Drinking Water Inspectorate: South East Water, Tunbridge Wells investigation conclusion – November 2025
The Drinking Water Inspectorate (the Inspectorate) has concluded its investigation into the loss of supply and boil water notice affecting up to 60,170 consumers in the Tunbridge Wells area in November/December 2025.
Our assessment concludes that the loss of supply and subsequent boil water notice were foreseeable and preventable. The event arose not from exceptional raw water conditions but from longstanding weaknesses in operational management, treatment optimisation, monitoring, maintenance and organisational preparedness at Pembury water treatment works. Taken together, the findings point to systemic and repeated failings across both operational control and emergency management arrangements, resulting in serious consumer impact.
Following a detailed assessment of South East Water’s overall performance, of which this investigation forms part, the Inspectorate has placed the company into a transformation programme. A transformation programme is one of the most significant steps the Inspectorate can take. It is used when a water company has shown a pattern of serious or repeated failures that cannot be addressed through individual enforcement actions alone. Under a transformation programme, the Inspectorate works with the company to identify the root causes of poor performance and formalise these programmes into legal instruments, to deliver the changes needed to ensure consumers receive the reliable water supply they are entitled to expect.
The Inspectorate continues to investigate subsequent loss of supply events affecting South East Water customers. Ofwat is also conducting its own parallel investigation under its own powers to consider whether the company has complied with its obligation to provide high standards of customer service and support for its customers.
The Inspectorate remains committed to ensuring that consumers in the Tunbridge Wells area, and across England and Wales, receive safe and reliable drinking water. England and Wales has some of the highest drinking water quality standards in the world, and where companies fall short of those standards, we will act.
