Legionella - risk controls

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Legionnaires’ disease is a potentially fatal lung disease that is caused by inhaling water droplets contaminated with legionella bacteria. There are around 300 reported cases in the UK each year.

The disease can affect anyone, but people over the age of 35, smokers and heavy drinkers are all likely to be at higher risk. It is fatal in approximately 12% of cases, but the percentage may be higher for those in the at-risk groups.

Due to the serious nature of the disease, outbreaks commonly hit the national headlines and can cause major disruption to local authority services.


The scale of the risks involved was illustrated by the Legionnaires’ disease outbreak in Barrow-in-Furness in 2002, which received widespread publicity. Seven people died and 180 suffered ill health. The source of the outbreak was found to be the arts and leisure facility owned by the council.

The failures that led to the outbreak have been summarised as:

  • poor communication and unclear lines of responsibility
  • failure to act on advice and concerns raised
  • failure to carry out risk assessments
  • poor management of contractors and contract documentation
  • inadequate training and resources
  • individual failings

The council and its design services manager were both accused of manslaughter and charged with offences under the Health and Safety at Work etc Act 1974. The manslaughter case against the council was dismissed on the basis that the design services manager was not at a sufficiently senior level within the council to “embody the corporation” and was not one of its “controlling minds”.

However, the council entered a guilty plea to the charge under section 3 of the Health and Safety at Work Act. The council was fined £125,000 and ordered to pay £90,000 in legal costs.

The design services manager was acquitted of manslaughter, but she was convicted under the Health and Safety at Work Act and fined £15,000.

Best practices

  1. Start by considering the type of system you need. For example, you may be able to replace a system that requires water with one that does not.
  2. In cases where using water is unavoidable, keep the system and the water used within it clean.
  3. Design and maintain water systems appropriately.
  4. Avoid keeping water at a temperature that encourages the growth of bacteria.
  5. Treat the water to limit the growth of legionella and other bacteria.
  6. Try to prevent water stagnating by keeping pipe lengths short.

Legal requirements

There is a framework of legislation and regulations that places duties on organisations that own, control or manage premises with hot/cold water services or wet cooling systems to ensure that they prevent the risk of exposure to legionella. Relevant rules include the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, and the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations.

The HSE’s approved code of practice on the topic describes the legal duties that apply, including identifying and assessing the sources of risk; preparing a scheme/course of action to control the risks; appointing a ‘responsible person’ to implement and manage the scheme; and keeping records and making sure that the controls are effective.

Some organisations employ contractors to carry out risk assessments, prepare written schemes, provide training and implement control measures. However, employing appropriate contractors is not, in itself, enough to discharge the duties imposed by legislation. The duty holder needs to have arrangements in place to make sure that contractors are doing what they are required to do and that there are clear lines of communication.

Since the Corporate Manslaughter and Corporate Homicide Act came into force in 2008, it has not been necessary to identify an individual senior manager as the “controlling mind”, making it easier to prosecute a large organisation for corporate manslaughter.

Arranging appropriate cover

Liability insurance policies often exclude ‘gradual pollution’ and the nature of Legionnaires’ disease is such that it may fall within this category. To remove this doubt, we have introduced an extension to our liability policies and we can also carry out thorough reviews of legionella management procedures.

Our reviews check an organisation’s legionella policy and the implementation of procedures in key areas, including:

  • risk assessment
  • roles and responsibilities
  • prevention and control
  • monitoring and inspection
  • record keeping
  • protection of people
  • cooling towers
  • other risk systems

How can we help you?

For more advice on how we can help lower the cost of your risk, please email contact@rmpartners.co.uk


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