The use of water generally also generates wastewater. This is divided into
- Domestic wastewater, which flows into the sewage treatment plant via the local sewer system after use in the household,
- commercial wastewater, which is either also discharged into the local sewer system after use or is discharged directly into a body of water after treatment in an industrial wastewater treatment plant,
- agricultural wastewater (slurry, liquid manure) and
- rainwater and
- liquids that are discharged and collected from facilities for treating, storing and depositing waste.
Wastewater may only be discharged into a body of water if it has been treated using state-of-the-art technology. The aim of the very high quality requirements is to achieve the lowest possible water pollution.
The purification performance of municipal wastewater treatment plants has improved steadily over the decades. Today, over 95% of pollutants are removed from wastewater in a modern wastewater treatment plant.
Approvals
Anyone wishing to discharge wastewater into a body of water requires a permit under water law.
Under certain conditions, the infiltration of unpolluted rainwater, for example from private (non-commercial) roof and yard areas, is not subject to a permit. Decentralized rainwater disposal (infiltration/evaporation/retention) helps to recharge the groundwater and relieve the sewer system. It therefore also helps to reduce costs and charges in the wastewater sector.
Waste water levy
Under certain conditions, a levy must be paid for the discharge of wastewater into a body of water. The official forms for the so-called wastewater levy can be found on the homepage of the Baden-Württemberg Ministry for the Environment, Climate Protection and the Energy Sector.
