Mineração Rio do Norte (MRN), the world’s fourth largest bauxite producer, encroached on riverine communities beside the Trombetas River in the Brazilian Amazon in the 1970s. Over the years, MRN became notorious for its contamination of local waters with bauxite mining waste, residents say.To resolve that problem, the company built 26 tailings dams. The largest of these waste-holding impoundments covers 110 hectares (270 acres). The entire system for managing mining waste encompasses 1,700 hectares (4,200 acres) and is located within a national protected area.Brazil has suffered two catastrophic mining tailings dam collapses since 2015, leaving Trombetas riverine community residents concerned about the 26 MRN dams.Brazil’s National Agency of Mining has rated one of MRN’s dams as “high risk.” Fourteen more, should they fail, possess “social, environmental, economic and mortality risk.” MRN says its dams are safe. Locals are also worried over possible water contamination and loss of traditional livelihoods This story is the second in a series reporting on the legacy, current status and likely future of bauxite mining in the Trombetas river basin and Amazon delta. Journalist Sue Branford and filmmaker Thaís Borges journeyed there in February, 2020. Their investigation of aluminum production is especially relevant now, as Brazil’s Bolsonaro administration pushes to open the Amazon’s indigenous reserves and other protected areas to large-scale industrial mining. ORIXIMINÁ MUNICIPALITY, Pará state, Brazil — When our Mongabay reporting team visited the Amazon riverine communities of Boa Nova and Saracá, one theme predominated: “My children’s future is here,” said one resident. “I don’t want to leave this land,” declared another. “I’m only leaving here to go to the cemetery,” a third emphatically stated. But this determination to remain on their land is interwoven with another, darker refrain: the people’s expressed unease at living in the shadow of numerous large tailings dams, some less than 20 kilometers (12 miles) from their homes, all constructed and owned by Mineração Rio do Norte (MRN), the world’s fourth largest bauxite producer, located beside the Trombetas River. This concern was first sparked in 2015 by an unprecedented environmental disaster occurring a thousand miles away in the town of Mariana in Minas Gerais state. There a tailings dam holding back iron mining waste belonging to Samarco — a joint venture between two international mining companies, Brazil’s Vale and the UK’s BHP Billiton — collapsed. A mud tsunami obliterated the town of Bento Rodrigues, killing 19, and polluting 500-miles of river to the Atlantic Ocean. Boa Nova community coordinator Fátima Lopes worries that an MRN tailings dam rupture would force riverine people to abandon their communities. Image by Thais Borges. MRN has 26 tailings dams, meaning that the municipality of Oriximiná, home to the bauxite mine, includes more dams within its boundaries than any other district in Pará state. But before the Mariana disaster almost nobody local knew much about the bauxite waste lagoons and the dams holding them back. Many were upset when they found out. “I got scared when I saw the large number of dams and the size of them,” remembered Fátima Viana Lopes, coordinator of the Boa Nova community, describing her first visit to MRN’s mining waste disposal operation. The lagoons are “so huge that they’ve even got boats sailing on them,” she said. The largest covers 110 hectares (270 acres); the dams holding back the waste are typically 17 meters (40 feet) high, lower than in Mariana. The entire system for managing waste encompasses 1,700 hectares (4,200 acres), according to MRN. “If one of those dams burst, I don’t think we’d be able to go on living here,” Lopes said.