BOGOTA, Colombia — Brazil’s Supreme Court has suspended an environmental permit for a major gold mining project in the Amazon rainforest, dealing a setback to a Canadian company’s plans to develop an open-pit mine along a river already affected by one of the country’s largest hydroelectric dams.

The decision by Supreme Court Chief Justice Edson Fachin, issued Monday and made public Tuesday, suspends the installation license for Belo Sun Mining Corp.’s proposed Volta Grande project in Para state, following years of opposition from Indigenous communities concerned about its environmental impacts.

Fachin found that the company had not demonstrated full compliance with environmental requirements and protections for Indigenous communities, including studies assessing the project’s impacts and their right to be consulted.

The proposed mine would be developed along the Xingu River, a major tributary of the Amazon, in an area already transformed by the Belo Monte hydroelectric dam. The dam has dramatically altered the river’s natural flow, affecting fish populations and communities that depend on the waterway.

Environmental groups warn that adding a large-scale gold mine could compound those impacts, putting further pressure on ecosystems and Indigenous livelihoods.

Sol Juruna, a member of the Middle Xingu Indigenous Women’s Movement, told The Associated Press that communities downstream of the Belo Monte dam are already struggling with reduced river flows and declining fish populations. She fears a proposed mining waste dam near the Xingu River could further threaten their livelihoods.

“We know that even the slightest contamination of the river would destroy everything for us,” she said.

According to a 2015 feasibility study, Belo Sun planned to extract 3.52 million ounces of gold over 17 years, excavating more than 600 million tons of material across a 24-square-kilometer (9.2-square-mile) site.

A 2021 independent assessment raised concerns about a proposed dam designed to hold some 35 million cubic meters (1.2 billion cubic feet) of mining waste and water near the Xingu River. Researchers warned that a failure could release waste containing toxic substances, including arsenic and mercury, potentially affecting Indigenous communities more than 40 kilometers (25 miles) downstream.

The ruling marks another turn in a yearslong legal battle over the project, which Belo Sun has promoted as one of Brazil’s largest potential gold mines.

The company regained its installation license through a lower court decision in February and subsequently told investors the permit would remain valid until 2029. But Brazil’s Indigenous affairs agency, FUNAI, has identified gaps in studies assessing the mine’s impacts on Indigenous communities, including those outside formally demarcated territories, and whether the combined effects of the mine and Belo Monte dam were adequately considered.

“FUNAI has maintained that protections must cover all affected Indigenous communities, including those outside formally demarcated territories,” said Ana Alfinito, Brazil legal adviser at Amazon Watch, an environmental and Indigenous rights organization.

The Juruna and Arara Indigenous communities have previously said they were not properly consulted about the project, a claim Belo Sun disputes. Indigenous peoples have consultation rights under Brazilian law and International Labour Organization Convention 169.

The AP contacted Belo Sun for comment but had not received a response by the time of publication.

The Alliance for the Volta Grande do Xingu, a coalition opposing the mine, welcomed the ruling. But the suspension remains provisional, pending further legal proceedings that could include an agreement under consideration by a federal court.

For Juruna and other Indigenous women opposing the mine, the decision brought relief but not an end to their campaign.

“It was happy news for us, even though we all know the fight isn’t over,” she said. “We will keep fighting, keep pushing to get Belo Sun out of the Volta Grande do Xingu. We want them gone.”

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