So how can we prevent fatbergs?

Eww: a piece of fatberg in the streets beneath London. Image: Getty.

Fatbergs – enormous solid masses of oil, grease, wet wipes and other hygiene products that congeal together to cause major blockages – are wreaking havoc on the sewers of cities around the world. A 130 tonne specimen described as a “monster” recently caused backups in sewers in London’s Whitechapel, and the cities of Baltimore, Singapore and Dannevirke, New Zealand have also all experienced similar issues in recent weeks.

Fatbergs are not a recent phenomenon, but have attracted increased attention in recent years as old sewerage systems struggle to cope with an increased consumption and disposal of everyday products like fats, oils and greases from cooking. This is a particular issue for cities like London with Victorian systems. The visceral disgust that runs alongside the image of fatbergs lingering under the city, and the potential impact they will have on local flooding, means that they will remain a topic that demands attention.

Strategies are already being put in place in order to prevent sewer fatbergs. Current water industry tactics tend to focus on removing sewer blockages and reducing the fats, oils and greases that enter sewers from commercial sources (such as restaurants). But around three quarters of the fats, oils and greases in sewers comes from domestic sources, making household disposal a key priority for change.

Awareness campaigns directed at the public currently focus on what people put down the kitchen sink. Current advice is that cooking fats, oils and greases should be disposed through food or solid waste recycling. But there is little information on how we can dispose of other products – like that fatty off milk at the back of the fridge – without pouring it down the sink. The mucky complexities of how people actually deal with fats, oils and greases in the home suggests that the solution might need to be more complex than awareness campaigns.

In a recent report we suggest that changing people’s broader behaviour related to food waste and disposal of fatty products is not going to be easy to change – and that we also need to look beyond the plughole.

Down the plughole

Fats, oils and greases are changeable, often smelly, visceral materials. The way we dispose of them is tied to attempts to reduce their impact on our kitchens and in our lives, and this becomes entrenched in our everyday habits and routines.

They can be troublesome materials to handle. The fact that they are liquid at cooking temperatures, and often at room temperature, makes them simpler to dispose of via liquid waste than via solid waste channels, yet their tendency to solidify and accumulate in the specific physical and chemical conditions of drains and sewers makes this disposal highly problematic. Fats, oils and greases are not only difficult to deal with, but many also find it unpleasant.

Evidence from research into food waste and disposal suggests that when food begins to deteriorate, its material properties – and the bodily reactions caused by its appearance, smell and feel in the people handling it – play an important role in how it is discarded. The more effectively and reliably it can be sealed off and ejected from the home with minimal human contact, the better.

Our research suggests that if the same is true of householders’ reactions to leftover fats then successful interventions to divert fats, oils and greases from sewers will mean providing an alternative, yet similarly effective, option for quick and seemingly hassle-free disposal than the kitchen sink.

These ideas of disgust, dirt, smell, and convenience are also likely underpinning similar dynamics for the disposal of wetwipes, nappies, and other hygiene products down the toilet rather than the bathroom bin.

Beyond the kitchen sink

But crucially, fats, oils and greases do not end up in our sewers purely due to decisions related to disposal at the kitchen sink. Rather, actions throughout the stages of food provisioning – including shopping, food preparation, cooking, dealing with leftovers, and clearing up – leads to fats, oils and greases entering sewers.

Another way of thinking about the issues is in regards to tracing the numerous decisions that occur in the process of carrying out routine household tasks: moments in which resources are used up and waste is produced. This is broader than just individual behaviours and involves a consideration of all of those moments where waste fat is indirectly or directly produced – such as when we are choosing what to cook; how much oil to use; whether to reuse that rendered meat fat from the Sunday roast in the next meal we cook or discard it.


Insights into what shapes behaviour at these points lead to a range of implications and recommendations for policies and intervention programs. For example, there needs to be a recognition that disposal of products like fats, oils and greases is part of a wider set of kitchen practices that are in turn shaped by wider systems of food provision (supply chains, retail, and so on) as well as waste disposal facilities.

Interventions that influence household behaviour therefore don’t just need to target the household but could involve product innovations that reduce likelihood of excess fat oil and grease production – for example, fryers that use less fat. Retail environments and packaging could be used as means of changing social norms. Sewerage systems could be rethought. Effective alternative waste fat and oil disposal infrastructures could be envisioned.

