The UK environment agency DEFRA is still advising dog owners in Essex not to let their pets swim in the river Colne two weeks after a 5,000 litre pesticide spill at Topplesfield Brook. A specialist containment team worked overnight to dam the brook in two places, pumping out contaminated water into nearby fields. Some 6,000 fish were moved to safety, but an estimated 4,000 mature fish and thousands of smaller ones died in the incident, along with invertebrates and plants.
“This is one of the biggest chemical spills into a watercourse in Essex in the last 15 years,” explained DEFRA’s Frank Saunders, who also described the effects as “devastating.” The diluted pesticides will work their way downstream and were expected to pass through Colchester around Midsummer’s Day before reaching the Thames estuary.
“We ask that if people see fish gasping or dead anywhere along the river, please ring the Environment Agency immediately on 0800 80 70 60,” Saunders added.
According to a previous DEFRA study, the UK is home to around 40 million hectares of treated arable crops, on which nearly 15,000 tonnes of pesticides were applied in 2010. These figures give no meaningful indication, however, of the toxicity or the impact such products have.