This article is part of POLITICO’s Global Policy Lab: Living Cities, a collaborative journalism project exploring the future of cities. Chapter 3 of the project is presented by Holcim.
Hold your pee when it rains – Brussels can’t cope with extra sewage flows during heavy downpours.
That’s the ironic advice of Canal It Up, a group of activists who want to clean up the Belgian capital’s heavily polluted canal.
His outlandish approach is part of a campaign to tackle one of the main causes of water pollution: sewage overflows.
Like most European cities, Brussels collects rainwater and sewage into one system, which means that on days of heavy rain, the system can overflow and flow into waterways, including the canal. .
Some 10 million cubic meters of wastewater ends up directly in Brussels waterways through overflows each year, according to Canal It Up. Add to that an estimated 6 million cubic meters of wastewater that is barely treated as factories struggle to handle the extra volumes on days of heavy rain.
Last year, the campaign counted 19 days in which sewage overflowed from a weir into the canal and 100 days in which it overflowed into the Senne, a small river that runs through the city, largely underground. This far exceeds the current standard in the Flemish region of the country, which limits overflows for newly constructed sewers to seven days a year. In October alone, the group recorded 10 days of overflows, two at the canal and eight at the Senne.
The problem will only get worse unless authorities in Brussels act, campaigners say, as heavy rains and storms are set to become more frequent and severe with climate change.
They ask the city to develop a comprehensive plan to retain more rainwater where it falls, copying a pioneering approach developed by the city of Copenhagen.
“Having untreated sewage, unfortunately, remains a problem in Europe” – and Brussels is an “exceptionally bad example”, said Sara Johansson, senior policy officer for water pollution prevention at the European Bureau of Water Pollution. environment, an NGO.
Such a waste
As part of efforts to create more green public spaces, Brussels plans to uncover parts of the Senne that were buried in the mid-19th century. Work on the project, which will cost around 20 million euros, is expected to start in 2023.
But the river is still far too polluted to be discovered, according to Canal It Up.
The paving of the Senne – where all the city’s effluent was discharged without treatment – aimed to prevent cholera epidemics and modernize the city.
But that hid more than it solved the problem. Brussels only started treating its wastewater in the 2000s, partly in an attempt to rid the river of its reputation as one of the most polluted in Belgium.
The city’s two treatment plants – built in 2000 and 2007 – have dramatically improved water quality, but overflows remain a key issue for improving the state of the Senne and other waterways, campaigners say .
It is also because the plants are not equipped to accommodate normal levels of rainfall as required by EU rules on wastewater treatment, according to Johansson.
The overflows are impacting the biodiversity of the region’s waterways, she said: “All these substances that are in our wastewater, whether from industry or road runoff, pharmaceutical residues , all this cocktail of substances passes without being treated with [Brussels] canal and further towards the sea.”
The Brussels Region says it addresses the issue in its latest water management plan for 2022 to 2027. Under European law, these plans must be renewed every six years.
The plan, which should be adopted in May or June after suffering delays, includes measures to fight in particular against the discharge of wastewater, said Martin Binon, legal adviser at the water service of Brussels Environment, the organization responsible for environmental issues in the capital. Region.
Among other measures, the city plans to strengthen the capacity of sewage overflow infrastructure to prevent spills and take steps to ensure that rainwater is retained as much as possible where it falls, according to Binon.
Campaigners say that is not enough, pointing out that more ambitious solutions are being rolled out elsewhere.
Best in class is Copenhagen’s Rainfall Management Plan, which aims to protect the city from flooding and water pollution during periods of heavy rain. Established in 2012, it will take 20 years to set up.
The city already had a head start on the matter: in the 1990s, it started building underground reservoirs along the harbor that hold rainwater, preventing it from entering the sewer system unitary and thus prevent overflows – a measure which made bathing possible in the region, said Lykke Leonardsen, Resilient and Sustainable Urban Solutions Program Manager for Copenhagen and one of the designers of the plan.
The plan became a necessity after a massive downpour in 2011 exposed the city’s vulnerability to flooding. It seeks to “build infrastructure essentially parallel to the existing sewer system” to retain rainwater where it falls and prevent it from flooding critical infrastructure or entering the sewer system, it said. she declared.
In parts of the city with sufficient space, this means creating new green spaces to allow the drainage of rainwater. Copenhagen is also building infrastructure such as tunnels to retain rainwater until treatment plants have sufficient capacity to treat it, for example.
Other cities are taking similar steps to prepare for more severe storms and protect their waterways: In a bid to make the Seine “swimmable” by 2024, Paris is building a huge reservoir that can hold 46,000 meters rainwater cubes. London is building a 25 kilometer tunnel which will intercept, store and transfer sewage from the Thames.
The Belgian capital needs an ambitious plan on the scale of Copenhagen to make up for its “historic” failure to properly tackle water quality, says Pieter Elsen, the founder of Canal It Up, on a recent clean-up trip on the city’s canal.
Elsen, 35, started fishing for litter out of the canal in his green kayak three years ago. At first, he focused on plastic waste floating on the surface of the water, but hours spent paddling the river made him want to take action on water quality more broadly.
Now, sewage overflows are one of the main issues Elsen mentions to locals and politicians before outfitting them with kayaks, nets and buckets and sending them down the canal.
Improving water quality is “the most complicated problem to solve”, he said.
This article is part of POLITICO’s Global Policy Lab: Living Cities. Chapter 3 of the project is presented by Holcim. The article is produced with complete editorial independence by POLITICO journalists and editors. Learn more about editorial content presented by external advertisers. You can sign up for Living Cities here.