Waste from the world’s richest tin mine has since March leaked into rivers flowing through an Indigenous reserve in the Brazilian Amazon, reportedly contaminating the water and killing fish and turtles.

Prosecutors in the state of Amazonas have demanded an immediate halt to the release of more waste from the Pitinga mine in the municipality of Presidente Figueiredo, and for repairs to be carried out. The mine, which has the largest estimated tin reserves in the world, is operated by Mineração Taboca, the Brazilian subsidiary of Peruvian tin mining giant Minsur.

The contamination was identified by residents of the Waimiri-Atroari Indigenous Territory and confirmed in two expeditions with the participation of Funai, the federal agency for Indigenous affairs, as well as Taboca’s own environmental coordinator. The team traced the tailings back to the Taboca facility near the reserve and verified that holding ponds there were leaking, with on-site verification and photos taken by drones.

A report by the Funai Waimiri-Atroari Ethno-Environmental Protection Front shows that the contamination has already altered the water quality of the Tiaraju and Alalaú rivers, which the Indigenous people depend on for drinking, washing, and for fishing. Twenty-two villages have been affected. Fish and turtle die-offs have been reported, and river water in the area is said to be cloudy, dense, and unpleasant smelling.

The area occupied by the mine was traditionally settled by the Waimiri-Atroari, but ended up being excluded from the demarcated reserve in the 1980s, amid pressure from the mining company.Taboca has denied that its tailings ponds are leaking or that it’s responsible for the rivers being contaminated. It blames the change in water quality to recent unusually heavy rainfall in the region.

But that’s not what the Funai report says. Harilson Araújo, a lawyer for the past 14 years with the Waimiri-Atroari Association, also questioned the claim.

“If the rain contributed, there was negligence [by Taboca] in not taking measures to foresee this amount of water,” he said. “The leakage problem exists and has been proven. Nothing was done until they were notified. You can’t blame the rain. At the very least, they sinned by omission.”

Araújo said the Indigenous communities had stopped consuming fish, hunting, and using water for fear of contamination. Children have reportedly fallen sick and required medical care. Araújo said the communities are most concerned about the extent of the problem and how long it will take for everything to be resolved.

“From the experience we have, the solution will not be as fast as many people think. The consequences for the future can last,” he said. “There are 22 villages that depend directly on water for their livelihood, their way of life, culture. The river is their life. It is a very strong aggression. The Indigenous people are extremely concerned.”

Disaster scale, times four

Brazil’s National Mining Agency (ANM) lists 15 dams and related structures managed by Taboca in Presidente Figueiredo — eight in operation and seven not — that aren’t included in the official data.

The main one in operation is identified as “158 (A-1),” with a capacity of 53.3 million cubic meters (1.88 billion cubic feet) of tailings — and no waterproofing membrane. The dam is four times larger than the tailings dam operated by Brazilian miner Vale in Brumadinho municipality, Minas Gerais state, that failed catastrophically in 2019, killing 270 people.

The ANM says the last survey on dam 158 was carried out on April 27 this year. The emergency action plan (PAE) for the dam, which the company is required to provide to municipal and state governments and civil defense agencies, lists its “potential damage” as high in the event of a failure, with significant environmental impact in protected areas.

Prosecutors have called on Taboca to take immediate measures to secure its dams and guarantee the supply of drinking water and complementary food to the affected Indigenous communities. They also questioned why Taboca did not take the necessary measures detailed in its emergency plan and alert the relevant authorities back in March, when the contamination was first identified. The surveys carried out in May show the situation has worsened since then.

According to Araújo, it took two meetings, marked by moments of tension and denial, before Taboca changed its stance and pledged to carry out emergency measures such as drilling solar-powered artesian wells for water, supplying clay filters for purification, and providing livestock as food for affected communities.

Internally, Araújo said, the authorities are demanding that Taboca take the necessary measures to resolve the leaks.

In a note, Taboca said “the dams are stable and safe, as attested in technical reports already submitted to the Amazon Environmental Protection Institute [IPAAM] and [state prosecutors] in the last week.”

The company also reiterated its stance that “there is no overflow in any of the Taboca Mining dams.” It adds that regular inspection and monitoring activities are being carried out.

“We are also, as preventive measures, building filtering dikes and dissipating channels designed to expand the filtration of suspended materials and reduce water turbidity in the area, which remains under monitoring 24 hours a day,” Taboca said.

Araújo said the Indigenous people are constantly concerned about the risk of a major environmental disaster linked to the tailings dams, as in Brumadinho and Mariana, in Minas Gerais, where another Vale dam burst in 2015 and killed more than a dozen people. The fear that one of Taboca’s dams will break is real, said Araújo, who recently spoke with community leaders after the contamination was identified.

“The fear is enormous. Taboca has a very large set of dams. Even those that are disabled, if there is no maintenance, what happened in Mariana and Brumadinho can happen [here]. If you break such a dam and reach the Alalaú River, which is the river of life for these Indians, it will be a huge disaster,” Araújo said.

The Waimiri-Atroari reserve is home to more than 2,000 Indigenous people, the last members of a tribe that was almost completely wiped out during Brazil’s military dictatorship.

In addition to emergency actions, a work plan is being defined to try to solve the problem permanently. An ongoing analysis by IPAAM, an independent research body, is expected to quantify the true scale of the contamination.

99 mining requests

While the Waimiri-Atroari Indigenous Territory is currently suffering the impact of the Pitinga mine just outside its borders, future problems may come from inside the reserve itself. Mining companies, including Taboca, have a combined 99 requests to operate inside the Indigenous territory pending before the National Mining Agency. Almost all the applications are for prospecting, and most date from the 1980s.

Taboca and its subsidiary, Mamoré Mineração e Metalurgia, have a combined 37 prospecting and mining applications pending, the earliest filed in 1978 and the latest in 2004. The applications list zircon, cassiterite and tin as the targets of their prospecting.

While mining in Indigenous territories is prohibited under Brazil’s Constitution, the current administration of President Jair Bolsonaro is seeking to allow it. The administration last year submitted a bill to Congress that would permit such activity. Arthur Lira, speaker of the lower house of Congress and a Bolsonaro ally, says approving the bill is his priority.

Taboca, however, has denied it is still interested in mining in the Indigenous territory. “Our performance is based on principles of social and environmental responsibility and we have greater respect for our neighbors, so we do not operate, nor will we operate on Indigenous lands,” it said.

The company says that as “the largest tin producer refined in Brazil,” it is “transparent and committed to the environment.” In 2020, Taboca, which also mines niobium and tantalum, reported revenues of 753 million reais ($144 million). The company was founded in 1969 and began operating the Pitinga mine in the 1980s. The mine has an estimated useful life for tin production of 100 years. The tin extracted from the Amazon is processed at a smelter in São Paulo.

In 2008, Taboca was acquired by Peru’s Minsur in a deal worth 850 million reais (about $500 million at the exchange rate at the time). Minsur is one of the world’s biggest producers of tin. The biggest consumer of the metal, in turn, is China, which buys about half of global production.

Minsur’s main investor is the Profuturo AFP investment fund, which is owned by Canada’s Scotiabank.

This story was originally published in Observatório da Mineração.

Banner image of a community in the Waimiri-Atroari Indigenous Territory. Image by Raphael Alves/Court of Justice of Amazonas.