BBC discovers over 6,000 potential illegal sewage discharges in a single year

BBC discovers over 6,000 potential illegal sewage discharges in a single year

Every major English water company has reported data suggesting they’ve discharged raw sewage when the weather is dry – a practice which is potentially illegal. BBC News has analysed spills data from nine firms, which suggests sewage may have been discharged nearly 6,000 times when it had not been raining in 2022 – including during the country’s record heatwave.

Water companies can release untreated sewage into rivers and seas when it rains to prevent flooding homes, but such spills are illegal when it’s dry. The firms say they understand public concerns around dry spilling, but they disagree with the BBC’s findings. They have said the spill data shared with the Environment Agency was “preliminary” and “unverified”, and also disagree with how the BBC defined a dry spill, which they say differs from the Environment Agency’s approach.

The latest findings follow a BBC investigation conducted last year which found 388 instances of possible dry spilling in 2022 by three water companies – Thames, Wessex, and Southern. The other six – Anglian Water, Northumbrian Water, Severn Trent, South West Water, United Utilities, and Yorkshire Water – had refused to share data about when they might be spilling with the BBC.

The regulator, the Environment Agency, who had the data, disagreed with the companies and handed over the data to the BBC. Overflow points where sewage is discharged have monitors that record when spills start and stop. The BBC cross-referenced the companies’ spill data with local Met Office rainfall data to identify potential dry spills.

The BBC’s methodology was independently reviewed by three academic experts in the field. Examples of potential dry spills in the data were presented to each water company, where some disagreed with the findings citing monitor malfunctions. Water and sewerage companies are responsible for outlets known as combined sewer overflows (CSOs), which release sewage into the UK’s waterways.

Reducing dry spilling would help prevent excessive nutrients from entering rivers and causing harm to aquatic life. The water industry has committed to spending £100bn between 2025 and 2030 to improve sewage treatment and reduce the impact of discharges on the environment.

Overall, the investigation highlights the need for increased transparency and investment in water infrastructure to prevent illegal sewage discharges and protect the health of people and ecosystems in England.