Risk Assessment of Tailings Disposal in a Portuguese Gold Mine Project. Contribution of Geostatistical Tools

Abstract

The specific of the waste management of mining industry (landfills and tailings dams) impose the need of detailed closure and emergency plans, even in the pre-feasibility mine project. Risk management in mining waste disposal facilities implies policies aiming hazardous risk assessment as well as the implementation of mitigation and risk control programs. The present work is based on a case study involving the tailings dam of a Portuguese Gold Mine Project. A risk assessment considering an inventory of the different causes associated to a probability of a possible accident versus the severity of the consequences was established. As a result, different scenarios of rupture of the dam were established. Geostatistical tools were used to estimate and design flood maps in the event of collapse of the tailings dam. These flood maps allow not only an a priori evaluation of the areas eventually affected and the impact on neighbouring populations, but also constitute key elements in the implementation of emergency procedures that must accompany the life of the structure.