The Legionella bacteria might be hidden away in your storage tanks, dead legs and little-used pipes, but it will soon make its presence felt if you don’t take it seriously.
Legionella is the main cause of Legionnaires’ disease, a severe form of pneumonia that attacks the lungs and respiratory system, and, in the most serious cases, can be fatal.
Sadly, some business owners take an out-of-sight, out-of-mind approach to dealing with such biological nasties.
This isn’t just foolhardy, it’s also criminal.
UK law has a lot to say about how businesses and organisations should handle the risks around water, especially biological buildup like Legionella that can devastate human health.
It also has a lot to say about the penalties for failing to take it seriously.
Below, we shine a light on some of the hidden dangers lurking in your water system.
Conditions
The Legionella bacterium loves warmish (20°C–45°C) water, especially if it has been left sitting around for a time – it will treat such water sources as a breeding ground.
The bacteria also love a good dose of biofilm.
Biofilm is that slimy layer of unpleasant gunk that accretes on pipe work and storage tanks if they are left untreated or aren’t properly cleaned.
This gives Legionella a rich source of nutrients and also acts to counteract the disinfectant biocide used to combat the bacteria.
This is why, when it comes to an effective cleaning regime for water systems, it’s important not just to use a cleaning agent like chlorine, but to get down to the hard work of physically descaling water systems so that biofilm is also removed.
Aerosols
Legionella affects the lungs, but to get to work there, it must first be aerosolised or vaporised into a mist or spray.
This means that Legionella can silently colonise a water system and sit innocuously around until the water it’s converted into droplets.
In fact, the first time many people will know they have bacteria lurking in their water is when someone reports breathing difficulties after visiting a contaminated site.
Sites
Given that it needs to be aerosolised to cause real damage, Legionella can be hard to pin down on a premises.
However, as we know that water vapour and mist are the biggest causes of bacteria-laden droplets, you can be sure that certain areas of a water system are more likely than others to be harbouring Legionella colonies.
With this in mind, it’s essential to pay particular attention to sites like:
- Hot and cold water systems (especially showers and spray taps).
- Cooling towers and evaporative condensers.
- Spas, whirlpools and hot tubs.
- Drinking fountains.
- Decorative water features.
Risk Assessment
Given what’s been said about the hidden dangers, a proactive approach to Legionella detection and removal is recommended.
The Legionella risk assessment lies at the heart of any proactive approach to water safety.
A thorough-going risk assessment will allow you to identify danger zones in your water system, and typically includes:
- System Survey: Identify all aspects of a water system to identify potential bacterial colonies.
- Hazard Identification: Highlight all spots that are known to be Legionella breeding grounds, like water tanks and showheads.
- Risk Evaluation: Assess the likelihood that bacteria are growing in a particular location the the consequences of potential exposure, prioritising high-risk areas.
- Control Measures: A list of actions like flushing ‘dead legs’, cleaning, disinfecting, and temperature controls.
- Documentation & Action Plan: Record the findings of the assessment, and importantly, assign responsibilities for checking and cleaning to key members of staff.
- Monitoring & Review: Establish monitoring and review procedures so that risk assessments can be updated and control measures adapted when needed.
Conclusion
Legionella has no smell, odour or funny colouring, and even when ingested, it won’t tend to do much harm.
This means a Legionella risk assessment is the only sure-fire way you can properly identify and root out bacterial colonies harbouring Legionella.
