Analysis of mine water from four decommissioned pits in south-western Ghana – implications for remediation programmes for mine closure

Abstract

Research into water quality status of accumulated water in decommissioned pits is a grey area in Ghana and could be of significant benefit in the effectiveness of remediation of pits after mining. Water sampled from four decommissioned pits in Amansie West District were analysed for their water quality status. Seasonal variations of physico-chemical parameters for determining water quality were reported as well as their average values. In general, the ion concentrations varied from season to season but were within World Health Organization (WHO) maximum permissible limits (MPL) with the exception of boron. Similar observation was made for heavy metals/trace elements analysed, with the exception of As and Fe. Seasonal and average concentrations of As were higher than the WHO MPL. Similarly, the mid-season concentration of Fe recorded from a water sample collected from one pit was higher than WHO limits. Turbidity levels were significantly higher in two pits. The studies revealed that some parameters for water quality determination were above WHO acceptable limits for potable water, an indication that the effect of mining on water quality from water bodies investigated persisted after mine closure. Hence remediation programmes should be broadened to include effective reclamation of mine water accumulated in pits during mine closure.