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Fatbergs Blocking Our Drainage Systems

Fat (mostly from restaurants/food outlets) + Wipes/Sanitary Products (mostly domestic) = THE FATBERG

Sewage workers in protective suits use high-powered jets and shovels to chip away at fatbergs – some as solid as concrete. They work in foul conditions, with dangerous gases and a sickening stench. The problem that causes fatbergs is preventable.

The removal of fatbergs is estimated to cost £1 million per month in London and the Thames Valley alone, at an average of 3 fat-related blockages every hour.

Between 32-44 million litres of used cooking oil is believed to be thrown away by London’s food outlets every year. Much of this ends up down the drain. Fat slips easily down the sink, but when it hits the cool sewer and solidifies with other waste – creates a big smelly hazard.

According to Thames Water, 1 in 5 people admit to flushing the next biggest culprit - wet wipes down the toilet.

“Wet wipes cling to the fat. Fat clings to the wipes. And pretty soon your fatberg is out of control and sewage is backing up into the roads, gardens and in the worst cases flooding up through toilets and into homes.” (Dave Dennis, Thames Water)


The Fatberg of Chelsea, London (2 metres beneath Draycott Avenue and Walton Street)

Discovered: March 2015

Weight: 10 tonnes/10000kg (2 African Elephants)

Length: 40 metres

Damage: Heavy enough to break the 1940s sewer. 39 metres of pipe needed replacing.

Cost: Around £400,000 and 2 months of work.

The Fatberg of Kingston, Surrey

Discovered: July 2013

Weight: 15 tonnes/15000kg

Length: ‘Size of a bus’

Damage: Took 3 weeks to break down using high-powered jets. Repairs to the damaged sewer took 6 weeks.

Nearby flat residents reported difficulty flushing their toilets and local sewage workers discovered that 95% of the 2.4 metre pipe near the main sewer was blocked. Kingston had come very close to having raw sewage on the streets.

The Fatberg of Whitechapel, London

“It’s a total monster and taking a lot of manpower and machinery to remove as it’s set hard.” (Matt Rimmer, Thames Water’s head of waste)

Discovered: September 2017

Weight: 130 tonnes/ 130000 kg (or 11 double decker buses)

Length: 250 metres (or 2 football pitches)

Sewer dimensions: 1,200mm high, 700mm wide, 3.5 metres deep

Displayed: 2 pieces were cut, dried and put on display at The Museum of London in February 2018.

Cost: Took 2 months to destroy at a cost of £1 million per month.

The Fatberg of Liverpool (Birchall Street)

“The Largest Fatberg in the UK to date”

Discovered: February 2019

Weight: 400 tonnes /400000kg (4 average sized BLUE WHALES)

Length: 250 metres

Cost: Was still being removed in July 2019, as proved difficult to break down with traditional methods. Current cost unknown.

The Fatberg of Sidmouth, Devon

The largest fatberg discovered outside a major UK city.

“Thankfully the Sidmouth fatberg has now gone, but we’ll need the help of the people of Sidmouth to make sure it never returns.” (Mr Roantree, South West Water)

Discovered: March 2019

Weight: 3,000 gallons removed, in 36 tanker loads of waste.

Length: 64 metres

Cost: Took 8 weeks to remove.

Recycled: The fatberg was fed into the anaerobic digester to power the local sewage treatment works.

Water companies are combining with renewable energy firms to find a way to make a positive out of this chronic problem. McDonalds already converts around 600,000 litres of its cooking oil from London restaurants into biodiesel – running half of its fleet of lorries on it.

While there are attempts to make the best of this dire situation by turning it into energy, the fatberg problem (and the size of them) is only increasing.

Water company slogans such as ‘Pee, Paper and Poo’ and ‘Bin it, don’t block it’ are aimed at educating the public about the limitations of our sewage system. We all need to think very carefully about what we throw away, including what we thoughtlessly put down the drain - and how it negatively impacts our environment.

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