Blog, Cleaning, Facilities Management

Legionella: An FM Expert Guide

Legionella needs to be taken seriously, it can be very harmful - and in fact, it can be fatal.

What is Legionella?

What is it: Legionella pneumophila is a bacteria that is commonly found in low numbers in natural water sources such as rivers, lakes and reservoirs, The bacteria can also be found in purpose-built water systems such as heating and air conditioning units, cooling towers, evaporative condensers, hot and cold water systems and spa pools.

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Why We Should Worry About Legionella

Why should we be worried about it: Legionella bacteria isn’t harmful in small numbers, but when it starts to grow it can increase the risk of legionnaires disease which is a potentially fatal form of pneumonia

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How Can You Catch Legionella?

How can you catch it: People contract Legionnaires’ disease by inhaling microscopic droplets of water containing the bacteria.  There are some conditions that can increase the risk of legionella, such as:

  • When water in all or some parts of a purpose-build system are between 20-50°C which is the ideal temperature for this bacteria to thrive
  • If equipment such as a cooling tower or water outlets are used where breathable water droplets can be created and dispersed
  • Where water is stored and/or recirculated
  • If there are deposits that can support bacterial growth providing a source of nutrients for the organism eg rust, sludge, scale, organic matter and biofilms
white thermometer at 36 degrees celsius

Guide to Compliance: Keeping Properties Safe and Meeting Legal Obligations

We understand organisations have a duty of care for everyone that uses their buildings, be it a school, office, house or commercial space. Download our Free Guide to Compliance and you can learn how we can keep your properties safe and ensure you meet your legal obligations.

What are The Legal Requirements in Relation to Legionella?

What are the legal requirements: Under health and safety law, employers, business owners and landlords must manage the risks of exposure to Legionella bacteria. Owners and operators of water systems have a duty to keep them safe to protect the health and safety of employees and visitors. This is true at all times but especially where buildings are closed, subject to low use or reopening. This requires a suitable and sufficient assessment of that risk.

Urban jungle

What do property/facilities managers need to know about Legionella?

What do property/facilities managers need to know: Where conditions for Legionella bacteria growth exist, there is always an opportunity to put measures into place that reduce that risk. 

  • Regular reviews should check that water is not becoming stagnant in tanks or pipework. Where this cannot be avoided, additional steps should be introduced, such as flushing the entire water system (all outlets) weekly and, if possible, dropping the level of stored water in tanks.
  • If hot water systems are switched off to conserve energy, ensure water stored in any associated tanks is also turned over within 24 hours.
  • Regular temperature checks across the water system at various outlets should help confirm that water is not warming up to a point at which Legionella growth may occur, and demonstrate that stagnation is being prevented if they are typically satisfactory and consistent across the system.

Compliance and Health & Safety are essential to effective Facilities Management.

If you’d like to know more about how a managed service can help you stay on top of the risk of legionella and other harmful bacteria, contact RFM today.

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Whether you need advice on a new project or have an existing property or portfolio - We're always happy to help. Please call or 08000 277 262 email


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