Protecting your tenants from Legionnaire’s disease

What is Legionnaires’ disease?

Legionnaires’ disease is a potentially fatal form of pneumonia caused by the inhalation of small droplets of contaminated water containing legionella. Hot and cold water systems can provide an environment with the right conditions for legionella to grow, i.e. suitable temperature range; water droplets produced and dispersed; water stored and/or recirculated; ‘food’ for the organism to grow – rust, sludge, scale, biofilm etc.

When Legionella is found in man-made water systems the risk of human infection soars drastically.

Legionella is most likely to be found in:

  • Closed systems that store water or recirculate water
  • Systems that release water droplets into the air such as air conditioning systems
  • Shower and spray taps
  • Water systems with a temperature between 20-45 degrees Celsius
  • Older water systems, which are susceptible to contamination from age related disrepair. Age and intricacy are also factors


What are your responsibilities as a landlord?

As a commercial landlord, it’s your responsibility to manage the threat of legionella as you would any other risk. The starting point of which is a regular risk assessment to comply with the mandatory legal obligations. The Approved Code of Practice: Legionnaires’ disease. The control of legionella bacteria in water systems contains practical guidance on how to manage and control the risks in your system.

You must understand how to:

  • Identify and assess sources of risk
  • Manage any risks
  • Prevent or control any risks
  • Keep and maintain the correct records
  • Carry out any other duties you may have


A risk assessment of the water system will flag any areas requiring improvement that currently pose a risk of harbouring legionella.  Keeping a thorough and accurate record of all testing and subsequent works is crucial in proving that all and any risks have been understood and managed.  Failure to carry out a risk assessment, failure to take the necessary action and failure to record the system management correctly can result in prosecution and a hefty fine.

The proper management of a water system will negate the risk of having to shut down an entire building in the event of a legionella outbreak – keeping your tenants, their businesses and their visitors both happy and safe at all times.

A Planned Property Maintenance contract our sister company Dareth Valley can navigate the legalities – keeping a building compliant by carrying out the necessary assessments and recording the findings in the correct manner.  Vast experience and undisputable knowledge – not only of large-scale commercial water systems but also of the legal requirements a commercial landlord must adhere to – makes Darenth Valley twice as competent at managing your building’s water system. A one-off risk assessment from a contractor unfamiliar with your building leaves you wide open to anomalies in the recording system that you just wouldn’t get with a Darenth Valley PPM Contract.