Water hygiene within hospitals and other healthcare estates is of paramount importance. Bob Blincowe, strategic account manager – UK Healthcare, at Trend Control Systems, explains how a building energy management system (BEMS) ‘can prevent the outbreak of waterborne diseases by monitoring and controlling supply, storage, and distribution systems’.

Primarily due to their large and often complex water supply systems, hospitals and healthcare estates are potential breeding grounds for the bacteria that can cause Legionnaires’ disease and other waterborne pathogens such as Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Mycobacteria. Preventative action, as well as ongoing monitoring and management, are therefore vital in order to maintain the highest levels of protection for patients, staff, and visitors.

A clear  and  present  danger

Legionella pneumophila bacteria are common in natural water  sources  such as rivers, lakes, and reservoirs, but usually in low numbers. They may also be found in purpose-built water system infrastructures, and unless conditions are kept within certain parameters, they can thrive in cooling towers, evaporative condensers, hot and cold water systems, and spa pools. Once the bacteria proliferate, Legionnaires’ disease becomes a distinct possibility, and can cause a potentially fatal form of pneumonia. Over many years, outbreaks of Legionnaires’ disease within hospitals have made the news headlines, and this particular pathogen continues to pose a potentially lethal threat. Its devastating impact was exemplified in the outbreak at Stafford District General Hospital in 1985, when a total of 68 confirmed cases were treated, and 22 of the patients died as a result of it. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires’ disease from the same source.

Government inquiry

A government inquiry was set up to investigate how the infection occurred, and why it became Britain’s largest epidemic of Legionnaires’ disease. Investigations showed how the chiller unit could have been contaminated, and how Legionella pneumophila bacteria could have been generated in the U-trap below the chiller unit. These results, together with the epidemiological evidence, suggested that the chiller unit was most likely to have been the major source of the outbreak. The impact was widespread, and it transpired that nearly one third of hospital staff had Legionella antibodies, and were likely to have worked in areas of the hospital ventilated by the contaminated heating, ventilation, and air-conditioning (HVAC) plant.

Ongoing problem

Despite the lessons that could – and should – have been learned from this tragedy over the past 30 or so years, new cases of Legionnaires’ disease are still occurring with alarming regularity. In early 2018, Royal United Hospitals Bath NHS Foundation Trust was  fined  £300,000 after failing to control the risk to patients from exposure to Legionella bacteria in its water systems. In 2015, Terence Brooks, a patient at Bath’s Royal United Hospital, died from Legionnaires’ disease from a contaminated water supply. The Health and Safety Executive (HSE) launched an investigation that found that the necessary precautions to minimise the risk to patients from exposure  to Legionella had not been put in place.

The HSE’s investigation revealed that the annexe where Terence Brooks was treated was on a separate loop of the hospital’s water system to that which supplied the main ward. This failure meant the required temperature checks and tests for the presence  of Legionella bacteria in the water had not been carried out in the annexe over this period. Bristol Crown Court heard that the hospital had been warned to update the plans of its water distribution system to reduce the risk of the disease, but had not done so.

Rules and regulations

As Legionella pneumophila bacteria are naturally distributed in aquatic environments, achieving  optimal  growth at temperatures of 25-42˚C, proliferation can be encouraged by water stagnation and sediment build-up in water systems, including fittings, pipework, and materials. It is therefore important to control and reduce the risk of Legionnaires’ disease and other  waterborne  pathogens occurring by introducing and continually adhering to appropriate measures.  There is some established and well-devised guidance and advice for water safety, efficiency, and management, and, coupled with the available guidance on water management systems, there is also a framework to provide safe and reliable solutions.

These documents include:

  • Health Technical Memorandum (HTM) 04-01: Safe water in healthcare premises.
  • Health Technical Memorandum (HTM) 07-04: Water management and water efficiency – best practice advice for the healthcare sector.
  • Health Technical Memorandum (HTM) 2005: Building management systems – Design considerations.
  • Health Building Note (HBN) 00-09: Infection control in the built environment.

