THOUSANDS of litres of diesel leaked into a ditch after a break-in at a farm.

It came two days after a major herbicide leak into the Sandon Brook, at Highlands Farm, in Rettendon.

D Chennells Ltd, a crop growing company which runs the farm, was fined £25,000 with £2,015 costs following the separate pollution spills last October.

The first incident happened after a farm worker over-filled a sprayer tank and mixed herbicide spilled into the surface water drainage system, contaminating 150m of the ditch with a pungent yellow liquid.

Two days later an estimated 4,000 litres of diesel contaminated the ditch for 350m after a storage tank was broken into at the farm and a hose left running overnight.

Harlow Magistrates’ Court heard the farm’s accident management plan was out of date, not all drains were shown on its drainage map, and sprayer filling areas were too near to surface water drains.

The farm’s straw dams could not contain the liquids.

Prosecuting for the Environment Agency, Claire Bentley told the court the company had not taken action to prevent pollution following an earlier diesel spill.

She said: “Following the 2003 incident, the defendant took a deliberate decision to not improve the oil storage system.”

Miss Bentley said the incidents demonstrated poor site management.

David and Janice Chennells, directors of the company, told investigating officers they had been filling sprayers at the designated area for more than 30 years.

They reported the diesel tank vandalism to the agency and police and said a gate to the area had been locked at the time.

They believed thieves got in through an automatic gate and there had been break-ins before and since the incident.

They are now looking to spend £100,000 to improve methods and provide better storage for chemicals and diesel.

After the hearing, agency officer Peter Cooke said: “This incident could have had a catastrophic effect on the aquatic environment if the flow of pesticide, and subsequently fuel, had not been stemmed.”