Legionella, the bacteria causing Legionnaires' Disease, are ubiquitous in natural fresh water. There are currently in the region of 250 cases reported in Britain each year, of which around 10 per cent result in death.
Legionella enter and colonise water supplies and have been detected in drinking water, hot and cold water supplies, swimming baths, whirlpool spas, showers, cooling towers, air-conditioners, and evaporative condensers. The correct management of these systems is vital to ensure that employees and the public are not exposed to danger from the bacteria.
In January this year, the Health & Safety Executive (HSE) published the Approved Code of Practice (ACOP) L8 The control of Legionella bacteria in water systems.
It provides practical advice on the requirements of the Health and Safety at Work Act 1974 (HSAWA), Control of Substances Hazardous to Health Regulations (COSHH) and Management of Health and Safety at Work Regulations (MHSWR), with regard to the risk posed by Legionella.
The latest document is much more demanding and rigorous than its predecessors and is likely to have a marked effect on owners and managers of any business property. Testing for Legionella is now required on a quarterly basis — twice as often as before.
The new guidance notes demand more comprehensive risk assessments, management strategies and record-keeping, with additional responsibilities for manufacturers, importers, suppliers and installers.
More rigorous risk assessments
Previously, risk assessments were required only for water systems with a capacity over 300 litres. As a result of the changes, such assessments are now required on any non-domestic water system to identify and assess the risk of exposure to Legionella bacteria and identify the necessary precautionary measures.
A fundamental part of both assessing and monitoring a risk is the testing of samples. This includes the testing of water for the presence of both general bacterial activity and Legionella itself, as similar conditions are required for the proliferation of both.
The person responsible for the assessment is either the employer or the person in control of the premises or systems.
This person must have access to 'competent' help in assessing the risk and deciding on the necessary control measures. This expertise may be provided by a person or department within the organisation or by an external supplier.
The frequency of the sampling should be dictated by the level and nature of the risk, for example, hospital wards may require more frequent monitoring.
Similarly, the frequency should be adjusted according to the results of the tests. Control systems should be flexible and the management programme should be reviewed in light of the results obtained.
The ACOP recommends that general micro-biological monitoring is performed weekly for cooling water in a cooling system, and tests for Legionella be performed quarterly. A water system treated with biocides, where the storage and distribution temperatures are affected, should be tested monthly.
The person responsible for the assessment is either the employer or the person in control of the premises or systems. Whoever carries out the assessment, draws up and implements precautionary measures, should be qualified to do so competently and safely.
The assessment must be reviewed at least every two years and should include identification and evaluation of potential sources of risk and the means by which exposure to Legionella bacteria is to be prevented or controlled.
Managing the risk
If the assessment demonstrates a risk and it is reasonably practicable to prevent exposure, someone should be appointed to take managerial responsibility for this, primarily to supervise the implementation of precautions. This person should have the relevant expertise, or where this is not the case, it may be necessary to use the services of a third party.
Whoever carries out the assessment, draws up and implements precautionary measures, should be qualified do so competently and safely. In particular, they should be aware of the potential risks, sources of contamination, safety measures and how to ensure that controls remain effective and significant.
When there is a foreseeable risk, the use of the water system or section of the system posing the risk should be avoided as far as is reasonably practicable.
Where this is not possible, there should be a written scheme for controlling the risk. This should include:
- an up-to-date layout of the system
- directions for the correct and safe operation of the system
- necessary precautions
- necessary checks to ensure the efficacy of the system
- remedial action in case the scheme is not effective.
The risk from exposure can normally be controlled by implementing certain measures to control the proliferation of bacteria and reduce exposure. These may include:
- controlling the release of water spray
- avoidance of temperatures and conditions which favour the proliferation of Legionella and other bacteria
- avoidance of stagnation
- avoidance of materials which harbour bacteria or provide nutrients for growth
- maintenance of the all-round cleanliness of the system
- use of water treatment techniques
- action to ensure the correct and safe operation and maintenance of the system.
Record-keeping
Under the latest guidelines, records must be kept of all aspects of the assessment, monitoring and management of the risk. These logs must be updated on a regular basis and must be retained for five years. They may indeed be best managed through an appropriate database. The records should include details of the persons responsible for conducting the assessment, the findings, the scheme for controlling the risk, its method of implementation and the results of any inspection or check performed.
How will this affect facilities managers?
There is no legal obligation to comply with these guidelines. However, an organisation must be able to demonstrate that all measures have been taken to the standards of the guidance notes to prevent a Legionella outbreak.
Members of the Health and Safety Commission and local environmental health officers may make unannounced visits to take random samples. If Legionella is found in these samples, it may lead to immediate closure of the premises.
This could be followed by court action against the company and responsible individuals. Six-figure fines have been imposed by the HSE on companies found to be in breach of Legionella control regulations. If an employee or member of the public becomes infected, the cost of litigation, and associated costs and could be much higher.
The ACOP applies to any non-domestic premises, business or other undertaking where water is used or stored, and where there is a reasonably foreseeable risk of exposure to Legionella bacteria.
A reasonably foreseeable risk exists in premises that contain water systems incorporating a cooling tower or evaporative condenser, hot and cold water systems or any other plant and systems containing water that is likely to exceed 20°C and that may release a spray.
Where the HSAWA applies, to comply with their legal duties, employers and those with responsibility for the control of premises, should:
- identify and assess sources of risk
- prepare a scheme for preventing or controlling the risk
- implement, manage and monitor precautions
- keep up-to-date records
- appoint a person to be managerially responsible.
The main changes in the new ACOP:
- Risk assessments should be reviewed at least every two years
- Records should be kept for five years
- Cooling water should be tested for Legionella quarterly
- Managers must have competent advice when performing risk assessments
- Information outlining bacteria control measures should be displayed to employees
- All water heaters should be assessed and monitored rather than only those over 300 litre.
- All laboratory samples should be tested by a UKAS accredited laboratory.
- Legionella sampling from domestic services is recommended where temperatures operate outside the desired range.
- Water treatment programmes should be environmentally acceptable and comply with local discharge regulations
- Standby equipment should operate on a rotational basis
- Automatic drain valves for showers are not recommended.
Source
The Facilities Business
Postscript
Julie Dedman is general manager of micro-biological testing consultancy Global Analysis.
Tel: (01924) 499776
www.globalanalysis.co.uk