have a water distribution or storage system has to have proper measures taken to stop the spread of disease-causing bacteria. It is a rare disease, but one that poses serious health risks and is easily preventable. This article will explain what Legionnaires’ disease is, and the steps you can take to prevent it.

What is Legionnaires’ Disease (Legionella)?

Legionella is a lung infection that is caused by the inhalation of water droplets from certain sources. It can be contracted from spa pools or hot tubs; showers, taps, or toilets; and air conditioning systems. It is extremely uncommon to get it from sources such as drinking water, ponds, or others with the infection.
Anyone can develop Legionnaires’ disease, but the elderly, smokers, alcoholics and those with cancer, diabetes or chronic respiratory or kidney disease are at more risk.
The symptoms of Legionnaires’ disease consist of a bad cough in conjunction with:

  • It being long-lasting
  • An inability to properly breathe
  • Severe chest pain
  • Flu-like feelings
  • A high temperature or feeling hot and shivery
  • Nausea and vomiting

It has a mortality rate ranging from 5-30% depending, mainly, on how quickly medication is administered. It is vitally important to contact a GP as quickly as possible should you develop these symptoms especially if you have been working or visiting any of the above locations. Property owners have a legal obligation to ensure equipment is working correctly and must at all times take steps to prevent the transmission of Legionella.

Managing Legionella in Water Systems

The bacteria that causes legionella dies in temperatures above 60°C, and lie dormant when below 20°C. They are at their most active between 20-45°C in sources with plenty of nutrients. As such, the primary method of managing Legionnaires’ disease is controlling water temperature; there are certain temperature thresholds at which water should be stored and controlled on the premises.
Hot water storage cylinders should store water at temperatures above 60°C, a requirement to kill any bacteria present in the water. The water distribution systems should transport the water at temperatures above 50°C, whereas cold water should be stored and distributed below 20°C.
Storage tanks for hot water should be checked monthly, and cold water tanks at a minimum of every six months. As stagnant water is where the bacteria grow best, dead ends in pipework should be removed. Infrequently used outlets (which includes taps and shower heads) should be flushed on a weekly basis, and shower heads and hoses should be descaled every three months. Hot water storage tanks should be frequently drained to check for debris or corrosion, and cold water tanks should be cleaned out on a periodic basis.
If you are in the process of planning pipework, steps can be taken to minimise the risk of growth of the bacteria causing Legionnaires’ disease. To do this, keep pipework as short as possible (minimising stagnant areas), preventing contamination by properly fitting lids and insect screens to pipe access areas, and adequately insulating pipes and tanks when being fitted.
Additional steps to help reduce the risks of allowing legionella bacteria to grow include water treatments. Ionisation treatments of silver or copper can reduce the likelihood of the bacteria growing in a water source, and the water should be treated with biocides like chlorine dioxide.
These treatments are most effective when used in conjunction with other measures such as a proper water monitoring programme. A water monitoring programme consists of periodically analysing water samples for the level of bacteria, with the frequency thereof being determined by how at risk any particular site is of harbouring the bacteria.
TutorCare Ltd offer a wide range of awareness training courses in our Health and Safety Essentials Training portfolio.  From IOSH working Safely courses  to Legionnaires Disease Awareness Training, TutorCare is the UKs number one provider for online and in-house training.

Further reading on Legionella

The HSE (Health and Safety Executive) has statistics and information relating to Legionella which can be found here – HSE – What is Legionnaires Disease?
In addition please follow this link for information on Legionnaires risk assessments