Miriam Rivera Bordones tends her goats in a dusty paddock in the russet mountains of Chile’s Atacama desert. She also keeps chickens and has planted quince and peach trees and grapevines, which are watered by a stream winding down the hills towards the Indigenous community of Copiapó. But now the huge British-Australian mining multinational Rio Tinto has signed a deal to extract lithium, the “white gold” of the energy transition, from a salt flat farther up the mountains, and she fears the project could affect the water sources of several communities in the area.
“We could be left with no water,” says Rivera. “How will we plant crops or feed our animals? It will make it very hard to survive here.” Rio Tinto has signed a joint venture agreement with the state-owned copper mining company Codelco to exploit Salar de Maricunga, Chile’s second-largest salt flat, 3,760 metres above sea level in the Atacama region. Lithium is a critical element for manufacturing smartphones, laptops, electric vehicles and battery storage for wind and solar farms, but its extraction is highly water-intensive.
The project will pose a direct threat to the Colla Indigenous people living here, says Lesley Muñoz Rivera, secretary of the Copiapó Indigenous community. “The Maricunga salt flat is the source of all life here. Hydrological studies suggest that it is the source of our water. It’s a sacred place for us.” All commercial lithium production in Chile currently uses an evaporation method: water is pumped from natural salt lagoons into pools, where it is exposed to sunlight for 18 months, leaving behind lithium salts. Between 85% and 95% of the water is lost in the process.
Rio Tinto acknowledges “the sensitive environments” where it will operate and emphasises its commitment to “responsible water use” and “minimal impact on local communities and ecosystems”. The company also says it is still determining which direct lithium extraction (DLE) method to adopt for its early-stage projects developed in partnership with Codelco and Chile’s state-owned mining company, Enami, referring to a technique that extracts lithium from brine more quickly and then pumps the brine back into the lagoon. But Cristina Dorador, a microbiologist at the University of Antofagasta who has studied Chile’s salt flats for decades, says reintroducing treated water into the Maricunga could destroy a unique and fragile ecosystem that is home to 53 animal species.
These include Andean flamingos, horned coots, rheas and guanacos, as well as 11 native plant species and prehistoric micro-organisms found only in the Atacama salt flats. “Maricunga is a hotspot of unique flora and fauna,” Dorador says. “The reinjected brine could have traces of chemical compounds such as surfactants and detergents that could affect the whole ecosystem of the salt flat.” The southern part of the Maricunga salt flat is within a protected national park, Nevado Tres Cruces. Although lithium will be extracted from the northern part of the salt flat, Dorador says it is unrealistic to regard them as separate bodies of water. “Everything in the local ecosystem is connected,” she says.
Rio Tinto said: “DLE supports water conservation, reduces waste and requires less land. The aim is to minimise fresh water consumption through recycling, and the use of processing and reinjection technologies that maximise the recovery of lithium with the lowest environmental footprint.” The company uses DLE at two lithium mines in north-west Argentina: its starter plant at the Rincón salt flat and the Fénix project on the Hombre Muerto salt flat, which it acquired through a takeover of Arcadium Lithium this year. Rio Tinto’s partner, Codelco, confirms it has not yet decided on the method of lithium extraction at Maricunga.
The Indigenous communities in this region are still recovering from the repression they faced under Augusto Pinochet’s dictatorship, which lasted from 1973 until 1990. Rivera’s 91-year-old mother, like most of the older generation of Colla Indigenous people, was born in the Atacama mountains. During the 1970s, the military regime sold tracts of territory to landowners and banned residents from collecting firewood, which they needed to survive, forcing many Colla people to migrate to the nearest city, Copiapó. But they often returned to their mountain communities.
