Expanding the hydrogeological base in mining EIA studies: A focus on Ghana

Conducive economic policies have led to a vibrant minerals and mining sector in Ghana, with the establishment of 12 new large-scale gold mines since 1988. The Environmental Protection Agency (EPA) has been strengthened and a robust monitoring regime is in place to prevent abuse of the environment. Insufficient attention has been paid, however, to the necessary hydrogeological detail of statutory environmental impact assessments (EIAs). This should be specified in order to furnish concise knowledge of the pre-mining groundwater conditions. Although such information is normally obtained through pumping tests, the cost involved has hitherto precluded its use. Yet hydrogeological data can be estimated from thin section and other studies on borehole cores obtained during routine mineral exploration. Combined with other “regional” methods of gathering groundwater information, these estimates provide a sound basis for baseline condition evaluation for less than 0.1% of the average expenditure incurred in locating an economic deposit. Apart from improving mining EIA practices, the proposed approach can also yield dividends for the mine operator, in terms of helping to find water for mine needs, and minimising water ingress to workings and associated pollutant release.