- Drinking Water 2025 – Summary of the Chief Inspector’s report for drinking water in Wales
- Foreword
- Introduction
- Water supplies and testing
- Compliance with standards
- Learning from compliance failures
- Learning from events
- Consumer contacts
- Asset health
- Water safety planning and risk assessment
- Poly and perfluoroalkyl substances (PFAS)
- Audit programme
- Recommendations
- Enforcement
- Security and Emergency Measures Direction - SEMD
- Network and Information Systems - NIS
- Materials in contact with drinking water (Regulation 31)
- Research publications
- Whistleblowers
- Working with stakeholders
Foreword
The provision of clean drinking water is fundamental to public health, wellbeing and economic prosperity, and access to clean water is recognised by the United Nations as a basic human right. Advances in water safety planning and systems management, underpinned by robust water quality regulation, continue to support some of the best drinking water in the world. Drinking water quality in Wales remains excellent, with public supplies consistently meeting the stringent regulatory standards for drinking water. Compliance with the standards in 2025 was 99.97%, providing strong assurance that consumers continue to receive wholesome water.
Drinking water supplies in Wales are protected through water safety planning, which provides a robust multi-barrier approach to preventing risks from materialising. Through this process, risks are identified from source to tap and appropriate mitigation is put in place before there is any deterioration in quality or sufficiency, or impact on consumers. The quality of supplies is further verified through extensive random sampling. Where things go wrong, the Inspectorate investigates, assesses compliance failures and events, and takes enforcement action where necessary to prevent recurrence. In 2025, regulatory activity highlighted the continuing importance of accurate risk assessments, representative monitoring, timely investigation and effective delivery of legal instruments.
The sector continues to face significant challenges. This report highlights the need for companies to improve asset health and resilience, with particular focus on air valves, distribution mains, treated water tanks and service reservoirs. Compliance risk in Wales remained elevated in 2025, driven by microbiological detections, turbidity and a continuing high number of iron-related failures. Events also demonstrated the importance of resilient alternative supply arrangements, effective tanker sampling, accurate asset records, reliable monitoring, and clear communication with consumers during incidents.
The report also shows that long-term improvement depends on companies moving from reactive operational responses to preventative, evidence-led management of risk. This includes stronger control of discolouration, improved management of lead and PFAS risks, more robust disinfection and treatment assurance, better understanding of asset condition, and sustained progress through transformation and enforcement programmes. Following the independent review of the water system in England and Wales, the Inspectorate is working with fellow regulators to realign the regulatory regime so that it better addresses climate change, population growth, new and emerging risks, national security and long-term resilience. This work will help lay the foundations for safe, secure and high-quality drinking water now and for future generations, balancing the needs of consumers while protecting the environment and public health.
Dr Marcus Rink OBE
Chief Inspector of Drinking Water