The ConversationRather than fatbergs just being seen as a water industry issue there needs to be greater collaboration across sectors (water, energy, food) to deal with the problem. Potential solutions need to range from the level of the household right through to new infrastructures that are experimenting with turning this mucky fatberg problem into energy and biofuel.

Alison Browne, Lecturer in Human Geography and the Sustainable Consumption Institute, University of Manchester and Mike Foden, Postdoctoral Research Associate, Keele University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Wild boar are moving back to Genoa, and not everyone is pleased

A wild boar, c1933. Image: Getty.

Crossing the Ponte Gerolamo Serra in the Italian city of Genoa, I spotted a small crowd clustered by the river wall. I approached, intrigued, and peered over the wall to discover the subject of their delight: a sounder of eight wild boars – the adults sheltering from the heat in the undergrowth, while the juveniles foraged among the foliage that grows in the river bed during the dry summer months.

In any other city, such a sight might have been surprising. But in Italy, and particularly in the region of Liguria, where Genoa is located, the population of wild boars has been increasing at such a rapid rate that these incidents are now common. Across the country, it’s estimated that the population has risen from 600,000 to 1m over the past decade.

But while wild boars may look comically out of place trotting about the city, it’s actually a natural result of the way people have migrated – and the wars they have fought – over the course of recent history.

Making a comeback

A species native to Europe, the wild boar (or “cinghiale”, in Italian) largely disappeared from its historical territories during the 18th and 19th centuries. Their decline was widely attributed to the combined effects of habitat change, competition for space and resources and, of course, hunting.

Wild boars were a prized quarry, revered for their ferocity – and the danger involved in pursuing them. According to local folklore from the region of Liguria, the last truly wild boar was hunted and killed in 1814, in the province of Savona.

After an absence of more than a century, wild boar began to return to Liguria, and to the neighbouring region of Piedmont. A further influx occurred during World War I, when it’s believed that military activities in the south-east of France forced parts of the population back into Italy over the Alps.

Although hunting fraternities were quick to augment this fledgling population with wild boars transported from elsewhere, the return of the species was primarily due to natural causes. From the 1950s onwards, traditional agricultural practices were abandoned as more and more people moved from rural towns into the cities. This meant that large areas of formerly cultivated terraces and pastures were rapidly overgrown, fast becoming dense secondary woodlands.

A city gone wild

This spontaneous “rewilding” has become a controversial issue in the region. Many conservationists and environmental organisations consider the region’s return to a “wild state” a success. But others believe that the encroaching wilderness signals a loss of traditional woodland knowledge and a reduction of biodiversity, associated with the pastures and meadows.


The province of Genoa is among the areas most densely populated by wild boar in Italy, with an estimated 25 boar per 10km². Rewilding processes have brought woodlands to the city limits, blurring the boundary between rural and urban areas. The species has expanded beyond the hinterlands, colonising highly urbanised, densely populated city spaces in Genoa, drawn by the abundance of food waste created by humans.

In 2009, the infamous boar Pierino made his home at Righi, on the outskirts of Genoa, where he was routinely fed with focaccia by enthusiasts. Today, a family of wild boar call the Albergo dei Poveri – a historical hostel for the Genoese poor in the city centre – their home.

But while their antics are often recorded and shared with glee on social media, the threats posed by the presence of wild animals has become a preoccupation for the city’s municipal administration.

Boorish behaviour

Wild boar have been involved in a number of traffic accidents, and have proven to be particularly dangerous when with their young, attacking dogs and even people. The city council in Genoa has put forward many proposals to reduce the number of animals in the city, ranging from forced removals, to sterilisation, increased attention to waste disposal and approved hunts. About 90 wild boar were reportedly culled in 2018.

Needless to say, each of these measures has been hotly debated. Animal advocacy groups staunchly oppose the proposals, and sometimes obstruct the authorities’ attempts to take action, often sending patrols to care for the animals, and even give them names. But other residents are displeased with the animals’ presence in the city, and have consulted with the council on how to address the problems that they cause.

And so Genoa continues to grapple with thorny issues surrounding the presence of wild boar in the city, with the city authorities seeking to resolve a polemical issue that embroils the lives of animals and humans alike. So far, a collective, coherent and communally agreeable strategy has proven evasive; one that considers the need for public safety, hygiene and health with the ethical responsibilities towards to wild boar themselves.

Meanwhile, the animals themselves continue to lounge and forage beneath the Ponte Gerolamo Serra and elsewhere, bringing a little of the wilderness into the city.

The Conversation

Robert Hearn, Assistant Professor in Human Geography, University of Nottingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.