Contents lists available at ScienceDirect Groundwater for Sustainable Development journal homepage: www.elsevier.com/locate/gsd Research paper Potential heavy metal pollution of soil and water resources from artisanal mining in Kokoteasua, Ghana Ebenezer Gyamfi a,* , Emmanuel Kwame Appiah-Adjei a,b , Kwaku Amaning Adjei a a Regional Water and Environmental Sanitation Centre, Civil Engineering Department Kwame Nkrumah University of Science and Technology, Kumasi, Ghana b Geological Engineering Department, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana ARTICLE INFO Keywords: Groundwater Artisanal mining Heavy metals Pollution indices Ghana ABSTRACT Effluents and mine waste from artisanal mining in Kokoteasua, a community in Ghana, are discharged directly to the environment without prior treatment and have the potential of polluting the soil and water resources that the populace rely on for their daily water need. Therefore, this study has assessed the impact of the artisanal mining activities on the soil and water resources in the community. The method employed involved mapping the water supply points in the community and sampling the water supply points and the soil (at 20 cm and 40 cm depths) to determine their heavy metal levels (i.e. Fe, Pb, Zn, As, Mn, Cu, and Hg). The water quality was assessed using the World Health Organisation (WHO) guideline values for drinking water while pollution indices were used to evaluate the levels of soil pollution. The results, generally, indicated that groundwater in the community is potable but unsuitable for drinking in isolated locations due to high levels of As and Zn. The stream, however, recorded high levels of Mn, Fe, and pH above the acceptable WHO drinking water guidelines. Again, the study found the soil to be extremely polluted with all the measured heavy metals (except Hg) from contamination factor, enrichment factor, geo-accumulation index and pollution load index assessments. Thus, the artisanal mining needs to be regulated to protect the water resource and soil from further pollution. 1. Introduction Groundwater constitutes about 97% of the available freshwater on earth and forms an important component of the water cycle (Delluer, 1999). It serves as a source of potable water for agriculture, industry and domestic use as well as in helping to maintain soil moisture, wet- lands and stream flows in many parts of the world (Oladeji et al., 2012). Qiu (2010) estimated that groundwater constitutes about 70% and 40% of the total water resources used respectively for domestic and irriga- tion purposes in China. Nickson et al. (2005) also estimated that about one-third of global population depend on groundwater as their source of potable water. In Ghana, groundwater serves as the main source of sustainable water supply for the populace living in rural communities and emerging communities in the urban areas (Duah and Xu, 2006). Groundwater of good quality is very important to these communities because it is their main source of potable water for drinking and domestic purposes. Commonly, anthropogenic activities such as farming, indiscriminate waste disposal and mining among others significantly influence groundwater quality either directly or indirectly (Teaf et al., 2006). For instance, mining activities generate waste such as waste rock, tailings and effluents at the various stages of processing the ore, which have the potential to leach through the soil into aquifers and directly pollute groundwater (Johnson and Hallberg, 2005). A typical pollution of groundwater from effluents of mine waste is reported by Obiadi et al. (2016) at a coal mine in the Enugu area of Nigeria, which contaminated surface water and shallow groundwater with high levels of acidity, iron, and sulphate. Studies by Mallo (2011) also found that effluents from mines usually have very low pH, which causes acid mine drainage and ends up in water bodies including groundwater. Oladipo et al. (2014), similarly, found evidence of heavy metal contamination of groundwater as a result of illegal mining activities in Zamfara State, Nigeria. Ghana is known to be one of the major gold producers globally, and the mining sector is believed to contribute significantly to the gross foreign earnings of the country. Artisanal gold mining has been on the increase in the country and it is said to be a major contributor of metals in water resources due to indiscriminate use of Mercury (Hg) and other harmful chemicals in the mining activities (Donkor et al., 2006). Globally, small-scale mining is noted to be a major contributor to the pollution of water resources because it makes use of huge volumes of water thereby polluting the water resources (Cunningham et al., 2005; Owens et al., 2005). Most artisanal mining operators have no https://doi.org/10.1016/j.gsd.2019.01.007 Received 26 July 2018; Received in revised form 24 December 2018; Accepted 21 January 2019 * Corresponding author. E-mail address: gyamfiebenezer@ymail.com (E. Gyamfi). Groundwater for Sustainable Development 8 (2019) 450–456 Available online 02 February 2019 2352-801X/ © 2019 Elsevier B.V. All rights reserved. T