Dark kitchens and the fight against FOG

What is a dark kitchen and why is it becoming a secret battleground in the war on FOG?

Elusive enemies

Dark kitchens. No, not a new style brought in by your local kitchen refurbishment shop down the road, but instead a new type of restaurant that is becoming a thorn in the boots of the water utilities war on fats, oils and greases (FOG).

A dark kitchen is a new type of food serving establishment (FSE) that has soared during the global pandemic. As the customers of restaurants became locked in their homes, many turned to takeaways and food delivery to get their fill.

Alice Nield, network protection manager at Thames Water speaking at the European FOG Summit in October, said: "A 'dark kitchen' refers to an FSE that is not a traditional food serving establishment, they will sell their food via delivery apps such as Just Eat or Deliveroo."

Operating without the need for a shop front, dark kitchens are the emerging delivery model for restaurants that focus entirely on takeaway food.

Otherwise, known as a ghost kitchen or a cloud kitchen, this new business model for has been a lifeline for the restaurant industry - allowing them to operate during lockdown.

"A 'dark kitchen' refers to an FSE that is not a traditional food serving establishment, they will sell their food via delivery apps such as Just Eat or Deliveroo."

However, while these dark kitchens are becoming the savour for the future of dining, they are close to becoming one of the biggest contributors to FOG in our water networks.

Their FOG output is a large contributing factor to the formation of fatbergs in the UK’s sewer networks.

At the third European FOG Summit, which returned to Brighton in mid-October, speakers from the UK’s water utilities, FSE's and governing bodies raised the concern around these dark kitchens and the impact they are having.

Bigger than you thought

FOG is a big concern for water companies and one that is set to get bigger and more expensive.

The UK has around 360,000 FSEs and they contribute significantly to the estimated 250,000 tones of FOG that is blocking sewers every year.

Thames Water revealed at the summit that it is spending £18 million a year on clearing blockages caused by FOG that FSEs are a large contributor along with residents.

Of the 366,000 sewer blockages that occur in the UK, 70 per cent of them can be attributed to FOG, and the total cost of clearing these blockages costs water companies £90 million.

One of the greatest challenges with dark kitchens is not being able to track and regulate them.

Thames Water revealed at the summit that it is spending £18 million a year on clearing blockages caused by FOG that FSEs are a large contributor along with residents.

"We have 44,000 FSE's in our catchment and we have challenges with shops opening and closing down. Throughout lockdown, we saw 'dark kitchens' pop up all over London and it was difficult to find their locations." Neild told the audience at the FOG summit.

As a result, the challenge comes with trying to open dialogues with these independent businesses that are producing FOG.

How utilities are fighting back

"At Seven Trent we have a pretty robust system of engagement and education and enforcement." Said Grant Mitchell, FOG strategy lead at Severn Trent Water, on the topic of dealing with FSE's.

"75 per cent of the FSE's that we deal with install and maintain the correct FOG traps, the other 25 per cent refuse to engage with us, the last thing we want to do is prosecute but we will do it - we are trying to protect our communities from being flooded." Mitchell went on to say.

Communication with FSE's is the first line to prevention when it comes to FOG but opening these dialogues is tricky when it comes to the unexpected nature of dark kitchens.

"We need an end goal, because if there is not one for FSE's why would they?”

Stephen Edwards, network protection and enforcement officer at Southern Water said: "20 per cent of the FSE's are chains and they are easy to deal with. The challenge for us is the 80 per cent of independents who do not have the reputational risk or finical backing that chains have."

What Edwards was suggesting was that dealing with independents FSE's presented more of a challenge than bigger chains as there is no direct point of contact for the utilities to work with.

"In Southern Water [catchment] we have 27,000 FSEs alone. Just Eat and Deliveroo is our way forward to get to these independents." Edwards concluded.

Another way utilities plan to fight FOG is through innovation.

"We have a two-pronged approach, there is no getting away from the fact that domestic FOG is huge, you are never going to catch all of that so we are very open to innovation and new technologies." Said Mitchell.

Mitchell continued to talk about the partnership between Severn Trent and Cranfield University, where the two are working together to find ways to use FOG as a resource.

Mitchell went on to argue that: "We need an end goal, because if there is not one for FSE's why would they [correctly handle their FOG?"

So is there an incentive hiding in broad daylight for these dark kitchens?

Pouring money down the drain, literally!

As of right now in the UK there is no regulated managed FOG collection available to FSE's or the public. If an FSE wants to safely and correctly dispose of its FOG it is not easy for them to do - and most do not even realise they can.

"We are dealing with a new project that relates to the new legislation coming in in 2023 where food waste collections become mandatory," Edwards said at the summit.

He was referring to the upcoming shake-up of England's bin collections regulations that is aiming to make it easier for households to recycle their food waste.

"FSE's are throwing money down the drain, literally!”

Currently, details are thin but there is no specific inclusion or exclusion of FOG, but if it were to be added, it would make the process of disposing of FOG easier for both FSEs and residents.

"I look at that as an opportunity for water companies to think outside the box to include FOG. Collecting FOG from two million households will make a difference." Edwards went on to say of the incoming regulation change.

Tony Griffiths, drainage and strategy planning manager at United Utilities said: "The term FOG has been around long enough now for everyone to know, what we need to do is recognise is that FOG is a valuable high energy-yielding resource."

FOG indeed can be a highly valuable resource if treated correctly, and one resource that Anthony Hodkinson, head of sales at oil & grease distributor and collector company Qautra, wants to get his hands on.

"FSE's are throwing money down the drain, literally. There has never been a better time to be in oil collection." He said speaking at the FOG summit, even going as far as to invite the representatives of the attending FSE's to have a chat with him after the event.

Going back to what Grant Mitchell was saying about FSE's having an incentive, the circular system that Hodkinson suggests could well be a way for FSE's to actually make money from their FOG.

Education still needs to happen

While there may be a way for everyone to be a winner when it comes to FOG, there is still the issue of education around the subject for FSE's.

"Many years ago I went to an FSE to investigate a blockage and I asked the manager if he used his dosing system and he had no idea what it was!" Griffiths recalled when debating the subject of employee education on FOG.

Indeed, it is fair to say that due to the lack of general knowledge and training on how to handle FOG, many FSE's face the challenge of retraining and upskilling their existing staff to properly manage it.

Speaking on the side-lines to Aquatech Online, Frederico Fernandes, CEO of Águas do Porto, said: "In Portugal, all our food establishments services have to be legalised and they have to have a separation for all oil, fats greases but I believe much more can be done.

We have to engage and there is much more to do cross-sector between the water companies and the entire city."

Dark Kitchens then are a growing concern for water utilities and one that does need to be managed in a strategic way. Opening dialogues with FSEs will be key, making the connections even more so.