On the morning of October 18, 2025, residents and local officials in Thetford, Norfolk, were met with an unusual and alarming sight: a thick, white foam blanketing a stretch of the River Thet. The mysterious foam, which quickly caught the attention of passersby and environmental authorities alike, prompted an immediate investigation by the Environment Agency, as reported by BBC and Sky News.
Images shared by the Environment Agency on Saturday morning showed the foam covering a significant area of the river, drawing concern from both environmental experts and the public. The foam’s sudden appearance in the center of Thetford set off a chain of events involving multiple agencies, including Anglian Water and Norfolk Fire Service, all working together to determine the origin and potential impact of the substance.
According to a spokesperson from the Environment Agency, “Our specialist teams have collected samples, detected the possible source, and prevented any further discharge. There will be an ongoing investigation to try and ensure that this does not happen again.” The agency also warned that a second foam plume could be possible, stating, “It is possible that we might see a second foam plume today and the foam will continue to travel down the river. It is still visible but will have little environmental impact as it dissipates.”
By October 19, 2025, the Environment Agency confirmed the source of the foam had been detected and that further discharge had been stopped. Despite these reassurances, the foam remained visible, floating downstream and prompting continued monitoring. Officials emphasized that, while the foam was expected to dissipate with little environmental impact, vigilance was still required. The Environment Agency urged members of the public to report any fish in distress, providing a dedicated hotline for such reports.
Norfolk Fire Service also responded to the incident, with firefighters attending the scene to assess potential risks. The service issued a public warning, advising people not to enter the water or allow their pets to swim in or drink from the river. This precautionary advice was echoed across social media and local news outlets, as the investigation continued to unfold.
Anglian Water, a key regional water utility, was quick to clarify their role in the incident. A spokeswoman from Anglian Water stated, “One of our managers is on site helping the Environment Agency with their checks which will then go back to the third party responsible.” She further confirmed that the foam had not originated from Anglian Water’s equipment or assets in the area, but was instead caused “by a third-party.” This detail added a layer of complexity to the investigation, as authorities sought to determine the identity and actions of the third party involved.
Throughout the weekend, the Environment Agency maintained a visible presence along the River Thet. Their teams, including fisheries officers, were on site from early Saturday, taking samples and monitoring the situation closely. The agency’s proactive approach included not only identifying and stopping the source of the foam but also preparing for the possibility of further plumes. “We have taken samples and continue to investigate into its origins. We are expecting a second plume and there may be more foam as a result,” the agency posted in an update on X (formerly Twitter).
Local residents, many of whom rely on the river for recreation and as a natural landmark, expressed a mix of curiosity and concern. The foam’s thick, white appearance was described as unusual, raising questions about the chemicals or substances involved. While the Environment Agency’s early findings suggested minimal environmental impact as the foam dissipated, the incident served as a stark reminder of the vulnerabilities facing local waterways.
The presence of a third party as the source of the foam has shifted the focus of the investigation towards accountability and prevention. As Anglian Water’s involvement was ruled out, attention turned to identifying the third party responsible for the discharge. The Environment Agency emphasized that the investigation would continue until the cause was fully understood and measures were put in place to prevent a recurrence. “There will be an ongoing investigation to try and ensure that this does not happen again,” the agency’s spokesperson reiterated.
This incident is not the first time UK rivers have faced contamination or mysterious pollution events. Over the years, environmental authorities have grappled with challenges ranging from agricultural runoff to industrial spills, each posing unique threats to aquatic ecosystems. The swift response in Thetford highlights both the preparedness of local agencies and the importance of public vigilance in reporting unusual occurrences.
Despite assurances that the foam posed little risk as it dissipated, the Environment Agency’s call for the public to report any fish in distress underscored the potential for unseen impacts. Fisheries officers remained alert, monitoring the health of aquatic life and the overall condition of the river. The hotline provided—0800 80 70 60—served as a direct line for concerned citizens to contribute to the ongoing monitoring effort.
As of Sunday, October 19, 2025, the foam continued to travel downstream, its presence still visible but gradually lessening. The Environment Agency and Anglian Water maintained their joint efforts, with managers and specialists on site conducting checks and coordinating with each other. The collaboration between these organizations, along with the involvement of Norfolk Fire Service, demonstrated a comprehensive approach to environmental incidents—one that prioritizes public safety, ecological health, and transparent communication.
While the immediate threat appears to have been contained, questions remain about the exact nature of the foam and the circumstances that led to its release. The ongoing investigation is expected to shed light on these details, with the Environment Agency committed to sharing findings and implementing safeguards for the future.
For residents of Thetford and environmental advocates alike, the incident has reinforced the need for vigilance and swift action in protecting local waterways. As the foam slowly dissipates and the river returns to its usual state, the lessons learned from this episode will likely inform future responses to similar events—not just in Norfolk, but across the country.
