In the second in a series of hospital wastewater-related articles running in HEJ this year (the first was published last month), Peter Orendecki, Senior Contracts manager and Water AP at University Hospital Southampton NHS Foundation Trust, highlights the apparent lack of understanding of the risks posed by hazardous bacteria in hospital waste systems among some designers, architects, and even infection control personnel. He asks whether there may here be an opportunity here for the UK to lead in such systems’ design.
The general design of effluent drainage within all buildings broadly relies on gravity to allow waste water from a number of different processes – including, but not limited to, handwashing, dish cleaning, showering, the use of toilets, macerators, bedpan washer-disinfectors, and other clinical uses, to drain away from the point of use into a vertical pipe, known as a stack. An individual stack receives all wastewater sources in its vicinity and all stacks link to the main sewer, effectively linking all drainage within a building. The lack of segregation of wastewater systems is a major factor in allowing microbes to move from one area of a hospital to another via different modes of transport, active growth, movement of air, and aerosols and the wastewater itself.
At the proximal end of the drainage system waste traps of various designs are used to hold water, thereby separating the drainage system air from the air in the local environment. This comes with its own issues. Bacteria dwell in the U-bend and form complex biofilms. Disposing of a carbon source down a sink drain will stimulate the growth of biofilm up the vertical section of the drain at a rate of 1 mm/hour, reaching the sieve at the top of the drain. Water from an outlet directly hitting the sieve can disperse organisms in the biofilm up to 2 m away. (see Figure 1).
Sanitaryware design and placement
Sanitaryware designs and placement are of equal importance in reducing risk from wastewater systems. The risk in hospitals and other healthcare facilities is exacerbated by poor practices by staff, who are often unaware that the drainage poses a threat. The materials used within drainage systems tend to be mainly plastic in modern construction, and are often installed poorly, with incorrect fittings used, incorrect camber on pipework to effectively drain away the wastewater, and over-use of sealant, particularly around sanitaryware connections.
In general, anything which impedes drainage is likely to lead to dispersal of organisms within and outside of drainage systems. This may be due to incorrect sizing of pipework, incorrect camber, not employing swept bends, incorrect disposal of items (builders’ rubble, wipes, paper towels, etc), or inadequate maintenance (no planned preventative maintenance to ensure that drains are cleared, but instead only reactive work undertaken when it is too late). Ironically, the act of reactively unblocking drains can exacerbate problems. This may, for example, occur through the introduction of microorganisms on contaminated equipment, when using a water jet above a blockage, as a result of poor hygienic practices by Estates staff, and through a general lack of emphasis on appropriate procedures for storing, travelling with, and cleaning, drainage equipment.
Drain-dwelling bacteria entering the environment
All of the above scenarios are likely to result in drain-dwelling bacteria entering the environment, and as antimicrobial resistance (AMR) gains momentum, they will increasingly result in negative outcomes for patients. The ongoing operation of a healthcare facility and the building services within present complex and dynamic challenges, and to reduce risks such as the build-up and spread of hazardous bacteria in drainage systems on an ongoing basis requires appropriate training and discipline from staff, and appropriate communication with, and sensible practice from, patients and visitors. All of this also involves improving communication on the key issues to be aware of.
Depending on the size of the estate, the age of the system, and levels of reporting, the number of drain blockages occurring in a healthcare establishment can be in excess of 1000 / year (see Table 1). The criticality of a blocked drain in a healthcare environment isn’t widely understood, leading to both under- and late reporting of slowly draining sinks. Work conducted at UKHSA Porton Down has shown that sinks with a rear drain show minimal risk of transmission on wastewater organisms.
However, if drainage is impeded, which is common in the clinical environment, then such designs will disperse wastewater organisms. Staff have not been trained on the risks, so impaired drainage is usually only reported by the time the drain is completely occluded. In the meantime, wastewater organisms are likely to have been dispersed into the healthcare environment.
