Wittfeld is responsible for both the technical and commercial aspects of planning, implementation, accounting and documentation of all work. While the two joint venture partners Eiffage Infra-Vortriebstechnik and Smet Tunneling are responsible for tunnelling work on the entire construction project, Wittfeld is responsible for the earthworks and civil engineering work, including the construction of excavation pits and construction aids as well as the construction of the engineering structures. Preparatory work began in December 2016. Construction work has been underway since February 2017.
 
ARGE Landwehrbach was given the go for the first construction phase, which stretches from the Rhine-Herne Canal to km 1,800 of the Landwehrbach. Approx. 330 m of DN1200/DA1560 pipes (1.20 m inner diameter) have already been laid north of the motorway A42 using pipe jacking. The 18-metre-deep excavation pit for the rainwater treatment plant has also already been excavated. Waste water is being dammed here during heavy rainfalls and later fed back into the sewer system. In the event of extreme heavy rainfall, the now heavily diluted waste water is discharged into the Landwehrbach via an emergency discharge.