Waterborne Legionella - Minimising the Risk

In many ways, water contamination seems like an issue consigned to history, yet outbreaks continue to occur causing illness and, in the worst cases, fatalities. In this article, Spencer Culley discusses why thorough processes are vital for compliance, particularly in a healthcare setting. 

Lots of people know about waterborne Legionella and how dangerous it can be, but few realise how prevalent it is. The bacteria responsible for Legionnaires’ disease multiply between 20-45°c when nutrients are available, offering a large window of opportunity for proliferation if systems are not managed correctly. 

Despite most people being familiar with the risks, outbreaks continue to happen across the public and private sector. In December last year, for example, Tendering District Council was fined £27,000 after a serious contamination at one of its public swimming pools left a man in a critical condition. Worse still, in February this year a woman died after contracting Legionella pneumonia from a hotel in Ludlow, with tests showing the deadly strain was contracted from her suite’s sink. While these are exceptional cases, it nonetheless demonstrates how common it is for harmful levels of bacteria to build up.  

What is Legionella and Legionnaires’ disease? 

Legionella is a pathogenic group of bacteria that cause pneumonia-type illnesses, with the most serious being Legionnaires’ disease. The bacteria are also responsible for other less serious conditions, like Pontiac fever. It  is common across many different environments, with at least 50 different species identified. Bacteria are found in low quantities in natural water sources such as rivers, lakes and reservoirs, but they may also be found in purpose-built water systems where conditions are ideal for  growth. Cooling towers, evaporative condensers, hot and cold-water systems and spa pools are common offenders.

While most of those who are exposed to Legionella will not become ill, it’s still vital to ensure water systems and their constituent parts are properly maintained. To remain compliant, businesses need to assess risks in their networks, manage any identified issues, and then prevent the possibility of an outbreak. All of this work requires documentation to remain on the right side of the law.  

A renewed focus 

The potentially fatal consequences of serious contamination means routine monitoring and inspection of at-risk areas is critical for those in charge of buildings. In no other environment is this more important than healthcare, where complex circulating hot water systems are commonplace and even minor outbreak can have a serious knock on effects for those recovering on a ward.

For some time, it has been recognised that failings in these environments often result from sub-standard risk assessments that overlook the different parts of a plumbing network. That said, thorough evaluations carried out by experienced assessors arestill the best way to identify probable areas of Legionella build up. For example, Churchill Environmental has found that a closer look at hot water return pipework often uncovers areas in need of urgent attention, with sinks, service ducts and pipes behind panels typically falling well short of the required temperature for correct control. In the worst cases, Churchill Environmental has uncovered regions where there was no circulation at all, posing a serious threat of contamination.

In response, Health and Safety Executive (HSE) has revised its own technical guidance document (HSG274 Part 2) to combat avoidable failings in Legionella control, particularly within healthcare environments. The update states that principle plumbing loops should now be checked monthly, with subordinate and tertiary loops checked every three months at a minimum. All of this again restates the need for a high-quality evaluation procedure. Without it, HSE’s new level of monitoring would be virtually impossible to meet, as the number and location of each loop would be unverified and therefore uncompliant.

Case in point

Despite HSE’s revision, there are still many cases where loops within plumbing  systems remain unchecked. For NHS hospitals, where even the slightest misstep can make national news, this kind of risk is simply untenable.  In support, Churchill Environmental has been working closely with a regional NHS property services team to develop robust documentation that builds on the HSE’s recommendations.

Soon after the first inspection Churchill Environmental found areas of hospital plumbing that posed a potential risk to patients. Further work found that the property services team were overlooking loops that were now subject to inspection as per HSE’s update. To combat these oversights, Churchill drafted an enhanced risk assessment and evaluation procedure that now includes a more detailed survey of the hospital’s hot and cold water systems, as well as an asset identification and barcoding system, and meaningful schematic diagrams for staff to reference. These three components not only allow the NHS property team to oversee all parts of the plumbing network but also create a comprehensive audit trail – a vital requirement for when inspectors inevitably arrive.

When the documentation is followed  correctly, the possibility of contamination is drastically reduced, assuring full compliance throughout all requisite loops. The latest inspection found all loops to be compliant and free from bacteria, keeping staff and, most importantly, patients well away from contaminated water. Legionella outbreaks can never be fully eliminated but, as this work with the NHS proves, they can be mitigated with the right procedures in place.