Every year, the four sewage treatment plants in Bonn produce around 7,000 to 8,000 tons of sewage sludge, which is currently incinerated in the incineration plant on the grounds of the Salierweg sewage treatment plant. The existing sewage sludge incineration plant will no longer be able to be operated economically in a few years' time due to its age (built in 1981) and the extreme strain on it. At the same time, the legal framework conditions for the disposal of sewage sludge have changed due to the new Sewage Sludge Ordinance in 2017.

In summer 2022, the City of Bonn therefore joined Klärschlammverwertung am Rhein GmbH (KLAR GmbH) as a shareholder in the construction of a new sewage sludge recycling plant in Cologne in order to ensure the long-term recycling of Bonn's sewage sludge from 2029. KLAR GmbH - the shareholders are Stadtentwässerungsbetriebe Köln, AöR (StEB Köln), Stadtwerke Köln GmbH (SWK), the City of Bonn and Klärschlammkooperation Poolgesellschaft mbH (KKP), an association of several smaller towns and surrounding municipalities - is currently planning the construction of a new sewage sludge recycling plant in Cologne-Merkenich; construction is scheduled to begin in 2025, with commissioning planned for 2029. According to a council resolution, sewage sludge is to be transported from the Bonn Salierweg sewage treatment plant to the new wastewater treatment plant in Cologne-Merkenich by ship using environmentally friendly propulsion systems.

A port facility in Bonn in the area of the Salierweg sewage treatment plant and in Cologne Merkenich in the area of the new sewage sludge recycling plant is required for the loading and unloading of the ship's sewage sludge. The new sewage sludge recycling plant in Cologne will use the port of Cologne Niehl II, while the neighboring port of Bonn will be used at the Salierweg sewage treatment plant.

For the handling of the sewage sludge during operation of the port, technical facilities must be created on an area of the port that is conveniently located to the sewage treatment plant. Detailed considerations of the handling technology and infrastructure as well as further coordination with the port operator will be required in the course of further planning. The majority of the technical facilities will be located on the grounds of the Salierweg sewage treatment plant, with a small part on the grounds of the Port of Bonn.

The facilities will be used to transport the dewatered sewage sludge from the sludge dewatering building by means of pumps and pipelines to newly constructed sewage sludge silos, which are required for the intermediate storage of the sewage sludge. From the sewage sludge silos, pumps and pipelines will also be used to transport the sludge from the sewage treatment plant site to the nearby transfer point at the planned berth of the sewage sludge ship in Bonn harbor.

The contract award procedure will be carried out by KLAR GmbH through the contract award office of Städtische Entwässerungsbetriebe Köln AöR (StEB Köln). The commissioning and conclusion of an engineering contract will take place after the award procedure has been completed by the City of Bonn.