As featured in Waterline Autumn 2022
From the Cradle to the Grave – The lifecycle of water management
Wednesday 8th June 2022
University of Greenwich, London
Governance – Getting it Right First Time Elise Maynard, Director, Water Management Society
Elise discussed the various Legislative and guidance documents which are applicable to water safety for all buildings and how they should be applied at the design and concept stages, especially for new healthcare buildings. This should include any CQC registered facility, including primary care and dental facilities. She advised that there are several new British Standards which have been written by a team who are actively involved in water management – these include:
• BS 8680:2020 Water quality. Water Safety Plans. Code of Practice
• BS 8580-1:2019 Water quality, risk assessments for Legionella control. Code of practice.
• BS 8580-2: 2022 Water quality, risk assessments for Pseudomonas aeruginosa and other waterborne pathogens. Code of practice.
• BS 7592: 2022 Sampling for Legionella bacteria in water systems – Code of practice (revision).
The process of risk assessment and the associated hierarchy of control is to remove or minimise the likelihood of harm. Elise showed examples of Contamination, Amplification, Transmission, Exposure and Susceptibility within new build designs and explained the costs of getting this wrong.
Design Components of Water Systems
Dr Ayse Cagla Balaban, Lecturer in the Built Environment, University of Greenwich
Cagla discussed the importance of water management in the built environment. – only 1% of the water on Earth is usable and thus supply, demand and the environment are crucial. Her field of study relates to mains water supplies.
With regards to the source of water supply – precipitation, surface water and ground water can be very polluted. The choice of source depends on location, quantity, quality and cost. Cagla introduced some key design terms i.e., “max flow, average flow and max probable flow” these are important when designing pipework. Essential units include “intake, intake main, pumping station and transmissive main”. The treatment system must be able to remove colour, taste and bacteria thus reducing the hardness, iron and corrosive qualities. The distribution system must deliver high water quality and pressure – the latter must be sufficient for firefighting equipment. System design is important for health; requiring good pressure, flow and low noise as water velocity can be very loud. To minimise bacterial growth, pipework must be as short and direct as possible with adequate insulation of pipes and tanks, choices of materials and tanks with lids. The future could include composite materials, nanomaterials, or smart materials – these are projects that are being worked on currently by her PhD students.
Waterborne Bacteria/Maintenance and Controls
Dr Elaine Cloutman-Green, Consultant Clinical Scientist, Great Ormond Street Hospital
Elaine discussed clinical risk assessments and how they differ vastly from a Legionella risk assessment i.e., the patient is at the heart of the former, the latter tends to be an engineering exercise. The hierarchy of controls for any risk assessment requires elimination of the risk as the first and most important step, followed by substitution with a safer option. If elimination is not possible, only then should control be an option. The environment includes air, surface and water e.g., taps, sterile water and equipment. Micro-organisms can contaminate the environment via aerosols, droplets etc. but it is important to also consider how long they can survive on surfaces, which can be hours or even days. Transmission routes are typically via hands, showers and drinking (or aspiration) and also via poorly maintained or ill-used equipment. Guidance is useful as a baseline but are not always helpful for clinicians and they can also stifle innovation as they are often interpreted as law. Interestingly approximately 60% of Legionella pneumophila clinical infections are not currently sero-grouped (sg). Traditionally sg1 has been assumed to have the highest virulence, but other sgs and species have been implicated in outbreaks. Thankfully nosocomial infections are relatively few.
Augmented care has no fixed definition but likely to include:
• Severely immunosuppressed – transplant and oncology
• Organ support – critical care, renal, respiratory, cystic fibrosis
• Breaches in dermal integrity – burns
The augmented care environment is different due to longer lengths of stay, indwelling devices, underlying conditions, immune status, susceptibility and numbers of daily encounters/manipulations.
Pseudomonas aeruginosa is ubiquitous, thrives in biofilms and can survive up to 48 hr on surfaces. It is an opportunistic pathogen and causes high numbers of bacteraemias. These are increasing year on year and are still a main cause of infection. Many outbreaks have been reported in the literature and the publication rate is still increasing – highly antibiotic resistant strains are also increasing. Many other Gram negatives are being reported as causing outbreaks and there are also other organisms such as fungi and non-tuberculous mycobacteria being reported. Exposure can include splash, but poor cleaning can also be a source. Drains are a source of contamination and amplification; the real requirement is to control the management of the equipment and surfaces in the vicinity.
