Key facts
- The UK's largest water reuse system, installed at Cambridge University's Eddington development, has been non-operational since 2021.
- The system is prevented from operating by the Drinking Water Inspectorate (DWI) due to current UK drinking water regulations.
- Residents could save approximately 25 litres of water per person per day by using recycled water for non-drinking purposes.
- Water companies are implementing hosepipe bans in the region due to critically low reservoir levels.
- Experts and water industry bodies are calling for urgent changes to legislation to permit large-scale water recycling systems.
The UK's largest water reuse system, located at the Eddington urban quarter in Cambridgeshire, has been non-operational since its completion in 2021 due to regulatory hurdles. The system, designed to recycle rainwater and grey water for non-drinking purposes like toilet flushing, could save thousands of residents approximately 25 litres of water per person daily. However, the Drinking Water Inspectorate (DWI) has deemed it non-compliant with the 1991 Water Act and the 2016 Water Supply (Water Quality) Regulations, which mandate that all water for domestic use must meet drinking water standards.
This situation arises as water supplies in England reach critical levels, with Cambridge Water and Anglian Water imposing hosepipe bans. Experts warn that such regulatory blockages are hindering the large-scale implementation of water recycling schemes necessary to meet projected water demand gaps by 2055. Despite awareness from ministers in both current and previous governments, legislative changes have not yet occurred.
Lutz Johnen, chair of the UK Water Reuse Association, emphasized the urgency, stating that rainwater harvesting and grey water recycling are proven technologies widely used internationally. He noted that the UK lags behind countries like Belgium and Germany, where similar systems have operated for over two decades, contributing to lower per capita water consumption.
The University of Cambridge, which developed Eddington, confirmed that the system's commissioning revealed a regulatory gap requiring a law change. They are engaging with the DWI and Defra, welcoming a ministerial commitment to review regulations, with the upcoming water bill seen as a potential opportunity for improvement.
Cambridge Water is actively working with Defra to identify solutions to the legislative constraints, expressing eagerness to unlock the demand savings at Eddington, especially given the water stress in the Cambridge area. The Environment Agency has projected a significant water demand gap in England by 2055 if urgent action is not taken.
In response to ministerial direction, the DWI established a framework for rainwater harvesting and grey water reuse in March, acknowledging the need for such systems to address water shortages. Their report recommended legal changes to allow dual-use water systems. A DWI spokesperson reiterated that while reuse is beneficial, it must be safe and comply with the Water Industry Act 1991, ensuring all water for domestic purposes is wholesome. Defra also confirmed its commitment to reviewing regulations with the DWI to facilitate rainwater recycling and grey water reuse.