We characterize a social clash over a gold mining project in terms of perception of environmental risks, preferred decision-making mechanism, trust in experts and government institutions, and fairness in the distribution of burdens and benefits. The results reveal that 85% of the local population were against the project. Disagreement between experts, the local population, and the mining company, distrust in institutions, and the lack of a participatory procedure for deciding local development strategies create serious difficulties in legitimizing the project assessment and approval. It seems that a ‘‘technical’’ solution is not possible due to the existence of conflicting value systems. We arrive at the conclusion that, in the present case, the final decision can be legitimized only if the adopted decision mechanism represents a shared meta-value principle, that is, direct democracy. However, the definition of the appropriate geographical scale for the voting process remains a contested issue.