Legionellosis is a collective term for diseases caused by legionella bacteria including 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.
The bacterium Legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools. If conditions are favourable, the bacteria may multiply, increasing the risks of legionnaires’ disease, and it is therefore important to control the risks by introducing appropriate measures.
Legionella bacteria are widespread in natural water systems, eg rivers and ponds. However, the conditions are rarely conducive for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth.
Legionnaires’ disease is normally contracted by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if: (a) the water temperature in all or some parts of the system may be between 20–45 °C, which is suitable for growth; (b) it is possible for water droplets to be produced and if so, they can be dispersed; (c) water is stored and/or re-circulated; (d) there are deposits that can support bacterial growth, such as rust, sludge, scale, organic matter and biofilms.
Who Is At Risk?
Anyone is at risk of catching Legionnaires Disease. However, the risk increases with age, but some people are at higher risk, eg people over 45, smokers and heavy drinkers, people suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease or anyone with an impaired immune system.
What should I do to prevent legionella causing harm?
It is important to control the risks by introducing measures which do not allow proliferation of the organisms in the water systems and reduce, so far as is reasonably practicable, exposure to water droplets and aerosol. This will reduce the possibility of creating conditions in which the risk from exposure to legionella bacteria is increased.
Legionella risk assessment is a legal requirement under the Health and Safety at Work Act 1974. The Management of Health and Safety at Work Regulations 1999 and the Control of Substances Hazardous to Health Regulations 2002, make specific requirements for risk assessment. These regulations apply to the control of Legionella and are embodied in the Approved Code of Practice and guidance document, ‘Legionnaires’ Disease: The Control of Legionella Bacteria Within Water Systems’, also known as ACoP L8.
How Is It Undertaken?
A Legionella Risk Assessment requires a full survey to be undertaken of the water system serving the building. The survey will take into account all aspects of the water system management, design, installation, condition, operation and usage.
Once the survey is complete, a report is produced outlining any remedial actions or recommendations to prevent, minimise and control the risk of Legionella. The Risk Assessment will provide a prioritised risk rated recommendation based on the most suitable course of action identified. Schematic drawings are also provided as part of the report.
Need a Legionella risk assessment? Get in touch with our friendly team for a free quote
How Often Should a Legionella Risk Assessment Be Reviewed?
A Legionella Risk Assessment should be reviewed on a regular basis with a minimum recommended industry standard of at least every two years. The document should also be reviewed regularly particularly when there have been changes to the original circumstances such as changes to the water system, changes to the use of building or changes in legislation.
How Long Will It Take?
The time taken to complete the risk assessment is dependent on the size of your premises and the water systems present within them, but we are normally able to complete a risk assessment within a few hours during the working day with little or no disruption to your normal business practice.
What is the L8 Approved Code of Practice? (ACOP)
The L8 Approved Code of Practice applies to the control of Legionella bacteria in any undertaking involving a work activity. It also applies to premises controlled in connection with a trade, business or other undertaking where water is used, stored and there is a reasonably foreseeable risk of exposure to Legionella bacteria (L8 ACOP, paragraph 22).
All water systems should be taken into consideration as part of the Legionella Risk Assessment. However, there are some aspects which are highlighted ib the ACOP L8 Code of Practice as higher risk. These include:
· Hot & Cold water systems
· Cooling water systems, cooling towers and evaporative condensers
· Spa pools
· Spray humidifiers, misters, air washers and wet scrubbers
· Safety showers, sprinklers, vehicle wash systems
· Fountains and water features
· Any other system containing water in which Legionella could grow and be released in aerosol droplets
How Can EMS Water Help?
EMS Water’s team are experienced, qualified and independent risk assessors. EMS Water is able to provide independent, comprehensive Legionella Risk Assessments. In addition, we are also able to provide independent consultancy services for any remedial work (if identified) in the Risk Assessment as well as ongoing support and training services to ensure compliance and safety.
Get in touch with the team at EMS Water. We will be happy to help with any questions