Giant freshwater aquifer in southern Africa under threat from mining

A huge underground water resource the size of Austria, the Stampriet Transboundary Aquifer System, stretches for 87 000 square kilometres (km²) across Namibia, South Africa and Botswana. It supplies 50 000 people in several towns with water pure enough to drink, and is their only source of water. But the Namibian government has awarded uranium prospecting licences to several mining companies across the aquifer system. Other mining companies already have the right to prospect for rare earth metals in the aquifer. Surina Esterhuyse and Anton Lukas are groundwater scientists and mining specialists. They say if mining goes ahead, the groundwater may become contaminated by metals that can cause cancer, kidney damage, bone fragility, cardiovascular issues and respiratory problems.



What mining licences have been applied for?

Uranium: At least seven uranium mining companies have applied to the Namibian government for uranium mining licences. So far, 35 uranium exploration licences have been issued by the Namibian government. These cover 3.3 million hectares of Namibian land and 29% of the 87 000 km² area. The exploration licences set out the ways that the mining companies may explore for minerals, before they start mining.



Each licence is different and is determined by the country issuing it. There is an ongoing battle between the Namibian ministry of agriculture, water and land reform and the mining companies over the exploration licences.



Namibia’s minister of agriculture, water and land reform, Carl-Hermann Schlettwein, said in June 2024 that his priority was to make sure that the Stampriet Transboundary Aquifer System would not be polluted and would continue to supply clean water in future.



Petroleum: Petroleum exploration licences for shale gas, petroleum and natural gas cover 37% of the aquifer system. Four oil and gas companies have applied for petroleum exploration licences in Namibia and one in Botswana.



Base and rare metals: Licences to explore have been granted in Namibia for base and rare earth metals across 10% of the aquifer. These metals include tin, lithium, rubidium and tantalum.



How could the aquifer be affected by mining?

The combined extraction of oil and gas, uranium leach mining and rare earth heavy metal mining could contaminate the aquifer. This has happened in the boreal zone in Canada, where 80% of mining for ferrous metals, precious metals, base metals, oil and gas, and precious gems takes place. Research has found that mine effluents and acid mine drainage have seeped into water resources. The groundwater is also contaminated by heavy metals.



It is difficult to rehabilitate groundwater that is contaminated by different chemicals that have interacted with each other. It becomes nearly impossible to determine how much each mine contributed to the damage and what percentage of the cleanup each mine is responsible for.



Oil and gas: Groundwater pollutants from oil and gas extraction sites could contaminate aquifer systems with saline waters. These pollutants may migrate from surface spillages into shallow aquifers. They can also migrate via leaking production wells to freshwater aquifers.



Base and rare metal mining: Heavy metal pollution is a known cause of groundwater contamination.



Uranium: In situ uranium leach mining could contaminate the aquifer system with radioactive leach fluids. This is because uranium mines drill thousands of boreholes over more than 1,000 hectares.



Sulphuric acid is typically injected into the aquifer rock that contains the uranium to dissolve it. The mine then pumps out the aquifer water and removes the uranium. The process repeats until economically viable amounts of uranium are exhausted.



At this point, the mine shuts down operations. The wastewater from the operations can be partially recycled at other active uranium well sites, or be injected into deep saline aquifers, or pumped back to an area of the mined aquifer, which is what Uranium One proposes.



This creates a risk for contaminated groundwater to be drawn to the outside of the mine area, where it can be pumped out by farmers or local communities.



Uranium One believes in “spontaneous neutralisation” – that the minerals in underground rock will neutralise the sulphuric acid and the company won’t have to rehabilitate the aquifer. But this kind of natural rehabilitation has not yet been proven.



How could people in the area be affected by the mining?

With large-scale irrigation projects in Namibia extracting water from the Stampriet aquifer, groundwater can flow from mine areas towards freshwater zones in the aquifer system, potentially contaminating it.



There is no alternative water source for farmers, and when farmers pump, they might draw out contaminated mine water for irrigation or livestock to drink from without realising it. The consequences to cattle could be inflammation, anaemia, and damage to their DNA and organs. The contaminated water could even unknowingly be consumed by the local communities.



Should mining be allowed?

We are not opposed to mining. Africa needs to profit from its wealth of mineral resources – but not to the detriment of African people in the long term.



The mining planned in the Stampriet aquifer system has not properly considered the overall effect on people and the environment. This is because most environmental impact assessments only focus on the effect of extracting one resource (gold or coal or oil, for example). Cumulative impact assessments have not been conducted in the Stampriet aquifer system, and we believe they should have been.



What can be done?

The Namibian, South African and Botswana governments must co-operate to protect the aquifer system from contamination. Currently, the Stampriet aquifer groundwater is domestically protected in each of the three countries by exploration and mining permit conditions. However, mining companies have not always obeyed these.



Already, Namibia is facing a devastating drought. The country has needed to cull animals to reduce the load on the country’s water supplies. Mineral exploration places additional stress on the country’s water supplies.



The Southern African Development Community must develop legal instruments and a water security plan for this aquifer system. Neglecting the water security in an arid region for short term gains is extremely concerning.





The governments must also ensure that people are not misled into supporting mining when it is to their detriment. Uranium mining and oil and gas extraction provide very limited job opportunities for local workers. They need specialised skills for operation and maintenance. Most jobs created are for trained technicians and engineers and not local people.



Finally, the governments of Namibia, Botswana and South Africa must jointly monitor and manage important water resources. They should develop a regional baseline monitoring network to keep an eye on how the water quality is changing.



If the governments cannot cooperate to protect this shared water resource, water disputes and international litigation may happen.



-The Athletic