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Legionella, Landlords and Legislation


There have recently been some changes in Landlords responsibilities towards their properties, tenants and the Legionella bacteria. The Health and Safety Executive now require all property owners to take suitable precautions to control the risk of the exposure to legionella. Below is a full description of the legionella bacteria and the responsibilities of landlords.

1.1 What is Legionella?

Legionellosis is the collective name given to the pneumonia-like illness caused by legionella bacteria. This includes the most serious legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection.

1.2 Where can the bacteria be found?

Legionella pneumophila is the bacterium responsible for Legionnaires’ disease and is often present in natural sources of water. When the bacteria enter man made water systems and are provided with ideal growth conditions, e.g. temperature and nutrients, they proliferate rapidly. When these bacteria are released as an aerosol, e.g. showers, spa baths, cooling towers, taps and other water fittings, they can be inhaled and cause the disease in susceptible individuals.

The current legislation and guidance is:

  • The Health and Safety at Work Act - 1974

  • Management of Health and Safety at Work Regulations - 1999

  • COSHH Regulations - 1999

  • The Approved Code of Practice and Guidance L8, “Legionnaires’ Disease - The Control of Legionella Bacteria in Water Systems” (ACoP L8)

1.2.1 Definition of Risk

Systems susceptible to colonisation by Legionella and which incorporate a potential means for creating and disseminating water droplets should be identified and the risk they present should be assessed.

To form an assessment of potential risk, a number of factors have to be taken into consideration, such as:

  1. Potential droplet formation.

  2. Water Temperature.

  3. Presence of Legionella bacteria.

The ACoP L8 identifies a number of different plant and systems that may create a risk from Legionellosis:

  1. Water systems incorporating a cooling tower.

  2. Water systems incorporating an evaporative condenser.

  3. Hot and cold water services.

  4. Other plant and systems containing water which is likely to exceed 20°C and which may release a spray or aerosol during operation or when being maintained.

This list is not exhaustive, but evidence to date indicates that the risk from plant and systems not mentioned above is very low.

1.3 Responsibility

Under general health and safety law, a person in control of a premises (i.e. landlady/landlord) has health and safety duties and need to take suitable precautions to prevent or control the risk of exposure to legionella. The Health and Safety Executive (HSE) now require landlords to carry out a risk assessment on their domestic water systems to identify any risks from the Legionella bacteria.

The risk assessment will identify any further action required and if any further periodic checks or actions are required. We expect properties with modern properly fitted water systems (in particular combi boiler installations) to need less ongoing checks than older systems.


Our plumbing contractors have been conducting inspections of systems and we are including written reports with photos and any actions necessary to our landlords. If you are concerned that your system needs to be checked then we can offer a competitive price for this service. Just give us a call on 02920 640 200 or email us at


1.4 Sources and further reading


Please make sure you read the following brief guide:

1.4.1 Other sources:

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