Image caption A stretch of the Mowhan River was affected, officials said

The Ulster Farmers' Union has won a test case taken on behalf of a former president fined £55,000 for polluting a river.

Ian Marshall challenged the Department of Agriculture and Environment in the High Court.

The judicial review was taken after it ruled he had deliberately polluted the Mowhan River in County Armagh.

Officials said 500m of the river had been affected with silage effluent in December 2011.

Mr Marshall accepted that pollution was coming from his farm, outside Markethill, but insisted it was accidental.

Image caption The pollution was traced back to a diverter on Mr Marshall's farm

Farmers who pollute are fined by the courts and are also subject to inspections under the system that approves European Union subsidies.

Under the penalty system, deliberate pollution carries a substantially higher fine.

It was applied in Mr Marshall's case and £55,000 of his payments were withheld.

A finding of negligence would have attracted a fine of about £3,000.

Officials said the pollution was traced back to a diverter on the farm.

When the silage store was empty, the diverter could be set so that rain water gathering in it could be directed to a drain that led to the river.

Image caption A farm inspection in January 2012 found the diverter was apparently set incorrectly with effluent running to the river

When the silo was full and producing effluent it could be switched so that the run off was directed into storage tanks for disposal.

A farm inspection in January 2012 found the diverter was apparently set incorrectly with effluent running to the river.

The court heard that Mr Marshall had been told repeatedly over the previous eight weeks that the river was polluted and the problem was his farm.

A barrister for the Department of Agriculture said it was Mr Marshall's responsibility to identify the source and he should have known to check the diverter.

The fact that he had not and the pollution had continued, made it intentional, the barrister said.

Mr Marshall's barrister said the department had only discovered the diverter problem during the January 2012 inspection.

Wider implications

He said before that, Mr Marshall did not know what was causing the pollution, and while it had been negligent, there was nothing to suggest it had been intentional.

Mr Marshall appealed the fine to an independent panel which found the pollution had been negligent, not deliberate.

However, a senior official in the department set aside that decision and applied the original finding.

On Tuesday, a judge ruled in Mr Marshall's favour, saying he found the decision making process "troubling in multiple aspects".

The judge said the decision could have been influenced by "erroneous" statements made by officials of the Northern Ireland Environment Agency (NIEA) or the department.

The Ulster Farmers' Union backed the case.

It said it believed that Mr Marshall had been "harshly treated". Chief Executive Wesley Aston said not only would "intent" now have to be proven "more robustly" in future cases, but that historic cases could also now be reviewed.

The department said it had received the judgement and would "examine it in detail and consider in full its implications and recommendations".