Mining impacts assessment using the LCA methodology: case study of Afema gold mine in Ivory Coast.

Environmental impact assessment studies are mandatory for major industrial or infrastructure projects in most countries. These studies are usually limited to on-site impacts during exploitation but do not consider indirect impacts generated off-site or those concerning other steps of the project, including dismantling. National regulations in various countries have recently begun to include these neglected impacts to obtain a better appreciation of project trade-offs. Several scientists have highlighted the substantial potential of using the life cycle assessment methodology to increase the level of detail and completeness of EIA studies. Even if mining activities are known to produce significant local impacts, their consequences outside an extraction site have not yet been well documented. The implementation of the LCA methodology in the EIA procedure has been carried out in a gold mining project by separating on-site and off-site impacts during the entire life cycle of the mine from prospection to site restoration following the end of exploitation. Mining projects occur over large time periods and require diverse materials and processes. The main difficulty of such analysis is the data collection that needs to be extrapolated for some of the activities. Even with these limitations, the Afema case study highlighted the significant share of off-site impacts (from a spatial perspective) and the major contribution of the exploitation phase of the mine (from a temporal perspective). Operating activities, especially excavation, ore and waste rock transportation, blasting, ore processing and tailing treatments, are the main impacts produced during the exploitation phase and are involved in climate change, particulate matter formation, and land destruction. Therefore, this standardized LCA method should be recommended by the regulatory authorities for use in EIA procedures. This article is protected by copyright. All rights reserved.