Last month, the US ordered its officials to evacuate or avoid key towns in Zambia’s northern ‘copperbelt’ region. This follows the spill of acidic and metal-laced water at a Chinese mine that was worse than previously believed.
In February, 50 million litres of toxic wastewater escaped from a dam at a copper mine run by Sino Metals Leach, a subsidiary of Chinese state corporation, China Nonferrous Metals Mining, in Chambishi, Naomi Mattos, a state department official, confirmed to Chemistry World. This wastewater was left over from the copper extraction process and while the acid used wasn’t specified, sulfuric acid is commonly used to leach copper from its oxide.
The wastewater flowed into the Kafue River basin, and from there onto agricultural lands. The US embassy in Zambia warned last month that even breathing air in places surrounding the mine may pose a health threat.
Zambia’s government, however, claims that the danger has passed. Its lab tests show pH levels and heavy metals concentration are returning to normal, said Cornelius Mweetwa, the information chief. ‘There’s no need to panic.’
However, experts and locals are still worried. In part, this is because Zambia has a history of contamination from mining facilities not being fully addressed. Anglo American was sued in 2020 over 5.8 million tonnes of lead allegedly left over from its operations between 1925 to 1974, during colonial rule, something that the firm contests.
Nsama Musonda, the executive director of Care for Nature Zambia, an environmental and ecology monitoring group, was one of the first independent observers to reach the scene in Chambishi in February. ‘This is one of the most devastating pollution incidents we have witnessed in a long time,’ she tells Chemistry World. ‘It was a horror to see maize, bean crops that were green the night before, just turn brown. Tonnes of dead fish were floating in local riverways,’ she says.
The wastewater spill brings into focus the laissez-faire methods of Chinese copper miners. According to the Belt and Road state portal, China has invested $3.5 billion (£2.6 billion) into Zambia’s metals industry in the past two decades. However, local environmental watchdogs have accused Chinese companies of negligence.
In the past, smaller pollution incidents on the copperbelt mostly involved waste spilling from dams in mines that use leaching. Leaching is a hydrometallurgical process used to extract metals or minerals from ore by dissolving them in a chemical solution, leaving behind the insoluble waste materials.
For instance, in the town of Chingola, small, illegal copper processing plants are being set up, says Musonda. Some local schools have closed because of the noise and sulfur dioxide pollution. ‘And these are all Chinese-run companies,’ she says. ‘This is an eye-opener as Zambia’s copperbelt is facing a pollution crisis from a wide range of prospecting – be it manganese, gold or copper,’ Musonda adds.
Local families in the copperbelt told Chemistry World that they have few options. ‘We lead bi-agriculture livelihoods; cultivating green crops and fishing,’ says Makanda Phiri, a tribal elder in Kitwe. The copper sludge has devastated aquatic life and contaminated soil in the region.
The biggest fear for local communities is that the toxic waste will spread further when Zambia’s seasonal rainfall arrives in January. ‘We can’t afford to buy safe bottled water too, and it’s so difficult to hold the Chinese accountable,’ Phiri says.
Care for Nature warns that locals were still exposed to this wastewater when they visited the site again in July. ‘We found children are still playing in waters laced with mine acid,’ Musonda says.
Environmental scientist Shamiso Mupara says that what’s often overlooked is a potential permanent loss of safe underground water in the region. Only 36% of Zambians have modern piped water. ‘My biggest fear is undeclared contamination of underground waters from whose wells hundreds of thousands drink,’ she says.
Musonda agrees and says that, though water samples were taken from local wells in the disaster zone, the results have not been made public, and there have been no independent toxicology tests.
‘Which water points are they picking these water samples from? They should visit districts outside the radius of the compromised [mine] run by Sino Metals because the Kafue River flows far, and we are hearing reports of widespread contamination,’ she says.
The ‘laughable’ $50,000 fine on Sino Metals is proof that Zambia has no capacity at all to clean up a disaster of this magnitude, Musonda adds. Zambia’s environment ministry budget is one of the smallest and donors like the UN Environment Programme usually fill gaps for environmental rehabilitation and wetlands protection.
Sino Metals Leach did not respond to requests for comment.