Southern Water has been ordered to carry out more than 400 improvements by the Environment Agency to meet environmental standards and avoid further action.
The regulator carried out over 730 inspections of the company’s wastewater sites during 2025–26, finding that 68% were meeting permit requirements.
However, inspectors identified a number of concerns, including poor maintenance and issues with identifying discharge points.
Problems such as poorly maintained equipment and inadequate storm tank management were also highlighted.
The Environment Agency says while many breaches were considered minor, they point to wider concerns about how sites are being managed and the potential risk of pollution.
Water industry regulation manager Dawn Theaker said improvements are essential, warning that “if things go wrong, the environment suffers”.
She added that inspections will continue until issues are resolved.
In response, Southern Water says pollution incidents have fallen by 30% since 2023 and that it is working closely with regulators and stakeholders to improve performance.
The company has also announced plans to invest more than £8.5 billion between 2025 and 2030 to upgrade infrastructure and better protect the environment.
Southern Water supplies around 4.8 million customers across Sussex, Kent, Surrey, Hampshire and the Isle of Wight.
