The last of Vermont’s abandoned copper mines are finally slated for clean up
The stream runs clear on the side of Corinth's Pike Hill. But the air smells of sulfur. And the water is more acidic than lemon juice.
Its pH is about 2, which means heavy metals like aluminum, manganese, iron and zinc are dissolved in the water.
“So you can get what looks like a nice, clean stream, but because of the pH, it can be absolutely loaded in metals,” Ed Hathaway explained.
He’s a project manager with the U.S. Environmental Protection Agency, and has been working to clean up old mining sites in New England like this one for more than 30 years.
“So you can get what looks like a nice, clean stream but because of the pH, it can be absolutely loaded in metals.”Ed Hathaway, EPA
Last month, the federal government announced new funding to help clean up Pike Hill, while money for the clean up of another nearby copper mine, the Ely Mine in Vershire, was set aside in 2021.
They’re both designated as Superfund sites for the toxic water that seeps out of them.
That water isn’t dangerous for people to be around, but it’s deadly for most bugs and fish for over a mile downstream.
“The pH of 2 is going to pretty much kill anything," Hathaway said. But if the acid somehow didn’t kill the stream critters, the metals would.
“High concentrations of copper and zinc, you’re gonna see 100% mortality,” he said.
The Pike Hill copper mines are the reason the stream is so acidic and full of heavy metals. The mines first opened in the 1800s, and for decades, workers here removed millions of pounds of copper from beneath the earth.
The mines wrap around the top of a small mountain. In some places, miners dug pits straight into the ground. In others, they blasted horizontal tunnels and hauled the copper-rich rock out with iron carts and horses.
“So they take the rock, they crush it,” Hathaway said. “Here they used both magnetic separation and froth flotation, meaning they would just put it in a bath and they would use, like, a pine oil or something, and the divalent metals — copper’s a divalent metal — would stick to that froth. They’d skim it off, concentrate it and ship it.”
That process left huge piles of dirt and rocks behind, which are still there, even though the mine shut down in the early 1900s.
When rain or groundwater hits those piles, it reacts with the sulfide inside the dirt and rocks and forms sulfuric acid.
That acid runoff, and the heavy metals it picks up along the way, are what make the stream so toxic.
Even though the Pike Hill mines were designated as a Superfund site in 2001, for decades, nothing here changed. The site was something of a local attraction.
“Whenever people came from out of town, we would go up to the mine just because it was an oddball destination,” said Virginia Barlow, a forester and writer who's lived in Corinth most of her life.
“I was always just taken aback to see how barren the landscape was, without any vegetation, the soil was a strange orangey color,” she said. “The brook that leaves the mine was just creepy looking. Even today, it looks terrible.”
Last year, the EPA announced its plan to clean up the Pike Hill mines.
There are some complications. A colony of endangered bats lives in the shafts, so the EPA isn’t going to seal up the mine tunnels.
“I was always just taken aback to see how barren the landscape was, without any vegetation, the soil was a strange orangey color, even after having been abandoned for a long time."Virginia Barlow, Corinth resident, writer and forester
Instead, they’re going to gather all the dirt that’s leaching acid into one or two big piles and cover it with plastic.
“We need to get it [the tailings] out of contact with water. And then we cap it,” said Hathaway, with the EPA. “That cap prevents that oxygen diffusion. So when you remove the water and limit the oxygen, then you shut that reaction off.”
This idea has worked before — at the much bigger Elizabeth mine in South Strafford, about 25 miles away. And it's similar to the clean up plan proposed at the Ely Mine in Vershire.
These projects are starting now because Congress allocated a lot more money for this kind of work — Vermont got $38 million through the Bipartisan Infrastructure Law that passed in 2021.
“The bipartisan infrastructure law injection of a lot more funding is sort of putting now on a fast track some projects that had been languishing, because there wasn’t either the federal funding or the private funding to make it happen,” says David Cash, the EPA’s regional administrator in New England.
Cash says federal lawmakers also brought back something calledthe "polluter pays" tax, which will create a big pot of money for future Superfund cleanups.
But in Corinth, not everyone is happy about the cleanup plan.
The project is projected to cost almost $20 million and require thousands of truckloads of materials to pass through town.
“I think the current plan is a little overwhelming to people, and I can understand that,” Virginia Barlow said. “It’s a huge expense of resources and time and money. Moving a massive amount of earth, both on the site and from away. And people of course are worried about the roads.”
“The disruption to the people that are here seems extreme for the amount of mitigation that they’re actually doing.”Olivia Harding-Tillman, neighbor
Olivia Harding-Tillman is one of those people. She and her husband own a winery on the same quiet dirt road that will see all the truck traffic.
“The disruption to the people that are here seems extreme for the amount of mitigation that they’re actually doing,” she said.
Harding-Tillman thinks things would be different if the mine were poisoning people’s well water, but it’s not.
That’s a complaint Hathaway, from the EPA, has heard a lot working on projects like this one.
He says the Superfund program isn’t just for cleaning up public health hazards — it’s also meant to address threats to the environment, like a section of river without any life in it, surrounded by toxic soils.
“Part of the sell is, ‘If it’s so important, why didn’t you ever deal with it? It’s been here so long,’” he said. “But you know, I think it just had to wait its turn.”
The work at Pike Hill won’t start until next year, at the earliest. Once it begins, it will take several years to complete.
Video by Kyle Ambusk.
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