A Green Light Metals crew hit water when it began digging a waste pit for its exploratory drilling project last week. Activists say it proves the project is occurring too close to the groundwater while the DNR and company say it's just rain water. (Photo obtained by the Wisconsin Examiner)

A Canadian mining company began work on an exploratory drilling project in the Chequamegon-Nicolet National Forest in Taylor County earlier this month, triggering local concerns that the project could harm groundwater and the nearby north fork of the Yellow River as the company and state Department of Natural Resources (DNR) insist the permitting and regulatory processes are enough to keep the environment safe. 

Green Light Metals, which runs its U.S. operations out of Medford, owns the mineral rights to the Bend deposit in Taylor County, about 19 miles north of Medford, and the Reef deposit near Wausau. The Bend deposit, which has been explored before, contains copper, gold, silver and zinc. The deposit is estimated to contain more than 4 million tons of ore. If the drilling exploration is successful, it could lead to a larger underground mine. 

The start of work on the project is the beginning of the company’s efforts to expand its operations in the U.S. after it went public on the Toronto Stock Exchange earlier this year. 

“Wisconsin is open for business,” the company’s CEO Matt Filgate said on an investing focused podcast earlier this month. 

Company officials say their aim is to protect the environment while nodding to the possibility that a mine in the region could produce materials necessary for green infrastructure — mostly tellurium, a metal necessary in the construction of solar panels. 

“There are very detailed environmental review and environmental studies that are done on virtually every aspect of the surrounding environment,” Steven Donahue, a Green Light Metals board member, told the Milwaukee Journal-Sentinel in April. “An important component of that is the water resources, but it’s also all the ecosystems. It’s the engineering of the project, it’s how the project is going to be closed and reclaimed, and how it’s going to be able to protect the environment, not only during construction and operations, but also after it’s closed. All those facets of a project would be evaluated by the state.”

Views of the project within the rural, largely conservative county — President Donald Trump won Taylor County with 73.5% of the vote last year — vary widely. Much of the county is covered by the national forest, which Juliana Reimann, a Madison resident who grew up in the county and remains a regular visitor, says is a “magnificent, breathtaking natural environment.” 

Conservative hunters and fishers in the area are concerned about the drilling project’s potential effect on those activities in the forest or on the Yellow River. Still, some community members are hopeful the mine can bring some economic benefits to the community and others are keeping a watchful eye on the project without making a conclusion. 

“Some of the people who are in our group are adamantly opposed to any mine, period,” Cathy Mauer, a member of the Friends of the Yellow River, says. “Some of us think that so far they’re trying to be careful without being naive about it because the goal is to make money for their investors.” 

“I’ve found sometimes the people from Green Light are being, I don’t think they’re lying, I think they believe it, but I don’t think they’re being realistic about the potential problems,” she adds. “I think they’re being straightforward, they’re either optimistic or aren’t being completely realistic about the potential problems. And maybe we’re imagining the worst case scenario, which we need to. It’s the worst case scenarios that cause the problems. That’s what we have to plan for.”

Some environmental activists remain much more concerned about the possible effect of the drilling operation on the local water. 

“I really have such a love for that forest, and that drilling site is right smack dab in the middle of it,” Reimann says. “The project will impact groundwater, as I see it, heavily. And of course, groundwater is critical as drinking water.”

She adds that the health of the forest is important for the community’s ability to “thrive.” 

Wisconsin was under a mining moratorium from 1997 until 2017, which required companies that wanted to mine sulfide ores such as copper and gold to prove that other mines operated and were closed for 10 years without causing pollution. While business groups lauded the law’s repeal as opening up the state to billions of dollars in investment, drilling operations in the state have yet to result in a full mine being opened. 

With the repeal gone, the DNR’s permitting process for drilling operations requires companies to obtain a license and file a notice of intent to drill, which the state can deny, approve or approve with conditions. The company must then obtain a number of permits relating to stormwater discharge, dewatering operations, endangered species and wetland preservation. Because the site is within the Chequamegon-Nicolet National Forest, the U.S. Forest Service also has its own permitting process. 

The DNR’s approval of Green Light Metals’ notice of intent included nearly two dozen conditions but despite that, environmental activists remain concerned about a number of aspects of the project. 

When the company drills into the bedrock where the minerals are, the drill must go through the layers, known as the glacial overburden, above it, which requires a steel casing to keep chemicals out of the groundwater. The company obtains cuttings from the bedrock that can be tested for the metals it is looking for. After drilling is complete, the hole is filled from the bottom up with cement, which pushes up the lubricants and water used in the drilling process and flushes out the hole. 

State regulations require that the pipe used to pump in that cement be submerged the entire time so as to prevent air pockets forming. This is often done using what’s known as a tremie pipe, but Green Light Metals is instead pouring cement through the drill rods themselves, which come in 10 foot sections and therefore require that crews stop as each piece is removed — a method that activists are concerned makes the process more likely to cause pollution but DNR metallic mining coordinator Molly Gardner says is common practice. 

The materials flushed out of the drill hole as the cement rises are then put into a lined waste pit dug by the company, encased with more cement and finally covered with the topsoil. 