Drains and Disease
Dr Mike Weinbren, Consultant Microbiologist and Infection Control Doctor, NHS Scotland Assure & King’s Mill NHS Trust
Mike reviewed some history of water contamination, such as the contribution of John Snow and his discovery of the source of cholera from a communal water pump. Transmission of P. aeruginosa via water was identified and reported in the 1960s but was not taken seriously as a risk until 2012 when several babies died and this was reported in the media. The focus is now on the periphery of the water system, such as taps and showers. Deaths linked to intravenous Total Parenteral Nutrition formulations were traced back to splashing from a drain in a sink in the aseptic preparation unit. The learning outcome is that sinks should now be placed outside the preparation area.
The wastewater system can be a conduit for transmission of faecal bacteria, P. aeruginosa, and viruses. As waste material is expelled into the soil stacks, contaminated air rises – this was demonstrated in the SARS outbreak in Hong Kong. The U-bends need to be full of water for them to be effective, but if they are not used, they can dry out. The water in the U bend can also become contaminated, however, so if backsplash is created then nearby surfaces are likely to become contaminated. Antibiotic resistance is also transferred via this route and blockage exacerbates the problem. Positioning of shower drains is an issue within healthcare as contamination can easily backsplash onto the surroundings. Mike noted that if bacteria have sufficient nutrients, they will form biofilm and he shared a number of images demonstrating splash of up to 2 metres. A CDC report has shown 20% of infections are related to the water supply (2).
With regard to design, elbow taps and correct fitting and placement of wash handbasins (WHB) close to patient beds – issues are still occurring. Storage areas do NOT need WHB! Hand detergent should not be placed above the tap outlet as it can drip down and provide nutrients and paper towels should not be placed above the WHB as fragments can block the drain. Taps should be mounted on the integrated plumbing solutions (IPS) panel with sufficient activity space and there should be no overflow and no plug. Many clinical and food items have been found in drains as well as excess sealant.
Human factors have a major impact, one study placed a video camera above a WHB and clearly showed that handwashing accounted for only 4% of activity. Cleaning is really important and training should be provided, but no-one is training the clinical staff in correct usage. Kitchen activities i.e. filling of water jugs have also been demonstrated to have a lack of staff awareness of how waterborne bacteria can spread from base of the jug coming into contact with the drain as it is filled.
Kearney et al. (1) recommend removing the hazard as a primary measure and if this cannot be done, then to isolate the hazard – engineering is the least effective policy and guidelines are not always effective. This reiterated Elaine’s advice earlier. Mike advised that staff need to be trained to report blockages as disinfecting drains can be hit and miss – due to maximum permissible concentrations, contact time etc.. He showed examples of chemotherapy patients losing hair and it blocking the shower drains. Toilets should be rimless as biofilm is harboured out of reach of cleaning implements. 90-degree bends have been plumbed into macerator waste outlets. Kitchen water spray taps have contaminated salads. Maintenance equipment (spanners, screwdrivers etc.) is often used from dirty to clean.
Looking to the future – Antimicrobial Resistance (AMR) related outbreaks are significantly increasing year on year so logically the removal of WHBs should reduce Gram negative colonisation. The second recommendation of the O’Neill report (3) is to improve hygiene and prevent spread of infection by handwashing, however, this is failing. With all the new Hospitals being built in UK – what learning will be transferred – have we returned to Victorian times?
Putting Learning into Practice
Alyson Prince, Built Environmental Infection Control Specialist
Alyson further confirmed the problems caused by opportunistic waterborne pathogens i.e., that they form biofilms, cause infections, are difficult to treat, they spread and become antibiotic resistant. Hospital uses of water are vast and need to be managed appropriately.
Hospital projects require appropriately trained Infection Prevention and Control (IPC) staff to input throughout each phase in order to:
• Link the clinical risk profile to that of the environmental data
• Provide insight into test results – if we are looking for it, what does it mean?
• Understand other clinical disciplines, what is it we are doing in the space?
• Provide input at all stages of installation, commissioning process
• Ensure water quality is suitable for the risk level of clinical service delivery
With regards to legislation and guidance – how can it be applied in practice? HBN 00 09 “Infection control in the built environment” hasn’t been revised since 2013 but nevertheless projects require IPC input on concept, feasibility, drawings, detail design, contract, construction, pre-handover inspection, commissioning and post project surveillance. Potential problems resulting from poor collaboration lead to poor design, maintenance and schematics, including change of use and too many water outlets installed without insight.
Other key aspects for good design practices are:
• Procurement of equipment and service
• Logistics and workflow
• Contractor selection for ongoing maintenance
• Service redesign/relocation
• New build concept to completion
• Bed allocation and design of high-risk patient areas
• Selection of fixtures and fittings
Alyson asked, “How can space be risk assessed without detailed knowledge of the clinical usage?” and advised that the Scottish SHFN 30 Part A manual has a very useful planning process example.
