How London won its fight against super gross, sewer clogging 'fatbergs'

A plan first hatched in London, Ont., as a way to fight sewer-clogging 'fatbergs' is now being used in other cities.

Other cities latch on London plan to give out cups to keep grease out of drains

The city of London hands out these paper cups, which can be used to collect hot grease. The cups provide an incentive to keep grease out of the sewer system, where it can mix with other materials and cause costly blockages. (Submitted: Fluks Aqua)

A plan first hatched in London to help stop the formation of disgusting, sewer-clogging "fatbergs" is now being used in other cities.

Ten years ago, the city of London was spending about $100,000 a year to clear large blobs of grease from city sewers. These masses of fat — called fatbergs — form when grease is dumped down toilets or drains.

Once inside the sewer system the grease cools, hardens and sticks to other material, everything from sanitary napkins to baby diapers. It's not long before the fatberg gets big enough to form a blockage. 

"When you put all of those not-flushable items together with congealed grease, they're very hard to get rid of," said London sewer inspector Barry Orr. "We have to use vacuum trucks and send personnel down to actually chip it out."

London isn't the only city forced to face its fatberg problem. Over in London, England, crews had to dislodge a 250-metre long fatberg blocking one of the city's major sewer lines. 

​And while London, Ont., didn't have a fatberg problem quite that bad, it was getting expensive to keep the sewer system clear, with some sections cleaned on a monthly basis. 

Orr and other city staffers first started to target restaurants, which Orr said were often not using proper grease traps. 

That helped, but then fatberg blockages kept cropping up in residential ares. 

To encourage people to stop flushing bacon grease and turkey drippings, the city began to hand out 32-ounce compostable paper cups for the disposal of fat, oil and grease. The cups can hold hot grease while it cools in the fridge or freezer. 

The cups — available at libraries, city hall and fire halls — can be thrown into the trash or sent to one of the city's four enviro depots for recycling. The cups are sold to municipalities, which then redistribute them. 

Orr said once the cups started to circulate in 2013, staff began to notice an immediate drop in grease-related pipe blockages. 

The free cups are also popular. A total of 100,000 cups have been handed out in London since the program started. 

"We had line ups of people waiting to get these cups," said Orr. "We're having a hard time keeping the library supplied."

This photo shows grease and fat coating the inside of an access tunnel in the London sewer system. By providing free disposable grease cups, the city has helped curb the formation of sewer-clogging grease clumps known as 'fatbergs.'

Since the program started, blockages caused by fat and grease have been eliminated in London, Orr said. 

Other municipalities fighting fatberg problems of their own have since latched on to London's idea, including Sarnia, and Windsor. 

"London has engaged its community, the community has accepted it, and because of that success, others communities are saying 'Hey, what are we doing?'"

The paper cup program success, however, hasn't stopped some Londoners from flushing stuff that doesn't belong in the sewer system.

Problem items include:

  • Baby wipes.
  • Plastic flossers.
  • Dead goldfish.
  • Candy wrappers.
  • Hair.

"The list goes on and on," said Orr. "It's very lengthy. We like to highlight that toilets aren't garbage cans."


Andrew Lupton is a B.C.-born journalist, father of two and a north London resident with a passion for politics, photography and baseball.