Building owners in the UK must take more care than ever before to guard against Legionnaires’ disease.
The new State of the UK climate report (published in the Royal Meteorological Society’s ‘International Journal of Climatology on July 13, 2025), concludes that weather extremes are now the norm in the UK, with record temperatures and rainfall becoming more frequent.
As the third heatwave of 2025 came to an end, Lizzie Ward, Managing Director of Staffordshire-based SAS Water, said: “With growing evidence of the effect climate change has on workplace and household water, we must all get used to a new normal. Rising temperatures make legionella growth ever more likely. This can be seen in nature and equally applies to the built environment.”
Legionella bacteria lie dormant in temperatures below 20°C. A warmer UK climate creates potential danger where water collects in water pipes, garden pools, hot tubs and even hose pipes.
Breathing in aerosols of legionella bacteria can lead to Legionnaires’ Disease, a potentially lethal form of pneumonia.
Added Lizzie: “There is already clear guidance for UK businesses. This states the need in law to undergo a legionella risk assessment, get expert advice, and to inform their staff to be aware of legionella risks.
“We must be vigilant at work, in leisure settings, and at home. For example, hot tubs are now extremely popular, but they must be treated carefully for bacteria, taps and showers should be flushed through regularly where use is limited, and hosepipes need to be thoroughly drained and stored, not left spread out on a lawn after use.”
Based in Leek, SAS Water are legionella and water in the workplace experts. The company has a team of legionella consultants and commercial plumbers working across the UK in diverse business settings from nursing homes to factories and holiday parks to sheltered housing schemes.
In the UK, the government Health and Safety Executive states ‘water samples should be analysed for legionella periodically to demonstrate that bacteria counts are acceptable. The frequency should be determined by level of risk, in accordance with the risk assessment.’
In domestic settings, Lizzie recommends people take sensible, precautionary measures. For example, running a shower and taps thoroughly when visiting a holiday cottage or hotel, and in other places where showers may be used infrequently, such as a bike shower facility in the workplace.
Garden taps may also go for long periods without use and the basic guidance to follow is legionella bacteria thrives in stagnant water.
When in commercial leisure settings, such as spas, it is reasonable to ask to see evidence of a company’s risk assessment.
The effect of heating natural water has been studied by scientists observing volcanic lakes. At Mount St Helens in the USA, researchers recorded that volcanic activity which increased water temperatures in the surrounding lake, caused the water to become contaminated with legionella, according to microbiologists from the Washington State Department of Social and Health Services.
Th UK Met Office said ‘the last three years have been in the UK’s top five warmest on record, with 2024 the fourth warmest year in records dating back to 1884. In 2024 specifically, we saw the UK’s second warmest February, warmest May, fifth warmest December, fifth warmest winter and warmest spring on record. Statistics like this are typical of recent years in the UK’s climate records and some of these have already been surpassed in 2025.’
The 2025 State of the UK climate report says, ‘when comparing the most recent decade 2015-2024 to 1961-1990, the hottest summer days and coldest winter nights have warmed around twice as much as average summer days and winter nights have in some parts of the UK.’
‘The number of days with temperatures 5°C above the 1961-1990 average has doubled for the most recent decade 2015-2024 compared to 1961-1990. For 8°C above average the number has trebled and for 10°C it has quadrupled.’
ENDS
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