Fatberg discovered in an east London sewer took nine weeks to clear

A 250-metre long “monster” fatberg, which was blocking an east London sewer has been cleared after a nine-week “battle”, Thames Water has confirmed.

The 130-tonne congealed mass of fat, oil, grease, nappies, wet wipes and other sanitary products was discovered beneath Whitechapel in September.

Thames Water engineers expected to complete the unclogging process within three weeks but said the process took longer than anticipated due to the damage caused to the Victorian sewer.

The water company announced plans to convert the fat, oil and grease into around 10,000 litres of biodiesel – enough environmentally-friendly energy to power 350 double-decker Routemaster buses for a day.

A team of eight worked to clear the sewer with the final stretch having to be removed manually using shovels.

Alex Saunders, waste network manager for Thames Water, said: “Our work is finished, and the beast finally defeated after a mammoth effort from the team.

“It was some of the most gut-wrenching work many would have seen on national television, and one of the reasons why the man-made Whitechapel fatberg captured the world’s imagination.

“The good news is it has helped Thames Water and other water companies around the world get the message across that cooking fat, oils and grease should never go down the plughole. As you have seen, when combined with wet wipes, sanitary products, underwear, nappies, and anything else that shouldn’t be flushed, we’re faced with having to clear out these giant, rock-hard fatbergs.”

Speaking at Utility Week’s Congress event in Birmingham last month Thames Water chief executive Steve Robertson explained that digitisation can help water companies deliver important messages to a greater number of customers than they have been able to do in the past.

He described how the fatberg became a media sensation which enabled the company to highlight the water sector’s campaign to ensure no unwanted products get flushed away.

Thames Water spends around £1 million a month clearing blockages from its 68,000-mile sewer network in the capital.