Germany – Engineering design services for the construction of civil engineering works – Ing.-Leistung LP 1-4, optional LP 5-9

The subject of the contract is the provision of services for the planning of civil engineering structures, structural design, and technical equipment as part of the construction of a retention soil filter (RBF) below the SKU Castrop-Rauxel Holthauser Straße and a new screening system at the SKU CAS-Holthauser Straße. The planned retention soil filter "RBF CAS-Holthauser Straße" is located on the left side of the Landwehrbach between km 3.9 and km 4.3. The planned retention soil filter is downstream of the SKU CAS-Holthauser Straße, which is located in the overall catchment area of the SKU HER-Langforthstraße. The current design envisages extending the diversion channel parallel to the Landwehrbach by approximately 130 m to feed the planned RBF. The mixed water flows at the end of the inlet channel over a total 90 m long inlet weir with a height of 51.60 mNN to the RBF. The retention soil filter is divided into two areas, each with a filter surface area of 2,520 m2, according to the explanatory report. At the end of the RBF is the filter overflow. After the RBF is completely filled, the water flows over a total 90 m long weir into the filter outlet channel and is then discharged into the Landwehrbach. The retention soil filter RBF CAS-Holthauser Straße will be operated in full flow. This means that the inflow to the RBF will not be restricted. The 1-year design inflow is Qzu,RBF = 11,969 l/s. According to the current planning status, no natural outflow to the receiving watercourse can be realized in free fall from the retention soil filter. Therefore, it is planned to lift the filtrate from the RBF (100.8 l/s) via a pumping station. In addition, the installation of a new screening system at the SKU CAS-Holthauser Straße is planned. A "Central Virtual Process Control System" (vPLS) is already implemented in the SKU CAS-Holthauser Straße. The screening system is to be integrated here.