New technology for the environmentally friendly wastewater treatment is now to be installed: By the end of 2022, the Eifel-Rur Water Association is investing around 4,00 million Euros in the conversion of four secondary settling tanks at Wastewater Treatment Plant Aachen-Soers in order to effectively relieve the polluted water load. The ozonation plant has already been built and, as the largest in Europe, integrated into the existing wastewater treatment system. The wastewater treatment plant has been treating the wastewater of the city of Aachen since 1913 and is dimensioned for 458,300 population equivalents. By 2022, four secondary settling tanks will be upgraded step by step with new stainless steel central structures and height-adjustable inlet structures. The DN 700 return sludge pipes will be replaced by new stainless steel pipes. The optimization of the secondary clarification system is expected to increase the capacity by approx. 20%. A joint venture with DAHLEM as lead company has been commissioned with the project and specialist planning. The state of NRW is funding both the large-scale technical implementation and the accompanying research on the entire project of the wastewater treatment plant.

It is almost cojmpleted - the reconstruction of Katernberger Bach: On a length of approx. 1,1 kilometers the stream receives new space next to the old waterway. Furthermore, the stream will run openly for 1,2 kilometers. Construction started in 2019. Since the 1960s, it has been flowing through the Katernberg district of Essen mostly with pipes. The opening up of the stream and the separation of clean and polluted water as well as the renaturation of blocked waterways should improve the stream ecologically. The redesign is part of the Century Project for the ecological improvement of the Emscher system between Dortmund and Dinslaken, which started in the 1990s. By means of subsidence, the pure water produced in the upper reaches will be pumped via a new pure water pumping station to the planned disclosure section. In addition to the hydraulic engineering planning, bottom slides, fords and bridges will be constructed and several culverts will be implemented. In addition to the ecological improvement measures, experience stations will be built to make the water accessible and thus integrate it into the life of the district. The Emscher River Association (Emschergenossenschaft) commissioned DAHLEM with the project planning, structural design, technical equipment and site management for the reconstruction of the watercourse.

At MARK 51º7, the former Opel factory site in Bochum, an industrial, technology and knowledge campus is currently being built that will fulfil the requirements of future work environments, supporting a work/life blend. With development at an advanced stage and the infrastructure almost entirely complete, the ambitious plan for the location is increasingly becoming a reality.For the development of the sewer and road construction, DAHLEM, as part of a joint venture, supervised the implementation of the gigantic and complex construction site. The design and construction supervision for the stormwater retention basin, with a volume of 6,500 m³ for protection in cases of heavy rain, has already been completed. The site was awarded the polis Award 2019 in its category as "Best urban surface recycling, MARK 51°7 - successful reactivation in eastern Bochum".

Even if there are no visible electrical installation works on the construction site of Pumping Station Oberhausen yet, the electrotechnical equipment ist making bis steps forward. At the factory acceptance test in Finland, two out of the 10 frequency converters of the "small" and "large" sewage pumps were successfully tested and approved by the manufacturer as the first components of the powerful drivelines. These are frequency converters with a nominal voltage of 690 V and a rated current of 1.180 A, respectively 1.700 A, which corresponds to a rated output of 900, respectively 1.250 kW. The high demand on the network repercussions with limit specifications to the harmonic, inter-harmonic and, for the first time, also to the supra-harmonic currents, required the frequency converters to install active line filters and correspondingly large-sized line reactors. These are, like the actual power electronics of the frequency converter, cooled by water. Each frequency converter consists of 5 control cabinets, with each frequency converter being approx. 3 m wide. Helmut Mangelmann heads the Electrical Engineering Department at DAHLEM and works in the team of the design consortium (Planungs-ARGE) of Pumping Station Oberhausen: "We have planned and built quite a lot in the field of electrical engineering, but these dimensions go far beyond the previous performance levels. In the low voltage sector, they are at the limits of what is technically possible in terms of circuit and transmission technology."

