A Berkshire-based dairy business that supplies Kraft foods and baker's Kingsmill has been fined £30,000 after milk from one of its depots polluted a nearby waterway, causing "extensive fungal growth" and damaging the natural environment

Medina Dairy, one of the UK’s largest family-owned dairy processing firms, pleaded guilty to breaching its environmental permit in January 2011, after the Environment Agency traced pollution in the Buzzards Mouth Sewer in Essex back to the firm’s Barking depot.

In a statement on its website, the company, which has an annual turnover of more than £200 million, pledges to “look for new ways to prevent pollution – and to train everyone who works here to do the same”. However, an investigation during 2011 revealed that when milk was spilled at the east London site employees washed it into drains connected to the surface water system, which then discharged the milk into the sewer causing the pollution.

“This case is an important reminder that companies have a duty of care to ensure that any wastes, liquid or otherwise, are disposed of in a safe manner,” commented James Burton, the investigating officer at the agency.

“Businesses must ensure that they understand where their drains lead and they have spillage prevention measures in place,” he said. “Small prevention measures can make a huge difference to the environment.”

Following the investigation by the agency, the firm has introduced new working practices at the site to prevent pollution, such as using sealed containers to store damaged containers to reduce the amount of milk spilled.

The company has also converted a large proportion of its drainage to foul drains, after obtaining a trade effluent consent from Thames Water Utilities, to safely dispose of spillages.

In England and Wales, organisations can, in some cases, dispose of waste liquids into the foul sewer system, but they must first receive permission from the local sewerage company and the Environment Agency.