Some of the polluted water discharged into the city. Screenshot from the video “LUBUMBASHI: Polluted water discharged by CDM is now putting lives at risk” on the Triomphe TV YouTube channel
While areas rich in rare minerals may be a blessing for the economies of countries like the Democratic Republic of the Congo (DRC), they can also be a curse for the local populations. They fuel the greed of rebel groups and foreign investors who don’t always respect environmental standards.
On November 4, 2025, a dam belonging to mining company Congo Dongfang Mining (CDM), a subsidiary of Zhejiang Huayou Cobalt Ltd, which mines copper and cobalt in the Haut-Katanga Province of the DRC’s second-largest city, Lubumbashi, collapsed. Highly toxic water spilled out from the dam, polluting the environment and rivers alike.
Following the collapse of the dam, ditches running along the streets of the city’s suburbs filled with acidic water, overflowed, and flooded the houses and roads adjacent to the mining company. The floods then reached the “Moïse Katumbi” market, forcing some merchants to cease trading. Movement became virtually impossible. Alain Kozongo, a resident of Kasapa close to the factory, told Global Voices.
La société chinoise profite souvent de la pluie pour nous vider ses eaux. Mais c’était étonnant de constater les inondations des routes dans une journée sans pluie.
The Chinese company often makes the most of the rain to empty its water on us. However, it was surprising to see the roads flooded on a day without rain.
In the hours following this incident, dead aquatic species washed up on the banks of the Lubumbashi River. After this environmental scandal, NGOs, such as Resource Matters, called for tough sanctions for crimes against the local people and environment:
Nous appelons ainsi l’entreprise #CDM… pic.twitter.com/OjkXRMPw3b
— Resource Matters (@resourmatters) November 7, 2025
The “Mazingira pour Tous (Environment for All)”consortium and Resource Matters expressed deep concern over the contamination of the Lubumbashi River, which killed some aquatic species and put people at significant health risk.
We call on the company #CDM and the relevant state institutions to immediately decontaminate the affected rivers and implement immediate measures to protect public health.
The English version of the attached images is available here.
pic.twitter.com/OjkXRMPw3b
— Resource Matters (@resourmatters) November 7, 2025
According to witness accounts, the Chinese company reportedly created several waterways that pass through the walls of the southern part of its site to dispose of large quantities of wastewater laden with acid. This water spills into nearby communities, often causing damage that the company seems to ignore completely. A local told Global Voices under the condition of anonymity:
Depuis 2012 à chaque saison pluvieuse les populations des quartiers Kasapa, Kamisepe et Kamatete dans la commune annexe (commune rurale de Lubumbashi) ont toujours été victimes des inondations et des effondrements de leurs maisons suite aux débordements des eaux. Elles ont toujours pointé du doigt l’Entreprise minière en l’accusant de s’appuyer sur le moment des pluies pour dégager les eaux de ses rétentions et souvent pendant les pluies nocturnes.
Each rainy season since 2012, the people of the Kasapa, Kamisepe, and Kamatete neighborhoods in the Annexe Commune [a rural commune of Lubumbashi] have been victims of flooding and landslides, with wastewater overflows causing their homes to collapse. They have always blamed the mining company, accusing it of taking advantage of the rain to discharge wastewater from its dams, often at night.
In 2020, the NGO Afrewatch repeatedly warned the mining company and authorities to take responsibility for protecting the environment and the neighboring communities.
However, the Chinese company denies any responsibility. To date, the government has proposed no solutions to resolve the conflict between this company and the neighboring communities.
A city on high alert
This technical incident released water containing dangerous heavy metals, such as lead and arsenic. Several provincial officials, including Matin Kazembe Shula, Interim Governor of the Haut-Katanga Province; Lucien Lumano, Minister of Mines; and City Mayor, Patrick Kafwimbi, raced to CDM to enquire about the unfolding situation.
The situation is clear. People face serious health risks due to soil, subsoil, and groundwater contamination.
