The present work introduces the development of a three-step decision support system for helping management to decide in contaminated sites remedial projects. Based on previous models, the first step of the system provides a risk assessment procedure to identify and classify sites suspected of contamination. A second step deals with the identification of the technically suitable remedial options for the identified sites. The third and final step of the system suggests the most appropriate technology for the management of the contaminated sites through the utilization of a Balanced Scorecard constructed for this purpose. The system introduces the points of view from all project stakeholders into its evaluation, which determines henceforth a more integral decision-support tool. The developed system can be utilized as a know-how transfer tool for developing countries. The system has been used in cooperation with the Chilean National Environmental Commission in the first land register of sites potentially contaminated in the Region of the Bio Bio, aiming to characterize the dimension of its contaminated sites problem. Finally, considering the identified contaminated sites situation in the Region of the Bio Bio, the activities needed for a future application of the developed knowledge-based tool in Chile are introduced, as well as the steps to follow for an adaptation of the state-of-the-art remedial technologies from the European experience to the Chilean situation.