Water Company Performance Reporting
What is the Environmental Performance Assessment?
The Environmental Performance Assessment, also known as the EPA, is a tool for comparing performance between the 9 water and sewerage companies in England and across years. The Environment Agency uses the assessment to identify where companies are performing well, where they need to improve and where further regulatory action may be needed.
The assessment supports our work as an independent, evidence-led environmental regulator. We use monitoring, inspections, intelligence and environmental data to identify poor performance, secure improvements and hold companies to account where standards are not met.
Where is it published?
We publish the EPA results on GOV.UK.
You can currently view the 2024 report and EPA results from 2011 to 2024.
View Environmental Performance Data from 2011 to 2024The 2025 results will be added to this page when they are available.
What does the assessment cover?
We assess each water and sewerage company against a consistent set of environmental measures.
These include:
- Pollution incidents, including serious incidents.
- How often companies report pollution incidents themselves.
- Compliance with permits for treated wastewater.
- The safe and satisfactory use or disposal of sewage sludge.
- Delivery of environmental improvement schemes on time.
- Maintaining the planned balance between water supply and demand.
We use environmental data, information reported to us by companies, inspections and other regulatory evidence to complete the assessment.
Each company receives an overall rating that shows how well it has performed.
How are the ratings calculated?
The 2025 assessment will be the final year using the current EPA methodology. A new methodology will be introduced from the next reporting period to reflect updated expectations for water company environmental performance.
How have water and sewerage companies performed?
The last Water Company Performance Report covers company performance during 2024 and was published on 23 October 2025.
The table below shows each company’s overall rating and how it changed from 2023.
| Water Company | 2024 rating - Stars (out of 4) | Change since 2023 |
| Anglian Water | 2 | No change |
| Northumbrian Water | 2 | Down 1 star |
| Severn Trent Water | 4 | No change |
| Southern Water | 2 | No change |
| South West Water | 2 | No change |
| Thames Water | 1 | Down 1 star |
| United Utilities | 2 | Down 2 stars |
| Wessex Water | 2 | Down 2 stars |
| Yorkshire Water | 2 | No change |
Sector result: The nine companies achieved 19 out of a possible 36 stars in 2024, six fewer than in 2023.
How we hold water companies to account
Water companies are legally required to comply with environmental legislation and the conditions of their permits. Where they fail to do so, we take a robust, evidence-led approach to enforcement, using the full range of regulatory and enforcement powers available to us.
We assess the seriousness of each breach, its environmental impact and the available evidence, and will take appropriate action where companies fall short of the standards expected. This can include investigations, enforcement action and prosecution where warranted.
The Water (Special Measures) Act 2025 has further strengthened the regulatory framework, increasing accountability for both water companies and their senior leaders. We also share performance information with Ofwat to support wider regulatory action, including decisions on performance-related pay.
Water companies are required to publish annual Pollution Incident Reduction Plans, setting out how they will reduce the number and severity of pollution incidents and improve environmental performance.
We also work with other regulators to share intelligence, identify common issues across the sector and support joined-up action where company performance falls short.
Working closely with the Drinking Water Inspectorate (DWI), Natural Resources Wales (NRW) and Ofwat, we are strengthening regulatory oversight across the sector and using all available levers to drive environmental improvement, secure compliance and deliver better outcomes for people, communities and wildlife.
Explore water company regulation and enforcement
