- Drinking Water 2025 – Summary of the Chief Inspector’s report for drinking water in England
- Foreword
- Water supplies and testing
- Compliance with water quality standards
- Learning from microbiological failures
- Learning from turbidity failures
- Learning from chemical, taste and odour failures
- Learning from pesticide failures
- Asset health and service reservoir integrity
- Consumer contacts
- Drinking water quality events
- Water safety planning and risk assessment
- Perfluoroalkyl and polyfluoroalkyl substances (PFAS)
- Audit programme completed by the Inspectorate
- Air valve audits
- Enforcement, transformation and recommendations
- Materials in contact with drinking water (regulation 31)
- Security and Emergency Measures Direction - SEMD
- Network and Information Systems - NIS
- Research publications
- Whistleblowers
- Working with stakeholders
- Annex A – Number of tests carried out by companies
- Annex B – Compliance with standards
- Annex C – Compliance failures and events
Consumer contacts
Consumer contacts provide an important measure of the acceptability of drinking water and of consumer confidence in the public supply. Acceptability can be affected by appearance, taste or odour, including discolouration, aeration, particles, chlorine, earthy or musty tastes, or other changes noticed by consumers.
Most appearance-related contacts are associated with black, brown or orange discolouration, commonly linked to the mobilisation of iron, manganese or aluminium deposits within the distribution system. These metals are rarely present at concentrations that pose a direct risk to health, but they can cause consumers to reject the supply. The Inspectorate therefore treats discolouration and other acceptability issues seriously, particularly where contacts are repeated, widespread or associated with operational events. Several companies have legal instruments in place to address the root causes of discolouration and improve the acceptability of supplies.
In February 2024, the Inspectorate issued Information Letter 01/2024, Annual Provision of Information on Consumer Contacts. This introduced more detailed reporting requirements so that contact data could be used more effectively to assess performance, identify repeat issues and link consumer experience to notifiable events.
- A unique reference for each contact
- Details of the district metered area the contact is located in
- The date and time of the contact
- The location of the contact
- The mode of contact
- Whether the contact is a repeat within a 12-month rolling period (that is a new occurrence or ‘case’ of a similar issue from the same consumer)
- If the contact is associated with a notifiable event, and the associated event reference number
The revised return requires companies to provide a unique reference for each contact, the district metered area, date and time, location, mode of contact, whether the contact is a repeat within a rolling 12-month period, whether it is associated with a notifiable event, and the relevant event reference where applicable. Companies must also record where a single consumer contact raises more than one drinking water quality concern.
The data submitted in 2025, covering contacts received in 2024, was the first return to include the additional fields. To maintain continuity with previous reporting and allow long-term performance trends to be monitored, companies continue to identify primary and secondary descriptors where multiple concerns are reported. Primary contacts are used to assess ongoing industry performance.
In England in 2025, companies wholly or mainly operating in England reported 57,759 consumer contacts relating to the appearance, taste or odour of drinking water. This equates to 0.97 contacts per 1,000 population. The table below shows the number of contacts by category. Brown, black and orange discolouration remained the most common reason for contact.
| Category | Consumer contacts | England contact rate | Industry contact rate |
|---|---|---|---|
| Appearance – Brown black orange | 24,810 | ||
| Taste Odour Other | 7,716 | ||
| DWQ Concern – Lead and analysis | 7,714 | ||
| Appearance – White Air | 7,474 | ||
| Taste Odour Chlorine | 5,618 | ||
| Appearance – Particles | 4,123 | ||
| Appearance – General Conditions | 4,088 | ||
| Illness – Gastroenteritis | 3,606 | ||
| Taste Odour – Earthy Musty | 1,888 | ||
| Illness – Skin | 1,469 | ||
| Appearance – Blue Green | 995 | ||
| DWQ Concern – Incident Related | 680 | ||
| Appearance – White Chalk | 497 | ||
| DWQ Concern – Lifestyle | 416 | ||
| Taste Odour Petrol Diesel | 402 | ||
| Illness – Oral | 280 | ||
| DWQ Concern – Campaign | 278 | ||
| Illness – Medical Opinion | 264 | ||
| Appearance – Animalcules | 148 | ||
| DWQ Concern – Pets Animals | 104 |
Discoloured water
Discoloured water is most commonly caused by the mobilisation of deposits within distribution mains following changes in flow, pressure or direction. These changes may occur during planned operations, valve movements, mains repairs, bursts, high demand, shutdowns, restarts or other network disturbances. Companies are expected to understand where deposits may accumulate, manage operational changes carefully and take timely action to minimise consumer impact. In 2025, around 63 events were reported in England where brown, black or orange discolouration was experienced by more than one consumer at the same time.
