Sewage ran from an Anglian Water manhole, through a dry reservoir used for flood water, into a low level drain and ended up in a lake at Dallington Lawn Tennis Club in Northampton.

Despite being aware of the overflow, the water company did not investigate where the sewage had run to and a clean-up was not completed for a month, Daventry magistrates were told today (Fri)

Anglian Water Services admitted causing trade or sewage effluent to be discharged into the lake contrary to the Water Resources Act 1991 and was fined £10,000 with £6,855 costs.

An Environment Agency prosecutor told magistrates that on the morning that officers had first visited the lake there were no dead fish, however five days later groundsmen at the tennis club found 138 dead fish on the lake and over the weir into Dallington Brook.

Organic matter such as sewage lowers the quality of the water and takes some time to break down, depleting the oxygen supply in the water as it does so, which can cause fish to die.

Anglian Water admitted that there was a blockage in the sewer resulting in an escape of sewage through the manhole cover but claimed that items put down the sewer had been put there maliciously and had caused a blockage to occur. These items included an acroprop, fold-up scooter, iron bar and concrete.

The company could not explain to the Environment Agency why it had not notified them for five days. A manager said they had not investigated the full extent of the pollution because they had not realised there was an outlet in the reservoir and did not clean up the ground immediately because the ground was too wet.

The sewage leak was first spotted by a man out walking his dog at night on 10 May last year who notified Anglian Water. He described a strong smell of sewage and seeing brown sewage water oozing from a manhole. He said the manhole cover was broken and water was coming about a foot out of the manhole and spreading over the ground.

On 19 May Anglian Water had agreed to have the contaminated water removed from the sump of the reservoir and to get the solids removed from the bank of the reservoir and around the manhole. But three weeks later there was still a considerable quantity of liquid in the sump and the area around the manhole was still wet and contaminated with foul sewage solids.

Anglian Water told Agency officers that there had been past problems on the foul sewer at the location due to fat deposits which had led to significant amounts of maintenance there.

Magistrates said that because Anglian Water had failed to notify the Environment Agency of the blockage and pollution there had been a delay of seven days before a clean-up began. There had been a potential for harm to the public and animals.

They did acknowledge Anglian Water’s efforts in cleaning up the pollution and co-operation with the investigation of the incident.

After the hearing Environment Agency officer Norman Robinson said: ‘This was a lengthy investigation which highlights the complex nature of the drainage system in this area. An overflowing manhole led to a discharge into a fishing lake almost 1/2 a mile away. During the course of the investigation it was discovered that items had been thrown into the foul sewer line and had caused it to block.’

‘It is important that if you notice a sewage discharge, or witness anyone throwing items into the sewer, you report it to the utility provider and the Environment Agency as soon as possible. In this way we can work together to prevent such incidents in the future.  Everyone must do their bit to ensure that our sewers stay clear. The Environment Agency has a 24 hour hotline on 0800 80 70 60 for all such incidences.’

Anglian Water Services pleaded guilty to:

On or about 10 May 2005 you did cause trade effluent or sewage effluent to be discharged into controlled waters, namely Dallington Lawn Tennis Club Lake at Dallington, Northampton.

Contrary to section 85(3) and section 85(6) Water Resources Act 1991