A leading dairy firm was fined the equivalent of 60,000 pints of milk after dumping its spillages into the drainage system.

Medina Dairy caused extensive fungal growth and damaged the environment at Buzzards Mouth Sewer in Barking after allowing the milk spillages to be released into a watercourse, the Environment Agency said.

The multi-million pound company was fined �30,000 and ordered to pay �7,853 costs after it admitted causing a discharge without authorisation at Barkingside Magistrates’ Court.

Environment Agency investigating officer, James Burton, said: “We hope the court’s decision today will highlight to other companies their responsibility to ensure safe waste drainage.

“Small prevention measures can make a huge difference to the environment.”

The Environment Agency said it first detected the spillage in January 2011 when it found a white substance being released into the watercourse from the surface water drain at Buzzards Mouth Sewer.

But the agency said the Medina milk depot in Thames Road, Barking, had since made changes to its working practices to prevent further pollution, adding the company had plans to introduce the changes nationwide.

The Environment Agency said that Medina Dairy had used sealed containers to store damaged containers to reduce the amount of spilt milk on the site surface, diverted a large area of the yard drainage to foul drains to allow washings to be disposed of safely and obtained a trade effluent consent from Thames Water Utilities.

Medina Dairy pleaded guilty to causing a water discharge activity contrary to Environmental Permitting Regulations (England & Wales) 2010.

An agency spokesman said: “This caused extensive fungal growth and was damaging to the natural environment.

“Through enquiries and drain tracing with Thames Water Utilities Ltd it became clear the pollutant was milk from Medina Dairy.”

The company, which has 19 depots in the country, was fined at Barkingside Magistrates’ Court on July 26.