Emschergenossenschaft, the largest water management association in Germany, is responsible for the Emscher river basin (865 km²). Its restoration is a project of enormous proportions that will extend across generations, with a total investment of € 4.5 billion. Pöyry has supported this extraordinary undertaking since 2006.

BACKGROUNDThe Emscher, a tributary of the Rhine, was straightened between 1906-1914 in the course of the industrialization of the Ruhr. The river was surrounded by dikes and used as a wastewater conduit in the following decades. In view of the decline of the mining industry in the region, the Emschergenossenschaft is now renovating the river and its tributaries into semi-natural waters, and thus developing the watercourse into an attractive destination for the inhabitants of the region.

With an investment volume of € 4.5 billion, the undertaking is one of the largest infrastructure projects in Europe. By 2018, a total of 400 kilometres will be transferred to the new underground wastewater conduits in the Emscher system. Pöyry is responsible for the design planning and implementation of a 42 km section of the new underground

shafts. Because of the dense population of the Emscher region, the conduit system is being built using pipe jacking – at depths of up to 40 m in some portions. The underground conduit has to bypass multiple crossings with the Emscher and the Rhine-Herne Canal, including an underpass of the Gelsenkirchen sluice. The association also faces challenges

wastewater conduit of the Emscher, as well as of the wastewater conduit for its tributary. In addition, two sewage treatment plants along the route will be expanded or upgraded by Pöyry: the Dortmund Deusen sewage treatment plant and the Emschermündung sewage treatment plant, one of the largest sewage treatment plants in Europe.

CHALLENGE FOR THE CUSTOMERThe entire wastewater discharge must be placed underground to make restoration of the above-ground river bed possible. Pöyry was commissioned to design and supervision the construction of the conduit section between Dortmund and Dinslaken, which is set up as a closed pipe system. This also involves the construction of 43 main shafts made of acid-resistant concrete with diameters from 9.50 m up to 25 m, as well as 29 secondary

New life for the Emscher region

SHARING SUCCESS

According to Reinhard Ketteler, Emschergenossenschaft Project Director, “Pöyry is a long-term, absolutely reliable partner with whom we share a successful collaboration. We very much appreciate the multidisciplinary expertise with which Pöyry has supported us in planning issues and technical challenges – both in the construction of conduits and sewage treatment plants, as well as in coordinating with authorities and communities”

Pöyry P.O.Box 4 (Jaakonkatu 3)

FI-01621 Vantaa, FinlandTel +358 10 3311

www.poyry.com

TECHNICAL DATA

Emscher wastewater conduit• Length: about 42 km• Diameter: DN 1400-2800• Depth: 10 - 40 m• 72 shafts, internal diameter:

9.50 - 25 m

Berne wastewater system• Length: about 13 km• 5 conduits with storage capacity and

overflow, 2 stormwater overflow tanks, 1 stormwater retention tank

Emschermündung sewage treatment plant• 1,600,000 EW • Volume of wastewater: 16.5 m³/s

Dortmund-Deusen sewage treatment plant• 705,000 EW• Volume of wastewater: 4.5 m³/s

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such as the geographical extent of the project, coordination with various local authorities, licensing authorities and land owners, and construction in some very densely populated areas.

As part of the restoration, the sewage treatment plants along the river course also have to be integrated into the new wastewater conduit. The Emschermündung sewage treatment plant in Dinslaken is currently operated as a river sewage treatment plant. The future feeding through the wastewater conduit with only 16.55 m³ (as compared to the previous 45 m³) per second requires extensive new construction measures in the inlet.

SOLUTIONSThe length of the Emscher wastewater conduit and its formidable depths in some portions present the Emschergenossenschaft with a a mammoth task.The operation of the channel will also be very complex. For example, because of its dimensions, outlet air disodouring treatment will be necessary. At Pöyry’s suggestion, photooxidation will be used for this purpose instead of the originally planned biofilter plant. Photooxidation reduces investment and operating costs and thereby ensures more stable operation

than the conventional biofilter technology, providing the Emschergenossenschaft with savings in the millions. The mechanical cleaning stage is being completely renovated for the connection of the Emschermündung sewage treatment plant to the wastewater conduit, and a new inlet lifting system and pumping station are being built as well. In addition, cutting-edge dynamic simulations were performed in order to manage the hydraulic adjustment, thus enabling optimization of the inlet route of the structure for deposit-free operation.

CUSTOMER BENEFITSIn Pöyry, the cooperative gains a long-time project partner who can handle all construction and planning technical requirements of each project under a single roof. The company‘s broad range of competencies in construction, in machine and process engineering, and in general planning of large water and infrastructure projects ensures smooth coordination and timely execution. In addition, they are the driving force behind innovative ideas for efficient operation, and they will enable significant cost savings. The use of cutting-edge tools, such as the hydrodynamic and procedural simulations that were carried out

in the Emschermündung sewage treatment plant, ensures efficient implementation of the restoration that is both ecologically and economically sustainable.

The Emscher

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