All too often we hear in the news that there has been yet another discovery of legionella bacteria, a bacterium that can cause illness collectively called legionellosis. This includes the most serious illness, legionnaires’ disease, a potentially fatal form of pneumonia.
This week we heard that a Wolverhampton hotel has been closed after officials concerned about its water management system discovered legionella bacteria.
The risk of being exposed to Legionella is most prevalent during refurbishment and demolition work in the construction industry, as the risks are linked to:
- Water stored or stagnating and re-circulated at temperatures between 20 – 45 °C, for example, redundant parts of water systems or water storage tanks where the water is not frequently replaced.
- Sources of nutrients such as sludge, scale or rust.
- Production of contaminated aerosol spray or water droplets.
- Workers and visitors who are more susceptible to infection due to age or illness.
But it isn’t just limited to construction – as we found with the Wolverhampton hotel.
Legionella bacteria are commonly spread through airborne water droplets. Mist or vapour contaminated with the bacteria can come from cooling towers (used as air-conditioning units in large buildings), and water used for bathing and drinking. The risks are wide-spread, how you control them is key.
How often should you conduct a Legionella Risk Assessment?
According to HSE ACoP L8 The Control of Legionella Bacteria in Water Systems, the assessment should be reviewed every two years and if there is a reason to suspect that is no longer valid, for example:
- Where there have been changes to plant, the water system or its use.
- Where there have been changes to the use of the building.
- Where new information about risk or control measures has become available.
- Where monitoring indicates that control measures are no longer effective.
Details of the specific law that applies can be found in part 1 of Legionnaires’ disease: The control of legionella bacteria in water systems – which is available on the HSE – Legionella and Legionnaires’ disease website.
However, if you’d prefer to speak to an expert please call us on 0161 926 8519.