The Inspectorate reviews consumer contact data for discoloured water each year. Companies performing worse than the industry average, or showing deterioration over time, are subject to further scrutiny and enforcement action where necessary. Legal instruments are in place for companies where discolouration risk requires sustained improvement:
Northumbrian Water
Figure 9 – Company discolouration trend
Severn Trent Water
Figure 10 – Company discolouration trend
Southern Water
Figure 11 – Company discolouration trend
South East Water
Figure 12 – Company discolouration trend
South West Water (including Bristol Water)
Figure 13 – Company discolouration trend
United Utilities
Figure 14 – Company discolouration trend
Wessex Water
Figure 15 – Company discolouration trend
Yorkshire Water
Figure 16 – Company discolouration trend
Company performance
Company-wide discolouration performance is considered alongside water supply zone performance when deciding whether legal instruments are required. These instruments are intended to address underlying causes, including deposit accumulation, network operation, asset condition and flushing or conditioning programmes, aiming for sustained improvements in consumer acceptability to be delivered.
Across England and Wales, the number of contacts reporting brown, black or orange discoloured water had reduced over recent years, but this improvement has now stalled. The industry rate deteriorated to 0.49 contacts per 1,000 population in 2024 and showed little improvement in 2025, at 0.48. This equated to 29,959 contacts in 2025 across the industry. In England, the rate followed a similar pattern, increasing from 0.40 contacts per 1,000 population in 2023 to 0.42 in both 2024 and 2025.
Figure 17 – England vs industry BBO contact rate
The England company ranking is shown below. South West Water remained the poorest performer in England, followed by United Utilities. These two companies have ranked worst and second worst in England since 2017. Both have nevertheless achieved material improvements over the longer term, with South West Water reducing its rate by around half over the past decade. Continued regulatory focus remains necessary to ensure that these improvements are sustained and that further reductions in consumer contacts are delivered.
Figure 18 – all companies BBO contact rate
More recent performance indicates that some company discolouration rates have deteriorated or plateaued. This suggests that current interventions may not be sufficient in all areas, or that additional investment and more targeted network management may be required. Companies with persistent or worsening performance are expected to use consumer contact data, event investigations, network modelling, flushing records and asset information together to identify root causes and prioritise action.
Taste and odour
Taste and odour contacts provide a direct measure of consumer experience and confidence in drinking water. As with discoloured water contacts, the industry rate had reduced over recent years, but this improvement has not been sustained. The industry rate deteriorated in 2024 and remained at 0.27 contacts per 1,000 population in 2025. In England, the rate was slightly lower, at 0.26 contacts per 1,000 population in 2025, but this also represents deterioration from the low point of 0.21 recorded in both 2022 and 2023.
Figure 19 – Taste & Odour contact rate
The compliance section includes examples of investigations into taste and odour failures. These failures do not always result in consumer contacts, and consumer contacts are not always linked to a compliance failure. Contact data therefore provides an important additional perspective on the acceptability of drinking water as experienced by consumers. General taste and odour contacts and chlorine-related contacts have featured prominently in recent years. While it is unrealistic to expect all contacts to be eliminated, companies should use the data to understand recurring causes, including the composition of the “other” category, and to identify opportunities for improved source control, treatment optimisation, residual management and customer response.