Industrial companies are recycling more of their wastewater. They are increasing their capacity or saving costs, and subsidies are also an attraction.

While normal wastewater from households goes to the sewerage system and then to municipal wastewater treatment plants, the situation is different in industrial plants. In many cases, their wastewater contains substances that destroy the bacteria used in conventional municipal wastewater treatment plants. It is for this reason that they must not be discharged into the sewer system by law. However, in the case of large industrial plants, the amount of wastewater produced can be so large that a standard municipal sewage treatment plant cannot accommodate it. In such cases, they have to arrange for the treatment or disposal of the waste water in another way.