As utilities consult the public on water reuse plans, the UK just experienced its hottest summer on record, with drought permits issued in several catchments. The need for reuse is clear, says Barry Hopton, Xylem, who in this Q&A outlines the proven technologies available to water companies.
What role will water reuse play in UK investment plans?
For the first time, large-scale indirect potable reuse is included in water companies’ 2025–2030 programmes. While upcycling wastewater to augment resources is not new – it has been used worldwide for decades to tackle scarcity and reduce reliance on freshwater – its arrival at scale in the UK reflects a global shift. In 2025, the World Bank described reuse as being at a “tipping point”, moving from a marginal idea to a “strategic necessity”.
What do reuse processes involve?
Technically, water reuse is a straightforward process: wastewater is rigorously treated to meet water quality parameters for the intended use, whether potable or non-potable. Potable reuse comes in two forms – direct potable reuse (DPR) and indirect potable reuse (IPR).
IPR is by far the most common approach globally, particularly in North America, Asia, Australia and parts of Europe – and soon in the UK too. This process treats wastewater to a very high standard before discharging it into a water source such as a river or reservoir or injecting it into an aquifer.
It will ultimately be abstracted from the source for drinking water supply. The river or groundwater acts as an environmental buffer between the treated wastewater and the downstream drinking water plant.
Which countries in Europe have been most proactive in water reuse?
The major factor driving water reuse is water scarcity, therefore utilities in southern European countries like Spain are frontrunners. The region of Murcia is reusing over 90% of its treated wastewater for agricultural irrigation.
With the introduction of EU Regulation 2020/741, which sets minimum requirements for agricultural reuse, more countries are exploring water recycling. Even in Germany, generally considered a water-rich country, seasonal and regional water shortages have increased interest in water reuse. Potable reuse is less common in Europe, but there are a few successful IPR installations, for example, in Barcelona, Spain, and Torreele, Belgium.
Now, in the UK, several water companies are actively planning indirect water reuse projects, under the Regulators’ Alliance for Progressing Infrastructure Development (RAPID) programme.
What about cost?
Thanks to advances in treatment technologies, reuse is now both cost-effective and sustainable. The World Bank says the case is compelling, noting that reuse can often be cheaper than desalination or long-distance transfers.
Its 2025 report concludes: “When water is properly valued and full lifecycle costs for various supply alternatives are considered, reuse stands out as both an economically sound and environmentally sustainable solution.”
Can you give an overview of Xylem’s experience with international water reuse projects?
Xylem has a range of solutions for IPR, which have been successfully implemented around the world in utility and municipal applications.
These include biological, chemical and physical treatment, such as reverse osmosis, ultrafiltration, ozonation, ultra-violet (UV) disinfection and advanced oxidation processes (AOP). The technologies are effectively demonstrating that wastewater can be purified well beyond drinking water standards and reused safely and economically.
For full-scale operational projects in Europe, Xylem equipment has also been installed for agricultural reuse in several countries including Spain and France. Pilot units are also being used onsite in several German Federal Ministry of Education & Research (BMBF) funded projects for non-potable reuse in applications such as industrial and agriculture.
These pilots have not only proven Xylem’s technical capabilities but have also played a critical role in engaging communities and regulators. This approach aligns closely with the RAPID scheme for England and Wales, in accelerating development of large-scale, strategic water infrastructure, which is increasingly focused on demonstration projects to address trust and prove feasibility.
In the US, Xylem technologies have underpinned several flagship projects:
- Silicon Valley Advanced Water Purification Center in California uses Xylem’s Wedeco® UV systems as a final disinfection step before supplying high-tech industries
- In Los Angeles, Xylem’s Wedeco MiPRO photo AOP was installed at the Terminal Island facility to produce high-quality recycled water. This was the first full-scale UV-AOP installation using free chlorine as oxidant in the world
- San Diego’s North City Water Reclamation Center deployed Xylem’s Wedeco ozonation system and MiPRO photo AOP for potable reuse
What are the biggest technical or operational challenges in delivering reuse projects?
From a technical standpoint, water reuse is not inherently challenging. The processes are well established, with proven technologies that can achieve virtually any required water quality. The key is working with specialists to select the right technology for the specific context and ensuring the supply chain has the capability and capacity to support it at scale.
There are, however, challenges to consider when it comes to project delivery. Unlike other global leaders in reuse, the UK currently lacks a defined regulatory framework for indirect potable reuse. This creates a unique hurdle: how do we select and validate technologies without clear national standards to guide us?
In March 2025, Ofwat, the Environment Agency and the Drinking Water Inspectorate – through the RAPID initiative – said they would be “putting in place the right regulation to enable the safe and efficient application of reuse projects over the coming years”. Once established, this will be a key project enabler.
Delivery challenges may also stem from limited public understanding and acceptance of water reuse. To overcome this, it is crucial that water companies, suppliers and regulators work together to deliver clear, consistent communication and robust stakeholder engagement.
By building trust and addressing concerns transparently – through, for example, demonstration plants, they can secure public support and ensure the successful implementation of these vital projects.