Scant attention to location of pipe runs
Scant attention is often paid to the location of pipe runs and the impact of blockages/ leaks on the local vicinity, and the resulting contamination in pharmacy store areas, food preparation areas, and susceptible patient groups, as well as the impact on continuing hospital activities, needs to be considered. While when a water system shows a contamination issue, or a flow problem, the design is almost always considered, often when drainage systems show the same, the design isn’t afforded the same level of concern
Most failings can ultimately be traced back to not placing patient safety at the front and centre of everything we do, and linking this to a risk-based approach. In order to mitigate against risk, the hazards not only have to be visible, but also brought to the attention of those with the ability and determination to make effective change
Risk visibility is, of course, determined by a variety of factors. The stakeholders involved in ensuring safety in the healthcare built environment extend beyond those who are immediately involved in a new-build project to include those who write guidance and compliance, manufacturers, and those involved in enforcing/ monitoring compliance.
Guidance has a long history across many industries, as indeed has the design and construction of buildings failing to achieve the necessary standards. Guidance should not be seen as a substitute for training and expertise, but in practice often is. When the Health and Safety Executive investigates incidents, the three main contributory factors are poor management, poor communication, and a lack of appropriate training
A loose definition of training
With regards to the latter, the word training is used extremely loosely nowadays, and may be used to cover anything from a 20-minute online course / lecture (which is no more than very basic awareness), to what the HSE are inferring by training, which is competency-based. While a lack of competence is a contributory factor in failures in new-builds, there is a perhaps a bigger problem with the understanding and definition of ‘competence’. To give an example – and indeed this could be equally applied to other professional groups – let us look at Infection Control. Input from this specialist discipline is rightly seen as an essential requirement for patient safety in a new-build healthcare facility. Infection control personnel will be recruited to join the project. However, many infection control personnel have had no training on, or experience of, the built environment, let alone possessing built environment knowledge as regards new-builds. Individuals are brought in who bring no added value to the project. While competent in their profession, they lack the necessary training/experience for this very specialised area.
A lack of specialist expertise
The same can be said of design teams and architects – why should they know where to place a clinical handwash station to minimise the risk to patients? They are likely to be competent individuals, but lack the necessary specialist expertise. One then ends up in a situation where uninformed architects and designers are producing work which may or may not be checked by Infection Control teams who also lack the relevant expertise.
Lack of an audit / feedback cycle
The current system of design, construction, and occupancy of buildings lacks an audit / feedback cycle / lessons learnt process to influence and improve future new-builds. There is a silo mentality in that design teams, architects, and construction firms, have often moved on to the next project before many of the issues become apparent, so are unaware of what works and does not work. No centralised system exists for collecting data on what goes wrong in new-builds, despite such occurrences resulting in patient morbidity and mortality on a potentially large scale. This lack of process would be unacceptable for a medical device or drug. The cost of undertaking remedial modifications once a building is constructed is extremely high, and potentially sucks much needed money out of the healthcare system, further impinging on patient care. Getting it right first time is not only safer, but also significantly less expensive
In summary, even when the risks are visible to all, there is currently no effective mechanism for ensuring that what we know to be best practice is delivered in a new-build. Guidance and compliance may also prevent progress. Guidance generates standards against which a product /or process needs to be compliant. Meeting compliance can now become the target, rather than patient safety. Thus, manufacturers, for example, may aspire to go no further than ensuring that their product is compliant, while from the consumer perspective, the assumption will be that provided it is compliant, they can opt for the cheapest product. In both circumstances the thinking is flawed – compliance does not equate with ensuring patient safety; it is often a minimal standard
If, instead, the manufacturer and consumer employed a risk-based approach and then then looked to see whether a product mitigated against the risks, it is likely that not only would better products ensue, but also that the consumer would choose the better products, and thereby drive a quality initiative across the industry. Compliance requirements, and the need to satisfy them further, drive the ‘value engineering’ process by allowing for lower quality systems to be installed that meet the minimum standard.
As the risks of infection from hospital drainage systems have not been fully recognised, industry is almost wholly unaware of the problems. Recognition of the risks is the critical first stage, followed by communication to all relevant parties – including manufacturers, designers, installers, and end-users – to assist in eliminating and reducing the associated risks.
Peter Orendecki
Peter Orendecki, Senior Contracts manager and Water AP at University Hospital Southampton NHS Foundation Trust, is an experienced Maintenance and Contracts manager with a demonstrated history of working in the healthcare, leisure, and travel and tourism industries. Skilled in customer service, water hygiene, mechanical ventilation, engineering, and maintenance management, he is currently studying for a BSc in Hospital Engineering.