Cologne's wastewater future: Tunnel boring machine Henriette” successfully recovered!

Cologne's wastewater future: Tunnel boring machine Henriette” successfully recovered!

The recent construction work in Cologne-Niehl has taken a remarkable turn: the tunnel boring machine “Henriette”, which weighs over 100 tons and has been working under the Rhine since May, was successfully recovered. As the WDR Reportedly, the rescue posed a challenge, particularly due to a stubborn lump of clay and nuts that were difficult to remove. These difficulties meant that the work could only be completed around midnight.

“Henriette” had dug an important tunnel during her operations under the Rhine between Cologne-Stammheim and Niehl. This tunnel is part of a larger project to replace the sewage pipes, which are now over 100 years old and are essential for the city's wastewater disposal. The renewal is not only necessary to modernize the infrastructure, but also to respond to Cologne's expected population growth.

Important step for the wastewater infrastructure

Around 80 percent of Cologne's wastewater is treated in the Cologne-Stammheim sewage treatment plant. In fact, this corresponds to an expansion size of around 1,570,000 population equivalents. The large sewage treatment plant, which is located in the north of the city on the right bank of the Rhine, currently serves around 800,000 residents as well as industry and commerce that generate wastewater for the equivalent of 500,000 residents. The plant purifies around 84 percent of the city's domestic and industrial wastewater STEB Cologne explained.

The new pipes that are being laid in the tunnels that have just been dug are intended to increase the efficiency of wastewater treatment and make maintenance work on the pipes easier. The large sewage treatment plant has been modernized several times, most recently in 1992, in order to meet changing legal requirements. Comprehensive renovations to the process technology as well as the electronic measurement, control and regulation technology are currently underway in order to further optimize the processes.

Outlook for the coming months

Construction of a second tunnel is now underway and is scheduled to be completed by November 2025. The new Rhine culvert is expected to be put into operation in 2028. By this point, pipes and cables still need to be laid and construction pits converted into shafts with platforms and control technology.

A large part of the future planning in the large sewage treatment plant also includes the conversion of the low-load revitalization system, which has been operated unchanged since the 1990s. Numerous measures are taken to improve the hydraulic even distribution and increase the biological cleaning performance. The sludge treatment process is also being modernized, like that Tuttahs Meyer underlined.

In summary, Cologne is well on the way to preparing its wastewater infrastructure for the challenges of the future. The successful completion of the recovery of “Henriette” marks an important step in the right direction.