Assessing the degree of pollution of groundwater by heavy metals in and around Kolomela Mine, Northern Cape Province

Abstract

This study has assessed the extent of heavy metal contamination in groundwater around the Kolomela iron ore mine in the Northern Cape Province of South Africa. A case study research design was employed, focusing on four existing groundwater monitoring boreholes (BH1–BH4) located in and around the mine. Groundwater samples were collected repeatedly over an eight-month period, thus covering different seasonal conditions to capture temporal variability or similarity in metal concentrations. Sampling followed standardised groundwater collection procedures, and laboratory analyses were conducted to determine concentrations of selected heavy metals, including Lead (Pb), Calcium (Ca), Copper (Cu), Chromium (Cr); Manganese (Mn); Nickel (Ni), Thallium (Tl); and Zinc (Zn). The data were analysed in the laboratory by means of Inductively Coupled Plasma–Optical Emission Spectroscopy and their patterns and trends were summarised by the use of descriptive statistical methods. The results were evaluated against South African drinking water standards (SANS 241) and World Health Organization (WHO) guideline values to assess groundwater quality. The results revealed a spatially and seasonally heterogeneous distribution of heavy metals across the monitored boreholes. While several metal concentrations remained within acceptable limits, elevated levels of certain metals were observed at specific boreholes and sampling periods, thus exceeding recommended guideline values and indicating potential risks to groundwater quality. These findings demonstrate that groundwater quality in mining environments may vary significantly over space and time, even within a single mining operation. The study highlights the need for improved groundwater management and regulatory oversight at Kolomela Mine, particularly in semi-arid regions where communities rely heavily on groundwater as a primary water source. The research indicates the importance of routine groundwater monitoring, adherence to national water quality standards, and transparent reporting of water quality data to regulatory authorities and affected communities. Thus, the findings provide an empirical basis to support evidence-based mine water management and policy implementation aimed at protecting groundwater resources and safeguarding environmental and public health in South Africa’s mining sector.