All public buildings should have a water management plan to help reduce the risk of Legionella. This is after all a brutal disease and more than ever there is a need for businesses and commercial buildings to have in place some sort of management plan to combat its presence. A site-wide Legionella Management Plan (LMP) is very much a staple in a lot of commercial buildings now and can very much ward out the risk factors that legionella can otherwise pose.
Legionnaires’ disease can be present in all water systems; however, it is mainly brought to the public’s attention when it is caught in offices, hospitals, hotels, and care homes. It is for sure something that needs to be taken very seriously.
What legislation applies to Legionella?
The Health and Safety at Work etc Act 1974 (HSWA) describes duties that may arise from work activities, encompassing risks from legionella bacteria. The Management of Health and Safety at Work Regulations 1999 (MHSWR) provides a broad framework for controlling health and safety at work. The Control of Substances Hazardous to Health Regulations 2002 (COSHH) provides a framework of actions designed to assess, prevent, or control the risk from bacteria such as Legionella and to help take suitable precautions.
What is good water management for the correct overall management of legionella?
The key to managing legionella bacteria lies in temperature control. Legionella bacteria can only multiply in water where temperatures range between 20–45°C due as the nutrients available at this temperature. Below 20°C, legionella survives but is dormant, and above 60°C, most bacteria cannot survive. Therefore, water management to prevent legionella means operating constructed water systems at temperatures that prevent Legionella growth.
Legionella in a commercial office environment
Like many buildings in the UK, commercial business office buildings have been affected by the Covid-19 pandemic, specifically, how often, and how they are used. With this, legionella is yet another factor to contend with and manage out. All commercial building operators in the UK have duties under the Health and Safety at Work etc Act 1974 (HSWA) which extends to risks from legionella bacteria, may arise from work activities.
Your moral responsibilities
As the duty holder in control of a commercial office, you must;
- Identify and assess sources of risk;
- Prepare a written scheme for preventing or controlling the risk
- Implement, manage, and monitor precautions
- Keep and maintain records
- Appoint a Responsible Person
Whether you are the landlord/owner or tenant, the actions above must be undertaken, but like many commercial offices, these tasks may be undertaken by different parties. Unless a “fully maintained” lease is in place it is ultimately the responsibility of the landlord or owners to manage the building, this includes the water systems and other Health and Safety risks (including Legionella). If you are a tenant of a building (without a fully maintained lease) and are responsible for your employee’s health and safety, it would be advisable to seek evidence of compliance from your landlord.
Whatever arrangement is in place, records of work carried out to manage Legionella need to be kept up to date and readily available for inspection. It is very much a legal obligation.
One of the more topical issues regarding Legionella in commercial office buildings is water system usage. These types of buildings have experienced different levels of use during the pandemic. This ranges from complete shutdown to reduced staffing levels. This impacts the water system as less water is being used daily. This thus creating reduced flow, stagnation and possible biofilm problems. The Legionella Control Association have reported that lockdowns have increased the rate of positive Legionella sample results. So, if your building has seen a different level of use recently, has the Legionella risk assessment been reviewed? Has the amount of stored water been assessed? Have different control measures been implemented?
Risk Assessments for legionella
The purpose of the assessment is to enable valid decisions to be made about the level of risk to health and the necessary measures required to prevent or control the risk from exposure to legionella bacteria. The risk assessment is carried out by or on behalf of the Duty Holder. The Duty Holder is identified as the employer; or a self-employed person. This can also be the person who is control of premises or systems. This is in a place where others may be affected, such as in landlord/tenant situations or public premises.
The assessment of risk for this report is based on site observations of the system(s) design and operation and from information provided by the relevant parties involved in the legionella control / water management programme. It takes into account the potential for legionella bacteria to contaminate the system(s). This is for legionella proliferation within the system(s), sources of aerosol formation, dissemination and the potential exposure to persons. Also, the susceptibility of potential persons exposed and the adequacy of current control measures and management control procedures.
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Where the assessment shows that there is a reasonably foreseeable risk and it is reasonably practicable to prevent exposure or control the risk from exposure, the duty holder should specifically appoint a competent person. This is to to take day-to-day responsibility for controlling any identified risk from legionella bacteria. The responsible person should have sufficient authority, competence and knowledge. This is of the installation and be suitably informed, instructed and trained. Training must be regularly refreshed and to a high level. This ensures tasks are carried out in a safe and technically competent manner.
All of these factors covered above here are combined to produce a good result. This is to get one comparable to the following simple risk assessment table. Whilst the worst case for persons exposed to Legionella bacteria is death, not all persons exposed will go onto develop Legionnaires disease. The actual risk to health (i.e. someone contracting Legionnaires’ disease or another form of Legionellosis, such as Pontiac Fever) will be dependent on the degree of exposure and the susceptibility of the individual. It should be noted that the attack rate of Legionnaires ’ disease for a normal population is about 1-2%. For a susceptible population is about 5%. These factors are taken into account when assessing the severity outcome. This is by adjusting the standard severity scale to include a clear evaluation.