The paper presents first results and ideas from an ongoing project dealing with the construction of a private closed-end fund for the municipal area of Hannover, Germany. It is argued that for assessing the economic prospects of the project it is helpful to apply a Monte Carlo (MC) simulation approach. Thereby, it is possible to account for contamination risks. Questions that must be solved are (1) to find probability distributions for the uncertain variables and the correlations among these, (2) to adequately intergrate legal and political parameters ...