Legionella: What do you need to know and do?
Legionella Disease can be fatal and is a form of pneumonia. There also less serious diseases arising from the same source Pontiac fever and Lochgoilhead fever. Older people and those with existing health issues or reduced immunity are at greater risk. The disease is caught when the bacteria are inhaled via water droplets in the air. The bacterium Legionella pneumophila is a common one found in natural watercourses and ponds and it is rarely a cause of illness in its natural habitat. Your dawn swim in the local river is not likely to result in this particular illness. A shower is a much more dangerous activity because the water sprays into droplets that you might breathe in.
The problem happens when these troublesome bacteria are in water that is stored between 20 and 45 degrees centigrade. That’s nice and warm for them and they multiply, but not hot enough to kill them. There is a particular problem with evaporative cooling towers and condensers but holiday accommodation does not normally have this industrial type of equipment so that leaves us with two places where trouble might be brewing:
- Hot water systems
- Spa pools
The law is somewhat unclear on this but essentially, the management of the risk of legionella disease is a general duty under the Health and Safety at Work Act, along with all the other things you need to worry about for the safety of guests and employees. If you are self-employed and do your own cleaning and servicing you can claim some exemptions from the Act but this does not prevent you being sued for every last farthing by the holidaymaker whose husband caught the disease in your bathroom, so it is definitely necessary to manage the risks.
Domestic water systems are pretty simple to manage and control. If you have a storage tank, this is where the bacteria will multiply. The thermostat needs to be set to a minimum of 60 degrees to kill them. The Temperature at the taps etc. should be 50 degrees or higher. If you have a continuous water heater it should heat the water to 60 degrees or more.
You do need to carry out and write down a risk assessment, possibly as part of a more wide-ranging risk assessment. It is important to review it when there are changes and every couple of years to show that you have not forgotten it.
Generally in a typical domestic hot water system the review is likely to conclude that the risks are very low, provided the temperature is maintained, and no further action will be needed. There is no requirement for regular testing unless your risk assessment shows this to be needed.
Cold water tanks should be below 20 degrees centigrade. If there is a situation that causes cold water to be heated unintentionally, this needs to be addressed and resolved as this could create the ideal breeding ground for the bacteria.
Shower heads should be kept clean and descaled regularly to ensure proper operation.
If you have a spa pool or anything similar, there are additional issues to consider. Spa pools generate water spray and may have water in them at a temperature favourable to the bacteria for a long time. The principal method of control is disinfection with chemicals according to the manufacturer’s instructions. Water testing needs to be carried out regularly. In addition the proper maintenance of the pool is important with cleaning and maintenance on a regular basis.
In holiday complexes where more elaborate hot water systems are in place, then specialist advice and assessment is likely to be a good idea, for example if there is a large-scale system that provides hot water to a block of flats or a terrace of cottages. These systems will have longer runs to the taps and present some greater risks.
For most people in self-catering legionella control is mainly going to be a matter of maintaining and adjusting a hot water system periodically, and recording a risk assessment. For some there is more work to do and more reading: The HSE website provides a lot of detailed information.
Extracted from the EASCO e-newsletter: Edition 106 September 2015