The main objective of this research is to conduct a cost-benefit analysis of water quality improvement that would be achieved through upgrading of wastewater treatment plants in Switzerland with the aim of reducing the levels of micropollutants. This project will identify the total costs of investments in terms of their net present value, which are needed for the planned upgrading of wastewater treatment plants. In the second step, the benefits of enhanced water quality that would result from these investments will be estimated based on a survey. The choice experiment will be applied in order to elicit the willingness to pay of Swiss residents for higher water quality resulting from reduced levels of micropollutants. The experimental design will consist of defining an increase in water quality, measured by a change in the levels of different micropollutants. Those changes will be translated into effects on human health and ecosystems in order to make them easily understandable to survey respondents. The respondents will also be carefully informed about uncertainties associated with the effects of micropollutants. Furthermore, the survey will examine the perceptions and awareness of Swiss residents about the current water quality, micropollutants, and the price they are presently paying for drinking water and wastewater services. Based on a comparison of costs and benefits of upgrading wastewater treatment plants, the project will conclude whether or not the investment is justified from an economic point of view.