Legionnaire's disease is a potentially fatal form of pneumonia which can affect anybody, but which principally affects those who are susceptible because of age, illness, immune suppression, smoking etc. It is caused by legionella bacteria, which can grow in water kept at unsuitable temperatures (between 20ºC and 45ºC) and infect the water in cooling towers, whirlpool spas and purpose built hot and cold water systems, as found in care settings.
Where conditions are suitable for the growth of legionella the risk is increased. There is a risk of disease when droplets of water, infected with the bacteria, are inhaled. Whilst showers may present a particular problem in care homes, water droplets created from taps is also a potential source. Any equipment that can generate water droplets that could be inhaled should be assessed for potential risk.
Under the Health and Safety at Work etc Act 1974 you have a duty to consider the risks from legionella that may affect people in your care, your employees and any visitors. Furthermore, the Control of Substances Hazardous to Heath Regulations 1999 and the Management of Health and Safety at Work Regulations 1999, require you to assess the risks to health posed and then determine what measures can be taken to reduce the risk.
This needs to be completed by a competent person, who understands the risks and can identify suitable controls to be put in place. The Risk Assessment should include identification and evaluation of potential sources of risk, for example:
Whether suitable conditions for bacterial growth exist. i.e. a water temperature range of 20ºC and 45ºC and a supply of nutrients within the system such as sludge, scale, rust, algae and other organic matter.
Whether there are means of creating and disseminating breathable droplets, for example aerosol spray from showers or taps.
The presence of vulnerable people who may be exposed.
Whether conditions allow water to stagnate within the system, for example, if the calorifier or any significant part of a hot water system is put on standby use or are taken out of service for more than one week, if there are any infrequently used or redundant showers and taps, and whether there are any dead legs in the pipework. It would be useful to draw a schematic diagram of the water system to help identify any specific areas that may pose a risk, and to indicate monitoring point (see "monitoring" below) The Risk Assessment must identify control measures to prevent or control exposure to legionella bacteria:
The particular means by which exposure to legionella bacteria is to be prevented, such as bringing water in a system that has been left on standby or not used for over a week, up to 60oC for 1 hour before use, removing redundant pipework, infrequently used taps and showers and dead legs.
If prevention is not reasonably practicable, the particular means by which the risk from exposure to legionella bacteria is to be controlled. Examples include frequent flushing of the system, using biocides, ionisation or ozone/UV treatment of the water. Monitoring: If controls are to remain effective, the water system will need to be routinely monitored.
This should be the responsibility of the responsible person, or, that of an external contractor if one has been employed. All water services should be routinely monitored for temperature, water demand and inspected for cleanliness and use. These will allow for early detection of problems should they arise. The frequency of monitoring will depend on the risks identified in the risk assessment and records should be kept. Find more info legionella risk assessment for landlords
Annual checks should be carried out, and should comprise of:
A visual inspection of the cold water storage tank to check the condition of the inside of the tank and the water within it. The lid should be in good condition and fit closely, and there should be an insect screen fitted over the water overflow pipe. Thermal insulation should be provided to the tank to prevent temperature extremes, and this should be in good repair. There should not be any debris in the tank, and the water surface should be clean shiny. Any faults found at the annual inspection should be rectified.
A record of the cold water consumption over a typical day is recommended, as this will help establish whether there is a reasonable flow through the system to prevent water stagnating in the cold water storage tank. This can be done by fitting a temporary water flow meter to the outlet pipe. Draining the calorifier and checking for debris, and cleaning as necessary.
Checking any plans of the water system for accuracy, bearing in mind any changes that may have taken place, and updating as necessary.
Checking that the operation and maintenance schedules of the hot and cold water systems are up to date, with named and dated actions throughout the previous year.
Checking connections to external water connections and ensuring that insulation is provided. Obsolete connections to outside services should be removed.