CreevX: IoT water management for Legionella compliance

Regularly, technicians will drive up to 50 miles to remote telephone exchanges in the Highland and Islands of Scotland. His job: turn on taps, let the water run for a few minutes, check the temperature, note it down. Then drive back. This scene plays out thousands of times across the UK and Europe – in office buildings, hospitals, airports, and industrial facilities. The reason: water that sits unused in pipes can become a breeding ground for legionella bacteria, which cause Legionnaires' disease – a severe and potentially fatal form of pneumonia. 

The risks of stagnant water made international headlines in August 2023, when legionella bacteria were detected in the water system of the Bibby Stockholm, a barge moored in Portland, England, that had just begun housing asylum seekers. All 39 residents were evacuated as a precaution. The water pipes had not been in regular use before the residents boarded – a textbook scenario for bacterial growth. Regulations such as the UK's Health and Safety Guidance HSG 274 require building operators to ensure that water moves through every outlet at least once every seven days and that temperatures stay outside the critical range of 20 to 50 degrees Celsius. 

Until now, legionella compliance has been primarily a manual process. Staff walk from outlet to outlet with handheld thermometers, open taps, and record readings on paper. The process is expensive, time-consuming, and fundamentally unreliable – because there is no way to verify whether the work has actually been done.  

The problem has intensified since the pandemic. Hybrid working means many office floors, kitchens, and bathrooms are used far less frequently than buildings were designed for. Where an office block was built for 2,000 people, 300 may now use it on any given day. Entire floors can go unused for weeks – and every unused outlet is a potential compliance risk. 

CreevX's approach follows a two-step logic. In the first phase, their IoT devices (see fact box) are installed in monitoring-only mode. Over four to five weeks, they collect temperature and water movement data across all outlets in a building. This data reveals which outlets are used regularly through what CreevX calls "organic use" – someone making tea, washing hands, or cleaning – and which ones sit idle. Only where the data confirms that water is genuinely stagnant does CreevX recommend installing automated valves. The rest continues to be monitored for temperature only. 

The results can be significant. At a government building in Wales, blanket flushing had been standard practice after the pandemic emptied the building. Once CreevX's system provided actual usage data, water consumption for compliance purposes dropped by 90 percent – saving 1.4 million liters per year, roughly half of it heated water that had previously been flushed straight down the drain. The associated energy savings were substantial. 

“Demand is high because legionella compliance is a colossal problem that has to be solved," says Nelson. "Everybody tells us it is a niche area, but it is an absolutely huge niche." The regulations that require legionella compliance apply across Europe – and the underlying drivers, hybrid working patterns, aging building infrastructure, rising energy costs, are not going away. For building operators, the business case is straightforward: CreevX customers such as Northern Ireland Water have reduced their compliance costs by around 60 percent while cutting CO₂ emissions by over 40 tons per year simply by eliminating unnecessary service trips. At the same time, they gain something manual processes could never provide: verifiable proof that every outlet in every building is compliant – every week, based on data rather than trust.