Legionella Risk Assessment For Duty Holders





    We will process your data in accordance with our Privacy Policy. You can opt out of these communications at any time by updating your perferences.

    By entering your details you agree that Comfort Services Group Ltd may use this information to market its services to you.

    We will never pass your information on to 3rd parties.

    What is Legionella?


    Legionella Compliance (The Law)


    Your Responsibilities


    How Comfort Services Group can help you

    At Comfort Services Group, our highly experienced engineers are experts in carrying out Legionella Risk Assessments. It is important to ensure that your programme of Legionella risk assessment and testing meets legal and regulatory requirements. At Comfort Services Group, we have the expertise to advise and help you to ensure that your legal obligations are met in relation to Legionella risk assessments.

    Regular risk assessments must be completed and Comfort Services Group have the experience and expertise to carry out regular testing of your water systems. Periodic testing and analysis allow us to identify any areas which require improvement. It is also recommended that further Legionella risk assessment tests are carried out when any changes have been made to the system. After thorough testing, we will provide a concise report outlining any areas requiring attention or recommendations for improvements to the system. The size and complexity of a water system is liable to affect the amount of action that is required off the back of a risk assessment. Low level systems will present a low risk, however, it remains essential that regular risk assessment testing is carried out to meet legal and regulatory obligations. At Comfort Services Group, we recommend that Legionella risk assessment testing is carried out at least every two years but contact us today and we will be happy to advise on your particular requirements.

    In addition to carrying out regular water system testing and legionella risk assessment, we are also able to advise on reducing high concentrations of Legionella. We will assist in setting up company procedures for water management and sampling to help ensure that all requirements are met. This includes assisting with recording and legal documentation to ensure your obligations, as an organisation, are covered.

    Our team of experienced engineers have been DBS checked and, for your complete peace of mind, will always present official identification.


    Primary School in Southampton closed after legionella bacteria discovered

    A Primary School closed for 4 days after legionella bacteria was discovered during a water quality test. The school was closed after traces of the bacteria above the threshold set by the Health and Safety Executive were found in its water system.

    High School closed after Legionnaires’ bug found

    Officials in Cardiff have confirmed that the bug responsible for Legionnaires’ disease has been found at a new super-school. Staff contacted parents by text message on Wednesday night to say the school would have to close.

    City College forced to close salon following legionella discovery

    A college salon was closed after legionella was discovered in its water supply. The college has temporarily suspended hairdressing and washing facilities at the salon as an extra precaution while water treatment specialists continue to resolve the issue.

    What is Legionella?

    Legionella is a group of bacteria which is most commonly associated with being the primary cause of Legionnaire’s disease. Legionella is particularly prolific within water systems which is why it is essential that regular risk assessments are completed to prevent the spread of Legionnaire’s disease, Pontiac fever and other illnesses. Legionnaire’s disease is an acute infection which primarily affects the lungs and manifests itself with symptoms similar to those of an individual suffering from pneumonia.

    Initially, a sufferer of Legionnaire’s disease will experience more mild symptoms including:

    If untreated, however, the infection may continue to grow within the lungs and cause more serious symptoms including chest pains and breathing difficulties. Those affected may also suffer from a persistent cough which will increase in severity and may include the coughing-up of phlegm and, in more extreme cases, blood.

    Knowing how Legionella develops, is contracted and how Legionnaire’s disease is spread is an important consideration when we undertake Legionella risk assessments. Legionnaire’s disease, unlike many illnesses, is not contagious insomuch as it cannot be transferred directly between individuals.

    Legionella is so called because of the first recorded case of Legionnaire’s disease which was documented as being at a convention hosted by the American Legion. At this stage in 1976, little was known about the Legionella bacteria and about the resulting infection it could cause. Fortunately, we now know a lot more about the causes of the disease and how to prevent to multiplication of Legionella bacteria and subsequent infection.

    The Legionella bacteria (primarily of the species L. pnemophila) commonly occurs in many natural bodies of water. Most rivers, lakes and ponds are liable to contain a level of Legionella bacteria but these levels are typically sufficiently low as to not present a significant risk of causing illness in humans. The risk of infection increases substantially, however, when Legionella bacteria is present in man-made water systems. Once present in man-made systems, the ideal incubation conditions allow Legionella bacteria to multiply rapidly. Infection is then caused when, from an open system such as an air conditioning system, the bacteria (which is hosted in minute droplets of water) is inhaled.

    Low level water systems such as those found in private homes provide less opportunity for the rapid reproduction of bacteria. However, with significantly larger and more complex water systems, the risk increases as, not only do these systems provide more optimum incubation conditions for the Legionella bacteria, the risk of a large-scale epidemic of Legionnaire’s disease is greatly increased. It is this increased level of risk, alongside regulatory and legal risk assessment requirements, that make regular testing of water systems in schools, colleges and universities so critical.


