- Drinking Water 2024 – Summary of the Chief Inspector’s report for drinking water in England
- Foreword
- Water supplies and testing
- Compliance with water quality standards
- Water quality events
- Asset health and service reservoir integrity
- Consumer contacts
- Water safety planning and risk assessment
- Perfluoroalkyl and polyfluoroalkyl substances (PFAS)
- Audit programme completed by the Inspectorate
- Enforcement, transformation and recommendations
- Lead in water
- Materials in contact with drinking water (Regulation 31)
- Security and Emergencies (SEMD)
- Network Information systems (NIS)
- Research publications
- Raw water data
- Whistleblowers
- Working with stakeholders
- Annex A – Number of tests carried out by companies
- Annex B – Compliance with standards
- Annex C – Compliance failures and events
Working with stakeholders
The Inspectorate works with a wide range of external organisations, other regulators, government departments, professional bodies and academic institutions in the delivery of its strategic objectives
Figure 43 & table 44 – Current DWI stakeholders
Defra
The Inspectorate is a business unit in Defra’s Water and Flood Risk Management Directorate. As the independent regulator for drinking water quality, it is not directly responsible for development of policy, although the Chief Inspector has a statutory duty to report on quality matters to Ministers and advise the Secretary of State of any regulatory changes required. The Inspectorate actively engages with Defra on matters relating to water quality and sufficiency, resilience and water emergencies.
Engagement with Defra during the year also included the area of water resources ensuring that water quality concerns are considered fully in the determination of options to meet future demand, and various matters relating to sufficiency, demand management and water saving initiatives.
Ofwat and innovation
The Inspectorate has monthly liaison meetings with Ofwat to share information on company performance. It has worked together with Ofwat to develop common performance measures, to ensure the regulators are aligned. Common performance measures are in place for two water quality metrics: water quality contacts and compliance with regulatory standards. Companies receive penalty fines if their compliance risk index is worse than a set benchmark, based on industry performance.
The Inspectorate works with Ofwat to support innovation within the sector, whist ensuring consumers remain protected at all times.
RAPID
The Regulators’ Alliance for Progressing Infrastructure Development in Water (RAPID) was established to coordinate development and delivery of large-scale water resources infrastructure schemes, some of which will cross company boundaries, and improve resilience of supplies.
During 2024 the Inspectorate has continued to support RAPID to liaise with the Strategic Resource Options (SRO) sponsor companies, to ensure that all drinking water quality risks are being appropriately considered and appropriate mitigations identified as the schemes are being progressed. This has included assessing the first gate 3 submission for the Hampshire water transfer and water recycling SRO which was submitted in July 2024 with the draft decisions published in November 2024 and the final decisions published in February 2025.
The Inspectorate has also met with the SRO teams to discuss the progression of the development of the monitoring plans which feed into the strategic water quality risk assessments and drinking water safety plan development, as the schemes head towards their gate 3 submissions, and in the later part of 2024 worked closely with RAPID to help shape the PR24 RAPID scheme submission and assessment process.
Regulators Pioneer Fund – StreamLine project
The Drinking Water Inspectorate is one of three regulators along with Ofwat and the Environment Agency who have set up StreamLine to make it easier for innovators to obtain advice
The Environment agency
The Inspectorate has been engaging with the Environment Agency on drinking water protected areas, and it has a data sharing agreement where it sends the raw water data it received from companies to the Environment Agency for river basin management plans. The Inspectorate uses the environmental surveillance data to inform its regulatory policy, for example, to identify and inform water companies about which PFAS to include in their sampling and catchment risk assessments.
European regulators
The European Network of Drinking Water Regulators (ENDWARE) meets twice a year, hosted by rotating members, to discuss matters concerning drinking water quality. Topics include substances of emerging significance, and compliance with standards. Differing approaches to monitoring, analysis, and mitigation are shared for learning and awareness of best practice. Research findings may also be shared for awareness.
UK Health Security Agency
The Inspectorate liaises with the Health Security Agency as required, to address emerging issues and to seek advice on toxicology.
Fluoridation of supplies for dental health
Where water supplies are artificially fluoridated at the request of the Secretary of State for Health, the Inspectorate has worked with Office for Health Improvements and Disparities (OHID), through reviewing and commenting on fluoride results that fall outside the target range. The Inspectorate also supports OHID more widely on the technical and practical aspects of water fluoridation, including maintaining a code of practice for water companies, addressing Parliamentary Questions and enquiries from the public.
Drinking water safety – guidance to health and water professionals The Inspectorate has provided guidance for healthcare professionals in England and Wales on drinking water safety, which provides information on public and private supplies, the role of local authorities and the use of restrictions such as boil water notices, to protect public health.
The World Health Organisation
The Inspectorate has been redesignated as a World Health Organisation (WHO) Collaborating Centre for Drinking-water safety until 2026. (Ref UNK-232). This recognises the Inspectorate’s knowledge of implementing risk-based regulation in the field of drinking water supply, practically implementing the WHO water safety plan approach that was first promulgated as drinking water policy globally in 2004. An important function of our collaborating centre role is to provide support in the form of regulatory and technical knowledge through WHO organised workshops, training programmes, benchmarking projects, and research studies.
