London, July 14 (IANS) It’s leaking lard from London’s sewers, authorities found to their dismay when they cleared an estimated 1,000 tonnes of fat – enough to fill nine double decker buses – while cleaning sewers in the capital’s Leicester Square area.

The area, home to London’s quality restaurants including Chinese and Southeast Asian food-joints, is the worst example of ‘sewer abuse’, according to Thames Water, which carried out the cleaning exercise Tuesday.

The putrid fat build-up must have been over years as people put it down drains, it said.

Tuesday early morning saw Thames Water staff donning full breathing apparatus and using shovels to dig out the fat. Powerful jets were then used to break down the ‘fat-bergs’ inside the sewer.

‘We’re used to getting our hands dirty, but nothing on this scale. We couldn’t even access the sewer as it was blocked by a four-foot wall of solid fat,’ Danny Brackley, Thames Water’s sewer flusher, was quoted as saying in the company statement.

Work started beneath Bedford Row near Leicester Square at the end of June. Thames Water is now working its way through the West End, including Holborn, Long Acre, Leicester Square, Piccadilly and up to Half Moon Street. The clean-up could take up to two months.

The company now wants to launch a ‘bin it, don’t block it’ campaign to ask people not to throw fat – used cooking oil and animal fat – down the drains.

‘As soon as cooking fat is poured away it cools down quickly and sets hard forming a solid obstruction. Other household products such as wet wipes, sanitary products and cotton buds make things worse still, sticking to the fat and forming solid blockages. Remember, even if these products claim they’re flushable, they’re not! We flushers know that from bitter experience.’

Thames Water, which supplies 2,600 million litres of tap water daily to 8.5 million people across London and the Thames river valley, also removes and treats 2,800 million litres of sewage for an area covering 13.6 million people.

Under a new programme called the London Tideway Improvements programme, it is providing a strengthened sewerage system for London fit for the 21st century.