As featured in Waterline Winter 2024-25
NHS Estates Technical Bulletin (NETB) No. 2024/3
by Elise Maynard, Steve Vaughan, and Mike Quest
Designing safe spaces for patients at high risk of infection from nontuberculous mycobacteria and other waterborne pathogens
Date of issue: 27 August 2024
On 27th August 2024, NHS England issued an NHS Estates Technical Bulletin (NETB) to enhance the guidance set out in HTM 04-01 (2016) to address risks from nontuberculous mycobacteria (NTM) and other waterborne pathogens and to identify measures required for new hospital wards/units, including major refurbishments to existing clinical spaces. The bulletin relates primarily to the design, construction and delivery of projects in areas where at risk patient groups are present, with reference to ongoing operation and management of water and waste-water systems and other use of water or other fluids in these areas. The bulletin is to be treated as a supplement to HTM 04-01 and implemented accordingly.
The publication of this new guidance is directly in response to a coroner’s prevention of future deaths report in November 2022. The report highlighted his concerns around the risk that Mycobacterium abscessus, and its colonisation in healthcare water systems, may have on patients who require augmented care, especially those who are immunosuppressed. He recommended a review of the current guidance, and for consideration to be given to additional measures which may be required in relation to the design, installation, commissioning and operation of hospital water systems in new hospitals.
This 79-page document contains a lot of information which requires some interpretation and will have different impacts on different areas of the industry. Steve Vaughan of Aecom has reviewed the document regarding the Public Health Engineering systems aspects and Mike Quest, who works as an Authorising Engineer (AE) for a number of Hospital trusts, has also provide a summary from his perspective. Their observations are combined below.
It should be noted that much of the document requires Healthcare client input. The NETB identifies specific measures required for new hospital premises and major refurbishments for those patients at greatest risk of healthcare-associated infections. It also explores the role of waste-water and antibiotic resistance in much more detail than HTM 04-01, as well as splash risks from sanitaryware.
What are NTMs?
This new guidance, although primarily focussing on nontuberculous mycobacteria (NTMs) is also relevant to other waterborne pathogens. NTMs are commonly found in the environment e.g. soil & water, however, different NTM have particular niches that they favour. Human-to-human transmission of NTM rarely occurs, similar to Legionella. There are ❯ 200 different species of NTM, many of which cause lung infections such as:
– Mycobacterium avium complex (MAC) – includes M. avium, M. intracellulare & M. chimaera
– Mycobacterium abscessus
Like many other waterborne pathogens they can withstand extreme temperatures, certain chemical treatments and multiply within biofilms. In a similar manner to Legionella, some are relatively difficult to culture and can take days or even weeks to grow in a laboratory test. The NETM provides some specific guidance to test labs to try to attain some standardisation of methodology while a new British Standard is being developed.
NTMs are often found in potable water i.e. taps and showers as well as being linked and found in medical equipment such as:
• Cardiac heater coolers
• Automatic endoscope reprocessors (AERs)/bronchoscopes
• Dialysis machines
• Ice machines
At-risk Patient Groups
At-risk patient groups are defined in the bulletin as those designated as a high risk to infection from NTM (as listed below) and should be considered within augmented care areas as defined in the current HTM 04-01:
• Lung transplant patients
• Cystic fibrosis (CF) patients
• Haematology/oncology patients undergoing chemotherapy where neutropenia is expected
• Solid organ transplantation and intensive treatment
• Allogenic stem cell transplantation
• Any patient with a long line in site (e.g. central venous catheter)
Appendix 3 of the NETB provides detail regarding the various stages of immunosuppression and appropriate protection measures which are summarised below:
• Protection level I: Mild immunosuppression
– Avoid elevated infection risks e.g. drinking water from uncontrolled sources
• Protection level II: Moderate immunosuppression
– Drinking-water should have an additional antimicrobial barrier to tap water
– Bathroom installations should be controlled for bacterial reservoirs
• Protection level III: Severe immunosuppression
immunosuppression – Any water for human use should have a very low bacterial count e.g. PoU filters/controlled carbonated water
– Strict control of bath installation & water for showering (avoid if no control possible)
• Protection level IV: Extreme immunosuppression
– Only sterile fluids for drinking, mouth care and washing allowed
Key Governance Requirements
• A Project Duty Holder with appropriate competence should be identified to take responsibility for safety of the whole building and who should set clear targets with expected outcomes for the project.
