Table of contents

• 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

Water supplies and testing

This report sets out key facts about the quality of public water supplies in Wales. These supplies are provided by two water companies and one inset appointee, supplying more than 3.3 million consumers. An inset appointee is a supplier that replaces the incumbent monopoly provider for a defined site within that provider’s area. The area served by each water company is shown in figure 2.

Figure 2 – Company boundary map of Wales

Public water supplies	Key facts
Population supplied	3,313,500
Water supplied (L/day)	926,342,000
Treatment works	69
Service reservoirs	384
Water supply zones	103
Length of mains pipe (km)	30,616
Surface sources	257
Groundwater sources	42
Mixed water sources	1

Table 1 – Public supply key facts – data provided by water companies

Private water supplies	Key facts
Population supplied	104,431
Water supplied (L/day)	108,582
Number of supplies	14,902
Number of local authorities with private supplies	22
Supplies without a risk assessment	11,756

Table 2 – Private supply key facts – data provided by local authorities

*An inset appointee or New appointment or variation (NAV) is defined by Ofwat as – https://www.ofwat.gov.uk/regulated-companies/markets/nav-market/