Legionella is on the rise with significant surges reported in Melbourne, London and New York, putting yet more pressure on facilities teams to improve site safety. Legionella causes Legionnaire’s Disease, a potentially fatal form of pneumonia caused by inhaling airborne droplets from contaminated water sources.
A combination of factors is driving this increase. Warmer global temperatures are creating more favourable conditions for bacterial growth, particularly in cold water systems that must remain below 20oC. At the same time, ageing infrastructure and changing building usage patterns – driven by hybrid working and fluctuating occupancy – are leading to more frequent water stagnation. Even in buildings that appear fully operational, low-use outlets can create hidden pockets of risk.
As a result, Legionella control requires a proactive, technology-assisted approach from facilities managers that combines regular monitoring, clear visibility of assets, and consistent preventative action.
Key methods for preventing Legionella
Maintain strict temperature control
Water temperature remains the primary defence against Legionella. Bacteria thrive between 20°C and 45°C, so systems must be kept outside this range: hot water stored in cylinders above 60°C, taps above 50oc and cold water below 20°C. This requires consistent monitoring of sentinel outlets, as well as regular checks of water storage cylinder systems. Thermostatic mixing valves are an essential component here too, regulating tap temperature to prevent scalding while allowing water heaters to be set at a higher temperature.
QFM’s Dynamic Forms are an ideal tool for controlling this, providing technicians with a customisable form via an app to take readings. Should the readings fall outside of the threshold, a work order is automatically triggered on the CMMS software. While this removes the element of doubt from the operative over what is a passable reading, the safest way for high-risk areas like hospitals which could have thousands of sinks and showers, would be to implement sensors to enable continuous monitoring. These can be integrated with CMMS software to create an alert when an upward trend is identified.
Reduce stagnation through planned flushing
Stagnant water is one of the biggest risk factors for Legionella growth. Changes in occupancy from hybrid working or underused spaces mean that many outlets may not be used regularly.
Facilities teams should schedule planned preventative maintenance (PPM) through CMMS software to flush low-use outlets at least weekly, and more frequently in high-risk environments such as healthcare settings. And it’s not just sinks of course, air conditioning units pose a risk of standing water due to the condensation produced, and large-scale cooling towers are very high risk for contamination. With the rapid growth of data centres – major users of water for cooling – this is becoming an increasingly critical area of focus.
Identify and track all water assets
In large or complex estates, one of the biggest risks is not knowing where every outlet is located. High staff turnover and incomplete records can result in missed assets, and therefore missed checks.
We recently worked with one of our healthcare clients to integrate L8guard software into QFM Space. We helped the Trust position and track all water sources on our space management software, and enabled them to send a floorplan image to their operatives to make it clear where each asset was that needed flushing. L8guard then generates risk assessment forms and tracks responses through to completion, escalating when necessary and providing a fully closed-loop audit trail.
Use BIM to uncover hidden risks
Where BIM data is available, facilities teams gain a real advantage through on-screen visualisation of the HVAC layer in the model. Users can trace water systems across the building from end to end, as well as identify tagged components such as pipes, tanks and valves. Not only does this make it easier to locate access points, BIM models can identify risks such as dead legs – pipework abandoned during renovations but not properly decommissioned, which can act as bacterial incubators if still connected to live systems.
When integrated with CMMS software, BIM models can also highlight ageing infrastructure (identified using the installation date data) or assets at risk of legionella, based upon historic maintenance records, helping teams prioritise maintenance activities where corrosion may reduce the effectiveness of disinfection.
Turning compliance into control
Managing legionella risk is becoming more complex, but the fundamentals remain the same: control temperature, prevent stagnation, and maintain visibility across your estate. Without the right systems in place, manual processes can quickly fall short, leaving gaps in compliance and increasing risk.
By combining real-time monitoring, intelligent workflows and complete asset visibility, facilities teams can move beyond reactive compliance and take full control of water safety.
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