Activists are concerned the company will not be thorough enough to protect the environment throughout this process.

“It’s like any industrial activity, there is room for error, and if not fixed, you could have a problem,” Dave Blouin, the political chair for the Wisconsin Sierra Club, says. 

Additionally, there has been a dispute about the type of land the company is operating on. Green Light Metals says there is some wetland in the area, but not where it is drilling, while activists say much of the area is wetland, directly connecting the groundwater with the Yellow River. A recent study by the Wisconsin Geological and Natural History Survey found that “the North Fork Yellow River and surrounding surface waters are connected to the shallow glacial aquifer.”

“The North Fork Yellow River is a river within the Chippewa Basin. Over 3,000 stream and river miles flow within the Chippewa River basin and with 156,200 acres of freshwater lakes, 22,711 acres of flowages and more than 150 acres of freshwater springs. The river basin watershed provides significant habitat, recreation, navigation and is a significant drinking water resource for northwest Wisconsin people,” Wisconsin Trout Unlimited said in a resolution opposing the Bend project. “Mining of metallic sulfide ores and minerals has a consistent proven record of surface and ground water contamination and pollution. This potential source of pollution threatens the groundwater of Taylor County and the surface waters of the Chippewa Basin watershed.”

When the company began digging the waste pit for its first drill hole last week, the crew hit water just four feet below ground, which opponents of the project say was the groundwater and proof the area is mostly wetland. 

State regulations require that waste pits for drilling “shall not be at or below the groundwater table at the time of the drilling activity and shall be constructed such that the base will remain above the normal local groundwater elevation.”

Reimann and other opponents believe the company moving forward puts the entire watershed at risk. 

“This drilling is taking place very close to the north fork of the Yellow River,” Reimann says. “It’s taking place in vast wetlands, the hydrology is such that any kind of contamination there will affect not only the Yellow River. The Yellow River flows to the Chequamegon Waters Flowage. People up there refer to it as Miller dam, that’s a very popular camping and fishing site, as well as close to the rice beds of the Ojibwe and ultimately those waters will migrate westward to the Chippewa River, to Lake Wissota and I guess ultimately to the Black River [and] to the Mississippi. You know that water doesn’t stay in one place, so it has a huge negative impact if those waters are contaminated.” 

But Gardner says those claims aren’t accurate and is confident in the department’s regulatory and inspection processes. She says the survey conducted by the company confirmed they weren’t drilling in wetlands and the water the crews found when digging the pit is just rainwater. She says the groundwater is actually 20 feet below the surface. 

The company’s wetland study was partially done as a “desk review” using maps, state data and satellite imagery. A field study by the company was conducted later, but “soils were not investigated,” and “WDNR Wetland Soils & Indicators (WSI) are prevalent across nearly the entire site,” a company memo states. 

“We’re looking at the access, we’re looking at the drilling operation, the sumps, the security, the safety, and everything that’s going on,” Gardner says. “We’re regulating, we’re inspecting that they follow their exploration plan.” 

She says that throughout the drilling process, which includes eight holes as part of the first phase and an additional 15 holes in the second phase, the DNR will have stormwater inspectors, exploration inspectors and Gardner herself on site at regular intervals and for occasional unannounced inspections. 

“It’s not common for the DNR to be able to go on site continuously with any type of construction projects,” Gardner says. “So mining and mining-related projects are allowed to have extra inspections to really ensure that things are going according to plan, because it is an important topic and it’s an important project, so we have more resources to do additional inspections for mining in relation to other types of construction projects.” 

Donahue, the company board member, says the company has been working with local officials and community members to keep them aware of what’s happening on the site and that the project will follow all “applicable regulations.” 

“The Green Light exploration team has been working diligently with the Wisconsin DNR and the U.S. Forest Service to secure all necessary permits and approvals for the exploration program,” he says. Green Light will work diligently to properly abandon the boreholes with the proper amount of cement in accordance with applicable regulations and permits.  In addition, the drill cuttings will be properly disposed by mixing the cuttings with cement in accordance with applicable regulations and permit requirements.”

Hydrogen has the potential to be a climate-friendly fuel since it doesn’t release carbon dioxide when used as an energy source. Currently, however, most methods for producing hydrogen involve fossil fuels, making hydrogen less of a “green” fuel over its entire life cycle.

A new process developed by MIT engineers could significantly shrink the carbon footprint associated with making hydrogen.

Last year, the team reported that they could produce hydrogen gas by combining seawater, recycled soda cans, and caffeine. The question then was whether the benchtop process could be applied at an industrial scale, and at what environmental cost.

Now, the researchers have carried out a “cradle-to-grave” life cycle assessment, taking into account every step in the process at an industrial scale. For instance, the team calculated the carbon emissions associated with acquiring and processing aluminum, reacting it with seawater to produce hydrogen, and transporting the fuel to gas stations, where drivers could tap into hydrogen tanks to power engines or fuel cell cars. They found that, from end to end, the new process could generate a fraction of the carbon emissions that is associated with conventional hydrogen production.