HTM 04-01 is considered the primary reference point for every aspect of water systems in relation to their hygienic operation. It covers design  and installation, through to daily maintenance, and managing the  procedures  required to keep any water systems safe. The document is split into three parts, plus a supplement covering thermostatic mixing valves (TMVs):

  • Part A: design, installation, and commissioning.
  • Part B: operational management.
  • Part C: Pseudomonas aeruginosa – advice for augmented care units. Serious Pseudomonas infections usually occur in people in the hospital and /or with weakened immune systems, and infections of the blood, pneumonia, and infections following surgery can lead to severe illness and death. Part C focuses on specific additional measures that should be taken to control and minimise the risk of Pseudomonas aeruginosa in augmented care units.
  •  Supplement: performance specification

D 08 – TMVs in healthcare premises.

Help is at hand

Water systems in healthcare estates are notoriously complex. One way that a growing number of innovative healthcare estates are achieving better management and infection control is through the use of a building energy management system (BEMS), which can monitor and manage up to 84 per cent of a building’s energy- consuming devices. The good news is that the vast majority of health estates already have this type of technology installed, so taking control of an asset that is already in place makes sense. In addition, the ability to monitor and control many different inputs/outputs (I/O) into the main plant area of the water system can be achieved by utilising unused capacity already on site. A BEMS comprises four key components:

  • Controllers – These receive signals from field devices according to their programmed operational settings, and take action to control plant equipment.
  • Supervisors – Supervisors are user interfaces that view or amend the system data, as well as providing a wide range of energy analysis and maintenance functions.
  •  Network – A network allows devices to communicate across a physical distance either using a local or wide area network – LAN or WAN – or remotely, by using standard browser technology.
  • Field devices – Field devices, such as sensors  send or receive data directly to controllers for either local or remote control and monitoring.

 A real-time overview

These four elements combine to provide a real-time overview of plant  infrastructure. A BEMS also has the capacity to monitor and record field data,  and  can  analyse and react to the information to improve  the performance of the building. In a healthcare estate, it enables the provision of correct environmental conditions.

A properly specified, installed, and maintained BEMS will ensure that plant is operating correctly, and will provide an alert if attention is required. Furthermore, the key to maximising the effectiveness  of a BEMS is information – the more connected devices in a single building, multi-building site, or multi-location estate, the more information is gathered and can be acted upon.

Prevention is better than cure

Utilising a BEMS for the management and control of water supply systems entails a number of key considerations, and perhaps the most important concerns temperature. When configured to provide an automatic early warning system,  a BEMS can monitor, control,  and  inform the user about a range of conditions relating to the status of the water system, and alert designated personnel via email and text messages if quality  conditions fall outside pre-defined levels.

Domestic cold water (DCW) storage tanks should be monitored and alarmed to check that the water temperature stays below 24˚C, since with temperatures above this level Legionella bacteria can grow. Furthermore, domestic hot water (DHW) flow and return temperatures should be monitored, and, if they fall below 50˚C for a prolonged period, an alert can be sent and the problem resolved before there is any risk.

Monitoring individual tanks

In addition, compliance with HTM-04 means that water stored in DHW and DCW tanks must be ‘turned over’ every 12 hours to guarantee a fresh supply.

This process can be monitored and alarmed so that if an individual tank does not reach the correct turnover in 12 hours, an alert is issued. A BEMS can be configured to carry out this task automatically, using outputs connected to solenoid valves to ensure that sections of pipework are flushed for a pre- determined duration.

HTM 04-01 also specifies the requirement for purified water. Chlorine dioxide is added in tightly controlled amounts to the water, and levels are closely monitored to make sure they do not fall below 0.2 parts per million (ppm). Monitoring and alarming the areas where  water dosing equipment is located and where the process is carried out is also necessary, because if a high level of chlorine dioxide is present as a result of a spillage or leak, the resultant gas could prove harmful to the health and safety of operatives.

Drilling down

By monitoring systems  such as metering, tank level and temperature, backflow prevention valves, filters, and pumps, not only does a BEMS provide a clearer picture  of the system, but it also avoids costly wastage of water either through leakage or – if the tanks have gone over- temperature – through ‘dumping’. In the event that this does happen, in a well- managed system this water can be transferred into a ‘recovered’ tank for use in toilet flushing/laundry etc., rather than simply being ‘dumped’ to drain.

