Water safety risk in healthcare settings

The NHS Estates Technical Bulletin (NETB) No. 2024/3 provides supplementary guidance to HTM 04-01: Safe Water in Healthcare Premises. The purpose of this bulletin is to highlight the importance of ensuring that healthcare environments are designed and managed to protect patients who are at high risk of infection from non-tuberculous mycobacteria (NTM) and other waterborne pathogens. While the principle is clear, an important question remains: what does this mean in practical terms for the day-to-day management of water safety in healthcare settings? Karina Jones, principal Authorising Engineer at Eta Projects, tells us more.

Through long-term involvement in healthcare water management, numerous conversations with professionals across the sector have highlighted a consistent and significant issue: a gap between estates-managed water safety systems and frontline clinical practice, including contractors who carry out a wide range of Planned Preventative Maintenance on water assets.

There is an operational gap in existence which creates a risk. Discussions with a wide range of professionals involved in water management, including:

• estates and facilities teams
• capital project managers
• Infection Prevention and Control (IPC) teams
• soft FM staff
• contractors

consistently reveal that the key issue is not a lack of awareness, but rather a lack of operational understanding and most importantly shared ownership. These discussions consistently point to a fundamental challenge: the issue is rarely a lack of awareness of guidance or risk, but rather a lack of shared operational understanding and ownership across disciplines.

Water safety is often managed as an estates-led technical compliance function, while the clinical implications of water system design, operation, and use are not always fully understood or embedded within frontline practice of clinical staff. As a result, responsibilities can become fragmented, with estates teams maintaining systems to specification, IPC teams focusing on surveillance and response, and clinical staff interacting with outlets daily without a clear appreciation of how their actions influence system risk.

The need for a shared framework

This operational gap means that controls intended to protect highly vulnerable patients — such as outlet design, flushing regimes, filtration, or restrictions on water use — may not translate effectively into consistent, safe behaviours at ward level. Equally, concerns raised by clinical teams about water use or infection risk may not always be understood in the context of system design constraints or regulatory requirements. This not only apply to our clinical staff but also to contractors’ way of preforming their task of remedial actions. Without a shared framework for decision-making, water safety measures risk being seen as burdensome, impractical, or detached from patient care rather than as integral to infection prevention.

Bridging this gap requires moving beyond compliance and documentation toward genuine integration of water safety into everyday operations. This means clearer articulation of roles, improved communication between estates, contractors, and clinical teams, and practical, risk based guidance that supports staff in making safe decisions at the point of care. Only by developing a shared understanding of how water systems, human behaviour, and patient vulnerability intersect can the intentions of HTM 04 01 and NETB 2024/3 be realised in day to day clinical practice.

Clinical staff have a good understanding of the infection risks associated with water systems. Most are aware that:

• Legionella bacteria can proliferate in water systems and cause Legionnaires’ disease.
• Pseudomonas aeruginosa is a significant healthcare-associated pathogen.
• Patients who are elderly, immunocompromised, or receiving critical care are particularly vulnerable.
• Water outlets can act as sources of infection.

However, many clinicians are understandably less familiar with how healthcare water systems function and how risks are managed operationally. In addition, contractors attending healthcare to carry out remedial works on the domestic water systems may not always be aware of the other aspects of water management and risks, other than the task in front of them to complete.

For example, the following system conditions can increase microbial risk:

• Water stagnation.
• Dead legs within pipework.
• Sub-optimal water temperatures.
• Infrequently used outlets.
• Flexible hoses and complex fittings.
• Scale and biofilm formation.
• Poorly maintained cold water storage tanks.
• Inadequate water turnover.
• Inadequate level of cleaning of tools used for remedial works.
• Hand hygiene.

These operational risks are often overlooked and even though they are well understood by estates teams they can be less visible to the larger clinical staff, even though day-to-day behaviours within clinical areas can influence these risks.

The role of training

One of the key reasons for this gap lies in how training is currently delivered.

In many organisations, water safety training for clinical staff, support staff (Soft FM) and contractors, is limited to generic eLearning modules or brief, compliance-focused toolbox talks. Contractors may receive only induction level information, often heavily procedural, with little emphasis on the ‘why’ behind controls or on their personal role in managing water safety risks. As a result, training tends to become a tick box exercise rather than a foundation for informed decision making and real accountability.

These approaches typically prioritise regulatory compliance over practical, operational understanding and are rarely tailored to the specific roles, responsibilities, or working environments of clinical teams, Soft FM staff (such as cleaning personnel), or external contractors. This can lead to a fragmented understanding of risk, where responsibility is assumed to sit elsewhere — often with estates — rather than being shared and actively owned by all parties who interact with water systems.

Conversely, technical guidance such as HTM 04 01 is often highly detailed and written primarily for engineering and estates professionals. While technically robust, this guidance does not always translate easily into practical, role relevant knowledge for clinicians, Soft FM teams, or contractors who may be undertaking tasks that directly affect water safety, such as outlet cleaning, maintenance activities, or system modifications.

