Anyone taking a harbor tour in Hamburg is sure to notice them: the distinctive digestion towers of the Hamburg wastewater treatment plant. The plant not only purifies all of the city's wastewater, but also uses it to generate electricity with a generator converting the digested gases rising from the sewage sludge into energy. Three wind turbines and a large photovoltaic system are also part of Hamburg’s wastewater treatment plant. In total, it even produces more electricity than it needs for its operation. To ensure that the interaction of these energy generators runs smoothly, Hamburg’s wastewater treatment plant relies on active filters from Reinhausen.