SEE THE FATBERG
Last September, Thames Water made a startling discovery. Lurking in the sewers beneath Whitechapel was a monstrous 130-tonne ‘fatberg’. Now, the Museum of London is putting it on display. We asked SHARON ROBINSON-CALVER, head of conservation and collectio
What makes a fatberg? A fatberg is a congealed mass of fats, oils and greases, plus things that go down the toilet that shouldn’t be flushed, such as nappies, wet wipes, sanitary products and condoms. So pretty unpleasant really! The Whitechapel fatberg really captured the public imagination because it was the biggest one that we’d ever found – over 250 metres long.
Why did the Museum of London decide to display a fatberg?
Many of the items in our collection have been discovered in cesspits – things such as teapots, bottles and coins – and these tell us a lot about how people once lived. In some respects, fatbergs are no different – they’re human-made objects that reflect modern issues such as population expansion, changes in diet, and the pressures we’re putting on London’s Victorian sewer system. It’s an important part of the story of the city, showing the challenges that urban living can create.
How did you go about getting a sample?
When we first heard about the monster fatberg, we asked Thames Water to take some samples for us. To excavate it, they blast the fatberg with high-pressure water jets, breaking it into smaller chunks that can be sucked up into a tanker. The fatberg is toxic – it off-gasses carbon monoxide and hydrogen sulphide, and there’s a real risk of bacterial diseases – so we spent some time analysing the samples to understand how we could handle and display them safely.
What’s the best solution you came up with?
Once we’d X-rayed the samples to check for things like hypodermic needles, we slowly air-dried them at room temperature, which turned them from their sloppy, mushy consistency to the harder, more oxidised material that you get sticking to the sewer walls. Once it’s dried and been left to off-gas, the material becomes chemically stable enough to display – in a protective case of course! The original fatberg has now been removed from the sewer and converted into biodiesel, so we’ll be displaying the last remaining piece – it’s about the size of a shoebox.
What does the fatberg smell like?
I didn’t come face-to-face with the original fatberg, but I’ve been told that it smelled like a combination of rotting meat and rotting nappies. By the time I got to experience it myself, several weeks later, it wasn’t quite so bad – more like dirty toilets.
How can we stop fatbergs from forming in the first place?
There are around 300,000 sewage blockages in the UK every year, and wet wipes make up 93 per cent of the problem. So the message from Thames Water is only to flush the three ‘p’s down the toilet: poo, pee and toilet paper. And put cooking fats and oils in the bin, not down the sink.