Since the dam break, the communities’ well water has been contaminated. Four days after the acidic water spilled into her plot of land, Aziza Muna, 60, told Global Voices:
Le puits que j’ai dans ma parcelle, c’est une survie pour moi et ma famille, car je suis pauvre et je n’ai pas le moyen de m’offrir l’eau du robinet. Maintenant mon puits est inondé d’eaux d’acide de l’entreprise. Que dois-je faire?
As I’m poor and can’t afford tap water, the well in my plot of land is a lifeline for my family and me. Now, my well is filled with the company’s acidic water. What should I do?
Long-term environmental impact
Environment expert and researcher Dickson Kabange explained to Global Voices that this incident will have serious consequences:
C’est un crime environnemental parce que ces eaux toxiques sont chargées de masses de métaux lourds, notamment de plomb et d’arsenic. Il y a donc érosion des écosystèmes et disparition d’espèces aquatiques, de plus les populations sont exposées à diverses maladies […] dans les jours à venir si l’état ne prend pas les dispositions préventives, il y aura des morts.
This is an environmental crime because the toxic water contains high levels of heavy metals, especially lead and arsenic. There is consequently ecosystem erosion, the loss of aquatic species, and people are at risk of various diseases. In the coming days, if the state doesn’t implement preventive measures, people will die.
Because of the poverty affecting local residents, some admit to eating dishes prepared with dead fish collected from the riverbed. Patrick Tshimanga shared with Global Voices:
J’ai ramassé au bord de la rivière environ septante tilapias et quarante-cinq poissons-chats. J’ai mangé avec ma famille une partie et j’ai vendu aussi l’autre partie […] oui on nous a dit que c’est toxique, mais ce jour-là je n’avais rien à nourrir la famille.
I collected around 70 tilapias and 55 catfish from the riverbanks. I ate some with my family and sold the rest. Although we were told it was toxic, I had nothing to feed my family that day.
Dickson Kabange stated that whatever killed the fish could also kill humans who eat them.
To prevent that danger, calls have multiplied in the city, urging people to avoid eating fish from the Lubumbashi riverbanks and to stop consuming water from these rivers. The toxic flooding could lead to long-term health issues as it has also impacted agricultural operations in the region, affecting food crops.
NGOs demand harsh sanctions
Several civil society organizations have successively criticized this pollution in their press releases. They demand that the Congolese authorities impose tough sanctions on CDM to serve as an example to the other polluting companies in the Haut-Katanga and Lualaba provinces (located in the south of the country), where most mining companies are based.
The NGO Resource Matters deplores the fact that similar cases have already been documented in the region: “unfortunately, this happens under the helpless gaze of environmental state services and the negligence of mining companies.”
Similarly, the NGO Justicia Asbl calls on the Attorney General of the Republic to intervene and prosecute the CDM executives for the toxic substance spills and negligence.
Furthermore, on November 6, 2025, Louis Wantum, the national Minister of Mines, who rushed from Kinshasa, the capital, to Lubumbashi, held a so-called clarification meeting with his ministry’s provincial technical services and the CDM executives. He announced:
« J’ai pris ma décision de suspendre toutes les activités minières de la société CDM, pour une durée de trois mois dans un premier temps. Et si c’est nécessaire, nous allons prolonger cette période ».
I made the decision to suspend all of CDM’s mining operations for three months to begin with. If necessary, we will extend this period.
Several mining companies, primarily Chinese, mine copper and cobalt without regard for the environmental standards.
The CDM disaster isn’t unique. Communities in the Lualaba, Haut-Katanga, and Tanganyika provinces find themselves caught between unregulated extractive industries and the authorities’ indifference. Many of these mining operations are extracting minerals and metals that are to be used to fuel the green energy transition; however, environmental activists argue that resource mining should include an effective environmental justice mechanism for situations such as this, where local communities are negatively impacted.
On November 22, 2025, Guillaume Ngefa, Minister of Justice and Keeper of the Seals, announced an investigation will be opened to identify those responsible and initiate legal proceedings against them.
