About 1,700 fish have died in a suspected chemical leak in a stream near Witney Lake in Oxfordshire. Thames Water said high ammonia levels were found in the water, caused by discharges from a nearby sewage treatment works.
The company said the cause was 'most likely substances being put into the drainage network which shouldn't be there'. The Environment Agency (EA) is investigating the death of fish on a 2km stretch of Colwell Brook and Queen Emma's Dyke.
An EA spokesman said: 'Investigations are ongoing and officers are on site, taking measurements from local rivers and conducting a fish survey, with an ecology survey planned for tomorrow.' Members of the public used social media to warn dog owners to keep pets away from the water.
A Thames Water spokeswoman said: 'We've identified high ammonia levels in the stream which we believe are due to discharges from our sewage treatment works. We're investigating what has caused these discharges to contain such high ammonia levels.'
Graham State, who runs a nearby tackle shop, said it was not the first pollution incident in the area, adding: 'We've had it happen several times in the past, but not for a few years.'
