No abstract

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 environmental impact assessment (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 life cycle assessment (LCA) methodology in the EIA procedure has been carried out in a Au 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. Integr Environ Assess Manag 2021;17:465–479. © 2020 SETAC

The chemical analyses of surface water revealed that almost all the studied water are of poor quality based on the water quality index (WQI). On soils and stream sediments samples the chemical analyses showed Cd, Pb and As pollution. While soil contamination by Pb may be due to mining activity as shown in the water case, Cd and As seems to be coming from agricultural activities due to the widespread contamination. This study allowed us to get an overall view of the state of the environment after the end of the mining activity with the focus on the state of the quality of water consumed by the populations. A more detailed study must be carried out in order to accurately characterize the origin of the metal pollution in the waters.