Anglian Water has been fined �22,000 and ordered to pay more than �4,000 in costs after a tributary of the River Yare was polluted with raw sewage twice in seven months.

A rising water main running through Hall Farm, in Shipdham near Dereham, burst on August 3, 2009 and again on March 25 this year, with sewage ruining crops and flowing in to the River Blackwater.

The aging main had burst on three occasions over the previous seven years, but the water company had failed to replace it, Swaffham Magistrates' Court heard yesterday (Tuesday).

Claire Bentley, prosecuting for the Environment Agency, said the incidents had been 'highly-forseeable'.

Anglian Water had been formally warned about serious pollution at the site following an incident in 2007, but a project to replace the sewage main had been passed over for funding two years later, she said.

The court heard the farmer's elephant grass crops, grown for use as a bio-fuel, had been lost and he had been forced to give up shooting after he was advised that game on his land was not fit for human consumption.

Anglian Water looked at replacing the main again in January this year, but it was not deemed a priority, Miss Bentley said.

'Anglian Water was aware of ongoing problems. On a cost benefit analysis, the company made a deliberate decision not to recommend replacement,' she said.

'Although OFWAT had determined the defendant's capital works budget for the next five years from April 2010, it is the company's own system that prioritises work.'

Anglian Water had refused to attend interviews under caution following both incidents, but it had provided a written account of the first, the court heard.

Arabella Prothero, for Anglian Water, said the company was sorry and regretted what had happened.

She told the court that the rising main would now be replaced - at a cost of �137,000 - by the end of March next year.

The fractures to the pipe, installed by the local authority in 1967, had been caused by its age, ground movement and its shallow depth in flinty ground and not negligence by the company, she said.

Ms Prothero said the temporary pollution had not been serious and the river had a low biological water quality regardless of what had happened.

She said Anglian Water had been denied access to the land when the main burst last year, preventing the company from carrying out damage limitation work.

Anglian Water was fined a total of �22,000 and ordered to pay �4,504.27 in costs.

Jan Smith, chairman of the bench, said: 'In our opinion, the only factor which might indicate a higher than usual level of culpability is that Anglian Water has committed previous offences of a similar nature

'We note that as a result of these two incidents there has been an internal review of procedures (at Anglia Water) and we are pleased to note that matters such as access have been addressed.

'We are concerned that the lack of immediate access by the landowner resulted in a higher level of pollution.'