It all started back in summer 1984. In the unhurried environment of Berne, Ralf Steeg watched people jumping into the rolling Aare river, just like that, when they wanted to cool down. At the time this was utterly unthinkable in his hometown of Berlin: People would not have dipped even their big toes into the Spree, so polluted it was with effluents. But Steeg, a landscape designer and environmental planner, just could not get the image of Berne out of his head and it subsequently became his mission in life to transform Berlin’s Spree river into a clean urban waterway – one in which people could finally swim. And so it was that starting in 2001, he developed the “Luritec” plant which in initially made the headlines under its original project name of “Spree 2011”.

The idea behind this is as simple as it is ingenious. Several times a year, heavy rainfall sorely tests urban sewage systems, and as a result sewage seeps into the rivers through overflow pipes. “In Berlin, this takes place more than 30 times per year, and in some other cities up to 100 times,” explains Steeg. And this is where the “Luritec” plant comes into its own. The system acts as an alternative overflow basin for rainfall and it is attached to the sewage pipes so that in extreme situations of the kind mentioned above the sewage backs up there and can subsequently be pumped back into the sewers as soon as capacities free up again. As a result, rivers are no longer be sullied by polluted water.

Just under two years ago, the first “Luritec” plant was installed at Berlin’s Osthafen inland port and the facility is now ready to go into mass production. The most recent “Luritec” plant is made up of only two modules: A cylindrical tank in which water is collected and a T connector that joins the tanks together and connects them with the sewage system. “Luritec” can be installed in next to no time – on water or on dry land, above and below ground. It has taken a mere eight months to set up the plant in Berlin. Another advantage is that it is easy to maintain – because the tanks (which are 3-10 ten meters high and come with a capacity of up to 700 cu. m.) are made of fiberglass-reinforced plastic they are easy to clean and there is no buildup of either weeds or noxious matter. There are filters to purify the contaminated air. The bottom line is that its comparatively short construction times and low cost mean “Luritec” can certainly compete with existing concrete overflow basins for rainfall, whose walls do become porous over time.

Although in future the system will probably be installed on dry land, as demonstrated by the €1.6 million test facility in Berlin, which is being monitored by researchers at Technische Universität Berlin, “Luritec” also works underwater. An additional plus point here is that the platform can also be used as an island, for instance, at beach bars. Nevertheless, there is still a great deal to be done before riverside life in Berlin can attain the standards set by Berne. According to Steeg there are 13 more overflow pipes to be installed all the way down to the center of town. And there has also been considerable resistance to the project from instances such as Berlin’s port and storage authority, known as Behala, which considers the islands in the Spree a thorn in its side. The State of Berlin and the Berlin water authorities threw another monkey wrench in the works last year when they informed Steeg that they would not be keeping the facility, which had by then retained more than 15 million liters of polluted water. However, Steeg remains undeterred. In the most recent past he came together for preliminary discussions with the organizers of “Flussbad Berlin” (river-current bath Berlin) who include, for example, Jan and Tim Edler of Realities United. The people he has engaged with all seek to redevelop the arm of the Spree running past Berlin’s renowned Museum Island such that people can swim in it. Moreover, a citizens’ action group is in the process of being established for the Rummelsburger Bucht area, consisting of people who, like Steeg, are interested in cleaning up the Spree. Meanwhile, Steeg is also offering his component system to other municipalities and operators. The engineer reports that there is considerable interest and that he has even received firm inquiries from Vietnam.