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GELSENKIRCHEN UND WASSER
Towards a New Order: Gelsenkirchen
provides Inspiration on Water Gelsenkirchen is situated in the Ruhr Area, a region that amounts to 4488 qkm. Here you find three rivers: In the south rises the Ruhr, farther north the Emscher and in the very north of this region runs the river Lippe. The Ruhr Area can be divided into three zones according to the river, draining the zone. From south to north you find the Ruhr zone, Emscher and Lippe zone. Gelsenkirchen is a town in the Emscher zone.
Figure
1
:
Extension of the Ruhr Area
The Emscher Zone is the region of the Ruhr Area which has changed most in the past 150 years. This is especially true when focusing on water. Going back 150 years in this region you might get a picture of a hilly landscape, soft hills only, you might listen to small rivers running in their natural bed. Here and there you might see a farm or a mill, grinding wheat, and you might see patches of forest. People live in farm houses and cottages spread over the country or in villages. The roads are not paved.
It
is not easy transporting heavy loads on the loamy streets. Coal is not
found in this region yet. Farther south close to the Ruhr, where the
coal was near the surface, people were winning coal next to their
farming activity. This picture of an agriculturally influenced and
rather poor region changed within half of a century very drastically.
Pioneers investing all they owned, tried to localize coal in 90 meters depth in the Emscher Region. Many ruined their lifes, few succeeded and became the so-called lords of coal. One reason for failures was the groundwater which has to be removed while digging deeper. The development of the steam engine allowed progress in coal mining after all.
Progressing in coal mining resulted in immigration of millions of people within a short period of time. Small villages turned into big towns, hastilly built to provide accomodation. While the highly populated region gained drinking water from the river Ruhr, it had problems with the high amounts of waste water from private households and from the industries, which developed enforced by coal and technical progress. Waste water was simply introduced into the drainage system of the river Emscher. Furthermore due to intense mining activity and following removal of coal and leavings the land began to subside. Consequently the way the water had found over a time of 10 000 years changed resulting in stagnating rivers spoiled by waste water. At the heydays of coal mining at the beginning of the 20th century cholera, typhus and Ruhr spread at the cost of many lives.
There was a call for managing the waste water situation. In 1904 the Prussian government released a law for the Ruhr Area in order to enable the foundation of the Emschergenossenschaft. It regulated the membership and the function of this federation. Thus the first Water Ressources Association of the German Empire was founded. The cities and counties of the Emscherregion, companies and mining enterprises became members. The tasks were clarification of water, sewerage, flood protection and water maintainance. Due to the underground movement it was rendered impossible to dispose wastewater into subterranean canals. Thus the Emschergenossenschaft started canalizing the river system of the Emscher. The Emscher became a wastewater canal above ground.
The sagging of land resulted furthermore in one third of the Emscher region being a polder. Polders are areas where the water does not flow off naturally. The Emschergenossenschaft installed 95 pumps within the region to transport waste water and groundwater to clarification plants or to a river with a flow off.
Until 1976 the Emscher and its inflows were only clarified mechanically by several sewage works. Then the first clarification plant with biological systems was built. At that time it was the biggest clarification plant in Europe. The Emscher as a whole flew through it, thus being clarified before flowing into the river Rhine. In the nineties the Emschergenossenschaft built two further sewage plants in Dortmund and in Bottrop.
Figure 2: The Emscher region with its clarification plants, black point: plants present or being reconstructed, black/white points: plants in construction, white: plants planned
In principal, waste water is treated in four steps in the clarification plant. Mechanical clarification separates big waste water components from water by a rake, a sand catcher or in a settlement tank. After mechanical treatment the waste water is introduced into a biological treatment tank where microorganisms live on organic waste water components. After biological treatment activated sludge (mixture of water and microorganisms) flows into final settlement tanks. Here sludge is separated from the aqueous phase. The clarified water is reintroduced into the environment. The sludge is partially reused in biological treatment, partially it is stored in digestion tanks to stabilize the sludge.
To improve water quality of the Emscher, is one of three steps of the reconstruction of the Emscher system. Since the mining industries moved farther north, the lowering of the land stopped and plans were made to renaturate the Emscher System and install underground waste water canals. Renaturating the Emscher amounts to 8,7 billions DM in a time period of 20 to 35 years invested by the Emschergenossenschaft, the government of North-Rhine-Westfalia and the IBA Emscherpark Projekt. The waste water canal has been installed close to the mouth of Emscher between Oberhausen and Bottrop. Its diameter is about 3 meters and it is located at a depth of 30 meters under the surface.
Some influxes of the Emscher are completely or partially renaturated yet, accompanied by waste water canals under the surface. Among others the renaturated rivers are the Läppkes Mühlenbach in Essen, the Deiniger Bach in Castrop-Rauxel and the upper part of the Emscher in Dortmund.
Furthermore the Emschergenossenschaft is involved in enhancement of rainwater percolation. In the highly industrialized Emscher Zone soils are sealed to a high degree. Thus rainwater flows into the sewage plants loading it unnecessarily at high costs. Additionally the rainwater does not give rise to groundwater. Accordingly the Emscher Zone is in the need of groundwater regeneration. Enhancing rain water percolation is a further step towards a more natural state of the Emscher System.
While the Emscher has been the waste water river during the heydays of coal and steel industries, the Ruhr, the Lippe and the dams of the Sauerland supply the Ruhr Area with drinking water (Figure 3 ). The Ruhrtalsperrenverein (since 1899) and the Ruhrverband (since 1913) take care of quality standards.
Figure 3 : Dams (Talsperren) of the Sauerland and the river Ruhr providing drinking water
An important provider of drinking water since more than 100 years has been the Gelsenwasser AG. It supplies 33 municipalities in the Ruhr and Münsterland regions with water as shown in the figure on the right. Among many others, Gelsenwasser AG maintains a waterwork in Essen supplying Gelsenkirchen with water. Its characteristics are shown in the table below.
Interesting
Links http://www.emschergenossenschaft.de http://www.route-industriekultur.de
The Author Dr.
Marion Schoone is biologist and environmental educationist. At present
she works at the Laboratory for Wastewater Technology at the Polytechnic
Gelsenkirchen. Furthermore she is assistant lecturer for “education on
sustainable development” at the Institute for Geography at the
Ruhr-University Bochum.
Present
address: Fachhochschule
Gelsenkirchen Fachbereich
Ver- und Entsorgung Labor
für Abwassertechnik Neidenburgerstr.
10 45877
Gelsenkirchen Mail: Marion.Schoone@fh-gelsenkirchen.de
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