    Virtually any building which operates hot and cold water systems may be at risk from Legionella. The complexity of a water system is a significant factor in determining the level of the potential hazard. Bacteria are likely to incubate and multiply at a higher rate in complex air conditioning systems and these have, historically, accounted for the majority of recorded outbreaks of Legionnaire’s Disease. Schools do not typically adopt such complex systems, however, regular testing and Legionella risk assessments are essential in all schools, colleges and universities. Asides from being a legal requirement, there are a number of other fixtures and facilities, more often found in schools and universities which present a potential legionella hazard

    Wet and dry cooling systems can harbour Legionella, facilitating the multiplication of bacterial and increasing the risk of Legionnaire’s disease spreading. If your establishment operates leisure facilities such as swimming pools then it is essential that regular Legionella risk assessment and testing is under taken. It is not solely the pools which can be at risk from Legionella, associated facilities such as showers and even water fountains can create a risk of exposure to legionella. At Comfort Services Group, we can undertake the appropriate level of testing for your facility to ensure the health and safety of its users and that all legal and regulatory requirements are met.

    The greatest risk from Legionella comes when a water system has been poorly designed. For this reason, at Comfort Services Group, we provide pre-installation risk assessments for Legionella. This pre-commissioning analysis allows us to identify and report on areas of the system that might cause a Legionella hazard due to poor or ineffective design. We can then report on any areas that need improvement and help carry out pre-emptive work to minimise risk.

    Legionella Risk may be minimised by ensuring that any new system uses appropriate materials of a high quality and will not deteriorate. Materials which are prone to impurities such as rust, algae or lime scale increase Legionella risk as these materials can be used as a nutrient by the multiplying bacteria. Legionella can only grow and reproduce in water between 20-45°C, it is therefore essential that any hot water is continually above 50C and all cold water below 20C.


    Legionella Compliance (The Law)

    As the person responsible for the premises (in this instance, a head teacher or site manager) it is your responsibility to ensure that regular Legionella risk assessments are completed. This obligation extends to the recording of the results of any such testing. At Comfort Services Group, we are able to advise and assist in the recording and reporting on regular Legionella testing to ensure that all legal and regulatory obligations are met. The regulations require that you identify any potential sources of Legionella risk and manage any identified risks through prevention or control.

    If you are in control of a premises which operates a system that may be susceptible to Legionella risk it is your responsibility to ensure the risk assessment is completed. Failure to complete suitable risk assessment on any open system that may present a potential Legionella hazard would be an offence and could result in anything from a fine to prosecution. By appointing Comfort Services Group to manage your Legionella risk assessments, you can be assured that all relevant legislative requirements are followed. Our expert engineers are highly experienced in Legionella risk assessment and can take care of every stage from identification of risk to reporting and risk management.

    “Under general health and safety law, as an employer or person in control of a premises, 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:

    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.”


    Your Responsibilities


    Water systems will vary in the level of Legionella risk they pose. Complex air conditioning systems, for example, are far more likely to harbour and spread the Legionella bacteria than a simple closed water system.

    It is important that Legionella risk assessments be carried out on all water systems (we recommend around every two years) regardless of their level of risk. Some low risk systems will require no further action however, some systems which pose a higher risk may require immediate preventative or control work to reduce the risk of an outbreak of Legionnaire’s disease. Systems which are more liable to harbour Legionella include:


    Any risk which is identified during the assessment of water systems must be managed. The task of risk management can be appointed to one or more competent persons who possess the appropriate experience, skills and knowledge of the system. In this instance you can delegate this responsibility to a third party rather than carry the responsibility yourself or rely on one of your staff to undertake risk management on your behalf.

    Comfort Services Group are highly experienced in the management of Legionella risk. Contact us today to find out how we can assist in your Legionella risk management and ensure that all relevant regulations are adhered to.


    In the first instance, it should always be considered whether the risk of legionella can be prevented without the need for control systems to be implemented. The ability to prevent legionella will depend largely on the type of system you will be operating and the required specification for that system. Where it isn’t possible to completely prevent the risk of legionella, it is essential that effective control measures are put into place.

    Comfort Servces Group can assist in the prevention of legionella by identifying areas of a water system which present  a hazard and taking the appropriate preventative measures. When the risk of legionella needs to be actively controlled we are able to advise on, or undertake the required work to ensure that all HSE guidelines are met.

    When introducing a control scheme to manage legionella risk it is essential that you follow the correct procedure to ensure that your personal responsibilities, as the person in charge of the premises, are met. You are required to determine who is responsible for carrying out the assessment and implementing the control scheme, this may be yourself, a colleague or a third party (e.g. Comfort Services Group). You will also be required to document the control methods you will be using and keep complete and accurate records of how often they are undertaken and what checks are completed (and with what results). Contact Comfort Services Group today to find out how we can assist you with your responsibilities in the prevention and control of legionella risk.


    Example tasks and how often they should be carried out:

    The above information is to be treated as a general guide only and is not to be considered an exhaustive guide to the assessment, management and control of legionella risk. Comfort Services Group are experts in legionella risk assessment and management and we strongly recommend that, if you are unsure about your legal or regulatory obligations that you contact us in the first instance. We can help you to identify if you have a need for legionella risk assessment and make recommendations on minimising your legionella risk.

    At Comfort Services Group, we’re impassioned about ensuring schools are aware of their legal obligations for domestic water systems, and can provide a wealth of knowledge as well as Legionella sampling.

    Comfort Services Group is a proud member of the Legionella Control Association and adheres to the Code of Conduct set out by the Legionella Control Association.