On Tuesday, February 18, a catastrophic failure occurred at Sino Metals’ tailings dam in Chambishi, Zambia, releasing over 50 million litres of acidic waste into the Mwambashi River.
The spill cut through farmland, poisoned livestock, and contaminated one of the region’s most vital water sources, leaving approximately 500,000 residents in Kitwe without water. The impact extended to Kalulushi and Mpongwe, raising widespread concerns about environmental and public health risks.
What Are Tailings Dams?
Tailings dams are engineered structures designed to store the byproducts of mining operations, including finely ground rock, chemical residues, and process water. When properly maintained, they prevent environmental damage. However, poor management can turn them into high-risk sites, prone to catastrophic failures.
A Growing Pattern of Mining Disasters
This disaster is not an isolated incident but part of an alarming trend of tailings dam failures worldwide. It highlights ongoing concerns about how mining waste is managed, particularly in countries heavily dependent on mining investment.
“There are two phases to this disaster,” said Adam Welz, a conservation journalist, in an interview with Daily Maverick. “There’s the immediate catastrophic impact—dead fish, groundwater contamination—but the long-term ecological damage from acidic, toxic waste will be even more severe.”
In Zambia, the Chambishi collapse exposes systemic risks—weak regulatory enforcement, limited oversight, and an economic reliance on copper mining that leaves environmental protections vulnerable to political compromise.
The Lead-Up to Disaster
Sino Metals Leach Zambia, a subsidiary of China Nonferrous Metal Mining (Group), has operated the Chambishi Leach Plant since 2006, initially processing copper from waste dumps left by earlier mining activities. In 2017, the company expanded operations with a $70 million investment in the Mwambashi Mine, aimed at producing 10,000 tonnes of copper cathodes annually.
Like all mining operations, Chambishi generates vast amounts of waste, stored in a tailings storage facility (TSF). Instead of constructing a new, well-engineered containment system, Sino Metals followed the example of its sister company, NFCA Africa Mining, and simply raised the walls of an existing tailings dam to increase capacity.
Warnings about the risks had been issued years earlier. A 2014 Auditor-General’s report flagged mismanagement at multiple Copperbelt tailings sites, including illegal artisanal mining at hazardous locations, uncontrolled effluent leaks, and weak regulatory enforcement by the Zambia Environmental Management Agency (ZEMA). Despite these concerns, Sino Metals proceeded with its TSF expansion in 2019.
A 2017 borehole study by Copperbelt University confirmed groundwater contamination near the company’s tailings facilities, indicating that the risk of failure was both documented and foreseeable—yet no preventive action was taken.
How the Collapse Unfolded
Engineering assessments and satellite imagery suggest that internal erosion—known as piping—occurred through a divisional wall between two upper compartments of the TSF. Over time, this erosion weakened the structure until it collapsed, sending waste into a lower, inactive compartment. Without adequate buffer space, the lower compartment overflowed, breaching the outer containment wall and unleashing toxic sludge into the Mwambashi River.
The consequences were immediate and devastating. Water samples indicated extreme acidity, with pH levels between 1.8 and 3.5—lethal to aquatic life and dangerous for human consumption. Local fish populations were wiped out, maize crops were contaminated, and tens of thousands of residents were left without safe drinking water.
Corporate Apologies, but No Accountability
In the aftermath, Sino Metals Chairman Zhang Peiwen issued a public apology:
“This will never occur again, and we sincerely apologise to President Hichilema and the people of Zambia for the spillage of acids into major water sources.”
The company pledged compensation to affected farmers and assistance in water distribution efforts. Government officials, including Mines Minister Paul Kabuswe and Copperbelt Minister Elisha Matambo, visited impacted communities and promised stricter oversight.
However, attempts to mitigate the damage were largely ineffective. Footage obtained by Daily Maverick showed Sino Metals workers dumping lime into the river by hand—a response that experts called symbolic rather than systemic.
Welz warned that while authorities focus on immediate damage control, the long-term consequences of the disaster could be ignored.
Weak Regulations, Strong Industry Influence
Zambia’s regulatory framework remains compromised by its dependence on copper mining. ZEMA, the environmental regulator, operates with limited funding and relies partly on fees from the same companies it oversees, reducing its independence.
The situation is further complicated by Chambishi’s location within the Zambia-China Economic and Trade Cooperation Zone (ZCCZ), a special economic zone designed to attract foreign investment through tax incentives and streamlined approvals—including environmental clearances. This arrangement effectively insulated Sino Metals from rigorous regulatory scrutiny.
This is not the first regulatory failure at Chambishi. In 2013, ZEMA temporarily shut down the Chambishi Copper Smelter for excessive emissions. In 2014, local farmers won a lawsuit against NFCA after tailings from Musakashi poisoned a stream and destroyed crops. Although ZEMA ordered stricter controls, inspections dwindled, and fines were minimal.
The Sino-Zambian Investment Dilemma
The Chambishi disaster also underscores Zambia’s economic vulnerability. After its 2020 sovereign debt default and prolonged negotiations with the International Monetary Fund (IMF), Zambia has relied heavily on Chinese investment to sustain its mining sector. Companies like Sino Metals, through its parent CNMC, play a key role in the country’s economic strategy—making strong regulatory enforcement politically and economically challenging.
While China enforces strict environmental laws at home, its companies operating abroad are held to much lower standards. This allows corporations to prioritize production over environmental safeguards in host countries with weaker regulatory oversight—like Zambia.
A Humanitarian and Environmental Crisis
The Centre for Environment Justice (CEJ) framed the Chambishi spill not just as an environmental disaster but as a violation of human rights. Zambia’s constitution guarantees access to clean water, food security, and a healthy environment—all of which were compromised by the spill.
“This is no longer just an environmental disaster,” said CEJ Executive Director Maggie Mapalo Mwape. “It’s a human rights crisis rooted in the structural exploitation of our people and our land.”
Will Chambishi Be a Turning Point?
Whether this disaster leads to lasting reforms or becomes another footnote in Zambia’s history of mining-related environmental failures depends on what happens next.
Short-term relief efforts are not enough. There must be a full, independent investigation with publicly available findings and clear accountability. Affected communities deserve not only immediate compensation but also long-term support for restoring their land and livelihoods.
Additionally, Zambia must strengthen ZEMA by ensuring independent funding and enhancing its inspection and enforcement capabilities. Adopting mandatory compliance with the International Council on Mining and Metals (ICMM) Global Standard on Tailings Management should also be a priority, embedding global best practices into national legislation.
Without these reforms, Chambishi will not be the last disaster. The Copperbelt is filled with aging, poorly maintained tailings dams—each one a looming catastrophe waiting to happen.
Source: Daily Maverick