• A Project-specific Water Safety Group (PWSG) must be established with the required skills and competencies to develop Project Water Safety Plans (PWSP) that address the infection risks of NTM and other opportunistic pathogens.
• The PWSG should be led by the Project Duty Holder and include appropriate clinical end-users (clients), architects, designers, the Authorising Engineer (Water), estates operations and maintenance representatives, infection prevention and control teams, and those involved in procurement, construction and commissioning.
• The PWSG shall report to, and brief, the organisation’s Water Safety Group (WSG).
• Risk assessments following HACCP principles should be undertaken at the concept stage of projects, at the tender specification stage and before the design brief has been developed, to mitigate risks from the earliest opportunity.
Key Technical Requirements
The following is a summary of the key technical requirements that aim to improve on the current guidance contained in HTM 04-01, in some case providing greater clarity, ensuring that water systems are designed, installed and maintained based around patient safety.
• It may be preferable to provide separate small systems, with independent water supply, waste and local heating sources for patients in augmented care units.
These may be advantageous over larger systems to keep pipe runs shorter, avoid over-complex systems and simplify control.
• Point of Entry Filtration (POEF) is essential and should be used for all stages of system installation from first filling, commissioning and operation and for the life of the system to minimise the risk of contamination from the incoming water supply. Reference is made to 0.2 μm sterilising-grade filtration as per ASTM F838-20.
• Hot water temperatures from the generating plant should be ≥60°C and the return temperature as it reaches the generating plant must be at least 55°C.
• The use of TMVs is challenged. Do not over specify, consider simple mixer valve/tap where scald risk is not present.
• Outlets used for drinking water supply should be sited remotely from parts of the system that could cause cross contamination from drains and splashing from outlets.
• Where cold water supply temperatures are known to exceed 18°C at the property boundary, cooling of the incoming water should be considered.
• Flow-through expansion vessels should be used over bladder type vessels.
Much of the document relates to provision and positioning of equipment, sanitaryware and floor gullies/shower outlets as this has significant impact on risk.
• The recommendations for the design of dirty utilities includes making provision for clear separation of dirty and clean areas, with sufficient space in both the dirty and clean areas for the setting down of articles to avoid contamination.
• The design of clean utilities excludes hand-washing facilities from areas used for preparing sterile fluids for infusion and other fluids, instead placing sinks close to the entrance.
• Remote monitoring of water temperature and flow should be designed into the systems, including at all outlets in specialist units to identify any lack of use and where required use automatic flushing devices.
• Wash-hand basins and clinical sinks should not be fitted in highrisk patient rooms where the risk of infection from outlets and drainage is high, and “water-free” care should be considered as an alternative.
• For some at-risk patients, consideration should be given to whether bathrooms with toilets are required.
• All outlets should be compatible to allow fitting of sterilising-grade (0.2μm) Point of Use (POU) filters.
• All showers should be fitted with POU filters.
• Shower drains should be offset so water from the shower does not directly hit the drain and located such that the patient does not make direct contact with the drain by standing over it.
• Splash zones of 2m around sinks and drains using contrasting colours on walls and floors should be considered, and these zones should be kept free of trolleys and equipment. Splash screens are an alternative if space is limited.
• Drainage pipework lines should be routed away from hot water pipes.
• Vacuum toilets should be considered, along with remote flush operation (outside the bathroom) as a means of avoiding infection risks from aerosols released during flushing.
• Access for preventative maintenance for the avoidance of drain blockage, along with access to pipework valves and other fittings should be outside of patient areas where possible.
Blue Card
The NETB recommends that all personnel involved in the installation of water systems and equipment should belong to the Energy & Utility Skills Register (EUSR) (Blue Card) and be Watersafe registered. However, it should be noted that the blue card training is not entirely relevant to healthcare and there is a potential gap for more specific training which should cover the points below, as described in the NETB:
• There is a requirement to avoid wet testing of plant and equipment, this includes manufacturing/factory tests. HTM 04-01 does refer to preventing contamination (HTM 04-01 clauses 3.42/ 3.43) but does not specifically mention avoiding wet testing.
