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What Is a Fatberg?

A fatberg is a broad term for objects that collect into a single mass, which then clog up pipes and drains. Fatbergs are a menace to drains and sewage systems. But despite the news reports and public notices, people continue to contribute to these troublesome masses.

Most people know that the fats from cooking should go into the bin after they cool. But it is surprising how people continue to pour cooking oils, grease, and fats from cooking meats straight down the drain. Fatbergs tend to be a combination of fats, faeces, and non-degradable materials such as wet wipes, sanitary towels, and Q-tips.

Is There No Limit to Their Size?

There seems to be no limit to the size a fatberg can grow to. The term fatberg took to the headlines in 2013 when a 15-ton clump of fat was discovered in one of the main sewer pipes beneath London. This fatberg was around the size of a bus and the biggest on record and earned “Fatberg’ a place in the 2015 edition of the Oxford English dictionary.

London fatberg in sewer

Image: BBC

Then in 2017, a 250-meter-long 130-ton fatberg as big as a blue whale or 11 double-decker buses – was discovered beneath Whitechapel. This specimen was so impressive that a section was put on temporary display in the museum of London.

Can You Smell a Fatberg?

Fatbergs are a combination of everything that can be flushed down a toilet, so you end up with a heavy combination of smells, and none of them are good. The smell tends to be like that of an unclean toilet that has a large amount of rotting meat sitting in it. This smell can make it up into a home during the flushing of a toilet and sometimes through the u-bends of sinks and showers.

If the U-bends are working, there should be no smell coming up. However, flooding and the restrictions of a fatberg can cause everything to back up into homes. The texture and appearance of a fatberg are close to that of candle wax. Fatbergs are buoyant and hard to the touch, which is why they are so difficult to remove.


Workers must wear full protective clothing and respirators when dealing with these masses. Fatbergs can hold a range of pathogens, toxic chemicals, and molds. This means a fatberg can pose as a serious biohazard – ready to disperse disease – if allowed to reach the surface.

How Do You Get Rid of Fatbergs?

Smaller fatbergs may find their way out of the sewers during storms. But washing smaller fatbergs through sewers can also cause them to form larger masses with other fatbergs further down the line.

On discovery, civil engineers will attempt to remove a fatberg to prevent it from clogging up other pipes. In most cases, high-pressure jets are used to cut through and break up the mass. Then workers can excavate and use vacuum tankers to suck the smaller pieces up and out of the sewer.

The Whitechapel fatberg was sent off for processing and used to make biodiesel. But the value of the resulting biodiesel did little to offset the cost of extracting the fat. Fatbergs cost the public around £100million each year in damages and the cost of removal.

At home, fatbergs can still be an issue, though not to the same extent as the mega-fatbergs of London’s sewers.

If you are worried that you have a growing fatberg lurking in your drains, you can try one of the following methods:-

Boiling Water

Fats that you pour down a plug hole will end up clinging to the inside of a cold drainpipe. It may be years before you discover the size of the fat blockage you have caused. But catching a fatberg early means that you may be able to dislodge the mass with hot water alone.

  • Fill up your kettle and boil the water.
  • Then pour the hot water down the drain – slowly.
  • You want to melt the fat and have it wash away with the water. If you pour a whole kettle full of hot water down the drain, you may cause the fat to come off in large chunks and cause a blockage further down.
  • You can repeat this process several times.

Caustic Soda/Drain Cleaner/ Acid

Caustic soda, drain cleaners, and acids are strong corrosives – you should use gloves and eye protection when using them.

For the best results:

  • Pour a few tables spoons of caustic soda down the problem plug hole.
  • Boil a half-litre of water and pour that down the plug hole – leave it to settle.
  • After 10 minutes, you can try flushing the pipe through with hot water from your tap.
  • If it still looks like the water is having trouble draining away, repeat the process.

Do NOT pour other chemicals down the plug hole to help the caustic soda, acid, or drain cleaner. Mixing chemicals may release corrosive gases and a volatile release of energy. If you want to try another fat-melting product, make sure that you have washed away the first product.

Drain Snake

This is a useful method for stubborn blockages that are too thick for chemicals to burn through. You can use a drain snake to break up the mass and then use chemicals for the final clearing.

Be careful when pushing a drain snake down since you do not want to cause another problem by breaking through a plastic pipe. And always use disposable gloves when cleaning your drains.


There is a lot of cost, time, and mess involved in clearing fatbergs, so try to avoid creating the problem. Some people seem to think that the kitchen drain struggles with fat because of pipe size and that it is better to flush cooking fat down the toilet.

A toilet is designed for pees, poos, and toilet paper – nothing else. And pouring anything hot down a ceramic toilet is going to crack the porcelain. If you have some cooking oil left in a frying pan, let it cool and save it in a jar for another day.

If you have a pan full of meat fat, let it cool and go hard. Once the fat goes hard, you can scoop it out into the bin and use kitchen paper to wipe away the remains.

It is impossible to remove all the fat from your cooking equipment, but the more fat you can put in the bin, the better it will be for your drains.

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