This opinion piece first appeared in The Water Report in August 2026.
By 2050, UK water companies will find themselves treating source waters affected by emerging contaminants, changing land use, climate pressures and growing demand for potable water. The industry’s response will include contributions from alternative water sources in certain circumstances, together with a broader acceptance that drinking water treatment must continuously adapt to an uncertain future.
The need for change
The central challenge is not that UK drinking water is currently of poor quality. In fact, regulatory compliance remains extremely high in comparison with other countries. Instead, the problem is that drinking water quality must be maintained and improved while raw-water quality deteriorates, assets age, carbon budgets tighten and supply–demand deficits widen. And all this must be achieved against the backdrop of low public confidence in the water industry.
Today, the combined population of the UK is 70 million people. By 2050 this is expected to rise to 72.5 million, with much of this growth coming from south-east England. This is already the most water-stressed area of the country, meaning it will face the most acute challenges in providing sufficient potable water for a growing population. Over the same time period, projections indicate we will see hotter, drier summers and warmer, wetter winters. During summer, we are likely to see heatwaves exceeding 40°C, droughts and superstorms.
So what will UK drinking water treatment look like in 2050? While no one can fully predict the future, it is informative, and fun, to attempt to answer this question! No single solution will cover the whole breadth of challenges across the UK. By 2050, the water industry will be designing, building and operating low-carbon and high-assurance drinking water treatment plants that effectively treat diverse and challenging source waters. Digital technologies will help make water treatment more efficient, such as through AI-assisted automated process control and predictive maintenance. The journey to 2050 is also predicted to involve the following.
Innovative treatment methods
By 2050, treatment plants may look very different from those operating today. Rather than relying on a small number of conventional processes, notably coagulation–flocculation–sedimentation followed by granular filtration and chlorination, utilities are likely to adopt multiple treatment barriers capable of treating variable and challenging source waters.
The Mayflower Water Treatment Works, which entered service in 2020 and supplies water to ~250,000 people across Plymouth, is an example. It is based on suspended ion exchange – inline coagulation – ceramic microfiltration – granular activated carbon – ultraviolet disinfection and chlorination.
The benefits of ceramic microfiltration and ultrafiltration membranes, typically as replacements for media filtration, are becoming increasingly clear in such situations. These can include the capability to treat variable quality raw waters, durability, low irreversible fouling and lower whole life costs compared with established polymeric membranes. Conversely, they do have higher capital costs than polymeric membranes. The application of ceramic membranes is already widespread in Scotland, especially at small, remote treatment plants, such as on Shetland, and for treating peaty upland waters. Earlier this year, Scottish Water awarded an £800 million framework contract for the design, construction, commissioning and handover of ceramic membrane water treatment plants throughout Scotland up to 2033.
Looking forward to 2050, there is keen interest in seeing whether current pilot trials involving ceramic nanofiltration membranes are successfully translated into full-scale operation. If they are, then there are many potential applications within drinking water treatment, such as for removal of PFAS and other micropollutants and controlling disinfection byproducts.
Alternative treatment options for PFAS include activated carbon adsorption and ion exchange resins. However, in a world where money is finite and has many competing demands upon it, the cost of upgrading treatment plants needs strong justification – and typically, regulatory support.
Conventional granular activated carbon is currently the benchmark for PFAS removal in drinking water treatment. It is effective for removing longer-chain PFAS, those with over six carbons, and evidence suggests that thermal reactivation at high temperatures, a standard part of operation, destroys PFAS compounds. Work continues to develop surface-modified activated carbons, which provide improved removal of short-chain PFAS.
Ion exchange resins and tight membranes (nanofiltration or reverse osmosis) can offer superior performance for PFAS removal, especially the problematic short-chain compounds, but both generate waste streams in which removed PFAS accumulate, leading to the common question of how to efficiently remove or destroy PFAS to avoid its release back into the environment. Combining a step to concentrate PFAS in waste streams, typically foam fractionation, with chemical degradation, such as an electrochemical process, hydrothermal alkaline treatment (HALT) or supercritical water oxidation (SCWO), has shown promise in research studies, though this is still some way off being deployed in full-scale water treatment.
Decentralised treatment
Today, someone designing a water treatment and supply system from scratch may favour a decentralised model, where water is sourced, treated and reused on a local level. Rather than installing and maintaining long distances of underground pipelines, decentralised water treatment has the advantage of being more sustainable, in terms of lower initial investment, facilitating water reuse and conservation and reducing pumping costs. Disadvantages include a higher operational and maintenance burden (and who is responsible for this?) plus developing a suitable regulatory framework.
Many existing examples come from low-income countries or remote regions and involve renewable energy, nature-based treatment, membrane filtration and remote monitoring. In a UK context, while there is little indication we are moving away from our existing centralised model, it is easier to foresee a role for mobile treatment units, to provide drinking water during emergency outages of public water supply, for instance, and to target pollution hotspots, such as nitrate-contaminated groundwater or point sources of PFAS, e.g., brownfield sites and airfields. Integrating decentralised treatment units with existing water/wastewater networks will widen potential applications.
Dr Tom Bond is a Principal Consultant on Water Treatment at the Water Research Centre (WRc), an RSK Group business based in Swindon, England, but operating globally. He is a chartered civil engineer who previously worked in academia, where he researched and taught water treatment for many years.
Laura Aspinall is Head of Treatment Sales for Clean Water Utilities, Industry and Aquatics at Xylem Water Solutions UK & Ireland. She works closely with utilities and industrial customers to develop treatment solutions that support water quality, resilience and long-term sustainability.