The government grant decision, which the Environment Minister Franz Unterseller (left) handed over to Lord Mayor Fritz Kuhn (middle) and City Director Wolfgang Schanz (right), Head of the Civil Engineering Department, on 3^rd September on the spot, was the starting signal for the expansion of the main sewage treatment plant Stuttgart-Mühlhausen with a fourth treatment stage. The main sewage treatment plant Stuttgart-Mühlhausen, built in 1916 as one of the first sewage treatment plants in Germany, is operated by Stadtentwässerung Stuttgart (SES) and should count to the most modern ones in the Federal Republic by 2028. Due to the complexity and the considerable investment, the expansion will take place in three construction phases. In the first phase, powder activated carbon silos and dosing stations will be set up at the Biology North and South as well as an energy control centre will be built. The federal state of Baden-Württemberg supports this project with just under 3 million EUR. With the construction of the treatment stage for the elimination of trace substances, the City of Stuttgart is making a significant contribution to water protection in the federal state. Dipl.-Ing. Mathias Kleffmann, process expert at DAHLEM and project manager of the design consortium, is pleased. "It's great that we can now start with the direct dosing on a large-scale and implement the new process technology on a industrial scale." 

By means of holistic optimization, Waste Water Treatment Plant Aachen-Soers has succeeded in reducing the enormous energy demand of the recovery by around 55 per cent. Together with DAHLEM, the Wasserverband Eifel Rur planned the modernization of the oxygen supply of the aeration tanks. The design was implemented at the beginning of the year, followed by the commissioning of the blower station mid-year. The RWTH Aachen accompanies the project scientifically. DAHLEM supported the process design, which was modeled in a 3D-planning and accompanied the award procedure. The enclosed article about the project provides detailed information about the modernization of the plant. The waste water treatment plant is also referred to as a nationwide model Enterprise.
Article, "Water & Waste Water Technology” magazine, July 2019

There was much enthusiasm at an unusual design meeting on the extension of WWTP Kleve-Salmorth, which is soon to be launched as a thermo-compact plant: plant manager Michael Offenberg and his team from the Kleve-based environmental operations were able to see how it felt in the new buildings of the waste water treatment plant. Is there enough space between the plant parts? Can one move well in between? Are there any missing components, etc. With the help of VR glasses, Torsten Wach, who is in charge of the project coordination, guided the participants through the building model, which was projected directly onto a screen. It made it possible for all involved to point out errors or changes and to rectify them before the start of construction. WWTP Kleve-Salmorth is regarded as a flagship project for innovative sewage sludge treatment and meets the requirements of the new Sewage Sludge Ordinance for Waste Water Treatment Plants to reclaim phosphorus from municipal sewage sludge in the future. Thus in the long run, the supply of this nutrient, which is central to all organism, shall be ensured. DAHLEM provides the design services, from the initial conceptual design to the award, including construction supervision.

The Rhine-Main area is booming and with the increase in population, the demand for potable water is also rising. It is the second dry summer in a row. However, the amount of water needed is not the problem, its distribution is, say the experts at the Hessen Water company. The company intends to build a reduntant potable water transport pipeline west of Darmstadt. The length of the planned steel pipeline with a diameter of DN 1000 will be about 17.4 km from Riedstadt-Wolfskehlen to Gernsheim-Allmendfeld (waterworks). This also includes a connection to the Eschollbrücken waterworks and a booster station to be built there. The route is partly located in potable water protection areas, crosses a Natura 2000 site and often finds itseld in areas with high groundwater levels. For the approval of the potable water transport pipeline, Hessen Water will apply for a planning approval procedure with public participation at the Darmstadt Regional Council. DAHLEM, as part of a joint venture, provides the technical engineering services for the planning of the construction measure (design, approval and implementation planning as well as preparation and participation in the contract award procedures).

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Large excavation of 95.000 tons of earth was necessary to move the former, dead straight and musty-smelling Köttelbecke into the new stream bed in the Pelkum field. Freed from dirty water, the renaturated border stream between Bottrop and Gladbeck now meanders cleanly through the reed-covered landscape. The measure is part of the Emscher Renaturation Generation Project and was celebrated on 18.09.2019 with Lord Mayor Bernd Tischler, City of Bottrop, Mayor Ulrich Roland, City of Gladbeck and the board members of the Emschergenossenschaft Prof. Dr. Uli Paetzel and Dr. Emanuel Grün. Emschergenossenschaft is investing a total of around five billion Euro in the generation project. In this way, the association is making a contribution to urban development and climate protection, said Paetzel. The enlarged water surface helps cool off heat islands and becomes a biotope for strengthening biodiversity. DAHLEM was commissioned with the construction planning for the conversion of the water body up to the involvement in the contract award.