In the thin air of the salt flats here, nearly 13,000 feet above sea level, the indigenous Atacamas people face a constant struggle.

They herd llamas and goats on arid land, knit Andean hats for extra money and chew coca leaves to fight off the altitude’s dizzying effects. They live in mud-brick homes with roofs made of sheets of corrugated metal weighed down with rocks against the stiff winds.

Yet beneath their ancestral land lies a modern-day Silicon Valley treasure: lithium.

The silvery-white metal is essential for the lithium-ion batteries that power smartphones, laptops and electric vehicles, and the popularity of these products has prompted a land rush here. Mining companies have for years been extracting billions of dollars of lithium from the Atacama region in Chile, and now firms are flocking to the neighboring Atacama lands in Argentina to hunt for the mineral known as “white gold.”

But the impoverished Atacamas have seen little of the riches.

According to previously undisclosed contracts reviewed by The Washington Post, one lithium company, a joint Canadian-Chilean venture named Minera Exar, struck deals with six aboriginal communities for a new mine here. The operation is expected to generate about $250 million a year in sales while each community will receive an annual payment — ranging from $9,000 to about $60,000 — for extensive surface and water rights.

Another lithium company here, a joint venture of an Australian mining company and Toyota Tsusho of Japan that began production in 2015, makes cash payments to the village where its plant is based. A company representative declined to release details of the contract but said the money has been used to help build a school hall.

In visits to all six of the indigenous communities, which lie on a mountain-ringed desert about 25 miles from Argentina’s northwest border with Chile, The Post found a striking contrast — faraway companies profiting from mineral riches while the communities that own the land struggle to pay for sewage systems, drinking water and heat for schools.

“We know the lithium companies are taking millions of dollars from our lands,” said Luisa Jorge, a leader in Susques, one of the six communities around the salt flats. “The companies are conscious of this. And we know they ought to give something back. But they’re not.”

Many in the communities also are worried that the lithium plants, which use vast amounts of water, will deepen existing shortages in the region, which receives less than four inches of rain a year. At least one of the six communities, Pastos Chicos, already has to have potable water trucked in.

“It’s like a joke,” said Bruno Fornillo, a researcher at Argentina’s National Scientific and Technical Research Council who studies the impact of lithium mining. The companies “really think the indigenous are like stones in the road. If there’s a problem, they have to kick it aside.”

In response to the complaints, the mining companies active here told The Post that they follow environmental regulations and that the lithium boom has yielded benefits for residents. They point to the creation of hundreds of jobs and investments of hundreds of millions of dollars in one of Argentina’s poorest regions. Some companies said they also engage in education efforts and economic development projects, such as testing whether quinoa can be grown in the area.

“There is no resistance,” said Alex Losada-Calderon, general manager of Sales de Jujuy, the lithium company that opened a plant on the Olaroz salt flat in 2015. “From the very beginning we worked very, very closely with the local community.”

But opposition is not hard to find. A protest banner, reading “The lithium belongs to the local people,” recently welcomed travelers outside the airport in Salta, which is frequented by mining executives. The drive to the salt flats leads past a barrier on a steep mountain pass with the spray-painted message: “No to the contamination of the mines.” And settlements are dotted with people concerned about the future.

“They are taking everything away from us,” said Carlos Guzman, 44, an indigenous resident who leads a group worried about contamination and water use by the lithium mines. “These lands are ancestral. We live by this. By the fields. By our cattle. This way of life is in danger.”

The lithium boom — with jobs for some, worries for others — has divided communities. It has spurred demonstrations and lawsuits. Guzman’s sister, Elva, made a protest sign that seemed to distill the fight.

“We don’t eat batteries,” the hand-painted sign read. “They take the water, life is gone.”

From salt flats to modern tech

It is difficult to know where the lithium from this area goes once it is extracted — or which mobile gadgets it winds up in. But there are some connections.

The Sales de Jujuy operation declined to say who its customers are, but it is in part owned by Toyota Tsusho, a trading company tied to the automaker, which is increasingly using lithium-ion batteries for cars. Lithium from Sales de Jujuy may also be sold to Panasonic, according to a news release announcing the lithium project. Panasonic has made batteries for Toyota and electric-car maker Tesla.

Toyota said in a statement that it does not buy lithium directly but tries to minimize the suppliers’ impact on local communities, “and we will ask our suppliers to take actions to avoid using certain materials if there is a concern about the source.”

