Buzz
Lurking in the sewer systems under your feet could be a threat so horrifying, so disgusting, that the mere mention of it sends a shiver down the spines of sanitation specialists everywhere: Fatbergs, mounds of grease capable of growing to massive proportions and blocking the flow of sewage with expensive—and potentially disastrous—consequences. Here’s what you need to know about fatbergs, and how you can help prevent them.
1. The word fatberg was coined in 2008.
It takes inspiration from the word iceberg, and first appeared in print in a story referencing photos of pollution on a beach in the January 22, 2008 edition of the Birmingham Post: “particularly memorable are the large, rock-like lumps of cooking fat [Alistair] Grant calls ‘fatbergs,’” the paper said. The word was added to the Oxford English Dictionary in 2015.
2. Fatbergs consist of fats, oils, and greases, collectively known as FOG.
“Fatbergs form from a buildup of fats, oils, and greases—called FOG for short—in the sewer pipes,” says Kimberly Worsham, founder of FLUSH (Facilitated Learning for Universal Sanitation and Hygiene), a company that, through edutainment events and advisory consulting, aims to change how the world perceives and does sanitation work. “This can include soap scum, dairy dregs, congealed fat from food, industrial grease, etc.”
Much of the grease originates from restaurants lacking grease traps, but individual households also contribute to fatbergs. “Your Thanksgiving food scraps are part of the next fatberg,” Worsham tells Mytour by email. “There’s a lot of fat in our holiday meals that are prime for fatberg parties in the sewers—all because we’re lazy and don’t want to open the trash bin.”
All that FOG, along with human waste, settles into crevices in the sewer pipes. The fat interacts with calcium—which can either come from concrete pipes or water in the system that has flowed over concrete—and undergoes the process of saponification, or turning into soap. “After a while, more FOG bits build up together on the sides of the pipes, creating congestion in the sewers,” Worsham says.
3. Fatbergs have existed as long as sewers have.
“Fatbergs have existed as long as sewers have—at least since the Roman Empire's Cloaca Maxima,” Worsham notes. “Historical records indicate that Roman slaves were tasked with removing the accumulated fatty substances from the sewers. The emergence of fatbergs was actually the catalyst for the invention of the grease trap in the 1880s, as it was evident that fat would eventually compromise the sewer systems. However, most fatbergs were relatively small compared to the massive ones observed today—their size has increased significantly in the past couple of decades.”
4. Wet wipes are a major contributor to today's fatbergs.
Wet wipes have become a significant problem for global sewer systems. Despite their packaging claims, wet wipes are not flushable—and flushing them has greatly contributed to the formation of fatbergs. “Instances of these larger and sometimes massive fatbergs began appearing in major cities like London around the time the use of wet wipes among adults started to surge, which was about a decade ago,” Worsham explains. She describes wet wipes as “absorbent cotton bastards” that, unlike toilet paper, don't dissolve in water but instead are excellent at collecting grease. “Imagine a bunch of fat-soaked wet wipes in a sewer about 2 feet wide—they’re going to get together and clump up.” Because they don't dissolve, wet wipes also wreak havoc on our waste treatment plants.
5. Fatbergs contain a variety of unexpected items.
People dispose of numerous items in their toilets, leading to a wide range of materials found in fatbergs, including condoms, tampons, dental floss, syringes, drugs, and wet wipes. Bones and false teeth have also been discovered in fatbergs, as have a typewriter and a bowling ball. “I think the fact that they’ve found items like whole toilets and mop heads in fatbergs is pretty strange—it’s very meta,” Worsham remarks. “Those probably somehow fell through a manhole or something, maybe.”
The makeup of fatbergs, including their size and color, varies significantly and depends on the community where they form. “We’re still learning quite a lot about fatbergs, and really fatbergs are not homogenous in their contents at all!” Worsham says.
However, there are still some insights we can glean from them—like whether there are a lot of restaurants in an area, for example. “Some things they do find in some of the fatbergs are concentrations of drugs in certain regions,” Worsham says. “There’s this story about the South Bank fatberg in London that had a lot of performance enhancement drugs in it—more than other drugs like cocaine and MDMA—and I recall people speculating was because that was connected to an area of London that has a lot of clubs and public places where the area has a fit culture.”
