Fatbergs – Not Always the Health Hazard People Presume


A year ago, a 64 metre fatberg was found in a sewer in Sidmouth. Eight weeks of work later, a crew of South West Water workers managed to remove the berg at a cost of £100,000 and sent four 10kg samples off to be analysed by a team from the University of Exeter, led by Dr John Love, Associate Professor in Plant and Industrial Biotechnology.

Using a mix of techniques – from simply extracting and identifying the waste materials by sight to DNA sequencing, the team sifted through the samples.

The results were surprising…

The Fatberg Findings and Autopsy

Fatbergs form when fats, oils and grease (FOGs) escape down our drains and into our sewers, where they cool and solidify over time.

Often wet wipes, which fail to break down once they are flushed down our loos, end up becoming a crucial part of the structure of the fatbergs, helping them to form faster. While they form, fatbergs trap anything and everything which happens to be flowing past in the sewer – whether that’s human waste or solid objects which have been flushed intentionally or by mistake.

Scientist with face mask using a pipette in a petri dish of blue liquid

In the moist and slightly warm conditions of the fatberg, harmful bacteria and other micro-organisms get to work feeding off of all of the gory details, until the fatberg is a stinking cocktail of nasties.

This means that handling a berg is usually pretty bad for your health – which is why the teams tasked with removing and studying them have to wear the full complement of health and safety gear at all times.

However, when the Sidmouth fatberg samples were cracked open, the team of Exeter experts found that, while the berg stunk, it wasn’t quite as dangerous as they first expected: there were no harmful bacteria or toxic chemicals.

Instead, the Sidmouth berg was simply a mix of FOGs and domestic waste  - wet wipes, sanitary towels and other household products which Sidmouth residents had put down the loo instead of throwing away.

Together with these, were solid specimens reflecting the population of the small coastal community of retirees: a set of false teeth and a number of incontinence pads.

These discoveries caused a great deal of doubt and prompted the question:

Are We Wrong About Fatbergs?

Sidmouth, with its population of just 13,000 people, is not a typical fatberg hotspot.

We are more used to fatbergs forming in places with high population density: lots of people living in a small area means that it is more likely that more FOGs will be poured down drains in the same area, entering the same sewers and adding to the same fatbergs.

This was true of the most famous fatberg, which hit headlines in 2017 after being discovered in Whitechapel, one of the most densely populated areas in the country.

And that famous berg set the tone for how the fatbergs which followed were covered in the news. Because the Whitechapel berg contained a deathly mix of harmful bacteria and toxic chemicals, we all came to expect that all fatbergs would contain the same. Because the fatberg in Whitechapel contained drugs and syringes, the fact that the Sidmouth berg did not felt like a further surprise.

What the Sidmouth Fatberg Revealed

Crossed out biohazard symbol

Because the famous Whitechapel fatberg set the tone for fatberg coverage, a lot of assumptions have been flying around about the fatberg problem. The Sidmouth berg unravels those assumptions and reminds us that all a fatberg really is, is an accumulation of FOGs.

They aren’t necessarily toxic and though you might find some strange things in them, those objects are a reflection of who the people in the local area are and what they tend to end up flushing down their toilets.

With another fatberg beginning to form in the same drain under the Esplanade in Sidmouth almost immediately after the 64 metre monster was removed, it seems that this problem in the seaside town is here to stay. And we shouldn’t be surprised if, over time, we see more bergs emerge in places where we wouldn’t necessarily expect them.

Serving as a Grease Filled Reminder

It Reminds Us That:

The fatberg problem is relevant to all of us, wherever we live and whoever we are. We all need to come together to tackle it and, as all a fatberg is is an accumulation of the FOGs which manage to slip down our drains, we all know what we need to do.

To stop fats, oils and grease getting into our sewers, invest in a quality grease trap today.