October 14, 2024

A plan to extract gold from mining waste is dividing a Colorado town that has been plagued by pollution for decades

LEADVILLE, Colorado (AP) — Rust-colored piles of mine waste and sun-bleached wooden derricks loom over the historic mining town of Leadville, Colorado, a legacy of gold and silver mining that continues to pollute the Arkansas River basin more than a century after the town’s boom days.

That’s where a young company called CJK Milling comes in, which wants to “remine” some of the waste piles to extract more gold from ore that was discarded decades ago when it was less valuable. The waste will be trucked to a nearby mill, ground into powder and bathed in cyanide to extract trace amounts of precious metals.

The proposal comes amid growing global interest in reprocessing waste containing discarded minerals that have become more valuable over time and are now easier to dispose of. These include precious metals and minerals used in renewable energy, which many countries, including the United States, are working to secure.

Supporters say the Leadville proposal would speed up the cleanup effort that has languished under federal supervision for decades and has no end in sight. They talk ambitiously of a “circular economy” for mining, in which the leftovers are recycled.

Still, the revival of the city’s ailing mining industry and the stirring up of mountains of waste have some residents and politicians reminding them of a polluted past when the Arkansas River was harmful to fish and at times turned red with waste from Leadville’s mines.

“We’re sitting in a river where 20 years ago the fish couldn’t survive,” said Brice Karsh, who owns a fishing farm downstream from the proposed mill, as he threw fish pellets into a pool full of rainbow trout. “Why go backwards? Why take the risk?”

Leadville – home to about 2,600 residents and the National Mining Museum – bills itself as America’s highest city at an elevation of 10,000 feet above sea level. This distinction has given the city a new identity as a mecca for extreme sports enthusiasts. Endurance race courses run through nearby hills where millions of tons of discarded mining waste have washed lead, arsenic, zinc and other toxic metals into waterways.

The driving force behind CJK Milling is Nick Michael, a 38-year mining veteran who describes the project as a way to give back to the community. Standing on a pile of mining waste with Colorado’s highest peak, Mount Elbert, in the distance, Michael says the debris has a higher concentration of gold than many large mines currently operating in the U.S.

“That wasn’t the case before,” he said, “but things have changed and that’s why it’s so economical… We just clear away these little piles and move on to the next one.”

City Council member Christian Luna-Leal grew up in Leadville – in a trailer park with poor water quality – after his parents immigrated from Mexico.

Disadvantaged communities have always borne the brunt of the industry’s problems, he said, dating back to Leadville’s early days when mine owners mistreated Irish immigrants who did much of the work. Nearly 1,300 immigrants, most of them Irish, lie buried in pauper’s graves in a local cemetery.

Stirring up old mine waste could undo decades of cleanup efforts, Luna-Leal said, leading to renewed water pollution and threatening the well-being of residents, including Latinos, many of whom live in trailers on the outskirts of town.

“There is a real fear in many parts of our community that this is not being adequately addressed and our concerns are not being taken as seriously as they should be,” Luna-Leal said.

The company’s process does not eliminate mine waste. For every tonne of ore milled, a tonne of waste remains – minus a few ounces of gold. At 400 tonnes per day, the waste adds up quickly.

CJK had originally planned to store the material in a huge open pit in the form of a wet slurry. After scrapping that plan, the company instead plans to dry the waste to a putty-like consistency and pile it on a hill behind the factory, Michael said. The open pit slope would serve as an emergency containment if the pile collapses.

The amount of mining waste worldwide is staggering: Tens of thousands of dumps contain 245 billion tonnes (223 billion metric tons), researchers say. And waste production is increasing as companies build larger mines with lower-grade ore, leading to a higher waste-to-product ratio, according to the nonprofit World Mine Tailings Failures.

This month, gold prices hit record highs and demand for key minerals such as lithium, used in batteries, has risen sharply.

Because of favorable economic conditions, mining has “spread like wildfire,” says geochemist Ann Maest, who advises environmental organizations such as EarthWorks. The advocacy group is critical of the mining industry but has cautiously viewed mining as a possible means to speed up remediation through private investment.

CJK Milling could help with that in Leadville, Maest said, but only if it’s done right. “The problem is they want to use cyanide, and when a community hears that cyanide or mercury is involved, they understandably get very concerned,” she said.

Greg Teter, district manager of Parkville Water, is responsible for Leadville’s water supply and sees CJK Milling as a possible solution to the water quality problems.

Numerous piles of garbage cover the district’s water supply, and Teter recalls that an eruption at the Resurrection Mine forced residents to boil their water because the district’s sewage treatment plant could not handle the dirt and debris.

Runoff pollution is consistently higher in spring and summer, when meltwater from the Mosquito Mountains flows through the dumps and drains of abandoned mines.

An average of 694 gallons (2,627 liters) of contaminated mine water flows out of the Leadville Superfund site every minute, according to federal records. Most of it is stored or sent to treatment plants, including one operated by the U.S. Bureau of Reclamation.

As much as 10% of the water goes untreated – tens of millions of gallons a year containing an estimated six tons of toxic metals, U.S. Environmental Protection Agency records show. By comparison, during the 2015 Gold King Mine disaster in Colorado, which polluted rivers in three states, an EPA cleanup crew accidentally triggered the release of 3 million gallons (11.4 million liters) of mustard-colored mine waste.

As long as Leadville’s landfills remain, their potential for pollution remains.

“There are literally thousands of mine sites that are overlapping,” Teter said. “We don’t want that going into our water supply. As it stands now, all the mine dumps … are in my watershed, upstream of my watershed, and if they remove them and take them to the mill, they’ll be below my watershed.”

The EPA has no authority over CJK’s planned work, but a spokesman said there is “the potential to improve conditions on site” by complementing cleanup work already underway. Relocating the mine waste would eliminate sources of runoff and could reduce the amount of contaminated water that needs to be treated, EPA spokesman Richard Mylott said.

Other examples of mining in the Rocky Mountains include East Helena and Anaconda in Montana and Midvale in Utah, Mylott said. Projects are planned at Gilt Edge in South Dakota and Creede in Colorado, he said.

Despite the chaos that comes with Leadville’s historic mining industry, Teter spoke proudly of his ties to the industry, including working at two now-closed mines. His son-in-law works at a nearby mine.

“Without mining, Leadville wouldn’t exist. And I wouldn’t be here,” said the water manager.

“There are no active mines in our catchment area, but I trust CJK’s plans,” he said. “And I will be able to keep an eye on everything they do.”

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