The challenge, therefore, is not a lack of available knowledge, but a failure of communication, relevance, and engagement. Clinical priorities understandably focus on immediate patient care, while contractors may focus on task completion and contractual scope. Infrastructure related risks can therefore appear remote unless they are clearly explained within a clinical, patient safety, and accountability context that makes individual responsibilities explicit and meaningful.

Legionella is not the only risk

Traditionally, healthcare water safety training has focused heavily on Legionella control. While Legionella remains a critical risk that must be managed carefully, experience across healthcare settings increasingly demonstrates that outbreaks and patient harm are frequently associated with other waterborne organisms.

In particular, Pseudomonas aeruginosa is commonly linked to taps, sinks, drainage systems, and water outlets, especially within critical care, neonatal, burns, and immunocompromised patient environments. Transmission pathways may include:

• Splash contamination from sinks and outlets.
• Aerosol generation from showers or certain types of taps.
• Contact with contaminated surfaces, equipment, or hands following sink use.

In addition to Pseudomonas, NTM represent a growing and often under recognised challenge across healthcare. NTM are naturally present in water systems, are highly resistant to standard disinfectants, and can readily persist within biofilms in pipework, outlets, and drainage systems. In vulnerable patient populations, particularly those with weakened immune systems, NTM can cause serious and difficult to treat infections.

Compounding this risk is the increasing prevalence of multidrug resistant (MDR) waterborne organisms. Healthcare water systems can function as long term reservoirs for antimicrobial resistant bacteria, allowing organisms to persist, adapt, and spread within clinical environments. This significantly increases the consequences of exposure, as treatment options may be limited and patient outcomes more severe.

Despite these risks, training and awareness programmes often remain narrowly focused on Legionella compliance. This can result in a false sense of security, where risks associated with sinks, outlets, drainage design, outlet usage, and routine activities are underestimated or overlooked — particularly by clinical staff, Soft FM teams, and contractors who interact with water systems daily.

For these reasons, water safety training should move beyond a narrow ‘Legionella awareness’ model and instead adopt a broader, more clinically relevant framework, such as:

• Water safety, drainage management, and waterborne infection control

This wider perspective better reflects the full spectrum of microbiological risks present within healthcare water systems, including NTM and MDR organisms. Crucially, it reinforces the link between infrastructure, human behaviour, and patient safety, supporting a more informed, shared understanding of responsibility across estates teams, clinical staff, Soft FM personnel, and contractors.

By framing water system risks in terms of real clinical consequences — rather than isolated regulatory requirements — training can better support effective risk ownership, safer working practices, and stronger infection prevention outcomes.

• Bridging estates and clinical practice

The gap between estates-managed water safety systems and clinical practice is structural rather than cultural.

Water systems are typically managed by estates or facilities teams, meaning that clinicians often view water safety as an infrastructure issue rather than a shared responsibility.

However, frontline staff play an important role in identifying potential risks. Examples include:

• Recognising rarely used outlets.
• Reporting poor flow or temperature irregularities
• Understanding when certain outlets should be removed or restricted in high-risk areas.

Improving awareness of these issues does not require extensive technical training. Instead, short, role-specific training sessions can significantly improve operational understanding.

Training sessions of 10—20 minutes, delivered as part of induction or annual refresher programmes, may be more effective than longer classroom-based courses. Such training should ideally be integrated into infection prevention and control education, rather than delivered as a separate topic.

The emerging challenge of NTM

The introduction of the NHS Technical Bulletin on non-tuberculous mycobacteria reflects growing awareness of these organisms in healthcare environments.

However, this area of water safety remains complex and evolving. Currently:

• There is no universally agreed NHS standard for acceptable NTM levels.
• Laboratory testing methods are not fully standardised.
• Detection and analysis can take several weeks.

As a result, organisations may struggle to interpret positive results or determine the most appropriate response. There is therefore a risk that some organisations may default to expensive engineering controls, such as widespread installation of point-of-use filtration systems, to demonstrate precautionary action.

The intent of the NHS Technical Bulletin is not to encourage blanket testing of hospital water systems for NTM, but rather to promote risk-based management. This approach prioritises:

• High-risk patient groups.
• High-risk clinical environments such as transplant units.

Where necessary, point-of-use or inline filtration can provide protection for vulnerable patients and while point of use filtration can be a valuable short term or risk mitigation measure — particularly during outbreaks or in high risk clinical areas — it should never be regarded as a substitute for fundamental risk elimination.

Filtration treats the symptom of contamination at the outlet, not the cause of microbial growth within the water or drainage system. Over reliance on filtration risks masking underlying system failures, allowing conditions that support biofilm development and pathogen persistence to remain unaddressed.

