"Look, a mattress! And here, an old carpet!" exclaims one of the visitors in amazement. The grabs take the waste into the hoppers to be recycled in the combustion chambers. But why is the waste constantly being mixed by the grippers? "For example, some waste is drier, some is wetter - we also talk about low and high calorific waste. As this burns differently, everything has to be mixed thoroughly. This is how we achieve a kind of homogeneous mass," explains Antonia Windheuser, who organizes guided tours at SWB Verwertung.

Curiosities from the slag
Curious objects can sometimes be found in the mountains of waste. It's not just mattresses and carpets that end up here. "We've also discovered brass Buddha statues or a safe in the slag," says Windheuser with a smile. "Whether there was a treasure hidden inside remains a mystery."

Successful soil testing
The waste recycling plant works around the clock, 365 days a year. Waste is constantly being recycled. The floor of the wider waste bunker - also known internally as the old bunker - has not seen daylight for around ten years. It goes down twelve meters from the first floor. It was last renovated in 2015. At the beginning of February 2025, it was partially uncovered again so that experts could take soil samples and inspect the concrete. The result: everything was in perfect condition. Meanwhile, operations continued uninterrupted.

District heating from Bonn's waste
The waste bunker extension was put into operation in 2016, increasing the storage capacity from 13,000 to a total of 27,000 cubic meters. This ensures a continuous supply of steam to the neighboring SWB Energie und Wasser combined heat and power plant. The plant not only contributes to waste recycling, but also to climate-friendly electricity and district heating production.

So what at first glance appears to be just residual waste is actually a valuable source of energy. The Bonn waste recycling plant is a fascinating place that shows how waste can become a sustainable resource.