Legionella FAQs

What is legionnaires' disease?
Where are legionella bacteria found?
Are there legionella risks in my workplace?
What are my duties?
How do I identify and assess sources of risk?
How do I manage the risk?
How do I prevent or control the risk?
What records do I need to keep?
Do I have any other duties?

What is legionnaires' disease?

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. However, some people are at higher risk, including:
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Where are legionella bacteria found?

The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. Since legionella bacteria are widespread in the environment, they may also contaminate and grow in purpose-built water systems such as cooling towers, evaporative condensers, hot and cold water systems and whirlpool spas.

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Are there legionella risks in my workplace?

Any water system that has the right environmental conditions could potentially be a source for legionella bacteria growth. There is a reasonably foreseeable legionella risk in your water system if: The most common places where legionella can be found include purpose-built water systems, cooling towers, evaporative condensers, hot and cold water systems and spa pools. There are also a number of other systems that may pose a risk to exposure to legionella, e.g. humidifiers, air washers, emergency showers, indoor ornamental fountains etc.

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What are my duties?

Under general health and safety law, as an employer or person in control of a premises (e.g. a landlord), you have health and safety duties and need to take suitable precautions to prevent or control the risk of exposure to legionella. Details of the specific law that applies can be found in part 1 of Legionnaires' disease: The control of legionella bacteria in water systems.

Carrying out a risk assessment is your responsibility and will help you to establish any potential risks and implement measures to either eliminate or control risks. You may be competent to carry out the assessment yourself but, if not, you should ask someone with the necessary skills to conduct a risk assessment. This can be done by someone from within your own organisation or from someone outside, e.g. an external consultant.

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How do I identify and assess sources of risk?

To identify the risks in your water system you, or a competent person who understands your water systems and any associated equipment, should establish any possible exposure to legionella risks, as listed above, as part of a risk assessment.

Your risk assessment should include: If you decide that the risks are insignificant and are being properly managed to comply with the law, your assessment is complete. You will not need to take any further action, but it is important to review your assessment periodically in case anything changes in your system.

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How do I manage the risk?

As an employer or person in control of premises, you must appoint someone competent to help you comply with your health and safety duties, e.g. take responsibility for managing the risks. A competent person is someone with the necessary skills, knowledge and experience to manage health and safety, including the control measures. You could appoint one, or a combination of: (Ref: Health and Safety Executive Legionnaires' disease: A brief guide for dutyholders Page 3 of 5)

If there are several people responsible for managing your risks, e.g. because of shift-work patterns, you need to make sure that everyone knows what they are responsible for and how they fit into the overall risk management programme.

If you decide to employ contractors to carry out water treatment or other work, it is still the responsibility of the competent person to ensure that the treatment is carried out to the required standards. Remember, before you employ a contractor, you should be satisfied that they can do the work you want to the standard that you require. There are a number of external schemes to help you with this, for example: 'The control of legionellosis: A recommended code of conduct for service providers.2'

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How do I prevent or control the risk?

You should consider whether you can prevent the risk of legionella in the first place by considering the type of water system you need, e.g. consider whether it is possible to replace a wet cooling tower with a dry air-cooled system. The key point is to design, maintain and operate your water services under conditions that prevent or adequately control the growth of legionella bacteria.

You should, as appropriate: If you identify a risk that you are unable to prevent, you must introduce appropriate controls. You should introduce a course of action that will help you to control any risks from legionella by identifying:
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What records do I need to keep?

If you have five or more employees, you have to record any significant findings, including any groups of employees identified by it as being particularly at risk and the steps taken to prevent or control risks.

If you have less than five employees, you do not need to write anything down, although it is useful to keep a written record of what you have done. (Ref: Health and Safety Executive Legionnaires' disease: A brief guide for dutyholders Page 4 of 5).

Records should include details about: This should include details about the state of operation of the system, ie in use/not in use.

These records should be retained throughout the period for which they remain current and for at least two years after that period. Records kept in accordance with the last bullet point above should be retained for at least five years.

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Do I have any other duties?

Under the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, you must notify your local authority, in writing, if you have a cooling tower or evaporative condenser on site and include details about where it is located. You must also tell them if/when such devices are no longer in use. Notification forms are available from your local environmental health department.

If you have a case of legionellosis in an employee who has worked on cooling towers or hot water systems that are likely to be contaminated with legionella, you must report this under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR).

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About Techright:

Techright Environmental is a leading independent provider of specialist services relating to monitoring the safety of water systems and in particular the risk from exposure to Legionella bacteria.

We work with a broad range of organisations assisting them in the prevention, control and compliance of the risks associated with Legionella bacteria in line with the Governments Health and Safety Executive Approved Code of Practice (HSE ACOP L8).
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Contact Us:

Tel: 02890 918 271

Email: info@techright.org

Techright Environmental
Scottish Provident Building
7 Donegal Square West
Northern Ireland
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Providing Legionella risk assessments & control services, water testing, tank cleaning, tank lids & refurbishment and all water hygiene services throughout, Belfast, Northern Ireland, UK and Ireland

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