Identifying problems early can also minimise expense and hassle in the long- term. For example, in a complex flow and return system, if one room reports no hot water this is obviously not just an issue  at the point of use, but also indicates that stagnation points exist in the system. Traditionally, this would result in an engineer tracing the cause of a ‘cold spot’ by trying to balance the system. However, by using temperature and flow sensors linked to a BEMS in each room, as well as the sentinel points at the inlet to each wing/ building/facility on the flow and return ring main, the problem can quickly be identified. The system can then be balanced, ensuring that all rooms get hot water and, just as importantly, avoid stagnation in the system.

Sophisticated configurations

BEMS can also facilitate highly sophisticated configurations, and the addition of solenoid valves on the hot and cold inlets and mixed outlet can  allow the testing and shutdown of TMVs automatically, with control and reporting. Furthermore, through the adoption of ‘smart’ outlets such as infrared taps and mixers, and touch-free and electronically controlled devices for flushing and showering etc., the overall ‘connected’ result can be maximised. Apart from the time saved, there are other issues that are subsequently addressed, such as unnecessary time taken to fault-find, and disruption/access to patient rooms, consistency of result, automated logging of data, and reports and alarms generated before an infection control incident.

Seeing is believing

Through easy monitoring and management, a BEMS gives healthcare estate managers the ability to identify issues quickly and easily, and to optimise their systems. The more inputs into the system, the greater range of reports available, and the greater control offered by the available outputs. The status of connected devices into a common graphical, real-time user interface or wider monitoring system can help integrate systems together, monitor specific activities, and initiate any necessary changes.

‘Cutting edge’ systems are now available that integrate controllers, third-party smart devices, and internet protocols, into a centralised software platform that offers the ability to highlight and investigate plant status, as well as energy use, and a building’s comfort conditions. They enable a  diverse  range of useful functions – such as centralised data logging, archiving,  alarming, trending, master scheduling, system-wide database management, and integration with enterprise software applications.

The introduction of the General Data Protection Regulation (GDPR) requires any organisation that operates in the European Union (EU), or handles the personal data of people that reside in the EU, to implement a strong data protection policy, encompassing access, secure storage, and destruction. Therefore, in hospitals and healthcare estates, it is important to use systems with the highest possible level of security; state-of-the-art ‘head end’ systems have in-built authentication that requires users to choose strong Lightweight Directory Access Protocol passwords that are then encrypted. To further enhance security, a comprehensive audit trail of database changes, database storage and back-up, global time functions, calendars, central scheduling, and control and energy management routines, can be configured.

Make the connection

The three desired benchmarks of BEMS implementation are:

  • Compliance – Conformity to guidelines, standards, and organisational goals and objectives.
  • Sustainability – Placing emphasis on economic and environmental sustainability, and the efficient use of all resources.
  • Resiliency – Minimising instances and the impact of non-compliance, and managing risk, people, and undertakings.

When these elements work together they can provide a high quality environment that is safe, hygienic, and poses no unacceptable risk. A BEMS can help achieve this by ‘connecting’ the requirements of HTM 04-01, HTM 07-04, HTM 2005, and HBN 00-09, indeed by providing monitoring, warning, and control, over all of a healthcare estate’s functions, and ensuring optimum functionality.

Don’t simply ‘fit and forget’

Health and safety should be of paramount importance to all hospitals and healthcare estates, and, as well as having the appropriate Water Safety Group and Water Safety Plan in place as per HTM 04-01, the data produced by a BEMS will make a water supply infrastructure more resilient and drastically reduce  the  risk of Legionnaires’ disease. This shouldn’t be a ‘fit and forget’ process though – it is advisable to regularly reassess any objectives and key performance indicators to make sure that compliance is ‘joined up’ and not counter-intuitive, and  to  harness all the functions and systems that are in place to use information in the smartest ways possible.

Bob Blincowe

Bob Blincowe originally qualified as an aerospace engineer, and has been working in the healthcare sector for 18 years. A member of the Thermostatic Mixing Valve Association, he was involved in developing the TMV2 scheme ‘Hot water burns like fire’, the goal of which was to prevent scald injuries, and was also heavily involved in the original thermostatic mixing valve standards for the NHS, committed to raising water standards.

His more recent experience includes work in Legionella control, water management and usage, and water movement and hygiene issues, and he has represented his company at IHEEM, BMA, and WRc/WRAS meetings. He is currently strategic account manager – UK Healthcare, for Honeywell, and is involved in developing the company’s ‘Connected Healthcare’ portfolio, part of which utilises BEMS systems to control water management functions.


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