Sustainable Decommission of Mining Lands: Landform Design for Eaton Tuner Shaft (ETS) Area, Obuasi, Ghana

Abstract

Ghana is the first country in the Sub-Sahara African region to reform its mining sector and has become the poster child for such change in the developing world. Obuasi is the hub of gold mining in Ghana. The Obuasi mine is currently operated by AngloGold Ashanti (AGA), and contributes immensely to the Gross Domestic Product (GDP) of Ghana. Mining is however, an activity that causes disturbance to the natural habitat and threatens biodiversity. Mining of mineral resources results in extensive soil damage, altering microbial communities and affecting vegetation leading to destruction of vast amounts of land which needs to be reclaimed and restored. Reclamation is the process to restore the ecological integrity of these disturbed mine land areas. Mining at the Eaton Tuner Shaft (ETS) area has been decommissioned and this paper seeks to explain processes leading to the sustainable design of a safe and suitable landform for the ETS as part of closure plan by reclaiming the vast land currently in the heart of Obuasi town. This is an exploratory study employing survey methods, geotechnical profiling and topographical survey to obtain data for the landform design and ultimate land reclamation. The study revealed that the soils at the ETS area have an upper stratum of sandy Gravels underlain by strata of silts or sands with average plasticity index of 14.46% and can be used as fill material with mean allowable bearing capacity between 781KPa and 1,413KPa. For a sustainable landform design, the study recommends a gentle slope transitions of about 2.5% and 1:2 for embankments.

Keywords: Reclamation, Mining lands, Sustainable decommissioning, Landform design, Obuasi

DOI: 10.7176/JEES/9-12-07

Publication date: December 31^st 2019