In the past, drainage problems within combined sewer networks have been solved exclusively by static and constructional concepts. Since the middle of the 1970s (at first in the USA, later on in Europe, too) real-time control has been applied to manage systematically existing drainage assets and thus to utilise the maximum of the systems capacities. The development of the integrated control of sewer network and wastewater treatment plant has been furthered in the last decade. Integration of the receiving waters and their processes has been partially taken into account as well. However, global real-time control strategies still show a lack of implementation for large drainage systems of high complexity.
In Berlin, Germany, a city of 3.5 million inhabitants covering an area of around 900 km², the demand for enhanced protection of the environment and the growing economic pressure have led to an increasing application of control assets and concepts within the sewage system. In the framework of the project “Integrated Sewage Management” the possibilities of a global and integrated control strategy for the Berlin system are examined.
The article is focused on the historical concept and design of the sewerage and the further improvement towards an environment-oriented system that builds the basis for today’s considerations. The operational method and functionality of local regulators that have already been implemented are described.
Furthermore, the model-based methodology for the development of global control concepts as well as results of integrated system analysis are stated. On the basis of model simulations it is shown that a global coordination of pump stations can lead to a reduction of total emissions from the wastewater system and consequently to an enhanced water protection. Main improvements can be achieved concerning combined sewer overflows. These improvements are of major significance due to the high hazard potential of combined sewer overflows. The high dynamic of the discharge event and the high fraction of biodegradable organic substrate causing oxygen depletion lead to particular stress on the water bodies.