6. Fatbergs can take a while to form.
According to Worsham, how long a fatberg takes to form depends on things like the type and size of pipes and what, exactly, is going into those pipes. “In London, some of the bigger fatbergs that they’ve pulled out—those 130 tons or more—took probably about a decade to create,” she says. “But I’m sure in a lot of places it takes much less time, especially in places where the pipes are smaller, and people are more careless with dumping stuff into sewers.”
7. Fatbergs show up in sewer systems around the world.
In the United States, fatbergs have been discovered in cities such as Baltimore, Maryland; Charleston, South Carolina; New York City; and Fort Wayne, Indiana. Globally, these substantial accumulations of fat and debris have troubled sewage systems in countries including Canada, the UK, Singapore, and Australia. Notably, a fatberg the size of a gas tanker truck was found in Melbourne in April 2020, believed to have grown so large due to a toilet paper shortage during the COVID-19 pandemic, which led people to use more wet wipes.
Fatbergs emit a foul odor. Worsham has never encountered a fatberg herself, but those who have likely wish they could forget the stench. John Love, a professor at the University of Exeter who was part of a group of scientists that performed a study on portions of a fatberg found in the sewage system in Sidmouth, England, told The New York Times that "It was my first time analyzing a fatberg, and when you smell it, you think this is going to be the last time because the smell was honking. It was awful to do, it smelled gross." The Guardian described the smell as "a heady combination of rotting meat mixed with the odor of an unclean toilet," while the BBC said it's "a bit like vomit, with undertones of poo."
Worsham has never encountered a fatberg herself (“that could be either a good thing or a bad thing knowing me, I guess,” she says), but those who have likely wish they could forget the stench. John Love, a professor at the University of Exeter who was part of a group of scientists that performed a study on portions of a fatberg found in the sewage system in Sidmouth, England, told The New York Times that “It was my first time analyzing a fatberg, and when you smell it, you think this is going to be the last time because the smell was honking. It was awful to do, it smelled gross.” The Guardian described the smell as “a heady combination of rotting meat mixed with the odor of an unclean toilet,” while the BBC said it’s “a bit like vomit, with undertones of poo.”
Discovering a fatberg can be a shocking experience. Charlie Ewart, a sewer worker in southwest England, found a 209-foot-long fatberg in Sidmouth when he went through a manhole in January 2019. He described his experience to The Guardian.
What’s it like to come upon a fatberg in a sewer? Charlie Ewart, a sewer worker in southwest England, found a 209-foot-long fatberg in Sidmouth when he went through a manhole in January 2019. He described his experience to The Guardian:
Upon seeing the fatberg, one might be struck with disbelief, thinking, 'What on Earth?' It’s an entirely unexpected sight. The part of the sewer where it’s found feels unsettling, almost as though it belongs in a horror movie, with everything congealed, glossy, and stuck together with all sorts of objects.
10. Fatbergs can be massive.
Fatbergs can grow to be absolutely enormous. To give some perspective, these massive blobs of fat and waste can stretch up to 800 feet in length, rise to 6 feet tall, and weigh as much as four humpback whales. In the UK, some have been as large as airplanes or double-decker buses, and longer than the height of the Leaning Tower of Pisa. One such fatberg found in Liverpool’s sewers was as heavy as 13 elephants.
11. It’s not easy—or cheap—to remove a fatberg.
Removing a fatberg from the sewer system is no simple or cheap task. The process requires extreme care and patience, with the removal being done very slowly and with blunt force. According to Worsham, using sharp tools could cause damage to the sewer pipes, which would undermine the whole effort.
To ensure safety, workers must wear specialized suits to protect themselves from the hazardous elements within fatbergs—potentially containing items like needles—and harmful gases and fumes. Crews then use shovels and blunt tools to break down the mass. 'They’re often hard, so it takes a while,' Worsham explains. 'It could take weeks, or even months if it's large enough.' This process is both labor-intensive and costly: Cities spend millions annually on combating fatbergs. 'Scientists are experimenting with bacteria to break down fatbergs without requiring workers to manually remove them from the sewers,' says Worsham.
Once a fatberg has been removed, it either undergoes analysis to further understand it, or it is sent to a landfill. According to Worsham, 'There are reports that in China, the oils from fatbergs are extracted from sewers and rudely refined to be used as gutter oil at street food stalls... so there's that.'
In 2018, researchers from the University of British Columbia created a method for converting fatbergs into biofuel. They tested this in pilot programs, but more progress is needed to make this approach viable on a larger scale.
