A $1.5 billion lithium deposit has been discovered in western Maine, but mining it could be hard
NEWRY — The richest known hard rock lithium deposit in the world lies a few miles northeast of the ski slopes of Sunday River and not far from Step Falls, where swimmers can wade in shallow pools formed by hundreds of feet of cascading granite ledge.
Smaller deposits have been known in Maine for decades, but this recent discovery, just north of Plumbago Mountain in Newry, is the first to have a major resource potential.
And that potential is staggering: At current market prices, the deposit, thought to contain 11 million tons of ore, is valued at roughly $1.5 billion. Measuring up to 36 feet in length, some of the lithium-bearing crystals are among the largest ever found.
Formed three miles underground during the cooling of granite magma, the crystals rose to the surface over hundreds of millions of years as the mountains above them crumbled and eroded. Now partially exposed, the deposit is estimated to have a higher percentage lithium content by weight than any other in the world.
“This is going to be a very important source of lithium in the future,” said Dr. William “Skip” Simmons, a mineralogist at the University of New Orleans and co-author on a recent paper describing the findings. A more detailed sampling and analysis needs to be done, said Simmons, but the crystals are undeniably “world-class.”
Lithium is prized because it is lightweight and can store lots of energy, making it an important component in batteries for electric vehicles and as reservoirs for excess energy generated by wind turbines and solar panels. Demand for lithium-ion batteries is expected to grow between five- and 10-fold by the end of the decade, and the world must ramp up production quickly to move away from fossil fuels.
This find could contribute to that. But under Maine’s recently enacted mining laws, it’s unclear whether it will ever be extracted.
“We know that the Maine mining laws are such that there’s not one single active mine in Maine,” said Mary Freeman, who owns the land with her husband, Gary, a co-author on the paper describing the find.
“We’d have to get clarification from the state,” said Freeman, when asked whether the couple planned to apply for a mining permit. “They don’t have an area of the rule that explains this kind of work.”
Maine’s metallic mining law was designed to protect the state’s natural resources and keep its water clean. But the state, and its residents, will also need lithium-ion batteries to store energy from wind and solar panels, and run electric vehicles.
Yet lithium is a metal, and state regulations passed in 2017 prohibit mining for metals in open pits of more than three acres, which would be the only way to cost-effectively extract lithium at Plumbago North.
“I don’t know of any underground and manganese or lithium mines in the world,” said Dr. John Slack, a geologist who co-authored a separate upcoming paper on critical minerals in Maine.
“Because those metals have a relatively low cost, in terms of their concentration per ton or per ounce, you need to excavate large volumes of rock cheaply in order to economically and profitably produce the metal you’re interested in.”
What’s the right level of regulation?
Commercial mining has resulted in a long list of disasters, from collapses and explosions to rivers dyed a sickly shade of orange.
Some of the gravest environmental concerns revolve around mining for base metals — such as copper, lead and zinc — which often occur in bands of rock rich in iron sulfides. When exposed to air or water, iron sulfides create sulfuric acid. And once the production of sulfuric acid has begun, it can be difficult to stop, polluting waterways for decades, a phenomenon known as acid mine drainage.
Indeed, Maine’s most famous mines are perhaps better known for their aftermath than what they produced.
In the late 1960s, the Callahan Mining Corporation was given permission to drain a 75-acre coastal estuary in the town of Brooksville and turn the area into an open-pit mine. The company extracted roughly 800,000 tons of copper and zinc before flooding the area, turning it into Goose Pond.
The former mine is now a Superfund site, and a 2013 study by researchers at Dartmouth College found widespread evidence of toxic metals in nearby sediment, water and fish. Cleanup costs, borne by taxpayers, are estimated between $23 million and $45 million.
With events like this in mind, lawmakers, environmental advocacy groups and the Maine Department of Environmental Protection crafted the 2017 metallic mineral exploration and mining law. It passed after years of deliberation and several failed attempts, and is considered one of the most stringent mining laws in the nation.
The law bans metallic mineral mining in, on or under public lands, lakes, outstanding rivers, coastal wetlands and high-value freshwater wetlands. Open-pit mines of more than three acres aren’t allowed, nor are mines that would require treatment of toxic wastewater in perpetuity or the ponds storing wet mine wastes.
In an effort to avoid what happened in Brooksville and elsewhere, the law also requires companies to set aside money for cleaning up or treating any environmental contamination for at least 100 years after the mine’s closure.
In the four years since the law’s passage, only one company, Wolfden Resources Corp. of Canada, has attempted to go through the process. Earlier this month the company withdrew its application for a zoning change required to begin the Department of Environmental Protection permitting process after state commissioners moved to deny the application, citing numerous deficiencies.
Wolfden CEO Ronald Little told commissioners the company planned to submit a new application after hiring a consultant more familiar with Maine’s regulations.
