Thames Water has admitted that it was responsible for killing thousands of fish in a popular river after accidentally allowing a large amount of industrial cleaner to leak into it.
Officers from the Environment Agency visiting the site discovered dead chub, barbell and eels as a result of the pollution and say that they are fully expecting that species of invertebrates and plant life have also been affected.
Witnesses described how the river had turned green as a result of the chemical spill and said there was a strong smell of bleach in the affected area.
An initial Environment Agency estimate said that at least 2,000 fish were killed during the incident on Monday, which affected a three-mile stretch of the Wandle, the river that runs through south-west London and is popular with anglers due to its brown trout population. Residents say that as many as 20,000 fish could have died in the incident.
It is hoped that larger birds and mammals living around the river have managed to escape the effects of the spill. The Environment Agency has already warned that it could take years to return the river to its former condition. The agency has now removed thousands of dead fish from the river and is assessing the level of damage caused by the incident.
Mike Denbigh, the agency's environment management team leader, said: "This very serious incident is being vigorously investigated. By looking at the fish in the Wandle that have survived, we will be able to assess the impact and make decisions about how best to rehabilitate the river's ecology. This will be a long-term process."
The river had recently been restored to a wildlife and fishing hotspot and Thames Water had been heavily involved in the project. Alan Suttie, who has headed efforts to protect the river for more than a decade, described the accident as a "complete disaster ... We've spent years turning the river from the sewer it was into an internationally recognised beacon of urban regeneration," he said. "It's virtually a dead lane now."
Thames Water, which is the UK's largest water company, has promised to clean the river and replace the lost fish and damaged habitats.
Bob Collington, the company's director of wastewater services, said: "We want to apologise to everyone in the community who enjoys the Wandle. A thorough investigation is being conducted and we are taking immediate steps to ensure this sort of event cannot happen again."
David Bellamy, the botanist who has also been involved with the Wandle's regeneration, was said to be "devastated" by the news of the chemical spill.
Last month, hundreds of fish in the Wandle died as a result of an unidentified pollution spill, still the subject of an Environment Agency investigation.Reuse content