The other lithium operation here, Minera Exar, is owned in part by SQM, a Chilean mining company that is one of the world’s largest lithium producers. SQM lithium is in the Apple supply chain, according to an industry executive.

“Apple is deeply committed to the responsible sourcing of materials for our products, and we work hard to ensure our suppliers adhere to the strictest standards in the industry,” Apple said in a statement, in response to questions from The Post. “We will soon launch on-site evaluations of major lithium producers and any that are unable or unwilling to comply with our standards will be removed from our supply chain. As we do across our supply chain, Apple will continue working hard to raise standards, protect human rights and safeguard the places where these materials are found.”

Minera Exar defended its relationship with local communities, noting that its contracts with them also include job training and promises to try to hire local workers. The company said it also has spent more than $241,000 in the past two years on local projects, such as a community building in Pastos Chicos.

“We are completely compliant with everything,” said John Kanellitsas, president of Lithium Americas, the Canadian partner in the joint venture behind the Minera Exar operation here.

More generally, however, the lithium supply chain is obscured by consumer companies’ refusal to divulge their suppliers. A few, such as Pulead, a maker of battery parts, answered questions about sources. Albemarle, the world’s largest lithium producer, discloses its major customers. Apple publishes a list of its top suppliers.

But most declined to reveal their sources or customers.

Samsung did not reply to repeated requests for comment. Tes­la would not identify which companies supply the lithium in its car batteries.

“Tesla is committed to ensuring all supply chain practices are safe and humane,” a spokeswoman, Alexis Georgeson, said in a statement.

A white-hot market

It’s a good time to own a lithium plant. The market is feverish, with contract prices up 250 percent over the past five years and often spiking higher. This summer, Sales de Jujuy unloaded one 60-ton batch of battery-grade lithium carbonate for $20,000 a ton, twice what it usually sells for.

Now, plans are being drawn up to double the plant’s capacity to 34,000 tons a year.

That will be good for local people, said Losada-Calderon, general manager of the plant, which is on the Olaroz salt flat.

He noted that 65 percent of the plant’s employees come from indigenous communities, though these operations, which suck lithium-rich water from underground, require many fewer workers than traditional mines. The company also has made $80,000 in zero-interest microloans for locals to launch contracting firms, for services such as catering for the plant. It says it has provided medical and dental services for 2,000 local residents.

Because of the jobs it offers, many among the Atacamas are pleased with the arrival of the lithium mining. Each position pays about $1,000 a month, a typical wage in Argentina and a very good one in this region. In Olaroz Chico, one of the six villages here and the one that sits closest to the plants, many expressed satisfaction with the lithium operations.

“Without lithium, we would be starving,” said Apolinar Nieva, who has worked for years as a miner, first in borax, now lithium. The lithium companies care for their workers much better, he said. “The lithium plants give us food, give us uniforms. They are really doing things legally. And they should — part of the land they’re using belongs to the community.”

At the local primary school, teacher Maria Donigian said she has noticed new wooden windows and doors on some of the mud-brick homes in Olaroz Chico. Her schoolchildren appear better dressed than before.

“There’s a good side and a bad side to mining,” Donigian said. The good side is the economic benefit; the bad side is potential pollution and water shortages. Even beyond that, many worry what will have been accomplished in 20 or 40 years once the lithium companies exhaust the reserves.

The Sales de Jujuy plant is built on Olaroz Chico’s communal land. In exchange, the community receives help with local projects, said Miguel Soriano, a community leader. He was asked whether the aid was worth as much as $50,000 a year.

He laughed.

“No,” he said. “No way.”

Richard Seville, chief executive of Australian-based Orocobre — which owns Sales de Jujuy with Toyota Tsusho, alongside a small stake held by the provincial government — declined to say how much is paid to Olaroz Chico.

A lithium sweet spot

Batteries have evolved rapidly in recent years, moving through different chemical combinations — from lead-acid to nickel-metal hydride to, now, lithium-ion.

The appeal of a lithium ion is its small size. A lithium ion can carry a positive charge in a tiny space. To be exact: A lithium ion is 76 trillionths of a meter in radius; sodium ions, which are being explored for use in batteries, are 102 trillionths of a meter, or about 34 percent larger.

The size advantage means not only that batteries can be smaller but also that they can charge more quickly. The speed of charging comes in part from a lithium ion’s ability to fit in amid gaps in a battery’s other components, said Donald Sadoway, a materials-chemistry professor at the Massachusetts Institute of Technology.

