The state of water hygiene in the UK

Matt Morse, Manager of the Legionella Control Association, discusses the challenges and gaps in water hygiene compliance in the UK

Compliance is a word often misused or misunderstood to mean following HSE guidance. Striving to comply with something that is there to guide is fundamentally flawed and shows a lack of understanding and competence. Duty holders must comply with the law, or they are committing a criminal offence.

The law requires that risks are assessed, eliminated or substituted, and that any remaining risk is controlled to a level that is as low as reasonably practicable. A common gap in water hygiene is to focus on the guidance before the risks have been identified. The place of HSE guidance is to inform risk assessment and design of mitigation and control measures. The scheme of control for any given building must be born from assessment of risk and follow the specifics of the HSE and other guidance where it is relevant. The written scheme of control is the ‘compliance’ document, rather than the HSE guidance.

Across many outbreaks and cases of disease, the common thread is a lack of suitable competence amongst those managing the risk. The law does not mandate specific training or competence levels that must be achieved but will prosecute individuals where there are failings. The requirement is for information, instruction and training to be sufficient for an individual to be competent, i.e. to have the capability to effectively do their job.

Understanding the water system in a specific building is a critical factor in water safety, yet it is often a gap. Experience shows that schemes of control based blindly on the HSE guidance without understanding the system often have serious flaws that have led to cases and deaths from Legionnaires’ disease. A lack of understanding or appropriate monitoring of circulating hot water systems is one of the biggest risks commonly seen.

High impact interventions

Legionella control has some very simple principles that are sometimes problematic to achieve in practice. Any innovation that focuses on monitoring or improving these core principles is likely to be useful.

These principles are:
• Avoid contaminating the water system
• Avoid growth temperature for Legionella
• Avoid stagnation that gives time to grow
• Keep the system, and the water in it, clean
• Use water treatment

Interventions that lead to better understanding of water systems, better data, and effective analysis of that data have the biggest impact on reducing Legionella risk.

Innovations in building design records such as digital twinning and three-dimensional modelling aid understanding of how water enters, moves through, and exits water systems. This sounds simple, but many issues arise from a basic lack of understanding of how the water system works.

Data has traditionally been collected manually, but data collection by fitted sensors provides far more data with less measurement impact, leading to a far better understanding of how buildings perform. More data points, collected while buildings are at rest, mean a more representative picture can be built up without changing the data by running water outlets.

Data on water movement, either inferred from temperature or measured directly, can be instrumental in managing water stagnation. Pressure on water resources makes the use of water for hygiene flushing unpopular. If the practice could be limited to only the required outlets, or better still, target the removal of underused outlets, less water will be consumed.

The technology for automated water flushing based on sensor data is available but is not widespread.

Analysis of data to sort scenarios into risk categories, rank them and present them for action has always been part of managing water hygiene, but it is now a common function of many software systems. Machine learning for further insights is already in use and is likely the way we will manage the large data sets of the future.

Automated sampling for temperature and flow allows organisations to approach water hygiene in a new way. Instead of reacting to a few tens of data points collected a month apart, rapid response can be achieved as soon as issues arise. Without control, Legionella doubling rates are measured in hours, so the benefit of acting on a loss of control immediately should be obvious.

The requirement for written schemes of control has always included a need for actions to be taken in the event of adverse results or a loss of control. Software-based systems and machine learning are enhancing this output to provide simple, tailored actions and a clear logging and closeout pathway.

Training impact

Training for duty holders, responsible persons and facilities teams in water hygiene is often lacking. The duty holder often has many other responsibilities to manage, meaning that their water hygiene training can often fall short.

Water hygiene tasks are often contracted to specialist providers, and while this gives some reassurance that specialists are handling specialist work, the responsibility still lies with the dutyholder. Case law from previous Legionnaires’ disease outbreaks shows that the courts expect dutyholders to retain enough in-house competence to be able to recognise what good work looks like from their specialists.

Innovations in training, with e-learning, online courses, and interactive resources, mean that there are more options available than ever before. There is no reason why any individual in the chain of control should not have appropriate training and be competent for their role.