Wastewater from settlements originates from households, trade and industry. It contains faeces and rests of food stuff, detergents and cleaning substances as well as other products consumed in households. Also, residues of chemicals originating from trade, agriculture and industry are input. Rainwater adds pollution from corroding building material, atmospheric deposits and traffic. Pollutants and nutrients are largely treated in municipal wastewater treatment plants, but micro-pollutions from settlement drainage continue to be problematic.
Assuring the supply with drinking water and wastewater treatment requires constant high investments. The objective is to largely cover costs by income from water rental fees imposed upon households, industry and agriculture. In future, the use of the environment and of resources will be integrated into the calculation of costs for services to a larger extent.