Lithium brine was discovered in the Andean region in 1962 when a U.S. mining company found it while exploring for water, at a place called Salar de Atacama in Chile. It would also be discovered in nearby portions of Argentina and Bolivia, forming what is today known as the “Lithium Triangle.”

It was not until the 1970s, however, when lithium was deemed useful for nuclear technology, that investors and the Chilean government decided to seize the opportunity.

The government, led by strongman Augusto Pinochet, declared the lithium reserves to be under its control in 1979. It then partnered with a U.S. company, Foote Mineral, to extract and sell the mineral. Foote had the technology — developed at its plant in Silver Peak, Nev. — for converting lithium brine into useful forms.

Since beginning at the site in the 1980s, Foote, which soon after bought out the government portion, and its successor companies have extracted roughly 300,000 tons of lithium carbonate from under the ancestral lands of the Atacamas.

At current prices, the market value of that much lithium carbonate runs into the billions of dollars.

Through 2015, the lithium operation, now owned by Albemarle, was not required to make any payments to the Atacamas. But in 2012 the outfit began making some infrastructure improvements to nearby communities, and under a new agreement, Albemarle in 2016 made an initial payment of an undisclosed sum to the indigenous groups. The payments are supposed to amount to 3 percent of annual sales and are to continue for the duration of the new agreement, which is pending final government approval.

“There is no doubt that the original deal with Foote was unfair to Chile and to the aboriginal communities,” said Juan Carlos Zuleta, an industry analyst from Bolivia who served on Chile’s National Lithium Commission.

The lithium rush these days is powered by the rise of mobile technology, which has led to a run-up in prices and, in turn, lured mining companies to Argentina.

The rush was set off in part by Tesla, which in 2013 announced plans to build a lithium-ion-battery “Gigafactory” in Nevada. In a few years, the company has said, the facility will produce as much battery power as the entire world did in 2013. A parade of car companies and technology makers have followed, heralding “Gigafactories” of their own.

Global lithium demand is expected to triple by 2025, according to Deutsche Bank and Goldman Sachs.

“If you look at growth projections, you need a new lithium plant every 12 to 16 months right now,” lithium-mining consultant Joe Lowry said.

Argentina is the world’s third-largest lithium producer, behind Australia and Chile. It is expected to leapfrog Chile over the next decade. A dozen companies are exploring Argentina’s salt flats, propelled by lithium’s skyrocketing price and a new business-friendly national government.

“This is the center of the lithium universe right now,” said Iain Scarr, a vice president at Vancouver, B.C.-based Millennial Lithium, which is digging wells on Argentina’s Pastos Grandes salt flat.

‘This is a sacred place’

The Atacamas’ ability to share in the lithium profits is compromised by complex mineral rights — in Argentina, the provincial government owns them.

Yet the Atacamas have legal rights, too, because a company needs the landowner’s permission to dig for minerals.

One problem is that the province lacks a formal process for negotiations between indigenous communities and mining companies, though government officials said they want to develop one.

In Jujuy province, home to the Olaroz-Cauchari salt flats, mining secretary Miguel Soler said his office is careful not to take sides.

“We need to support the companies,” Soler said, pointing out that he works for the office of mining, not the office of preventing mining. “But we also support the communities.”

Several measures adopted in recent decades appear to bolster the Atacamas’ case for receiving lithium profits.

In 1994, the country changed its constitution to acknowledge the rights of indigenous people to hold communal land titles. And in 2000, Argentina adopted an international standard on indigenous peoples that requires, among other things, that in mining cases “the peoples concerned shall wherever possible participate in the benefits of such activities, and shall receive fair compensation for any damages which they may sustain as a result of such activities.”

Jujuy started formalizing land titles for indigenous communities in 2003, making it one of the first provinces to do so. Yet problems persist. Fifty miles from the Olaroz-Cauchari salt flats, also in Jujuy, indigenous groups have been fighting for six years to prevent lithium mining of the picturesque Salinas Grandes salt flat.

“Our grandparents taught us that this is a sacred place. It’s part of the Pachamama,” said Nelda Lamas, 26, of Santuario de Tres Pozos, near Salinas Grandes. The Pachamama is the Incan goddess of the earth, revered by many indigenous people. “That’s why we don’t want to see this place destroyed.”

Recently, mining interest in the Salinas Grandes has renewed. And the provincial government said it intends to allow lithium mining there in the near future.

