From the Environment Agency
Pollution from a water pumping station caused the death of over 5,000 fish in an Essex river.
On 6 June 2016, Environment Agency officers were called to Shenfield and Hutton Water Recycling Centre, a sewage treatment works operated by Anglian Water, following an incident. It was found that all 3 pumps in one of the pump stations at the site had failed following a fire. As a result, untreated sewage was flowing out of an emergency overflow.
Officers followed the sewage into the River Wid, where they carried out tests and found high levels of ammonia among the cloudy, polluted water.
In the following days investigators returned and found dead fish and invertebrates at many different sites along the river.
It was later found that the bearing on one of the pumps had failed but continued to operate. The precise cause of the fire is unknown. However, it was accepted that heat built up to cause the fire which spread to other electrical components stopping all 3 pumps from working. This left no way for the sewage to be pumped.