Olumide Ajayi

Acid Mine Drainage (AMD) is one of the most complex and damaging forms of mining pollution in South Africa, with long-term consequences for groundwater, river systems, biodiversity, and public health. Given the increasing impact of climate variability—particularly intensified rainfall that accelerates contaminant migration—a systematic and interdisciplinary approach to AMD mitigation is essential, combining science, technology, and policy management.

One of the most powerful tools in identifying and tracking AMD is geochemical fingerprinting, which enables precise differentiation between natural background geology and anthropogenic contamination. The use of isotopic analyses (e.g., sulfur, lead, strontium isotopes) and trace element profiling significantly improves the identification of contamination sources and migration pathways—critical prerequisites for effective remediation planning.

In terms of remediation technologies, passive treatment systems such as constructed wetlands and reactive barriers using limestone or natural zeolites show strong potential in the African context. These systems require minimal maintenance and can be integrated into local ecosystems. Additionally, bioremediation using sulfate-reducing bacteria offers a sustainable solution by precipitating metals as sulfides and neutralizing acidity, which is especially valuable in remote or under-resourced areas.

From a governance perspective, robust legal and institutional frameworks are essential. Strengthening regulations that mandate post-mining rehabilitation, establishing monitoring systems that utilize satellite and sensor technologies, and ensuring data transparency through open-access platforms are key steps. Engaging local communities in monitoring and decision-making further enhances the legitimacy and sustainability of interventions.

In summary, a combined approach involving advanced geochemical diagnostics, sustainable remediation technologies, and strong policy enforcement offers the most promising path forward for mitigating AMD impacts and protecting Africa’s vital groundwater resources.

With 35 years of remediation experience I suggest there are multiple steps required. First is source removal which would be a massive undertaking. Thus the second first to limit additional adverse effects on surface and groundwater is applying gas infusion to change the oxidation state in a barrier which would allow for the metals to precipitate. Some research will be needed to identify which pathways can work.

There is a much longer answer than that biogeochemically.

Also without significant coercion by the government(s) agencies nothing will be done.

First one, set the basic grounds for the (potential) responsibles to take action. So, first step should setting a comprehensive policy framework.

Then, you should study the problem, generating conceptual model(s) (from mine/site to watershed scale), doing field investigation (sampling/analysis of sludge/waste, leachate, groundwater, surface water...). Geochemical fingerprinting would fit this step.

Finally, if AMD is confirmed and unacceptable effects (actual or potential) identified, remediation should be done, sustainable remediation technologies being the ones that would probably offer a "better" result.