As Legionella risks continue to rise across the UK, Greg Rankin explains how installers can play a vital role in risk assessment and early detection to help protect public health.
In 2023, the UK recorded its highest number of confirmed Legionnaires’ disease cases on record. Official statistics showed an incidence rate of 1.0 per 100,000 people in England and 1.4 per 100,000 in Wales, highlighting a significant year-on-year increase and underscoring the ongoing public health challenge posed by the bacteria.
For HVAC and plumbing installers, and anyone responsible for installing or maintaining water systems, these figures are more than just numbers – they are a call to action. With Legionella cases continuing to rise, anyone involved in the design, installation or upkeep of systems that could harbour the bacteria has an opportunity to take a proactive role as the first line of defence. But to understand why and how, it’s important to first consider why Legionella has become such a profound safety concern.
Why Legionella is a growing threat
Legionella bacteria, the culprit behind Legionnaires’ disease, thrives in warm water systems, particularly where water is stagnant or poorly maintained. Modern water networks, with their increased complexity and energy-efficient designs, can unintentionally create environments conducive to bacterial growth. Coupled with rising global temperatures, these systems have become more vulnerable than ever. This escalating risk has significant implications for installers. As professionals working directly with these types of infrastructures, installers are uniquely positioned to help detect, prevent and mitigate Legionella contamination in commercial, industrial, and residential HVAC and plumbing systems. This makes it more critical than ever to stay informed about the latest detection solutions and best practices to enhance building safety.
Beyond their role as public safety custodians, ensuring high Legionella control standards is also a matter of selfprotection. The UK’s installer workforce is predominantly male and aging. Given that individuals over 50 – and men in particular – are at higher risk of Legionnaires’ disease, those working with unmanaged systems may be exposing themselves to significant risks. Compliance alone is not enough But while regulatory standards and guidance for water safety provide a
necessary baseline, simply meeting these requirements is often insufficient.
Current guidelines from the Health and Safety Executive (HSE) and the Water Regulations Advisory Scheme (WRAS) provide frameworks for risk assessment system maintenance and regular testing. However, Legionella outbreaks continue to occur even in compliant systems, highlighting the limitations of reactive approaches. Traditional lab-culture Legionella testing, while important, often provides only a snapshot of the system at a single point in time. Bacteria can proliferate between tests and results can take up to 10 days to return, delaying corrective action. Water samples can also be damaged during transport, risking false negatives, and lab culture testing cannot detect Viable but Non-Culturable (VBNC) Legionella, which can remain dangerous and even infect human cells while dormant.
For installers, this underscores the importance of proactive monitoring and considered system design, rather than relying solely on periodic testing to catch problems after they have arisen. Best practice for installers So, what can installers do to stay ahead of Legionella risk? First, system design matters. Avoiding dead legs in piping, ensuring adequate water flow and incorporating accessible points for cleaning and monitoring are foundational steps. Insulation, temperature management and the use of materials less prone to biofilm formation can further reduce risk. Maintenance is equally critical.
Installers should advocate for and implement robust maintenance schedules that include regular flushing, disinfection and temperature checks. Encouraging clients to invest in rapid testing technologies – which enable detection of Legionella in just 25 minutes and are incredibly accurate at quickly detecting the potentially fatal Legionella pneumophila – can provide near real-time alerts for contamination, allowing rapid intervention before bacteria proliferate. Not only does using this approach minimise potential exposure, but it also offers additional information during necessary reviews of risk assessment, and provides peace of mind for the customer.
Training and awareness are also key. Installers who understand the latest Legionella research, emerging risks, and technological solutions, are better
equipped to provide guidance and solutions to clients. Historically, installers have had limited involvement in Legionella detection and prevention. By embracing this responsibility, they can differentiate themselves in a competitive market and enhance their professional reputation. Proactively identifying potential Legionella breeding conditions and incorporating rapid on-site inspections or testing as part of installation or maintenance work can help clients manage risk and create a new revenue stream for installers.
Early adoption of this approach also positions installers to gain market share as awareness of Legionella and the need for preventative measures grows particularly in sectors with strict health and safety priorities. Ultimately, well-designed and properly maintained systems not only reduce Legionella risk but also operate more efficiently, with fewer blockages, less downtime, and predictable maintenance cycles. In today’s climate of heightened public health concern, the expertise installers bring to Legionella mitigation can have a tangible impact on both their business and the communities they serve.
As Legionella risks continue to climb, installers can transform water safety from a regulatory obligation into a mark of professional excellence and responsibility. In doing so, they not only protect clients, end-users and themselves but also reinforce the crucial value of their expertise in modern plumbing, heating and ventilation systems.
