A Lincolnshire drain ran red with 'grossly polluting' blood and other abattoir waste for half a kilometre due to poor site management at a turkey plant, the courts have heard.

Lincs Turkeys Ltd was fined £8,000 and ordered to pay costs of £3,410 after pleading guilty to pollution offences under the Water Resources Act 1991.

Magistrates were told the company had committed the same offence in 1997 and had a history of non-compliance with conditions of its consent to discharge.

The court heard how, in October 2008, the Environment Agency was alerted to the fact that a local drain had been running red, blood was seen trickling down a bank next to the factory and a pink/yellow substance was seen pouring out of a manhole.

The grossly polluting waste liquid came out of a manhole 50m upstream of a point where cleaned-up waste liquid was allowed to be discharged by the company under a discharge consent from the Environment Agency.

Agency officers alerted management at the site to what was happening and advised the polluted drain be dammed off and then pumped out.

Operations director for the company Mr Michael Houghton told investigating officers that he believed the pollution had happened because of a blocked drain resulting in the manhole cover lifting and the blood and abattoir waste flooding into South Drain.

Samples taken from 150m downstream of the discharge showed the water starved of oxygen, with levels of Biological Oxygen Demand (BOD) at 752 milligrams per litre.

BOD is a commonly used to assess the health of a watercourse. Typically clean river water will have a BOD of less than 3 milligrams per litre.

Ammonia levels at this point were 25.9 milligrams per litre (levels of ammonia above 5 milligram per litre will, in most cases, have a toxic effect on aquatic life) and suspended solids were 362 milligrams per litre (the higher the reading for solid matter in suspension, the more likely it is that it will settle and smother aquatic life).

Mark Cawthorne, operations manager for the company, said in mitigation that the company sincerely apologised for the incident and has taken steps to prevent future pollution incidents including spending £80,000 on the current treatment plant.

After the hearing Environment Agency officer Emma Benfield said: "Lincs Turkeys Ltd caused a serious pollution which could have been avoided if routine checks had been made to the site's foul water drainage collection system.

'This case highlights the importance of having an up-to-date site drainage plan and staff being made aware of what to do in the event of a spillage.'