The incident occurred last September at the company's Pleasurewood Hills sewage pumping station. A pump failure over a weekend had resulted in crude sewage overflowing into a watercourse.
On the advice of the Environment Agency, a dam was constructed to prevent further pollution of the stream, and a second dam was built later after it was found that the sewage had spread 1.5 kilometres downstream. Aeration equipment was also deployed for four days to raise oxygen levels in the water and prevent further fish deaths.
Anglian Water appeared before Lowestoft magistrates on 13 June to plead guilty to causing sewage effluent to enter controlled waters, contrary to section 85(3) of the Water Resources Act 1991. It was ordered to pay costs of £3,442.