A major factor behind the massive 130-ton fatberg Thames Water in London discovered in its sewer system last month is the fact that a significant majority of food establishments in the city do not have grease traps.

In a recent survey the utility did of more than 700 food outlets across London, it was found that 92 percent of them lacked a grease trap. None of the establishments visited on Whitechapel Road, where the 130-ton fatberg was discovered, had a working grease trap. Workers are still trying to completely remove the massive sewer blockage, one of the largest fatbergs the utility has ever found.

“We’ve always known food outlets play a huge role in contributing to fatbergs, but it was really surprising to find out just how few are doing the right thing when it comes to managing fats, oils, greases and food waste from their kitchens,” Stephen Pattenden, sewer network manager, said in a press release. “We’re not suggesting anyone intentionally pours the contents of a fat fryer down the drain, but it’s more about the gunk that comes from dirty plates, pots and pans. A simple, well-maintained grease trap will capture that stuff and stop it entering the sewer and turning into a monster fatberg — like the ones found in Whitechapel and Chinatown recently. Sadly, most of the businesses we speak to don’t even know about them.”

Thames Water engineers arrived unannounced on the visits to food outlets, which included schools, hospitals and care homes, to look at what’s in place to capture fat, oil, grease and food waste. In most cases, where there was nothing, free advice packs — including posters for display near sinks and drains — were handed out.

Outlets identified as needing improvement will be visited again in a few months, and this will continue until they take the necessary fat-trapping action, with the possibility of prosecution if they fail to make the changes, according to Thames Water.

“We’ve been welcomed with open arms by many food outlets who regularly clear internal blockages,” Pattenden says. “They were delighted when our experts told them how to prevent it. We need to help more take action though, plus continue in our bid to get our domestic customers to change bad habits when it comes to disposing of fat and items like wipes, cotton buds and sanitary products. Everyone needs to do their bit in this fight against fatbergs.”

In the last year, Thames Water has written to almost 600,000 homes in its area with information on its "Bin it – don’t block it" campaign in a bid to encourage customers not to put fat down their kitchen sinks or wipes down the toilet.

The utility is also funding a Ph.D. student to look at the sources of fat, its impact on sewers and treatment sites, and what alternatives there are for disposing of it, as well as the ways to best use it as a source of renewable energy. That is part of Thames Water’s goal to self-generate a third of its own power by 2020.

Source: Thames Water