In a study appearing today in Cell Reports Sustainability, the team reports that for every kilogram of hydrogen produced, the process would generate 1.45 kilograms of carbon dioxide over its entire life cycle. In comparison, fossil-fuel-based processes emit 11 kilograms of carbon dioxide per kilogram of hydrogen generated.

The low-carbon footprint is on par with other proposed “green hydrogen” technologies, such as those powered by solar and wind energy.

“We’re in the ballpark of green hydrogen,” says lead author Aly Kombargi PhD ’25, who graduated this spring from MIT with a doctorate in mechanical engineering. “This work highlights aluminum’s potential as a clean energy source and offers a scalable pathway for low-emission hydrogen deployment in transportation and remote energy systems.”

The study’s MIT co-authors are Brooke Bao, Enoch Ellis, and professor of mechanical engineering Douglas Hart.

Gas bubble

Dropping an aluminum can in water won’t normally cause much of a chemical reaction. That’s because when aluminum is exposed to oxygen, it instantly forms a shield-like layer. Without this layer, aluminum exists in its pure form and can readily react when mixed with water. The reaction that occurs involves aluminum atoms that efficiently break up molecules of water, producing aluminum oxide and pure hydrogen. And it doesn’t take much of the metal to bubble up a significant amount of the gas.

“One of the main benefits of using aluminum is the energy density per unit volume,” Kombargi says. “With a very small amount of aluminum fuel, you can conceivably supply much of the power for a hydrogen-fueled vehicle.”

Last year, he and Hart developed a recipe for aluminum-based hydrogen production. They found they could puncture aluminum’s natural shield by treating it with a small amount of gallium-indium, which is a rare-metal alloy that effectively scrubs aluminum into its pure form. The researchers then mixed pellets of pure aluminum with seawater and observed that the reaction produced pure hydrogen. What’s more, the salt in the water helped to precipitate gallium-indium, which the team could subsequently recover and reuse to generate more hydrogen, in a cost-saving, sustainable cycle.

“We were explaining the science of this process in conferences, and the questions we would get were, ‘How much does this cost?’ and, ‘What’s its carbon footprint?’” Kombargi says. “So we wanted to look at the process in a comprehensive way.”

A sustainable cycle

For their new study, Kombargi and his colleagues carried out a life cycle assessment to estimate the environmental impact of aluminum-based hydrogen production, at every step of the process, from sourcing the aluminum to transporting the hydrogen after production. They set out to calculate the amount of carbon associated with generating 1 kilogram of hydrogen — an amount that they chose as a practical, consumer-level illustration.

“With a hydrogen fuel cell car using 1 kilogram of hydrogen, you can go between 60 to 100 kilometers, depending on the efficiency of the fuel cell,” Kombargi notes.

They performed the analysis using Earthster — an online life cycle assessment tool that draws data from a large repository of products and processes and their associated carbon emissions. The team considered a number of scenarios to produce hydrogen using aluminum, from starting with “primary” aluminum mined from the Earth, versus “secondary” aluminum that is recycled from soda cans and other products, and using various methods to transport the aluminum and hydrogen.

After running life cycle assessments for about a dozen scenarios, the team identified one scenario with the lowest carbon footprint. This scenario centers on recycled aluminum — a source that saves a significant amount of emissions compared with mining aluminum — and seawater — a natural resource that also saves money by recovering gallium-indium. They found that this scenario, from start to finish, would generate about 1.45 kilograms of carbon dioxide for every kilogram of hydrogen produced. The cost of the fuel produced, they calculated, would be about $9 per kilogram, which is comparable to the price of hydrogen that would be generated with other green technologies such as wind and solar energy.

The researchers envision that if the low-carbon process were ramped up to a commercial scale, it would look something like this: The production chain would start with scrap aluminum sourced from a recycling center. The aluminum would be shredded into pellets and treated with gallium-indium. Then, drivers could transport the pretreated pellets as aluminum “fuel,” rather than directly transporting hydrogen, which is potentially volatile. The pellets would be transported to a fuel station that ideally would be situated near a source of seawater, which could then be mixed with the aluminum, on demand, to produce hydrogen. A consumer could then directly pump the gas into a car with either an internal combustion engine or a fuel cell.

The entire process does produce an aluminum-based byproduct, boehmite, which is a mineral that is commonly used in fabricating semiconductors, electronic elements, and a number of industrial products. Kombargi says that if this byproduct were recovered after hydrogen production, it could be sold to manufacturers, further bringing down the cost of the process as a whole.

“There are a lot of things to consider,” Kombargi says. “But the process works, which is the most exciting part. And we show that it can be environmentally sustainable.”

The group is continuing to develop the process. They recently designed a small reactor, about the size of a water bottle, that takes in aluminum pellets and seawater to generate hydrogen, enough to power an electric bike for several hours. They previously demonstrated that the process can produce enough hydrogen to fuel a small car. The team is also exploring underwater applications, and are designing a hydrogen reactor that would take in surrounding seawater to power a small boat or underwater vehicle.

This research was supported, in part, by the MIT Portugal Program.