Several geologists applauded the 2017 law, but said it means Maine’s lithium and manganese deposits (Aroostook County’s manganese reserves are thought to be the largest in the country) may never be extracted as long as open-pit mining is banned.
“It starts being extremely expensive if you do underground mining. So it’s just not a viable way to produce a deposit like (Plumbago North),” said Simmons, the University of New Orleans mineralogist.
But those reserves also would not present the same type of potential environmental issues as Wolfden’s proposed project on Pickett Mountain and other base metal sulfide deposits in Maine, such as Bald Mountain. That’s because the Plumbago North deposit does not occur in, or contain, sulfide-rich rocks, said Slack and Simmons. Mining for lithium there would instead be similar to quarrying for granite or gravel.
“Those rocks being exposed now have been sitting there for 200 million years and they haven’t dissolved away,” said Simmons. “I don’t understand why metal mining would be applied to this type of mine at all. It doesn’t make any sense to me.”
Slack agreed that the deposits shouldn’t fall into the same category as mining for base metals such as zinc and copper in sulfide-rich rocks.
“The environmental restrictions implemented in the new Maine mining law were long overdue,” he said, “but unfortunately I think the law went way too far in completely banning open-pit mining for these kinds of purposes.”
In an email, the DEP mining coordinator, Mike Clark, said it has been three or four years since department staff visited Plumbago North, which at that point was operating similar to a granite quarry and gemstone prospecting operation.
At less than an acre, said Clark, the quarry was small enough that it was not required to file a notice of intent.
Asked whether the new law would apply to lithium mining at Plumbago North or elsewhere, Clark wrote: “The Department would evaluate a specific proposal and make that determination based on detailed information.”
Acid mine drainage, however, is not the only environmental problem Maine’s law attempts to prevent. Many of those who spoke in favor of the law when it was passed were against open-pit mines altogether, which are often hugely disruptive to the local ecology.
“The call to restrict open pit mining — that’s the open sore in the face of the Earth argument,” said Dr. Martin Yates, laboratory manager and instructor at the School of Earth and Climate Sciences at the University of Maine. “Once you’ve opened a hole like that, it’s not really going to grow back.”
Nick Bennett, staff scientist at the Natural Resources Council of Maine, who was deeply involved in the most recent law’s passage, said Maine’s mining laws were not designed to deal with lithium and manganese.
“They very likely present a whole bunch of different issues,” said Bennett. “If those became something someone wanted to mine and process in Maine, I think we’d have to look at best available practices.”
Landowners uncertain about proceeding
Mary Freeman said the couple would wait to learn more about the reserves and speak with the DEP before deciding what to do with the find.
“I think it’s quite exciting for Maine to have this,” said Freeman. “Maine has kind of stepped forward as being leaders in paying attention to the environment. You see the windmills, you see the charging stations for electric vehicles. I live down in Florida, and we don’t have that.”
The couple has prospected for gems in Oxford County for years and kept buying land in the area because they were interested in the type of coarse granite that’s common there.
“These were explored years ago. They were full of holes when we bought them,” said Freeman of the land. Geologists had known of small crystal deposits of this type, but there hadn’t been much active exploration for years. “We just went exploring to see what was out there … Lo and behold, there were these enormous crystals. We were like ‘wow.’ ”
Freeman is aware that Maine’s mining laws are strict and wasn’t certain if the lithium could ever be excavated. If they are able to extract it, she said, the couple would likely send the material elsewhere for processing.
“We’re also very interested in making sure the forests and the land are maintained,” said Freeman, “but if we could do something positive toward green energy, I’d be honored to do that.”
The Freemans aren’t interested in selling the property and would like to continue exploring there as long as possible.
“I don’t expect our find will be life-changing and, to be honest, we are happy, so we don’t want to change our lives anyway, unless we can slow down aging,” wrote Freeman in an email. “Gary is up there every day exploring. I will be retiring soon and can’t wait to spend more time up there too.”
Creating a U.S. supply
The United States has extensive lithium reserves but produces less than 2% of the world’s annual supply, much of it from a single large-scale mine, Silver Peak, in Nevada. Most of the world’s lithium extraction occurs in a handful of operations in Australia, Argentina, Chile and China, which also dominates the processing and battery construction industry, with other countries in Asia.
U.S. officials are attempting to change that. In March, President Biden’s energy secretary, Jennifer Granholm, announced $30 million in grants aimed at increasing domestic supply of critical minerals, including lithium, an important component in the batteries of electric vehicles.
“America is in a race against economic competitors like China to own the EV market, and the supply chains for critical materials like lithium and cobalt will determine whether we win or lose,” said Granholm. “If we want to achieve a 100% carbon-free economy by 2050, we have to create our own supply of these materials, including alternatives here at home in America.”
The shift to a mineral-intensive world is well underway. A typical electric car requires six times the mineral inputs of a conventional car, and an onshore wind plant requires nine times more mineral resources than a gas-fired power plant, according to the International Energy Agency.
