Wastewater is water whose properties have been altered by domestic, commercial, agricultural or other use, and water collected from precipitation running off built-up or paved areas (precipitation water), cf. also the Water Resources Act (WHG).
The toilet is not a garbage chute Please also help to prevent waste materials from entering the wastewater, as they cause major problems both in the domestic installation and in the sewer network and wastewater treatment plant. 100 million m³ of water are used for car washing every year! Please drive your car to the car wash or clean it only at advertised car wash locations that have modern technology.