Desalination and recycling: Lessons for the UK’s water future 

The UK has long relied on rainfall and groundwater, but these sources are showing signs of strain under the twin pressures of a changing climate and rising demand. As a result, the sector is rethinking its reliance on traditional supplies and considering more integrated strategies that include strategic resource options (SROs) such as new reservoirs and major transfer schemes. This will enable water to be shared across water company boundaries, demand-side efficiency, desalination and water recycling.

The UK Government’s National Framework for Water Resources 2025: water for growth, nature and a resilient future sets out five regional water resource groups for England and Wales:

• Water Resources West

• Water Resources North

• Water Resources East

• West Country Water & Environment

• Water Resources Southeast

The government estimates that an additional supply of five billion litres of water per day will be needed by 2050. Each region has been working on integrated plans that include the key concept of “environmental destination”, aiming to deliver more water into the environment. This integrated planning approach is essential for a sustainable and efficient water supply system that supports a healthy environment, society and economy.

Desalination is being recognised as a strategic option for the Southeast, where water stress is intensifying. While it may not replace established sources, desalination can act as a safety net during droughts or emergencies. However, its effectiveness depends on planned integration into regional supply networks, investment in future-proof assets and the careful siting of infrastructure to minimise carbon and environmental impacts. A key consideration for any desalination plant will be the operating regime and plant asset management, to manage the long-term operational life of the plant.

Water recycling is another vital part of the puzzle. Indirect potable recycling — where treated wastewater is returned to the environment before being abstracted for drinking water — has been adopted successfully in places like the United States, and pilot schemes are gradually appearing in the UK.

GHD has supported several feasibility and pilot studies for water recycling projects, including advisory work on indirect potable recycling schemes for water companies in southern England. These projects demonstrate how integrating new supply options with reduced water demand can help create a more resilient, circular economy for water, echoing the “reduce, reuse, recycle” ethos already familiar in the waste sector.

The UK Government policy paper “Water recycling for public water supply: Environment Agency position statement” published on 8 October 2025 provides the latest government position on water recycling as a public water supply option in England.  It explains why water recycling is needed, along with some of its benefits.

In accordance with the national framework, the regional water resource groups will support the connected set of plans and the regulatory framework needed to deliver a sustainable water supply system. The plans include the delivery of nine new reservoirs, strategic transfers as well as desalination and water recycling schemes, all of which come with significant regulatory and environmental challenges.

To fully realise the benefits of desalination and recycling in the UK, a range of technical and regulatory challenges needs to be addressed. One notable barrier is the lack of a Drinking Water Inspectorate (DWI)–approved reverse osmosis (RO) membrane suitable for use under Regulation 31 (materials in contact with drinking water). Achieving approval is a costly and time-intensive process, putting the UK a step behind regions where such technologies are already standard.

Environmental considerations are also critical. The European Chemicals Agency’s plans to ban the production of per- and polyfluoroalkyl substances (PFAS), including polyvinylidene fluoride (PVDF) — a key component in many desalination membranes used in desalination and recycling treatment plant — may reshape the technology supply chain. Finding alternatives will be essential as these regulatory shifts take effect, potentially influencing procurement and supply choices for UK utilities.

Other environmental challenges include the waste streams from desalination and recycling processes. Leading edge technologies will be needed to minimise sludge generated from any chemical pretreatment and to concentrate brine generated from RO membranes.

GHD’s project teams have navigated similar regulatory landscapes in Australia and Singapore, working closely with clients and regulators to secure approvals and demonstrate compliance. For example, in Australia, early and close engagement with regulatory authorities has enabled the successful delivery of innovative desalination and recycling plants, often by embedding environmental outcomes at the heart of project design.

In the UK, meeting ever-tightening environmental requirements — from lowering energy usage to limiting brine discharge — will be essential to delivering desalination and recycling solutions that support sustainable water resilience.

Technical solutions alone won’t enable water resilience if public concerns and stakeholder interests are overlooked. Building trust is critical to bringing desalination and water recycling projects to fruition, especially given the UK’s cautious stance towards direct potable recycling because of perceived water quality risks.

Early and transparent engagement with communities, regulators and key stakeholders is vital. This means making the technical case — demonstrating how new technologies meet or exceed stringent drinking water standards — but also listening to, and addressing, local concerns about environmental impact, quality and value. The DWI 2022 Report.

In supporting the delivery of some of Australia’s large-scale desalination facilities, we’ve helped lead community discussions, develop public education campaigns and establish ongoing feedback mechanisms. These efforts helped demystify desalination and recycling, foster trust and ultimately secure buy-in.

In the UK context, similar approaches will be needed. Clear communication, consistent updates and genuine opportunities for public input are all essential to building confidence in new solutions. As public perceptions shift, there will be a greater appetite for innovation — and for embracing the integrated approaches required for water resilience.

Moving the debate forward

While desalination and reuse will not replace traditional sources, they are becoming more critical as climate pressures mount. International lessons from Australia, Singapore and the United States underscore the importance of planning, regulation, innovation and engagement in driving successful outcomes.

For the UK’s water sector, the way forward is clear:

• Recognise desalination and recycling as integral elements of strategic water resource planning.
• Overcome regulatory barriers, particularly around approved desalination membranes.
• Invest in transparent communication and engagement to build public confidence.
• Adopt integrated approaches that pair new water sources with robust demand reduction and circular economy principles.

Ultimately, the debate is about technology, leadership and collaboration. The UK must act swiftly to adapt these lessons, making sure that resilient, sustainable water management becomes the norm for the future.