Owners of large yards are being warned to manage their muckheaps efficiently — or face a huge fine.

Fiona Marner, a former director of Kingwood Stud in Lambourn, Berks, was fined £24,895 after her manure heap burst into flames, causing an environmental hazard.

She was ordered to pay £20,000 in fines, £4,880 in prosecution costs and a £15 victim surcharge by Newbury Magistrates earlier this month (Monday, 11 April) after operating the company in an “environmentally unfriendly” way.

The Environment Agency told H&H vast amounts of muck were being stored and were in danger of contaminating the ground water in the Lambourn Valley with nitrates, ammonia and phosphates.

Magistrates heard that the fire brigade was called on 6 October 2009 after 500tonnes of manure ignited and burnt for several days. Smoke could be seen from half a mile away.

The Environment Agency visited the site on 9 October, but six weeks later it found a smaller fire in the same place. There were 14 reports of burning horse bedding and manure at the site between October 2002 and November 2009.

The Environment Agency had previously issued two warning letters to the company and two advisory letters.

The waste used to be taken away by a local farmer, but Mrs Marner said it had become “too expensive”. An estimated cost to remove manure is between £10-£15 a tonne.

It is illegal to burn manure and Mrs Marner denied setting the heap alight. She said the manure fire had been caused by a combination of warm, dry weather followed by rain.

She admitted keeping controlled waste on land in a manner “likely to cause pollution of the environment or harm to human health” under the Environmental Protection Act 1990.

This longer edition of this story, including comments from the Environment Agency, Mrs Marner and the British Horse Society, was published in Horse & Hound (21 April, 2011)