Consumer Council for Water
The Inspectorate shares and exchanges information with CCW on drinking water quality issues, with an emphasis on issues that directly affect consumers, through attending meetings and providing reports.
United Kingdom Accreditation Service
To maintain public confidence in drinking water sampling and analysis the Inspectorate collaborates with UKAS and other UK regulators (Drinking Water Quality Regulator for Scotland, and Department of Environment for Northern Ireland) to ensure that the sampling and analytical practices of water companies and the laboratories they use can be independently verified. In addition to meeting the requirements of ISO 17025, the Inspectorate and UKAS have published additional guidance for the water sector (Reference LAB 37), which makes specific requirements to ensure water companies meet their regulatory obligations.
Standing Committee of Analysts
The Standing Committee of Analysts comprises a series of working groups of experts in their fields, who provide guidance on methods of sampling and analysis for determining the quality of environmental matrices. Guidance is published as Blue Books within the series Methods for the Examination of Waters and Associated Materials. The guidance can be found on the SCA website: www.standingcommitteeofanalysts.co.uk.
The Inspectorate’s Chief Inspector is the current SCA strategic board chairman, which provides strategic direction for the organisation’s forward programme of work.
British Standards Institute
The Inspectorate assists and participates in the writing of British, European, and International standards that are associated to drinking water. This includes the analysis of drinking water, including quality control, drinking water products such as taps and thermostatic mixing valves, treatment chemicals and products, as well as general guidance standards such as temporary supplies.
Standardisation meetings may require attendance, but membership can be by email correspondence and comment. A committee meeting is generally held either annually or biannually.
Local authorities in England and Wales
The Inspectorate continues to support local authorities in their role as regulators of private water supplies by reviewing and updating guidance on implementing the Regulations where necessary, and producing topic focussed case studies and guidance as learning opportunities arise. The Inspectorate visited local authorities, to discuss challenges and developments in ways of working, and to see private supply types such as those used at temporary events. These visits help the Inspectorate to write its technical guidance, ensuring that guidance is practicable. The Inspectorate’s website has a dedicated area for private water supplies and the team maintain the guidance and resources made available to private water supply managers, users, and local authorities.
The Inspectorate is a member of the steering committee of the Water Health Partnership for Wales, and each year contributes to the Partnership’s annual conference by participating in exercises and delivering presentations.
The Chief Inspector produces two separate reports on private water supplies in England and Wales, to inform Ministers of their quality, and the impact of their regulation. The private water supplies team assess the data and information submitted by local authorities, including test results and risk assessment summaries to produce the statistics and disseminate messages and common learning.
Supply chain
The UK chaired the joint management committee of the four Member States group (4MS) with meetings in London, Berlin, and Lisbon. The 4MS is a voluntary group of countries including the UK, France, Germany, and the Netherlands, which works together on procedures for approval of materials and products in contact with drinking water with the intention of reducing the testing burden placed on industry by different approval schemes. The group has agreed to take forward a twin track approach, exploring opportunities for mutual recognition of existing approvals alongside the work already in hand on full harmonisation.
The Inspectorate has also responded to enquiries from and engaged with trade bodies, including the industry consortium for products in contact with drinking water. It has held two meetings with WRAS and Water UK on 4MS issues.
The Inspectorate also liaised informally with various supply chain members and representative bodies on drinking water supply matters.
Water Safe
The Inspectorate has a six-monthly liaison meeting with Water Safe and works collaboratively on campaigns. This year, it shared information on compliance breaches attributable to domestic plumbing, to enable Water Safe to promote safe practices and encourage the use of suitably trained plumbers.
Water quality standards advisory group
The function of the Drinking Water Inspectorate (the Inspectorate) is to protect public health and maintain public confidence in drinking water in England and Wales. The Inspectorate holds water companies to account to ensure they supply safe and clean drinking water, now and for future generations.
The Chief Inspector of Drinking Water has an advisory duty to the Secretary of State under Section 86(a)(ii) of the Water Industry Act 1991. In his letter to the Minister of July 2022, the Chief Inspector recommended a review of the list of the water quality regulations to address emerging risks and other contaminants. Over time, additional risks to drinking water quality have emerged due to the use of industrial chemicals and plastics, and the impact of climate change. Legacy issues, such as lead in older properties, remain.
Throughout 2024 the Inspectorate facilitated meetings of a group of experts convened by the Chief Inspector to review and advise on changes to the water quality regulations. The expert advisory group considered the scientific evidence, including toxicology and potential occurrence in drinking water supplies, of a defined list of 15 parameters, which included lead and per- and polyfluoroalkyl substances (PFAS). The review considered the addition, removal, tightening and relaxation of parameters to protect public health. International regulatory approaches were considered when evaluating the most appropriate options.
The full report and its recommendations and published on our website – https://dwi-production-files.s3.eu-west-2.amazonaws.com/wp-content/uploads/2025/02/28110805/Recommendations-and-full-report-of-the-advisory-group-Dec-2024.pdf
WIRED – Water Innovation – Regulators Exploring Data
The Inspectorate engaged with Ofwat and the EA in a joint project funded by the regulators pioneer fund to explore the use of data within the three organisations and how we could potentially share data between us in a safe and controlled manner to gain new insights into water company behaviour.
The basis for this was four design sprints and a one-day hackathon to investigate what may be possible should all three regulators decide to invest further into the ideas generated.