What can IPC and clinical teams do?
• Attend Water Safety Groups!!
• Ensure equipment and systems in their remit are being maintained, ideally with photographic evidence.
• Ensure routine testing and maintenance is carried out.
Water safety is a collective responsibility and a partnership, it is important to have good awareness, be competent and communicate well – from the top to the bottom. Engineers also need to collaborate, follow method statements, communicate in a timely fashion and perform appropriate remediation. For technical commissioning, buildings can be live a full year before pressure testing and thus contamination can ingress at any point. Ideally, systems should be left water-free for as long as possible but when filled, it is vital that temperatures are correct, schematics are accurate and data monitored. The WSG should be advised of any exceptions.
Modern methods of construction require that equipment arrives clean and is installed correctly. The water safety risk assessment should be initiated at the start of the project and reflect the clinical activity for that building or area. It needs to be reviewed regularly and referenced in the WSP as there can be significant legal ramifications of when it goes wrong.
Research to support the outbreak response
Dr Ginny Moore, Scientific Lead, Biosafety, Air and Water Microbiology Group, UKHSA
Ginny discussed how applied microbiology research has helped UKHSA better understand how the indoor built environment can contribute to transmission of infection.
Ginny showed images of specialist aerobiology equipment used by UKHSA to investigate outbreaks of infection and to assess risk. For example, specialist aerobiology has been used to assess the aerosolization of respirable droplets from domestic spa pools and to investigate heater-cooler units as a source of invasive Mycobacterium chimaera infection. In this case, they were able to demonstrate the aerosolization of potential pathogens, including M. chimaera, from within heater-cooler units and identify specific areas of aerosol release. The data was communicated to various manufacturers and design changes have since been implemented. The study also highlighted difficulties associated with the disinfection of these units and different disinfection protocols were researched.
Following several high-profile incidents of P. aeruginosa infection, studies were carried out to investigate the formation of biofilm on tap components. These studies were carried out using a dedicated “tap rig” which initially incorporated taps fitted with different designs of flow straightener and, subsequently, solenoid valves made from different materials.
Similarly, and as a result of a Carbapenemase-producing Enterobacterales (CPE) outbreak, the team developed a model sink and drainage system. This incorporated different designs of sinks with differing drain positions and could also mimic blockages within the drainage system. Their research confirmed that sink design can minimise dispersal of potential pathogens present within the waste trap and/or drain hole of a sink and demonstrated that efficient drainage is essential to minimise splash-back and transmission of drain-associated pathogens. Subsequent studies assessed the efficacy of chemical disinfection in reducing contamination within sink waste traps. Results suggest that chemical disinfection provides a short-term solution only. Model systems can be very useful for pre-concept research.
Ginny’s team have numerous research publications in the literature and were recently awarded funding to design and build a full-scale research ward, which is now complete and looking for projects!
Understanding drinking water biofilms and their impact on water quality
Dr. Kat Fish, Postdoctoral Researcher, University of Sheffield
Sheffield Water Centre has 150+ researchers. Kat’s area of research focusses on water distribution systems but the challenges are very similar to those for in-premise plumbing. Water quality failures are increasing, often due to complex and ageing systems and to biofilms, which are overlooked in policy and practice.
Studying Drinking Water Biofilms at Full-scale Researchers at Sheffield have designed and built a fullscale, representative drinking water distribution system experimental facility and can insert coupons to enable biofilm analysis (based in Civil and Structural Engineering, at the University of Sheffield). Smaller versions of this experimental system have been developed for use on-site at operational treatment works and within operational distribution systems.
Biofilm monitoring devices have also been developed to enable evaluation of water quality impacts on biofilm growth rates, also within operational drinking water systems.
Integrated biofilm analysis utilises state-of-the art techniques to determine cell concentration and viability (flow cytometry), microbiome characterisation (molecular analyses) and physical/chemical composition of the biofilms.
Kat presented an overview of the team’s world-leading biofilm research to date examining interactions between biofilm growth, mobilisation (by increasing shear stresses) and water quality, in particular the impact of hydraulics, disinfection, coatings and carbon upon these.
Some research highlights:
• Low varied flow hydraulic regime – lowest discolouration, lowest biofilm cell numbers and highest Extracellular Polysaccharide (EPS)-per-cell, compared to a Steady State (consistent flow) or High Varied Flow. PODDS (Prediction of Discolouration in Distribution systems) is a research consortium, steered by water company partners, addressing the use of hydraulic regimes to manage discoloured drinking water. It has resulted in lower operational costs and improved water quality.
• Temperature – looking at low water temps in relation to climate change i.e., 8°C and 16°C showed that varied flow is better at reducing discolouration, but this is more obvious at higher temperatures (4).
