The Environment Agency has confirmed the presence of dead fish and a large stretch of white foam on the River Thet in Norfolk, describing the pollutant as 'an unknown substance'. Officers reported seeing small dead fish and fry, prompting an investigation into the source of the pollution.
Specialist teams were dispatched to collect samples from the river, which flows through Thetford, on Saturday. The source of the foam was detected and further discharge stopped, but the foam remains visible. Norfolk Fire Service warned the public not to enter the water or allow pets to swim or drink from the river.
Anglian Water confirmed that a 'third party' was involved and that the incident was not linked to any of their equipment or assets in the area. The Environment Agency noted that further foam might occur but would have 'little environmental impact as it dissipates'.
An Environment Agency spokesperson stated: 'Our specialist teams have collected samples, detected the possible source, and prevented any further discharge. There will be an ongoing investigation to try to ensure that this does not happen again.' The agency added that it would wait until the pollutant had gone to assess longer-term effects.
This incident follows a similar occurrence on 23 December 2024, when foam was reported on the River Thet but the source could not be identified. In 2023, an investigation by the Guardian and Watershed found toxic PFAS substances, including firefighting foams, polluting the protected River Wyre in Lancashire at extremely high levels.
