Casting bread upon the waters

Budapest, in Hungary, takes its water seriously: its innovative approach to water management goes from wastewater treatment to civic engagement.

  • Location: Budapest, Hungary
  • Population: 1.7 million
  • Theme: Water and wastewater management
  • Places visited: South-Pest Wastewater Treatment Plant, Danube riverbank, Nehru Park

If there is a common denominator that represents Budapest, that is the Danube river. While crossing 10 countries in total, its connection towards Budapest is undeniable. Thus, the capital of Hungary is, in a big way, its link with these waters. No wonder that that relation has translated into a long tradition and extensive knowledge in water related issues, as well as into a highly developed water infrastructure and water management expertise. Nevertheless, water pollution is still a considerable problem here, having pushed the country to establish stringent legal regimes and solid institutional frameworks in water and sanitation management to safeguard the liquid resource.

Organica Water Inc. upgraded the water and wastewater treatment of the South-Pest Wastewater treatment Plant with its Food Chain Reactor solution. Photo: Viktória Selmeczy.

In Budapest, around 500.000 m3 of wastewaters are generated on a daily basis. The main sources of this contamination come from industrial and agricultural activities, but also from societal use. In the meantime, the traditional wastewater treatments have stood as large, centralised facilities, with the added aspect of the strong odours they tend to produce. That is why they have also been constantly built outside of populated areas, thus needing massive infrastructure requirements and much higher water treatment costs. This was the case, too, of the South-Pest Wastewater treatment Plant. But since 2009, Organica Water Inc. came by with its novel Food Chain Reactor (FCR) solution, meant to act as an upgrade to the treatment plant.

The FCR facility is a type of Fixed-Film Activated Sludge system using both natural (i.e. plant roots) and engineered (i.e. a biofibre inspired by root structures) media to allow for the growth of a robust and healthy biomass that effectively gobbles up the incoming load in the effluent. By means of their roots, the plants not only provide a huge amount of surface area, but they also complete the food chain that exists in the biological reactors, thereby enabling a diverse ecologic and resilient biofilm that is able to handle a higher amount of fluctuations in influent quality and quantity — compared to conventional suspended or attached growth systems.

Fixed-Film systems are based on the Activated Sludge process, whereby micro-organisms and bacteria consume the contaminants in wastewater. Organica’s FCR has drastically improved this process by leveraging a fixed-bed biofilm that grows on both natural and engineered root structures in a cascading reactor design, allowing a much greater quantity and diversity of organisms to thrive in the same physical space.

Organica’s FCR solution uses natural and engineered media to effectively gobble up the incoming load in the effluent. Photo: Viktória Selmeczy.

The FCR upgrade to the South-Pest Wastewater Treatment Plant successfully resolved the secondary treatment-related issues, thus enabling the plant to treat 80.000 m3/d. It also came to enhance the overall reactor efficiency, providing an average 50% reduction in effluent total nitrogen, while requiring over 50% less aeration, 25% less sludge production, and also resulting in energy savings. The final result is a solution which offers a significantly reduced physical footprint and lower operational and infrastructure costs when compared to conventional wastewater treatment solutions. And the cherry on top of the cake: it all comes in the form of a pleasant botanical garden-like environment.


Budapest is called the Pearl of the Danube, because its 525 km2 are situated all along the two banks of the Danube — dividing the city in the Buda and Pest areas. Twelve road bridges and two rail bridges connect the two sides, connect the city. But, most importantly, connect the people with the water.

In this line of connectivity, the interrelation and activities of citizens with the river are becoming a base of life. In other words, civic engagement. That is what The City and River Association (Valyo) understood, coming to birth as an independent organisation of Budapest citizens who share the enthusiasm for the Danube and its potential to help make the city a better place to live in.

The association is currently working on finding ways to reconnect the city and its inhabitants with the Danube, considering that the river’s bank is a perfect location for sports, cultural events and other leisure activities — romance included, perhaps. Among their activities to connect people through water, they started the Szabihíd project, redefining what water management can also get to be. The project dates back to 2016, when the Liberty bridge became the most popular hang-out spot of locals due to its closure to traffic for reparations. Its temporary reconversion to a social gathering spot resulted in Valyo to start a campaign for the city administration to make this scenario reiterative. And now, car-free weekends occur frequently, allowing for city dwellers to take the bridge and relate with the river life through concerts, movie screenings, theatre plays and many more, having turned the Liberty bridge in a real island of liberty above the Danube. Valyo, of course, is not alone. Local municipalities, together with NGOs and citizens, are constantly working on to create new strategies and activities to create a more liveable, smart and green urban environment in Budapest. Because, as the idiom goes, come on in, the water is fine.

Photo: Viktória Selmeczy.

Going beyond – The renovation of Nehru Park

One of the most promising possibilities of Ferencváros, Budapest’s 9th district, is the renovation of the Nehru Park, located in the Danube’s riverbank. Thus far, the playground and green surface of the park have been renewed, a biodiverse garden has been installed, sports facilities have been renovated and expanded — including a soccer field, three basketball courts, chess tables, a BMX and skate park, and equipment for open-air workouts. Its further renovation potential, even more, is still under ongoing discussions to better relate locals with the Danube.