In an email, Phil Coupe, managing partner at ReVision Energy, said Maine will require significant energy storage in the form of batteries to fill gaps when the sun isn’t shining or the wind isn’t blowing.
Battery storage is the fastest growing part of ReVision’s business, said Coupe, who said the discovery in western Maine was “revelatory” and called on the legislature to study whether Maine could “quickly and safely ramp up” its extraction.
“If we are able to extract Maine’s lithium deposits in a way that is not environmentally destructive, then I think we have a tremendous opportunity to help accelerate the transition to renewable energy + storage while strengthening Maine’s economy,” Coupe wrote.
Some minerals can be substituted for others — manganese has begun to appear in batteries as an alternative to cobalt — but lithium appears likely to remain an important component of batteries and other appliances, from air conditioners to electric stovetops.
By 2030, the International Energy Agency estimates that supply from existing mines and projects under construction will produce only half the amount of lithium and cobalt necessary to meet international needs.
There is a role for recycling as well: Unlike fossil fuels, metals can be melted down and reused, some indefinitely. It’s a resource that remains largely untapped: Less than 20% of electronic waste is formally recycled, according to U.N. estimates. But even with robust recycling programs, it’s unlikely the world will ever be able to move away from mining entirely.
The mineral requirements of non-fossil fuel technologies should not deter the world from a rapid shift away from fossil fuels, said Slack. When it comes to mining, societies will have to strike the right balance between environmental protection and their needs. “It’s a difficult issue that requires a lot of thought.”
There are also environmental justice concerns at stake. With production of many minerals dominated by a handful of countries in Africa, Asia and Latin America — many with track records of human rights and environmental abuses — some are pushing for the U.S. to shoulder more of the burden for the minerals it consumes.
“We are altering the environment,” said Ian Lange, associate professor of economics and business at the Colorado School of Mines. “If we just don’t let the U.S. mine any of these things, then we’re going to buy them from these places that don’t have the same labor and environmental safeguards the U.S. does.”
Most of the world’s lithium is extracted from rocks or brine. Deposits below the salt flats of Chile, Argentina, and Bolivia — together referred to as the “lithium triangle” — are estimated to contain more than three-quarters of the world’s supply. (It may also be possible to extract lithium from seawater, but researchers have yet to find a way to compete with cheaper lithium mining on land.)
Brine extraction, in which minerals are pumped to the surface and left to evaporate in massive pools for months or years, is relatively simple and inexpensive. But the process consumes huge amounts of water in some of the driest places on earth.
There are attempts underway in California to extract lithium from underground volcanoes below the Salton Buttes. A new technology, in which the metal is extracted from brine already being used in geothermal plants to generate electricity, is being touted as an environmentally friendly alternative. But similar efforts have failed in the past and the geothermal electricity also requires billions of gallons of water for cooling each year.
Lithium is also mined using traditional methods, in open pits, from rocks like those found at Plumbago North. The reserves at Plumbago North are thought to contain roughly 11 million tons of ore — far less than the 77 million tons in the world’s largest hard-rock lithium mine, in Greenbushes, Australia. Maine’s reserves, however, are exceptional in the size of the crystals and the richness of the deposit.
The Freemans and researchers at Plumbago North knew the crystals they found were extraordinary as soon as they uncovered them. To determine the concentration of lithium, they sent bulk samples for analysis at labs in Australia and Germany.
The results, said Simmons, were astonishing. The deposit showed an average lithium oxide content of 4.68% by weight. That’s three times the average concentration of the world’s top 10 hard rock lithium mines. By comparison, the world’s second-richest hard rock lithium deposit, the Bernic Lake mine in Manitoba, has a lithium oxide content of 2.76% by weight and contains roughly eight million tons of ore.
Maine in pivotal position
The Freemans have not yet filed an application to extract the deposit, which was first described last year. But with lithium in everything from stove tops to smartphones, the discovery raises the question: What role should Maine play in metallic mineral production in an increasingly mineral-intensive world?
“Minerals, whether they’re critical or not, we as humans don’t have a say in where they are,” Slack said. “We in the U.S. and Maine need to seriously discuss the issue and realize that we have to mine those metals somewhere to support renewable energy. We have to face that head-on.”
It will likely take years before any lithium is produced at the site, if Maine laws allow it at all. Even without the threat of acid mine drainage, permitting a mine raises numerous environmental and social concerns.
But finding new lithium resources and quickly getting them out will also be necessary to meet our renewable energy goals.
“Many very educated people who are environmentally conscious don’t want mining anywhere,” said Slack, “and yet they fully support, in many cases enthusiastically, renewable energy. You can’t have your cake and eat it, too.”
This story was originally published by The Maine Monitor. The Maine Monitor is a local journalism product published by The Maine Center for Public Interest Reporting, a nonpartisan and nonprofit civic news organization.