Dairy farmers in North Tuddenham have been told to pay more than £4,000 after polluting around a mile of the River Tud with dirty water.
Around 1.3km of a tributary near land owned by FS Dann and Son Ltd at Pound Farm contained 'grossly polluting' levels of ammonia and bio-chemical oxygen demand on January 30 last year, following an Environment Agency investigation.
Wendy Foster, prosecuting on behalf of the agency at Norwich Magistrates Court on Thursday, said the source had been an irrigator on already waterlogged land.
'Attempts to locate the source of the pollution led officers upstream to Pound Farm, owned and operated by the defendant company,' she told the court.
'Officers carried out investigations of the site and found brown liquid was coming from a pipe was discharging into a water course from the corner of a field to a ditch which flows directly towards the A47.'
Samples were taken from various locations on the tributary, showing high levels of ammonia.
Staff blocked the ditch when they attended the farm, as it had been unmanned when investigators arrived. Two days later when officers visited the levels of ammonia had returned to normal.
Ms Foster said the high levels of bio-chemical oxygen demand meant aquatic life can suffocate, and the levels recorded would have an 'unacceptable effect' on the watercourse.
Ammonia, she added, was 'directly toxic' to the environment and the levels found were 'grossly polluting'.
The company had already received a caution in November 2013 after slurry made its way into the watercourse.
Malcolm Savory, mitigating, said it was an 'unusual' event after dirty water made its way into a sealed pipe on the farm.
'You have got a situation where if you do not get rid of liquid it backs up into the milking parlour and that is a crisis,' he said. 'They selected 15 acres which doesn't have any land drains. It is still a mystery how it got into a public pipe which was sealed. There is no reason it should have happened.'
Chair of the bench Richard Meadows, fining the company £1,000 with costs of £3,215 and a victim surcharge of £100, said the case 'could have been much more serious.
'We accept this was negligence and the extent of the pollution was extensive,' he said.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here