How can the drive to net zero and the NHS be compatible with safe water delivery?
This was the question posed to a panel of specialists at Armitage Shanks’s fourth Water Safety Forum (WSF) held in London in July to discuss what interventions and innovations might be needed and could be developed by industry in order to reach the targets laid out in NHS England’s “Delivering a ‘Net Zero’ National Health Service”.(1) As we have reported previously in Looking Deeper (see Issue 14, Autumn 2023), this 2022 document, which followed on from the 2020 launch of the pioneering ‘Greener NHS Programme’, has set out ambitious targets in response to the NHS’s remarkable CO2 burden – believed to be around 4% of the UK’s total emissions. These key aims are hugely challenging:
• To reach net zero by 2040 for all emissions directly controlled by the NHS (referred to as the NHS’s carbon footprint), with an ambition to reach an 80% reduction by 2028 to 2032.
• NHS Carbon Footprint Plus: to reach net zero by 2045 with regards to the emissions that the NHS can influence, with an ambition to reach an 80% reduction by 2036 to 2039.
In addition, the Health and Care Act of 2022 (2) has also updated the NHS constitution to place new duties on all NHS England Trusts, Foundation Trusts and Integrated Care Boards: to take action on statutory emissions and environmental targets by building resilience and adaptation into NHS processes. In order to deliver net zero decarbonisation, key opportunities – and challenges –for NHS decarbonisation would include the supply chain for pharmaceuticals and medical devices, travel, and estates and facilities, with the hospital environment providing scope for some of the greatest reductions.
The constant consumption of huge volumes of water also represents an enormous challenge to the overall sustainability of the NHS. While not strictly within the remit of the NHS’s drive to net zero, this issue has been poorly defined as the associated energy use has not been adequately identified from source to tap. In 21/22 alone, the NHS is believed, according to ERIC (NHS England Digital: Estates Returns Information Collection), to have consumed 14,000,000 litres, while water and waste and building energy contribute around 15% towards the total carbon footprint across both the secondary and primary care estates.
So How To Decarbonise?
The WSF panel were presented with a series of questions to consider – stimulating a lively, far-reaching discussion and leading to interesting and constructive interactions between participants. To ensure we report back the key points, this article highlights part of the discussion initiated by several of these questions; the remainder of the panel’s thoughts will be reported in the next issue of Looking Deeper in Spring 2025.
An Absence Of Data
A major point immediately highlighted by the group was the ERIC estimation of NHS water usage: since this figure appears to be based only on hot water usage per in-patient bed, this was considered likely to be a huge under-estimate, perhaps nearer to 1,000,000,000 litres per year if based on the NHS 2021/22 £260 million water and sewage bills.
Prevention of water stagnation is a crucial element of infection control to prevent the build-up of waterborne pathogens in water systems, making it probable that two thirds of actual cold water usage might be described as ‘wastage’ from flushing. But what is meant by ‘wastage’?
This was debated at length: water is needed to flush, but how much flushing is needed? Taps that are used regularly don’t need flushing, but those not often used do need extra water movement.
This certain under-estimate of NHS water usage led the group to an emphatic discussion on the yawning absence of data– both of water usage and CO2emissions from energy consumption. This is a serious consideration: Trusts use different methodologies to log data – that is if they can keep track of which outlets are flushed and how often. Without reliable data how can estates and clinical teams work out where and how to make savings? Without usage data how would it be possible to compute how much of this might be wastage?
For example, if good flushing data were available it would be possible to remove some time from flushing protocols, saving both on cleaners’ time and water usage.
Panel member Professor Elaine Cloutman-Green of Great Ormond Street Hospital discusses the difficulties of capturing data, ideally in real time, in some detail in an interview, in the subsequent blog feature. In particular she emphasises the need for innovative smart tap technology that would identify tap usage, with a “technologically-enabled flush” for under-used outlets.
In this context, Steve Vaughan, Technical Director for AECOM, described a project to identify the effectiveness of using remote sensors to map water movement and temperature in line with guidance across a large healthcare water system. This revealed:“Flushing is the most expensive and labour intensive process that there is... looking at the locations that the Trust actually had to flush, there were hours and hours and hours of work just on flushing...So reducing that[need for flushing] not only reduces the carbon element, but as long as appropriate flushing is [carried out].. we can still maintain safety while reducing labour costs.”
Authorising Engineer Stephen Van De Peer concluded: “Ultimately, I think we can reduce tap flushing, but...we do not have the data at this point to be able to actually influence flushing. And once we know what is wasted and what isn't wasted, then we can actually target that.”
Going Waterless
Independent consultant on the healthcare built environment, Alyson Prince, raised an issue much under discussion by the water hygiene industry: reducing numbers of water safety outlets, particularly in areas with the most vulnerable patients, such as augmented care units – in order to reduce the risks from water and also to save on water usage and energy to heat that water. She noted:
“Everybody's trying to take things out of the clinical environment – and that is a knee jerk reaction to how to manage and maintain water safety... because then we don't have to think about it.”
In this context, Stephen Van De Peer and Prof Cloutman-Green both emphasised the importance of understanding how people actually use hand wash basins. More recognition would lead to design of facilities and fewer potentially stagnant little-used outlets.
Alyson Prince emphasised the importance of mapping risk department by department. However: “The problem is that decisions get made for buildings before people come into that space and actually use the building...There's a disconnect between those two in terms of there being nobody at the front end of the design thinking about how the clinical team [in a particular] area will use the outlets in that area.”
Could It Be Viable To Dispense With Hot Water Storage Facilities?
