The famously clean Austrian city boasts one of the world’s most innovative waste processing systems.
Visiting Vienna for the first time, what’s absent from the city’s streets can be as striking as what’s present. Certainly, you’ll notice the endless slabs of hefty baroque and historicist architecture (surrounded by a thick band of well-maintained public housing) and the ubiquitous public transit and bike lanes that have helped keep the city at the top of the Mercer Quality of Living Ranking for the past eight years. But you’ll also notice something just as striking: trash. Because there isn’t any.
Vienna’s almost eerily spick-and-span appearance isn’t just the product of an obsessive interest in public order. It’s the only visible trapping of one of the most innovative garbage management systems in the whole world. Unlike any other major world city, Vienna manages its residual waste entirely within the city limits—and even turns trash into a key resource that keeps hundreds of thousands of citizens warm through the winter. To find out more about the system works, I caught up with the city’s head of waste prevention, Martina Ableidinger, at last week’s ReSITE 2017 urban development and design conference.
Vienna may be wealthy, but it faces many of the same problems as other cities. As across the developed world, Vienna’s recent history of trash management has been about struggling to manage a dizzyingly steep growth in waste, as the graph below reveals.
Look back a century and the amount of waste the city produced was both limited and stable. Bar a dip during the hard times of World War II and a spike immediately after as the city cleaned up, things stayed fairly static until the 1960s, when a growing economy and population, as well as a new packaging system, saw the volumes of waste start to rise. Faced with this steep climb, Vienna started burning trash in the 1960s and separating it for recycling in the 1980s. Waste levels have continued to climb ever since, and just about stabilized last year. (That blip downward in 1987 was caused by the destruction of an incinerator by—you guessed it—fire.)
The continued growth of incineration in the city might seem like little to cheer about, were it not for one of the most striking elements of Vienna’s scheme. Ever since the city installed incinerators in 1963, they have channelled their heat into the city’s district heating system, which in itself now provides heating and hot water for 350,000 Vienna apartments, around a third of the city’s total. The actual proportion of energy the waste supplies the city varies from season to season.
“In summertime, about half of Vienna's district heating energy comes from waste incineration. That's a period when demand is pretty low, of course, and is needed mainly for hot water, a very small amount of heating and some district cooling systems,” Ableidinger explains. “In winter, when demand is much higher, the proportion of district heating from waste drops to a third.”
That’s an impressively large saving for the city. During the coldest months, around 120,000 Viennese homes are being kept warm solely on trash that would have been destined for incineration anyway. Add to that the emissions reductions from not shipping recycling waste beyond Austria (as many European countries do) and you’re looking at a considerably more sustainable way of managing the city’s trash mountain.
Such waste-to-energy systems are not entirely uncontroversial. Trash incinerators, like any form of combustion, produce carbon emissions and pollution; they’ve been rejected by some other urban areas over fears of lead and mercury contamination. Vienna claims its incinerators produce 90 percent less than the legal annual limit for emissions, processing all fumes to relative cleanliness through a triple filter viewable in the diagram on this page.
The system is also climate-friendlier than leaving waste unburnt in a landfill site: As this article notes, incinerated waste is on average comprised of two-thirds biomass which, as it decomposes, produces substantial amounts of methane, a more potent greenhouse gas than carbon dioxide.
But even if Vienna’s melding of the trash and heating systems is on a considerably greater (and greener) scale than in most cities, the sheer growth in volume of the trash that needs processing is still alarming. That’s why the city also engages in numerous public education drives, variously encouraging citizens to switch from disposable to multi-use cups for takeaway coffee, to cut down on their food waste or to use washable diapers for their babies. Perhaps the most striking tool adapted by the city, however, is a semi-commercial one. The city of Vienna sells trash back to citizens.
Not any old trash, mind you. In 2015, the city opened its own store, called 48er Tandler (or “48 Junk Shop” in Austrian German, referring to the waste management service’s official name, Department 48). Here it sells choice items gleaned from the city’s waste collection services back to locals, in surprisingly salubrious surroundings.
The store matches discarded items in good condition with objects that have been left unclaimed in the city’s lost-and-found office for over a year. The goods on offer are all in near-mint condition, if sometimes a little unusual: Current options include a British flag rug and a “Chinchilla cage.” The main point of such transactions is arguably not to claw back funds or cut recycling (though both of those are a great idea) but to open a dialogue with residents.
“Vienna is not a city with an enormous amount of space, but we try to stay close to citizens, think about what they want or need,” says Ableidinger. It’s not easy, it turns out, to get Viennese to face up to their garbage. “For a long time, our city planners felt strongly that trash cans should not be seen because they were a kind of eyesore. But if people don't see them, people don't use them.”
Now, Vienna’s 18,000 trash cans have a bright orange band around them, and a phone number encouraging citizens to call the city in case of problems. “We’re trying to become a little less invisible, in a way.”