Germany – Engineering design services for the construction of civil engineering works – 26-059 | Abbau bestehendes RÜB und Neubau RÜB in Minseln

As part of the general drainage planning for the district of Minseln, the City of Rheinfelden (Baden) plans to implement the measure M5 "New Construction of RÜB Minseln with Inlet and Outlet Structures". The measure is part of the water law-coordinated renovation concept for the mixed water treatment of the district and serves to adapt the existing drainage infrastructure to the current water management and hydraulic requirements. The existing combined sewer overflow tank is located at the southern end of the district of Minseln, between the composting plant of the company Lützelschwab and the Mühlbach on parcel No. 4456. The structure was originally built in the 1980s and in 2002 extended by a throttling shaft with mechanical throttling device and hydraulically optimized. The existing rectangular tank has a usable volume of around 130 m³ and a throttled discharge of 40 l/s. The plant essentially consists of an inlet channel DN 1500, the combined sewer overflow structure with integrated tank overflow, the settling tank, a throttling shaft, the clarifier overflow pipe, the relief pipe to the Mühlbach, and the associated measuring and monitoring devices. As part of the planned measure, the existing plant, including the settling tank, throttling shaft, relief and clarifier overflow pipes, and other associated plant components, is to be dismantled and replaced by a new combined sewer overflow tank. The construction of a structure with a storage volume of approx. 1,030 to 1,200 m³ and a throttled discharge of 65 l/s is planned. In addition, the necessary inlet and outlet structures, new channel connections, and the complete electro-mechanical equipment of the structure are to be created. According to the current concept plan, the new construction includes, among other things, a flow-through tank, a settling tank, a throttling shaft, tank overflow and clarifier overflow devices, flushing devices, and the necessary measuring, control, and regulating technology. The measure forms a central component of the renovation variant provided for in the general drainage plan. By significantly increasing the storage volume, the requirements for mixed water treatment are to be met and the hydraulic load on the Mühlbach or Dürrenbach is to be reduced. The catchment area assigned to the structure comprises around 24 ha of effective mixed water areas of the district of Minseln. The current cost estimate is around 6.0 million € net. According to the cost estimate for the general drainage plan (as of July 2024), this includes around 475,000 € net for the inlet and outlet channels, 4,520,000 € net for the new combined sewer overflow tank, and 980,000 € net for the electrical and mechanical equipment. The total costs of the measure are currently estimated at around 5.98 million € net. The subject of the current tender is initially the services of the design planning for civil engineering structures according to § 41 HOAI for the dismantling of the existing plant and the planning of the new combined sewer overflow tank including the associated inlet and outlet structures. The necessary specialist planning services, in particular for the technical equipment, the structural design, and further project-related expert opinions and investigations, will be commissioned in separate procurement procedures and must be integrated into the overall planning by the design planner. The above-mentioned procedure is currently in the first stage, the competition for participation. As part of the competition for participation, three bidders are to be selected on the basis of the criteria listed in the notice, who will then be invited to submit an offer and make a presentation.