While flushing is a key infection control measure, hot water is the fundamental mainstay in meeting the major challenge of water safety in healthcare – with heating needed to temperatures of 60°C or higher to kill bacteria such as Legionella. To date water is often heated by energy-hungry gas fired boilers and then stored in large calorifiers. But is all this hot water essential? Is this an area where energy use – and therefore CO2 emissions – could be reduced? What options might there be to reduce hot water usage?
Alison Prince highlighted how difficult it can be to balance a huge system and get the correct pressures through a whole large building:
“That process of balancing [can] end up stagnating some of it, or reducing or increasing the temperature range. And that's when you get biofilm growth. So people are focused on flushing...[but could we] actually go back and think about why we are filling and trying to maintain two 250,000 litre tanks?”
Richard Wainwright, Programme Manager for CBRE and a senior Authorised Person for water, also highlighted: “If you've got a system where you've got two calorifiers in parallel and one of them can support the building, by definition your system is 50% over size or 100% over size.
”The panel considered that it could be possible to dispense with major hot water storage in calorifiers to reduce energy use for heating – in certain situations. Options could include smaller localised water circuits with their own heating loops, point-of-use water heaters and air source heat pumps.
However, they noted that these solutions would be difficult to introduce into existing hospitals – but could certainly be considered in new wings and new buildings within existing Trusts. They emphasised the importance of expert design for completely new healthcare facilities – although with a new Government, at the time of going to press, there is now uncertainty over the development of those that may have been in the pipeline through the previous New Hospitals Programme.
There was also concern about resilience if large scale storage capacity is removed since HTM 04-01 guidance states a requirement for a nominal capacity for 12 hours storage of water on site.
Would Smaller Localised Water Circuits With Localised Heating Loops Be More Cost Effective?
Richard Wainwright highlighted that small localised heating loops or satellite systems with small hub sets would require less monitoring, which would reduce some facilities management costs.
Moving away from huge centralised hot water systems would be entirely viable according to Steven Van De Peer and could be achieved by fitting individual wards with plate heat exchangers. He described how this could work with smaller hot water loops per ward or [for] two wards that are off plate heat exchangers:
“Rather than having centralised hot water storage and loads of little tertiary loops that all have to be balanced... I'm much more in favour of having smaller satellite loops around areas that, even with linear drops that don't have returns on them for the hot water system that can be just fed by cold water, which gives great usage across the cold, to all the different areas.”
Greg Markham, Estates and Assets Director at Serco Health, noted that the small size of some plate heat exchangers provides scope for fitting them into ceiling voids.
A small primary storage and distribution system or network could work from these hubs and reach each individual area, eliminating the need for tertiary loops. This would come back to design, perhaps designed with the plant room external from the ward, but feeding the ward.
The group agreed that it would these smaller decentralised systems would certainly be an option for new facilities and refurbishments, but would be too disruptive to fit into an existing working hospital.
However, Peter Orendecki, Senior Contract Manager for Water at University Hospital Southampton, still felt that such a system might have the potential work in an existing hospital: “as long as you can put your primary supply to what's going to feed [the] heat exchanger and ...if there is a [suitable] connection into the existing pipework.”
Is The Use Of Instant Hot Water Heaters At Point Of Use Practical And Viable?
The panel considered that instant hot water heaters would be practical and viable in certain locations, with induction heating of a single cold water pipe to the temperature required by the guidelines. The actual capacity that could be supplied would need to be measured against a hospital’s existing hot water system capacity.
However, they had certain provisos:
• Dead legs, which could cause stagnation and biofilm build-up when not in use
• Potential compatibility issues with thermostatic mixing valves. Richard Wainwright noted: “They will needed to be adjusted for healthcare usage so that they can't heat water above a TMV-suitable temperature”
• Will they heat fast enough to reach the required water temperatures?
• Failure of the life cycle of the equipment
• A localised circuit may not have enough capacity to deal with a surge of hot water usage.
Steven Van De Peer also highlighted: “We have to stick to the HTMs and HBNs... [but] we now have a requirement ...to go back to the design concept, .... to formally derogate to NHS England every time we're moving away from guidance...[so] it's almost ludicrous then at this point that we're having to formally derogate away from guidance that is out of date in the first place.”
No One Size Fits All
The discussion also focused on digital innovation and other technical fixes that might facilitate the removal of stored hot water or reducing heating to lower temperatures. These will be explored in Part 2 of our Water Safety Forum coverage, and will look at: air source heat pumps, copper/silver ionisation, other biocides, heat pumps and solar.
Overall, the panel were clear that there won’t be any one solution that fits all healthcare environments. Every different patient population will have different needs and different risks, and what the risk assessment might want to address in one unit could be very different in another.
They also highlighted the contradiction that sometimes systems can become complicated in reaching for decarbonisation goals, and therefore the importance of looking back to the HTM guidance – that instructs on avoidance of over-complication of systems.
Whatever solutions might be adopted to reduce water heating, there was a consensus mantra the group came up with:
Keep it clean, keep it cold, keep it moving, and heat only where needed.
References:
[1]NHS England: “Delivering a ‘Net Zero’ National Health Service”, 2022.
[2]Health and Care Act, 2022: www.legislation.gov.uk/ukpga/2022/31/contents
The July 2024 fourth Water Safety Forum took place at Ideal Standard’s London Design and Specification Centre as part of Armitage Shanks’ ‘Thought Leadership’ programme — which aims to facilitate conversations between users and industry on areas of concern to together develop ideas for the marketplace.