• Assimilable Organic Carbon (AOC) analysis shows different rate and structure of biofilm formation, when biofilm is subsequently mobilised, this then impacts the AOC concentration in the bulk-water, demonstrating the cyclical nature and impact of biofilms on water quality downstream.
• Chlorine – greatest discolouration response at high chlorine residuals, but this has no impact on fungal cells. It did, however, select out resistant bacterial strains. Low chlorine had high EPS and the lowest discolouration response.
Looking to the future, the group will be undertaking the following projects:
• Examining different disinfection regimes and their impact on biofilms (WIRe PhD)
• Rapid pathogen detection (in collaboration with Sellafield Ltd and HSE)
• Biologically stable drinking water
• Biofouling monitoring
• Hydraulics of intermittent supply and self-cleaning velocities
Kat noted that biofilms are critical and studies require an holistic approach, balance, collaboration and translational research. We need to be considering the impact of upstream biofilms on our downstream premise plumbing and water quality, understanding these interactions is critical.
Multidisciplinary studies in wastewater by medical microbiologists and engineers
Fusun provided a summary of research into novel bacterial detection materials and methods such as Artificial Intelligence (AI) and Raman technologies.
At least 1500 “new” pathogens have been identified since 1970 both viral and bacterial. Detection of virus in waste-water can give an early indicator of community spread. Waste-water epidemiology (WBE) is a powerful tool to monitor pandemics, detecting viral RNA. Some of the newer techniques are listed below:
• Droplet digital polymerase chain rection (ddPCR)
• AI can be used for reading Gram stains and bacterial culture plates
• Matrix-Assisted Laser Desorption/Ionization-Time of Flight (Maldi-ToF)
• Whole genome sequencing
Raman spectroscopy can be used for antibiotic susceptibility testing and can be combined with AI for processing data and machine learning. Surface enhanced Raman spectroscopy is more sensitive and newer techniques include Laser (optical) tweezers.
Bdellovibrio bacteriovorus is a predatory bacterium that can invade a number of Gram-negative bacteria and can be used as a surface coating.
Quorum Quenching has been shown to prevent the building up of biofilm by disrupting the chemical signalling between bacteria.
Microbial self-healing concrete is based on the bacterialinduced calcium carbonate precipitation. In nature, a lot of bacteria are capable of precipitating calcite (CaCO3).
Several themes were noted from the conference:
• Disconnections exist throughout the whole design and build process from the architects, designers through to the building users.
• There are very few people who understand guidance and its application, especially where that guidance is contradictory as it has been superseded.
• There is a definite need for more study days to educate designers, architects and specifiers. Could the problem be that staff are not being listened to at the design stages – who is the client and who has input at the planning stages? Clinical staff are too busy managing patients, but their behaviour affects water quality. Such behavioural aspects are paramount and pro-active management needs to be put in place to enable key staff to attend meetings. Very little water hygiene training is provided during early learning for any clinical staff and this will affect behaviour due to an overall lack of understanding of the various hazards linked to water.
The whole building needs to be reviewed, not just the sinks, showers and drains. Guidance is useful but there are gaps as they can conflict and very little is available in clinical terms. Sadly, derogations can over-ride common sense at times.
There is a clear need to invite all disciplines to future events to attain better communication with development of educational tools that can be shared by professional bodies to their respective silos.
(1) Kearney A, Boyle MA, Curley GF, Humphreys H. Preventing infections caused by carbapenemase-producing bacteria in the intensive care unit – Think about the sink. J Crit Care. 2021 Dec;66:52-59. doi: 10.1016/j.jcrc.2021.07.023. Epub 2021 Aug 24. PMID: 34438134.
(2) Perkins KM, Reddy SC, Fagan R, Arduino MJ, Perz JF. Investigation of healthcare infection risks from waterrelated organisms: Summary of CDC consultations, 2014- 2017. Infect Control Hosp Epidemiol. 2019 Jun;40(6):621-626. doi: 10.1017/ice.2019.60. Epub 2019 Apr 3. PMID: 30942147; PMCID: PMC7883772.
(3) Price R. O’Neill report on antimicrobial resistance: funding for antimicrobial specialists should be improved. Eur J Hosp Pharm. 2016 Jul;23(4):245-247. doi: 10.1136/ ejhpharm-2016-001013. PMID: 31156859; PMCID: PMC6451500.
(4) Fish KE, Sharpe RL, Biggs CA, Boxall JB (2022) Impacts of temperature and hydraulic regime on discolouration and biofilm fouling in drinking water distribution systems. PLOS Water 1(8): e0000033. https://doi.org/10.1371/journal. pwat.0000033