Legionnaires’ disease in water systems: managing the risks effectively

Legionella bacteria are responsible for several diseases which are collectively known as legionellosis – including Pontiac fever and Lochgoilhead fever. The most serious is Legionnaires’ disease, a form of pneumonia that has the potential to be fatal. People catch legionellosis disease by breathing in small droplets of water – sometimes referred to as aerosols – which contain the bacteria.

The risk of contracting a legionella infection from natural water environments is small. The majority of cases arise via contact through man-made water systems, and several factors can be involved:

• Water temperature – waterborne pathogens can multiply when water in all or part of the system is in the range 25 – 45 °C
• Formation of water droplets – certain locations where water may be released in fine droplets – cooling towers, horticultural ‘misting’ humidity systems and showers, for instance – heighten the risk of inhaling bacteria
• Stored and recirculated water – systems featuring water storage vessels and where water is contained in a closed network can provide ideal conditions for legionella to grow
• Infrequently used systems – pipework and storage containers where water is not regularly passing through can be prone to bacterial growth
• Deposits in water systems – rust, scale, organic matter, biofilm and sludge within water systems provide nutrients for bacteria which can help them survive and thrive.

At-risk location

Legionella is most likely to be a serious risk in large premises with complex water systems. Public buildings such as hospitals, clinics, education establishments, care homes, hotels, leisure complexes, offices, apartment blocks, prisons and detention centres are more typically at risk of harbouring legionella, and potentially producing an outbreak of Legionnaires’ disease.

The risk is currently heightened in buildings that have been closed due to the pandemic, or premises that have had reduced occupancy over this period. Water stagnation may arise in closed and under-used buildings, so the Legionnaires’ disease risk is increased.

A duty of care

In the past, Legionnaires’ disease has struck with tragic consequences in the UK and around the world, leading to strong legislation and regulation to protect against further outbreaks.

Today in the UK the duty of care and those responsible for it are clearly defined by the Health & Safety Executive (HSE). This duty of care extends to employers, those in control of premises and those with health & safety responsibilities for others.

Practical actions for preventing and controlling the risk

There are a number of ways that an existing water system can be improved and made less likely to develop legionella or other bacterial contamination including:

• Prevent water from stagnating
• Use appropriate materials
• Keep the system’s water clean
• Record risk assessments, maintenance, and repair work

Operational measures

Solutions ensuring the risk of legionella is prevented or effectively controlled are centred on three important areas:

• Water temperature control
• Physical measures – such as regular movement of water in hot and cold water systems, and flushing of outlets and point-of-use (POU) filters
• Biocide treatments

No one treatment regime can fully ensure effective control in every case. No two systems are the same, and factors such as age, design, size, and water chemistry will dictate the best mix of measures for a given installation.

While there are many options available to address the threats posed by water-borne pathogens, currently the most commonplace method of control is by maintaining appropriate water temperature.

Monitoring water temperature

Accurate and reliable monitoring is clearly a crucial element in maintaining safe water supply. With so many variables present in extensive water systems, the importance of keeping a close watch cannot be overstated.

However, in a large complex system, reliable temperature checking can be a demanding and time-consuming task. Furthermore, achieving constant real-time monitoring is not possible via conventional methods.

The limitations of conventional temperature monitoring

Even regular site visits and temperature measurements cannot guarantee 100% safety of water supply. Issues can arise quickly, and if they occur between monitoring sessions there will be a potentially dangerous time lag in identifying a problem.

Human error, site access issues, manual data inputting – such challenges can and do compromise the effectiveness of conventional monitoring. Safety is of course the paramount concern, along with maintaining compliance. But the time and labour costs of conventional monitoring can also pose significant challenges, which the dutyholder is legally obliged to meet.

In practical terms, the lack of constant real-time monitoring can increase risks aside from bacterial outbreaks. Scalding from over-hot water is a possibility; at the opposite extreme frozen pipe damage can also occur when data is not available in real-time.

The shortcomings of conventional monitoring also correlate with more maintenance engineer callouts, water leaks, and energy wasted in heating water needlessly.

A digital alternative

Today there are effective digital solutions to help organisations manage bacterial risk in water supply with much more insight and control such as DVS Inform temperature monitoring system box and digital platform.

The HTM-04-01 guidelines state that “More extensive use of automatic sensors and reporting systems should be considered for surveillance of systemic temperature profiling. Sensors should be located throughout the whole hot and cold water systems to ensure they give representative temperature values.”

DVS’ Inform real-time temperature monitoring is one such solution. It offers a digital way to maintain constant oversight of water system assets, by feeding accurate data 24-7 to a secure cloud-based platform.

Inform provides reports, alerts, and data through an intuitive dashboard, which can be accessed on a PC, mobile phone, or tablet.

How KWC DVS Inform remote monitoring works

Remote Inform devices are installed across the water system. These communicate via Narrowband IoT Low Power Wide Area Technologies (LPWA) – to ensure increased building penetration. This provides reliably effective communication in dense urban settings and remote areas alike.

The data from all the system sensors are relayed to Inform’s cloud-based central management system, linking to the user through the solution’s dashboard. The system’s prime function is to ensure the safety of water supply around the clock to the highest standards.

Because Inform delivers real-time data which can be accessed and analysed instantly, reporting is easier to perform and far more detailed.

Inform makes it far easier to achieve and maintain compliance with regulations, for far less cost. It is also a very flexible solution – qualified installation teams can fit Inform to all kinds of systems, regardless of their design, complexity, or age.

Operating a system with Inform monitoring gives a level of information that can identify potential problems before they arise.

Digital efficiency and simplicity

Clear graphic displays make the Inform system easy to adopt, whether a PC, tablet or mobile is used.

All reporting is based on automated temperature measurements made every 10 seconds, with minimum, medium and maximum readings recorded every 15 minutes. This means Inform will automatically generate alerts as issues or potential problems begin to develop.

The rich data also provide a full audit trail of all events, with accurate reporting and documents stored securely in the cloud-based system. It is a self-contained solution with no requirement to access IT data networks.

Inform includes an anti-microbial system box, and the battery-powered sensor units can run for up to five years before battery replacement becomes necessary.

The dashboard displays six key function icons, making it simple to use. These include:

• New alerts – email notifications report new issues as they happen
• Active alerts – both acknowledged and unresolved alerts remain open, and default reminders help support compliance
• Closed alerts – rectified issues will be closed, but the history remains readily available
• Administration – A space to manage assets, buildings, and users
• Reports – real-time 24/7 data and reporting on water temperature for every asset
• Information – to contain plans, user manuals, instructions and other key information on assets and the dashboard

Digital temperature monitoring’s primary benefit is clearly increased safety and accuracy. Real-time monitoring equates much better temperature control and therefore less risk of harmful bacterial growth.  However, the benefits of digital control in terms of operational considerations are also hard to ignore. The Instant alerts and reporting, less costly reactive maintenance and enhanced control prove that the case for digital temperature monitoring is compelling.

As water temperature remains the most appropriate and practical legionella control in many public premises across the UK, it is clear that effective real-time temperature monitoring by digital means can increase safety, save costs and support sustainability.

To find out more about our Inform water temperature monitoring system, visit https://dartvalley.co.uk/inform