Painless extraction? : mining and water-resource protection

This article recounts the experience gained during environmental impact assessment (EIA) of several gold mining projects in south-west Ghana. A survey of water use and quality in the area revealed that water sources were frequently of poor quality and that this was compounded by mercury and high levels of suspended solids present in gold processing wastes. Local water bodies held significant stocks of freshwater fish. Several types of water-related diseases were observed. The environmental impacts of gold mining include: reduced availability of water sources for domestic use and fisheries; increased risk of vector-borne diseases; and (bacteriological and chemical) pollution of water. These impacts are a result of the mining activity itself and of the influx of people seeking work. Mitigation measures involve altering proposals to avoid sensitive areas or to prevent the creation of sites, such as pools, which can be used by disease vectors. Control measures involve both the treatment of sewage and of processing waters. Compensation can be given as financial renumeration for lost resources (e.g. fishing sites) or it can involve the replacement, for example, of drinking-water supplies. Restoration of resources is also a means to compensate for adverse environmental impacts. All these measures require a clear understanding of the local political environment. Mitigation projects should be careful not to encourage over-dependence on external support.