Mining Influenced Water

Mining has shaped South Africa's economy for over a century, but it has also left a profound and enduring legacy of water quality degradation across large parts of the country. Mine-impacted water encompasses a range of water quality problems associated with both active and abandoned mining operations, the most significant of which is acid mine drainage (AMD) – the acidic, metal-laden leachate generated when sulphide minerals in exposed rock and tailings react with water and oxygen. AMD is characterised by very low pH, elevated concentrations of sulphate, iron, manganese, and heavy metals, and extremely high electrical conductivity, making it toxic to aquatic life and unsuitable for most water uses without extensive treatment.

South Africa's most critical AMD challenges are centred on the Witwatersrand gold mining basin in Gauteng, where decanting mine water poses a direct threat to the Vaal River system and urban water supply infrastructure, and the Mpumalanga coalfields, where large volumes of mine water affect the Olifants River catchment – one of the country's most heavily water-stressed river systems. Beyond AMD, mine-impacted water also includes tailings seepage, process water from mineral processing, and dust and runoff from mine waste facilities. The management of mine-impacted water is a national priority, with significant implications for water security, public health, ecological integrity, and long-term liability for both the mining industry and the state.

The resources below provide access to data, mapping tools, research outputs, and regulatory guidance relevant to mine-impacted water in South Africa.

Data & Mapping

South African Mine Water Atlas (WRC) The primary national reference for mine water data in South Africa, providing online and downloadable maps of groundwater vulnerability, mining and mineral distributions, and mine water threat assessments across the country. An essential starting point for any research on mine-impacted water.

Council for Geoscience – Mine Water and Environmental Geoscience The CGS conducts research and provides data on the geological and geochemical controls on AMD and mine water quality across South Africa, including geological maps and borehole data relevant to mine-affected areas.

DWS Resource Quality Information Services (RQIS) National water quality monitoring data from DWS stations in mine-affected catchments, including long-term datasets on pH, sulphate, iron, and electrical conductivity in rivers and groundwater.

PHREEQC Geochemical Modelling Tool (USGS) A widely used geochemical modelling tool for simulating the chemical behaviour of mine water, including mineral dissolution, metal speciation, and neutralisation processes.

Key Research & Reference Resources

WRC – Mine Water Research The Water Research Commission has funded extensive research on AMD characterisation, prediction, treatment, and management across South Africa. Search the WRC Knowledge Hub for reports on AMD, mine closure, tailings management, and passive treatment systems.

Centre for Environmental Rights – Mining and Water Legal and regulatory resources on mining's impact on water resources in South Africa, including litigation, compliance monitoring, and community rights in mine-affected areas.

Inter-Ministerial Committee on AMD (IMC) The South African government's inter-ministerial response to the Witwatersrand AMD crisis, including reports on the short-term and long-term interventions commissioned for the Central, Eastern, and Western Basins of the Witwatersrand.

Treatment & Management

Mine water treatment in South Africa employs a range of active and passive technologies, including:

Active treatment — lime dosing, high-density sludge (HDS) processes, reverse osmosis, and ion exchange, used where rapid neutralisation and metals removal is required
Passive treatment — constructed wetlands, anaerobic compost bioreactors (ACBs), and permeable reactive barriers, increasingly used for lower-flow, lower-risk situations at lower operating cost
Desalination and resource recovery — technologies for recovering sulphate, metals, and clean water from AMD, moving towards a circular economy approach to mine water management
Neutralisation ponds and evaporation dams — commonly used at operational mines but with significant long-term liability if not properly closed

WRC – Passive Treatment of Mine Water Research on cost-effective passive treatment approaches for AMD and mine-impacted water, including constructed wetland performance data from South African case studies.

Regulatory Framework

Mine-impacted water in South Africa is regulated across several pieces of legislation, reflecting the intersection of mining, environmental, and water law:

National Water Act (Act 36 of 1998) — water use authorisation for mine water discharge and abstraction
Mineral and Petroleum Resources Development Act (MPRDA, Act 28 of 2002) — environmental management programme requirements for mines, including water management plans
National Environmental Management Act (NEMA, Act 107 of 1998) — environmental authorisation and compliance for mining activities with water impacts
National Environmental Management: Waste Act (Act 59 of 2008) — classification and management of mining waste including tailings and AMD-generating waste rock