Tailings Dam Failures Highlight Need to Start Seabed Extraction

At least nine tailings dam failures have occurred in the first few months of the year at mining sites across three continents.  These failures have threatened the health of millions of people, contaminated food and fresh water supplies, killed workers, and left toxic residue behind that will never go away.  Seabed nodule harvesting offers an alternative to terrestrial strip mining that requires no tailings dams because nodule processing creates no/limited solid waste. 

Studies show that the rate of serious tailings dam failures is increasing – a circumstance that is especially troubling as it accompanies an increase in mining due to strong demand for minerals (link).  Unfortunately, the problem is systemic and very difficult to mitigate –  tailings dams are destined to fail in many areas due to high amounts of rainfall, deforestation associated with mining, seismicity, and topography.  A secular decline in ore grades adds to the problem, creating higher levels of waste for every unit of metal produced each year that passes. 

We can do a better job at many dams with more robust engineering, but even the best engineered dam can be overwhelmed by a large seismic event or tremendous runoff, exacerbated by deforestation, from big storms.  Heavy rains/monsoons are associated with tropical regions where many energy mineral mining operations are located.   

Zambia

At least two dams failed in the copperbelt of Zambia early in 2025 impacting the Kafue river.  That river supplies approximately 60% of the nation’s 20 million people with drinking and agricultural water, meaning that up to 12 million people may have been exposed to toxic water and food.  Zambia is in the midst of a large increase in copper production which locals worry will only compound the public health and environmental issues already associated with mining in the region. 

 “People unknowingly drank contaminated water and ate affected maize. Now many are suffering from headaches, coughs, diarrhea, muscle cramps and even sores on their legs,” she told Climate Home News. The community fears having to find alternative farm land to survive, she added.  link

Indonesia

At least six tailings dams associated with nickel processing plants in Indonesia have failed since the start of the year, killing three people and threatening the health of over 1,000 people with toxic runoff according to reporting from Ellen Moore at Earthworks and Dave Petley at EOS.  The dams failed due to heavy rains in the area, with runoff exacerbated by the deforestation associated with the tremendous extent of nickel strip mines. 

This problem was predicted by experts and was avoidable according to engineers.  Nickel HPAL (high pressure acid leaching) processing plants generate large volumes of toxic waste (each plant creates enough to fill around 1,700 olympic size pools each year) and that waste needs to be stored somewhere.  An engineering study had cautioned against building dams in the area because of the extreme risks from heavy rains, topography, deforestation, and seismicity.  The engineering report recommended piping the waste offshore and dumping it in the waters surrounding the islands, as this could spare human lives and human health.  But under pressure from environmental groups and the international community, the government decided to authorize the use of tailings dams instead. 

We covered the danger from tailings dams in Indonesia in our report, A Deadly Moratorium, last year:

In fact, in Indonesia a study was published which concluded that it was more dangerous to store tailings in dams on land than to dump them in the ocean due to the seismicity in the region and the high amounts of rainfall received (Gultom, 2020). Waste systems frequently fail, and spill large amounts of toxic tailings into rivers and oceans. These failures can kill people (Silva, 2023) (Bilgic, 2019) (Sullivan, 2017). Mine waste poses an existential danger to many Indonesian communities, yet the process continues to this day as there are few other options.  Deadly Moratorium

While the decision to use tailings dams may have satisfied some international activists, it was a bad one for the people of Indonesia as the events of the last couple of months have made clear.  Unfortunately, this story will only get worse in the coming years as nickel demand continues to grow and ore grades continue to decline (unless nodule harvesting supplants or reduces the need for Indonesian nickel). 

Bolivia

A tailings dam associated with an older tin mine collapsed in March near the town of Andavilque in Bolivia.  Two people were killed in the landslide, caused by heavy rains, and 47 homes were destroyed.  Approximately 70% of the population in Andavilque was impacted by the collapse. 

There is a Better Way

The immense human and environmental toll from mining energy minerals could be reduced or avoided by substituting polymetallic nodule harvesting for terrestrial mining.  Lifting seabed nodules non-invasively from the deep ocean to extract the same minerals is far less costly to humans and to the environment.  Case in point, nodule processing creates no/minimal solid waste, so no need for tailings dams or dumping tailings into the ocean. Unfortunately, groups such as WWF, Pew Research, and Greenpeace stand against this commonsense approach, even supporting a moratorium against this low-impact alternative. 

The arguments upon which these activists rely for their protests are built on misinformation and critical omissions.  We are hopeful that with political changes happening all over the world, a more rational and thoughtful approach can take hold as more attention is brought to the matter, and critical thinking and empirical data replace NGO fearmongering.  We believe that NGOs who take government funding and then use that funding to undermine efforts to introduce technologies that create genuine win-win solutions for society should be prohibited from receiving government support.  We also think that NGO’s who promote blatant misinformation should have their tax-exempt status scrutinized. Society affords these groups certain advantages based on a level of trust, and that trust has been broken.