Yorkshire Water has removed more than five tonnes of fat in a single blockage from a stretch of sewer in South Yorkshire.

In what was the largest sewer clean-up operation Yorkshire Water has carried out so far this year, last week the company removed the putrid fat which had built up in a Rotherham sewer.

The fat build-up, which was the result of fat being poured down kitchen sinks and drains, was discovered during a camera inspection of a meter-wide sewer under under the town’s Corporation Street.

In some places, the fat filled up to 80% of the pipe and if left alone, would have continued to grow before completely blocking the pipe. The blockage could ultimately led to sewage backing up and discharging into the environment and potentially even into people's properties.

To remove the massive blockage, a Yorkshire Water team deployed a special industrial vacuum to suck the fat out of the sewer and into a tanker, before it was taken to a special waste disposal facility for treatment. Folowing the work, a camera was also sent down to check that all of the fat had been removed.

Going forward, the company said it will be dosing the sewer with special fat-busting bugs, which will eat any fat that does enter the network.

Matt Thompson of Yorkshire Water commented:

"We're sadly used to removing blockages caused by fat in our sewer network, but it's very rare that we ever encounter anything on the scale of the fat mound we've seen today.

"We estimate we've removed around seven tonnes of putrid, foul-smelling fat from our sewer network under Corporation Street which is pretty shocking.

"Whilst many people are doing the right thing, clearly there are still people out there who are pouring their cooking fats, oils and grease down the kitchen sink and into our sewer network where it hardens and builds-up over time.”

Between January 2011 and June 2012, 587 blockages have been removed from the sewer network in Rotherham, with many of these occurring as a result of fat build-ups.

Across the region as whole , since January 2011 the company has dealt with approximately 15,000 blockages, with an increasing amount of these occurring as a result of items such as wetwipes and sanitary products being wrongly flushed down the loo.

Last year the company unveiled its latest weapon - fat-busting bugs - to help tackle fat-build-ups and keep sewers flowing freely in a number of well-known blockage hotspots. Whilst these are having a major impact, Yorkshire Water has renewed its plea for customers to play their part and ensure that nothing inappropriate is disposed of down their drains.