Fatbergs, despite their strange fascination, are undeniably dangerous. 'Fatbergs act like a blockage in a heart artery,' says Worsham. 'If they aren't removed, they continue to accumulate, and the sewer system suffers something akin to a heart attack.' When fatbergs block the pipes, waste backs up into homes and the surrounding environment, including waterways and wetlands.
The allure of fatbergs doesn't overshadow their inherent dangers. As Worsham states, 'If we don’t remove them, they begin to accumulate, and the sewer system essentially experiences a heart attack.' This blockage causes waste to flow back into homes and local ecosystems, including waterways and wetlands.
'Fatbergs still contain dangerous pathogens, as well as hazardous materials like needles,' says Worsham. 'Once these fatbergs cause sewage spills, those pathogens mix into our environment, leading to potential health risks for people.'
There’s also the added danger for those tasked with removing fatbergs: 'For a sewer worker trying to clear a fatberg, being pricked by a sharp object is even more dangerous—there's no telling what the needle might contain, who used it, or the reason behind its use,' Worsham explains.
13. A fatberg was put on display in London.
In 2017, workers uncovered an 820-foot fatberg in the sewers beneath London’s Whitechapel neighborhood, which took nine weeks to clear. A segment of this fatberg, dubbed 'The Beast' and 'The Monster of Whitechapel,' was exhibited at the Museum of London in 2018. The exhibit, titled 'Fatberg!', featured a mannequin dressed in protective gear and displayed the necessary tools for fatberg removal, with the specimen housed in a sealed unit inside a display case.
'Displaying a part of a fatberg had been on the museum’s wish list for some time, and when we heard about the Whitechapel fatberg—the largest one ever discovered in the UK—we knew we had to act fast to secure a sample,' said curator Vyki Sparkes in an interview on the museum’s website. 'It’s grand, magnificent, fascinating, and disgusting. The perfect museum object!'
While the fatberg was on display, flies emerged from it, and it even changed color and began to sweat a bit. According to Andy Holbrook, the collections care manager who was the only one to handle the fatberg outside of its display (and wore full protective gear to do so), 'The fatberg samples were surprisingly light, with a texture similar to pumice stone, but crumbly. Since being on display, it has evolved. When it was first acquired, it was waxy and wet, but a year later, it became much lighter, with a bone-like color and a soap-like texture.'
Currently, the fatberg is no longer on display and is in quarantine under Holbrook's supervision. It is the only item in the collection with a livecam (dubbed the 'Fatcam'), which you can watch here. Despite being air-dried for preservation, it has continued to change. It has developed toxic aspergillus mold, appearing as yellow pustules, as stated on the museum’s website.
14. Scientists are studying fatbergs.
There’s still so much we don’t know about fatbergs. 'We don’t yet understand how to remove them cost-effectively, what happens to them over time, or all the insights they could offer about our communities,' Worsham says.
But science is on the case. In addition to performing 'autopsies' on fatbergs, scientists have conducted molecular analysis, revealing the presence of parasite eggs and bacteria such as Campylobacter, E. coli, and Listeria, along with antibiotic-resistant bacteria. They've even analyzed the fatberg’s DNA. Worsham compares this to 'a new kind of forensics study.'
15. You can take action to prevent fatbergs.
Are you worried about sewage potentially flooding your home or business after reading this? There are steps you can take to address the issue.
The top priority for commercial businesses in fighting fatbergs is to install grease traps. 'Recent fatbergs have often been found near restaurant districts, where fats and oils are regularly poured down the drain. Avoid doing this, and it can greatly help prevent fatbergs,' advises Worsham.
Individuals can help too by being mindful of what gets flushed. 'Sewers are frequently treated like garbage cans, but they don't function the same way. Only human waste, water, and legitimate toilet paper should go down the toilet. Nothing else,' Worsham stresses. 'And when using the drain, avoid dumping coffee grounds, tea leaves, food scraps, oils, or similar items. It’s surprising how these things combine with grease and fats in the sewer. For example, floss acts like a lasso, tying fats together and contributing to larger fat blockages.'
Finally, Worsham says, 'Never, ever flush wet wipes down the toilet. I personally love bidets and believe everyone should switch from wet wipes to bidets. They are absolutely fantastic.' If you're interested in purchasing a bidet, we have some great recommendations here.
