In his work the market potential of on-site treatment systems are estimated on a spatially explicit scale with help of geographical information systems (GIS). With help of the developed methodology the relationship between the Swiss settlement structures and wastewater infrastructure costs are examined. The results show that from an economical point of view the marginal existence of decentralized wastewater systems not justifiable.

The master thesis was carried out at Eawag (ESS and SWW department) and was supervised in collaboration with the Department of Geography of the University of Zürich.