500-metre long ‘fatberg’ discovered in sewer near Colnbrook

A 500-metre long wall of congealed fat has been discovered in a sewer near Colnbrook.

Thames Water said its engineers unearthed the blockage in a sewer beneath Poyle Road, close to Heathrow Terminal 5.

The fatberg was the equivalent size of more than 700 suitcases laid end to end and took more than two weeks to be removed, from February 16 to March 10.

Workers used excavation tools to chip away at the solid mass before blasting the remaining deposits with high-pressure water jets.

Fatbergs are formed when oils, fats and grease are washed down sinks and drains.

These substances cool and solidify in the pipes, trapping other waste materials like wet wipes and cotton buds which leads to severe blockages in sewer pipes.

Steve Crabb, Head of Waste Operations for Thames Water home counties, said:

“This was a stubborn and sizeable blockage, but our teams have worked relentlessly to break it down and keep the network flowing.

“Fatbergs like this are entirely avoidable, and we’re urging everyone including businesses to think carefully about what they pour down the drain to help us prevent repeats of this in future.”

Across the Thames Water network, fats, oils and grease cause more than 20,000 blockages each year.

These blockages lead to more than 60 per cent of sewer floods annually and cost Thames Water approximately £40million per year to tackle.

The utility firm said many residents across London and the Thames Valley are still unknowingly contributing to the problem.

A recent survey found 40 per cent of people had poured meat juices down the sink, 39 per cent gravy and 18 per cent animal fat.

Thames Water has shared the following advice to ‘starve the fatbergs’:

• Scrape food waste into a bin or food caddy and not into the sink
• Ensure your plughole has a strainer fitted to catch food scraps and prevent them going down the drain
• Don’t pour liquid foods down the sink like milk, cream and oil
• To dispose of hot oil, let it cool then scrape it into the bin or consider storing it in a container to take to a local recycling centre
• Avoid pouring boiling water or bleach down the drain – this only moves the issue further down the pipes
• Only flush the three Ps down your loo – Pee, Poo and (toilet) paper. Do not flush wet wipes, cotton buds or paper towels
• Always clean your drain regularly