Signing, then regretting

Many of the communities here seem overmatched in the negotiations with the mining companies.

The Post sought to speak to several of the community leaders in the six villages who signed the Minera Exar agreement.

Yolanda Cruz, one of the leaders of the village of Catua, said she signed the contract with Minera Exar but now regrets it. At the time, she valued the opportunity to create jobs for her village. But she now worries “we are going to be left with nothing,” she said.

“The thing is that the companies are lying to us — that’s the reality. And we sometimes just keep our mouths shut,” she said. “We don’t say anything, and then we are the affected ones when the time goes by.”

Carlos Quispe, who signed for Pastos Chicos, said Minera Exar has helped build a community-center extension and offered contributions for other projects. But, he said, the community should have sought a larger amount from the lithium company. When he signed several years ago, he said, it was not clear just how much lithium would be extracted.

“We would like to negotiate for more,” said Quispe, who works for Minera Exar. “We could use a sewage system.”

In Puesto Sey, another of the six villages, Rosana Calpanchay said she had no time to talk when a Post reporter stopped by. But Nestor Arjona, president of the community commission, said Calpanchay signed the contract because she was looking out for her job at Minera Exar, not for her community.

“She works for Exar — she had a personal interest,” Arjona said. “The community is mad at her now.”

Calpanchay did not respond to inquiries seeking additional comment.

‘They are making fools of us’

Exar plans to start constructing a $400 million lithium-brine plant here next year. Production is to begin in 2019, eventually reaching 25,000 tons of lithium carbonate a year. That would be about $250 million annually, at today’s prices.

Exar’s contracts with the six local communities promise that once lithium production has started, annual payments would be about $9,000 to the Catua community; about $12,000 for Susques; about $25,000 for Puesto Sey and Huancar; $47,000 for Olaroz Chico; and $59,000 for Pastos Chicos. The figures are to be adjusted for inflation.

Each community gets small bonuses for certain milestones, too, such as signing the contract.

By the time the plant is running, Exar will have paid about $250,000 to the indigenous groups. And after that, the six communities would share a total of about $178,000 each year.

Many indigenous residents were unaware of the contracts, learning about them from Post reporters who were able to review the documents at the provincial mining office.

Hector Luzco, who served as a regional leader when the contracts were signed, had no idea that local communities were supposed to be getting paid by the mining companies.

The beneficiaries included Luzco’s home town of Huancar.

Huancar is a dusty village of 400 people where clothes and food are bartered for as often as purchased. Now, as Luzco read a summary of the document provided by The Post, he fell back in his chair.

“I am really shocked at this,” he said.

Until late 2015, Luzco had served as the region’s top government official. He represented all six indigenous communities.

While he was unaware of Exar paying Huancar, he said he knew exactly what he would do with the money.

“We could put heating in at school. Children freeze in winter,” Luzco said. Or build a slaughterhouse, “something that is more practical and hygienic,” so they could sell their llama and goat meat.

When Sales de Jujuy started construction in 2013, Luzco posed for ribbon-cutting photos with corporate officials and dignitaries who had traveled from Australia and Japan. His participation lent credibility to a venture that some local residents viewed with suspicion.

The next year, Luzco posed for more photos on the salt flat, this time for the opening of Exar’s pilot plant.

Now Luzco said he felt betrayed.

“It’s like they are making fools of us,” he said.

Water worries

Possibly worse than being excluded from the mineral bonanza, some indigenous people say, is the possibility that the lithium companies could exacerbate existing water shortages. Already, the area has suffered a drought of several years.

Earlier this year, in Huancar, residents barricaded the nearby highway after losing the village water supply for more than 50 days. They set fires and held signs. No one could afford to fix Huancar’s only well pump. Eventually, the provincial government installed a new one.

While scientists are divided and uncertain about the environmental effects of lithium mining, it is undisputed that lithium refining depends on gargantuan amounts of water. Concentrating the brine, which contains only traces of lithium, requires burning off lots of water, and even more is needed to wash the finished product. A ton of lithium generally requires as much as 500,000 gallons of water.

At the Sales de Jujuy plant, for example, the wells pump at a rate of more than 2 million gallons per day.

The wells feed thick, black hoses that stretch like tentacles for miles across the salt crust. The hoses, drawing brine water from hundreds of feet underground, empty into a series of rectangular evaporation ponds surrounding the plant. The ponds cover almost two square miles and are filled with water that ranges in color from turquoise to azure blue, like views from different tropical beaches.

