Making water safer

We speak to recent CABE Webinar presenter Pete Tyson – Commercial Director of the Water Hygiene Centre Ltd – about how the construction sector can help mitigate the risk from waterborne pathogens.

Think of waterborne pathogens and, certainly in the UK, most thoughts tend to lead towards Legionnaires’ Disease and the deadly, albeit thankfully rare, public health crises it brings. But, as the Water Hygiene Centre’s Commercial Director and recent CABE Webinar presenter Pete Tyson explains, the potential pathogens lurking in water supplies are far more than ‘just’ Legionella.

"Certainly, the more we find out about water and the risks associated with it, the more other waterborne pathogens are seen as an increasing problem,” Pete says. 

"Pseudomonas Aeruginosa is one in particular, Cupriavidus is another. And it’s not just about those two and Legionella – there are lots of others. So we ought to start thinking about water risk assessments as a whole, rather than just specific Legionella risk assessments, and I think that is something that will become common place in the near future."

Design and construction

The reason why water risk assessments should become a matter of course is because the risks posed by waterborne pathogens are completely controllable, starting at the design phase and continuing through the construction phase of any building.

"At the initial design stage, you need to consider who the population of the building is going to be and who is the building for? You should also consider what are the aspirations for the build," says Pete. 

"The design should be reviewed by a water hygiene specialist with some background, training and competency. There are also other documents that outline specific factors for specific sectors, for example, the NHS has guidance documents such as NHS Estates Technical Bulletin (NETB) No.2024/3. 

"An initial risk assessment should be completed in relation to what is happening during the build phase; with another risk assessment at the completion phase."

Those latter two risk assessments are key because changes to design can have a significant impact on the final performance of a building. In fact, even more gradual changes, such as the way that plumbing is approached – and the tendency to favour cheap and easy solutions such as flexible hoses rather than hard plumbing – has also had an effect on water hygiene safety.

"The problem with things like flexible hoses is that Legionella and biofilm can form on the rubber internals of the flexible hoses. In fact, such is the problem that one NHS Trust replaced all of its flexible hoses at one of its hospitals. So laziness and differing practices have caused more opportunities for waterborne pathogens to propagate," Pete notes.

"We have to be mindful of one of the things that designers, installers and manufacturers often talk about: ‘added value engineering’. Added value engineering can be fabulous, but it must never detract from the actual goal of the safety of the project: if a building has been designed in a specific way, try to install it as designed. Changes can become detrimental to safety, often without those making the changes even knowing it."

Consulting the experts

However, there are also signs of more positive changes. Increasing numbers of people in the construction sector are now aware of, and willing to take steps to mitigate waterborne risks.

"This is, in my opinion, one of the biggest changes in the industry that we have seen for a number of years," Pete says.

"There’s a greater buy-in now for getting people involved from Water Safety Groups earlier on, and allowing water safety specialists to review the designs and installation and water systems. This ensures that when a building is handed over, nobody is left dealing with water hygiene issues and the systems in place are as good as they can be, in accordance with the guidance at that particular moment in time. 

"The probability of contracting Legionnaires’ Disease is relatively low, but the consequences are exceptionally high if a fatality occurs.

"However, we can control it, and if we can control it, we can manage it. The more systems we have with good design and good construction, the better it helps with that control.

"So what I’d like CABE members to take from this webinar is an awareness and understanding of how design and construction and management of sites can help with overall safety when it comes to water hygiene issues. We can’t all be experts, but we can all get experts to look at these issues before we start the process of signing a building off."

Watch Pete’s CABE webinar in full below.

Further reading

The Water Hygiene Centre has an extensive library of informative blogs, guidance documents and a Free Legionella Risk Assessment Review Tool. 

Blogs

Water Safety Projects: Design Control – Getting it right!
Steps to Take to Get Projects Right at the Design Stage
Legionella Control for Architects and Building Engineers
Biofilms – Part 1: What are Biofilms?

Technical guidance

NETB NHS Estates Technical Bulletin
HTM04-01 – Safe Water in Healthcare Premises explained
HSE ACoP L8 & HSG274: Understanding the basics
FREE Legionella Risk Assessment Review Tool