• Implementation of robust processes to ensure safe storage of fittings and components – this should apply to both project sites and operations maintenance facilities.
• All components should be inspected before installation to ensure packaging is intact and that they are dry, clean and free of defects.
• Ensure all installation and maintenance tasks are carried out only by personnel who are verified as being trained and competent with up-to date knowledge of manufacturers’ guidance, relevant regulations, guidance and appropriate standards.
• All personnel installing and maintaining water systems and equipment must be trained in aseptic techniques.
• Separate teams, equipment and clothing should be used for the installation and maintenance of clean and dirty water systems.
• Wastewater installation personnel should be trained to understand the risk to patients from poor installation practices. Audits should be used to ensure appropriate methods are being followed.
• Regular checks for hygienic practices and compliance during installation should be carried out by a trained and competent clerk of works.
Commissioning
The filling and commissioning of water systems is one of the highest risk stages of any new build or major refurbishment project and there should be multiple check-points put in place for each stage of the project. The PWSP should define processes from completion to handover e.g.
• Initial pressure testing with inert gas or air.
• Water systems should be dry until the first-fill of disinfected water from the supply via the POEF system, and the whole system flushed.
• Ensure that the systems and associated equipment are filled at the latest possible time at a time and date agreed by the PWSG and after all other aspects of building commissioning have been completed.
• Pre-commissioning checks, filling protocols and the commissioning requirements should be agreed and defined at design stage by the PWSG and overseen by a competent person representing the PWSG throughout.
• Ensure that all valves are fully opened; no isolating valves should be used to balance systems as part of the commissioning process.
• Before handover, systems should run at normal operational levels for at least eight weeks to verify they are safe for occupation. This requires flushing through one volume of water per day, seven days per week, at every outlet and plumbed-in equipment.
• Assurance sampling of water by competent personnel should be included in the PWSP. This should include pre-flush sampling from each outlet for TVC, E.Coli, Coliforms, Legionella pneumophila and species, Pseudomonas aeruginosa and NTM. To be considered safe, TVC results should be <10 cfu/mL and all other target organisms should be absent, positive results should trigger pre-flush and post-flush investigative sampling and appropriate remediation.
• All documentation should be available prior to handover and the PWSG should not accept handover until it is provided.
Recommended Actions:
The following actions are recommended for all WSGs to ensure organisational governance for water safety embraces the recommendations of the NTEB in line with the current HTM 04-01:
• Ensure your project team plays an integral part of your WSG and regular engagement with your project teams takes place, maintaining awareness of forthcoming and ongoing projects for the construction or refurbishment of areas affecting “at risk” patients.
• Ensure PWSGs are established for all relevant projects in areas affecting “at risk” patients.
• Review and, if necessary, update any tender specifications to include the requirements of the latest HTM 04-01 and this NETB.
• Review your WSP to ensure the requirements and procedures for engagement with project teams and the establishment of PWSGs and PWSPs is clearly defined and understood, along with the requirements for training and competence for personnel involved in projects and ongoing operational maintenance.
• Consider developing a template PWSP for all relevant projects and seek approval from all members of the WSG and project teams.
• Ensure all suppliers of relevant equipment are aware of, and comply with, the requirements for maintaining hygiene and safety standards throughout the manufacturing and supply process.
• Ensure effective management of competence (note the requirement in HTM 00 for the appointment (or approval of) Competent Persons) to ensure all installation contractors meet the requirements for safe storage and installation of water system components, including the use of a clerk of work to undertake regular checks.
There is clear indication that HTM 04-01 is under review and will, at some point in the future, be reissued to incorporate the contents of the bulletin and provide enhanced guidance on the requirements for competence for key personnel in healthcare settings. Whilst the bulletin is primarily aimed at new build and major refurbishment projects, it also contains guidance on the ongoing use in existing buildings and therefore should apply to all minor projects and routine maintenance work.
This document will be challenging to apply – pre-commissioning, for example, will be a very onerous requirement for the contractor during construction/completion, prior to hand-over, which will be many weeks, even months! It is likely to be very resource and water intensive.
Organisations such as NHS Assure have a wealth of information and tools which may assist (see Hayley Kane’s presentation from the WMS event in Glasgow in this issue, pages 14 – 16. The problems at Belfast Maternity Hospital will no doubt strengthen the need to comply with this technical bulletin.