Lithium mining is “really mining mountains of water,” Daniel Galli, an Argentine professor of thermodynamics, said during a scientific meeting in San Salvador de Jujuy, the provincial capital.

Scientists who have investigated water issues across the Atacamas’ lithium-rich lands — which span the Argentina-Chile border — warn that the effects of lithium mining on local water are unclear.

On the Chile side, where lithium-brine mining has been going on since the 1980s, there are at least some signs that portions of the salt lakes have been declining in size.

According to a recent paper by David F. Boutt, a geoscience professor at the University of Massachusetts at Amherst, and his colleagues, remote sensing shows that the surface area of the two saltwater lagoons at Salar de Atacama declined slowly between 2003 and 2015.

Boutt, whose work has been in part supported by Albemarle, cautioned that the cause of the shrinkage is unknown. He said, for example, that lower rainfall during the period measured might have been a reason. But if the lagoons continued to shrink, it may have effects on the wildlife.

“It is clear that both companies [SQM and Albemarle] are violating rules regarding the use of water for extraction of lithium,” Marcos Espinosa, a member of the country’s Chamber of Deputies, told local media in November. If well-established norms were being followed, he said, “the environmental problems that we have in the Salar de Atacama would not have happened.”

On the Argentina side, Victoria Flexer, who leads a new government research center focused on lithium mining and lithium-ion battery technology and based in the province of Jujuy, said scientists are divided on the effects of lithium mining. Some, she said, think pumping brine water from the ground will have no effect. In this view, the underground caches of lithium brine are completely closed off from the other water sources that the Atacamas and their herds depend on, so extracting the brine wouldn’t harm any living thing. Besides, brine water is useless, they say, 10 times as salty as the ocean.

“So some people say, who cares? It shouldn’t matter,” Flexer said. “But it’s really an open question.”

Other scientists propose that the lithium-brine aquifers could be connected in some way with the other water sources. And if they are connected, it is possible fresh water will refill the remote spaces that are emptied by brine pumping, and that would reduce the water resources available for residents.

“There’s no proof this is going to happen, but we don’t have proof going the other way,” Flexer said. “So we cannot say this will not harm our environment if we keep doing this.”

Raising even more suspicions among locals, the lithium companies have been fined for environmental violations.

In August, Soler, the mining secretary, fined Sales de Jujuy $1.4 million for changing, without permission, how it was drilling in the salt flat. A portion of the fine was also for spilling sewage on the white salt crust. Orocobre, the company that runs Sales de Jujuy, said it is contesting the fine and denied it broke any rules.

In October, Soler’s office fined Exar about $190,000 for not doing all of its required quarterly environmental sampling, tests that would examine brine quality and the salt flat’s condition.

Exar declined to comment on this issue.

Fight has strained relations

Worries about water consume Elva Guzman.

“The amount of water the mining industry uses, it scares us,” she said.

She lives in Susques, by far the largest settlement near the Olaroz-Cauchari salt flats. It serves as the region’s capital, with a tiny medical clinic, a handful of restaurants, a single ATM and the province’s oldest church, Our Lady of Bethlehem, built in 1598 with cactus beams.

Susques, just 25 miles from the salt flat, is also home to Colectivo Apacheta, a group that opposes mining. The name refers to the Incan tradition of building a small stone pile to honor the Pachamama. The group is made up of animal herders who say the water has disappeared in recent years.

The group has hired an attorney, Jorge Iglesias, who learned about what has happening on the salt flats when he stumbled upon Susques as a tourist.

“The mining never should have been approved,” Iglesias said recently. “We think they are taking advantage of the ignorance of the indigenous people on this subject.”

Iglesias and Colectivo Apacheta went to court in 2014 to contest the government’s approval of the lithium mines, claiming “irreparable irregularities” in the approval process and arguing the local communities were not properly notified about the process. The court dismissed the lawsuit last year.

Iglesias wanted to appeal. But Colectivo Apacheta did not have enough money.

In Susques and other indigenous areas, the fight has strained relations in a place dominated by a communal way of life that extends even to land rights. Families have been fractured, too. Half of the Guzmans favor the mines; the others are members of Colectivo Apacheta.

“There has been division in the community,” Carlos Guzman said. “Doubts, distrust, loss of respect.”

Xu Jing and Selene Fernandez contributed to this report.