Berlin technology in wastewater treatment plants

Berliner Wasserbetriebe have continuously enhanced the treatment performance of their wastewater treatment plants and hold a leading position worldwide in the use of suitable technologies – all of which are developed in Berlin.

Compared with 1990, 81 percent less phosphorus and 98 percent less ammonia nitrogen are discharged today into Spree and Havel from the Berlin wastewater treatment plants. Phosphorus as a nutrient is mainly responsible for the growth of algae. Particularly toxic for fish is ammonia nitrogen which consumes the oxygen in the water. Both substances have a direct influence on the water quality.

This reduction in these values illustrates the significant improvement in quality that we at Berliner Wasserbetriebe have been able to achieve, both through the increased treatment performance of the wastewater treatment plants and through a change in the distribution of the wastewater streams. More than four billion Euros have been invested in the capital’s infrastructure since 1990 to discharge and treat the wastewater.

Protection of the water resources is of great importance for Berlin. The extensive water areas are intensively used recreational zones for the people of Berlin and habitats for plants and animals. The percolated water from the rivers and lakes feeds the groundwater from which Berlin draws all its drinking water. Not only that: as far as water is concerned, Berlin is a low-exchange region. The Spree and Havel are in effect not so much rivers as an extended chain of lakes. Two-thirds of the water has already seen human consumption at least once.

That is also why the regulations of the Berlin authorities for the treatment performance of the wastewater treatment plants are far stricter than the national regulations of the Federal government. Even today, we already lie around 61 percent below the values specified by the Federal government in all six wastewater treatment plants – and 23 percent below the values stipulated for Berlin. The technology needed to achieve this – the combination of biological phosphate elimination with nitrification and denitrification – was developed in Berlin.

During the 1990s, the volume of wastewater to be treated fell by 28 percent and has remained more or less constant since 1998. That is why the wastewater farms and the Adlershof, Marienfelde and Falkenberg wastewater treatment plants were closed down. The redistribution of the wastewater streams, such as the diversion of Spandau wastewater to the Wansdorf wastewater treatment plant and the splitting of the wastewater volumes of the Falkenberg wastewater treatment plant shut down in 2003 between the Schönerlinde und Waßmannsdorf wastewater treatment plants have had a positive effect on the water in the Spree and Havel in Berlin. In order to protect the bathing water in the Lower Havel (Wannsee), the discharge of the Ruhleben wastewater treatment plant is diverted during the summer season into the Teltow Canal which effectively then functions as a ‘by-pass’ for the Spree in the city centre.