Legionella testing must be carried out by a competent person(s) to identify any possible conditions that encourage proliferation and a Legionella Risk Assessment may be required. As certified members of the Legionella Control Association, Swiftclean are fully qualified to carry out legionella testing, risk assessments and advise on compliance to L8 standards.
Legionnaires disease is a severe form of pneumonia, which causes potentially fatal complications to occur within the human lungs. The disease is not contagious; it is contracted when bacteria, in the form of tiny contaminated water droplets or aerosols, is inhaled into the lungs.
Legionella bacteria is found to be present in up to 13% of water samples and it is common to find harmless levels of legionella and other bacteria in mains supplied drinking water.
For this reason, it is recommended that you do not use a Legionella testing kit as results can be inconclusive and may have not been taken from specific high risk areas (such as poor temperature distribution, low usage outlets etc).
It is recommended to test for Legionella when:
- A water system is being treated with biocides and hot water is stored or distributed at lower temperaturestemperature is not the primary control for Legionella.
- The limits of a control regime, e.g. temperature or disinfectant concentrations, are not being consistently achieved.
- There is a high-risk area or a place where there is a population with increased susceptibility, e.g. in healthcare premises such as care homes.
- A water system is suspected or identified in a case of an outbreak of legionellosis.
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The Legionnaires’ disease Approved Code of Practice (ACoP) L8 is aimed at dutyholders, including employers, those in control of premises and those with health and safety responsibilities for others. The code of practice has been put into place to help businesses comply with their legal duties in relation to Legionella.
It’s imperative that every employer has a duty of care to ensure an employee’s health, safety and welfare. This specifically includes controlling the risks of hazardous substances, including Legionella bacteria.
Under the Control of Substances Hazardous to Health (COSHH) regulations, owners and operators of all commercial premises (including: Social Housing, Facilities Management, Hotels & Stadiums, Healthcare, Education and others) have a legal responsibility to control the risk of Legionella bacteria in water systems. Owners and operators of all commercial properties are required to:
- Identify and assess the sources of risk (see Legionella Risk Assessment for more information)
- Prepare a scheme for preventing or controlling the risk
- Appoint a person to be managerially responsible
- Implement and manage precautions
- Keep records of the precautions implemented
The risk of Legionella can be controlled by implicating stringent water temperature controls.
Water services should be operated at temperatures that prevent Legionella growth, such as:
- Hot water storage units should store water at 60°C or higher
- Hot water should be distributed at 50°C or higher (55°C in healthcare)
- Cold water should be stored and distributed below 20°C
Cold water systems should be designed to comply with the relevant Water Supply (Water Fittings) Regulations 1999.
Legionella growth can occur in stagnant water, so to reduce to the risk of this, water systems should be designed to ensure any stored water is turned over within a 24 hour period (12 hours in healthcare) and does not contain dead leg pip work or infrequently used outlets.
Hot water systems should be designed to enable water distribution to achieve 50°C or higher to all served outlets within the recommended time limit of one minute.
Hot and cold water systems should also be regularly maintained to help minimise conditions, favourable for Legionella bacteria proliferation, occurring. This will include regular cleaning and disinfection of stored water units, servicing of thermostatic mixer valves and removal of scale from outlets etc.
Other methods to control Legionella should include the analysis of water samples periodically to demonstrate that bacteria counts are acceptable. The frequency of the water samples should be determined by the level of risk, in accordance with the risk assessment.
The most effective way to test for Legionella bacteria is to take a water sample which is then analysed by a UKAS accredited laboratory to determine the presence of bacteria and, if present, identify the amount of colony forming units and strain. Identification of the amount of colony forming units and strain will then help determine what actions are required to remove or minimise the risk.
To be conducive, samples should be taken from both hot and cold water storage units and sentinel outlets (nearest and furthest to the associated water source) as a minimum to help identify if contamination (if present) is localised or system spread.
Microbiological monitoring of domestic hot and cold water supplied from the mains is not usually required, unless the risk assessment or monitoring indicates there is a problem. Is sampling is determined to be required then sampling should target;
- areas where the required control parameters are not met (i.e. where disinfectant levels are low or where temperatures are below 50 °C (55 °C in healthcare premises) for HWS or exceed 20 °C for cold water systems);
- from areas subject to low usage, stagnation, excess storage capacity, dead legs, excessive heat loss, crossflow from the water system or other anomaly.
Legionella proliferation is favourable when the following conditions are available
- Temperatures between 20 – 45°C (cannot multiply below 20°C and cannot survive above 60°C)
- Availability of a nutrient source such as rust (in the form of ferrous iron), sludge, organic matter and biofilms
- Stored and / or re-circulated water (where stagnation is possible)
In order to control and reduce the risk of Legionella, we recommend that where the risk cannot be removed, planned preventative maintenance tasks are implemented. Such tasks may include;
- Weekly flushing of infrequently used outlets
- Monthly temperature monitoring of hot storage units
- Monthly temperature monitoring of sentinel hot and cold outlets and percentage (usually 10%) of representative hot and cold outlets
- Quarterly descaling and disinfection of aerosol generating outlets / attachments
- Annual inspection of hot and cold storage units
- Annual inspection and servicing of thermostatic mixer valves
- FREE quotation/technical advice – Nationwide – call 0800 243 471
- Works carried out in accordance with the Legionella Control Association (LCA) code of conduct
- Risk Assessments and control schemes carried out to L8, BSRIA and CIBSE guidelines
- All works fully certified and legionella control log books provided
- Fully trained and directly employed staff
- Method Statements and Risk Assessments provided site specific as required
- Training for your own staff following risk assessment