The most effective and sustainable approach to water safety is therefore to address the foundations of system design, operation, and use, eliminating or controlling risks at source wherever possible. These upstream measures remain the cornerstone of effective prevention and include:

• Removing stagnation points where water remains static for prolonged periods, creating ideal conditions for biofilm formation and microbial amplification.
• Eliminating dead legs and redundant pipework, which can act as long term reservoirs for organisms including Pseudomonas aeruginosa, NTM, and MDR bacteria.
• Managing low use outlets, ensuring they are either removed, routinely flushed, or redesigned, rather than allowed to deteriorate into unmanaged risks.
• Maintaining correct temperature control throughout the system to discourage microbial growth and reduce the reliance on reactive controls.
• Implementing robust, risk based flushing regimes, aligned with actual clinical use rather than generic schedules.
• Reviewing outlet and drainage design to minimise splash, aerosol generation, and cross contamination between sinks, taps, hands, and nearby clinical activities.

Addressing these root causes reduces the opportunity for pathogens to establish within systems, limits biofilm development, and diminishes the likelihood that water infrastructure becomes a persistent reservoir for infection. This is particularly important given that organisms such as NTM and MDR bacteria are highly resilient, difficult to eradicate once established, and often resistant to both disinfectants and antimicrobial treatment.

Importantly, failure to tackle these foundational issues can create a cycle of dependency on additional controls — such as filters, intensified cleaning, or increased monitoring — without ever resolving the underlying problem. Over time, this approach increases cost, complexity, and operational burden, while providing only an illusion of safety.

Particular attention must be given to high risk patient environments, where the consequences of exposure are most severe and patient susceptibility is greatest, including:

• Intensive care units (ICUs).
• Neonatal wards and special care baby units.
• Haematology and oncology units.
• Transplant and other highly immunocompromised patient areas.

In these settings, even low level or intermittent contamination can result in serious infection. As such, the expectation should be that water and drainage systems are intrinsically safe by design and operation, rather than rendered ‘safe’ through layered compensatory measures alone.

Ultimately, effective water safety management requires a shift in mindset: from reacting to detected contamination at the outlet to designing, operating, and maintaining systems that minimise the opportunity for contamination to occur at all. Addressing the root causes is not only more effective in protecting patients, but also supports long term resilience, clearer accountability, and stronger assurance across healthcare organisations.

Moving forward

The opportunity for the healthcare sector is not to identify fault but to strengthen collaboration between estates teams, clinical staff, and contractors.

Three key principles can support this approach:

• Training as a risk-reduction tool.
• Improved understanding of waterborne pathogens and system risks enables staff to recognise and manage hazards more effectively.
• NTM management should be risk-based, not test-driven.

Testing should support risk management rather than drive unnecessary interventions. Filtration should be targeted, and filters should protect the most vulnerable patients where necessary but should not replace fundamental risk control measures.

The publication of NHS Estates Technical Bulletin (NETB) 2024/3 represents an important and timely evolution in healthcare water safety, reinforcing the need to protect the most vulnerable patients from a broader range of waterborne pathogens, including NTM, Pseudomonas aeruginosa, and MDR organisms. However, the real challenge for healthcare organisations lies not in understanding the guidance itself, but in translating its intent into consistent, effective day-to-day practice.

This article highlights that fact that the most significant risk to patient safety arises from an operational gap between estates managed water systems and the realities of frontline clinical practice and contractor activity. Water safety has historically been treated as a technical, estates-led compliance function rather than a shared, multidisciplinary responsibility directly linked to infection prevention and patient outcomes. As a result, ownership can become fragmented, training overly generic, and critical system risks insufficiently understood by those who interact with water systems on a daily basis.

The increasing recognition of NTM and other resilient, treatment resistant organisms further emphasises why reactive or downstream controls alone are not sufficient. Measures such as point of use filtration have a role, particularly for protecting high risk patients or during incident response, but they do not address the underlying system conditions that allow pathogens to persist and proliferate. Without tackling root causes — such as stagnation, dead legs, poor outlet and drainage design, sub optimal temperatures, low use outlets, and inconsistent human behaviours — healthcare organisations risk creating an unsustainable reliance on compensatory controls that provide reassurance without long term resilience.

A shift in mindset

Fundamentally, effective water safety management requires a shift in mindset: from reacting to contamination when it is detected, to proactively designing, operating, maintaining, and using water systems in ways that minimise the opportunity for contamination to arise in the first place. This approach aligns with the hierarchy of risk control, supports antimicrobial resistance (AMR) objectives, and provides stronger assurance for high risk clinical environments where the consequences of exposure are greatest.

Moving forward, success will depend on integration rather than escalation — integrating water safety into clinical practice, infection prevention and control education, contractor management, and everyday decision making. This includes developing role specific, practical training; clearly articulating responsibilities; fostering open communication between estates, clinical teams, Soft FM staff, and contractors; and applying risk-based, proportionate controls aligned to patient vulnerability.

By addressing the foundations of water system risk and embedding shared operational understanding, healthcare organisations can ensure that the principles set out in HTM 04 01 and NETB 2024/3 are not only complied with, but meaningfully realised — delivering safer environments, stronger governance, and, most importantly, improved protection for patients.

Bibliography

•  NHS Technical Bulletin (NETB) No. 2024/3. https://www.england.nhs.uk/wp-content/uploads/2024/08/prn01343-nhs-estates-technical-bulletin-2024-3.pdf.pdf