The owners of Newby Bridge Hotel have been accused of discharging high levels of effluent into the River Leven, South Lakeland Magistrates court heard.

Lakeside Inns Ltd are accused of nine offences over an 18-month period between October 2002 and April 2004 on the basis that samples of effluent discharge were above the permitted biochemical oxygen demand (BOD) limit. The company has also been charged with two offences of being unable to provide representative samples from their sampling chamber.

The prosecution took evidence from Environment Agency officers who said it was possible to take a representative sample and recorded the presence of sewage fungus on the river bank.

The court also heard evidence from expert witness John Pomfret who used a correction factor to compensate for any differences in readings taken in the sampling chamber and at the point of discharge into the river. When this was applied to the results of the samples the calculation still showed them to be clearly above the legal limit.

Eric Shannon, defending, used an expert witness to refute the claims and put the case forward that possible discharges from a nearby guest house and farm could mix with the hotel's discharge before it reached the river. He also asked the court to look at storage and administrative errors with the samples that could have affected the quality of the results. Referring to the consent, Mr Shannon said an emission into the river must be proved otherwise the offences are not made. There was only evidence to prove there was a discharge into the river on two occasions.

In answer to the charges of being unable to provide representative samples from the sampling chamber he said: "If it's impossible to put a sampling point representative of what goes into the river you can't convict someone of the impossible."

The case was adjourned until October 19 when the district judge will give his verdict.