Grass on Gray Mountain

Adventures in Tailings Remediation

by Samantha Tisdel Wright

Every workday morning back in the 1970s, Joe Smart would kiss his wife and little son goodbye, step out into the bracing dawn, and tune his ear to the rhythm of the Pandora Mill, a mile and a half up the valley from his company house in Telluride.

As long as he could hear the tick-tick-tick-tick-tick of the big gray mill’s powerful vacuum pumps, that meant it would be a good day.

“But if the mill wasn’t running, I knew it wasn’t gonna be a good day,” Smart said. “Everybody would be scurrying to get the mill back running.” Every minute the mill was down, the Idarado Mine lost money. Muck-bound ore. Idle miners. Cranky bosses. Empty con trucks. Not a pretty picture.

On good days, though, the Pandora Mill hungrily gnashed its way through up to 1,800 tons of ore – more than a ton each minute – transforming it into rich copper, lead and the zinc concentrates and gleaming loaves of gold doré (a mixture of gold and silver that was poured once a month at the mill).

Only about 5 percent of the ore contained these valuable metals. The remaining waste, or gangue, came out the back end as an acidic slurry of crushed, depleted rock and water known as tailings. Lots, and lots, and lots, and lots of tailings.

Back in the old days, the historic mills around Telluride dumped their tailings straight into the San Miguel River. But by the time Idarado came along, this practice had long since been outlawed. Instead, Idarado slurried its tailings into a series of piles alongside the river between Telluride and Pandora.

The upper four piles, 1-4, eventually blended into one long linear scab that snaked its way down the valley, while the lower two piles, 5 and 6, merged together into a big gray mountain just upstream of Town Park.

The Red Mountain side of the mine, where Idarado milled its ore prior to 1956, also had its fair share of tailings, including a large pile in Ironton Park known as Red Mountain Tailings Pile #4.

When Joe Smart arrived in Telluride in 1972 and started working at the Pandora Mill, he found out Idarado had been experimenting with growing grass on the big tailing piles ever since the 1960s – both to make them look a little nicer, and to prevent wind and water erosion.

Smart, who had a degree in forest science from Colorado State University, got on board with that effort, consulting with the Plant Materials Center of the Soil Conservation Service at the United States Department of Agriculture to find more species of high-altitude plants that might grow on the barren, sandy tailings.

“All you had to do was give it water and fertilizer, and we had lots of sunshine. That’s all you needed,” shrugged Smart, now Idarado’s most senior employee, safety guru and water sampling go-to guy.

It wasn’t rocket science. But those early efforts at tailings revegetation were just as ingenious in their own way as the Pandora Mill’s flotation system that separated precious and base metals from the gangue in the rock coming out of the mine.  

Smart and his crew were engaged in a different sort of alchemy in the 1960s and ‘70s – figuring out how to coax tender green life out of a big dead place.

Dirty, Seedy Science

Dr. Ed Redente picked up where Smart left off. A professor of rangeland ecosystem science at Colorado State University, Redente spearheaded Idarado’s innovative tailings remediation throughout the years of the Remedial Action Plan. He first got involved with the project as an expert witness for Idarado/Newmont during the legal battle leading up to the cleanup.

Today, he’s the guy who led the research proving direct revegetation could be successfully done on a large-scale, high-altitude tailing remediation project, and his team’s work is emulated around the world.

Idarado’s tailings piles started out as veins of metal sulfide ore deep inside the mountains between Ouray and Telluride. By the time that rock had been mined, crushed, digested, rejected and ejected out the back side of the mill as tailings, it had been finely ground to sand or clay-sized particles. It mostly consisted of a lot of inert materials with residual levels of unrecovered lead, zinc and copper, plus some chromium, cadmium and manganese.

An analysis of the tailings showed the chemical reagents applied in some stages of the milling process were not present in tailings to any substantial degree. Rather, the two biggest issues with the tailings piles were low pH and residual heavy metals, combining to create an exceedingly difficult environment for vegetation.

But throw in some cow poop, straw, crushed limestone and lime – not the citrus fruit, but powdered limestone with powerful pH-buffering properties – et voilà! “Now we have a material that is more favorable to plant growth,” Redente said. “And that creates a stable tailing environment not subject to wind or water erosion.”

Creating a welcoming, friendly growth medium was just one of the challenges in Idarado’s tailing revegetation adventure. Redente and his team of researchers also developed two distinct blends of grass and wildflower seeds – one for the Telluride tailings, and one for the higher-elevation tailings on Red Mountain – that would grow into self-sustaining plant communities hardy enough to survive the weather extremes of the San Juan Mountains.

Most of the species Redente selected took root in the tailings and are still growing there today; others grew quickly for a short period of time, helping to get the plant community established, then faded away.

Certain plant species did better than others as they all competed with one another for water, nutrients, space, light and all the other resources plants need to grow.

Orchardgrass and smooth bromegrass turned out to be the rock stars of the mix, contributing the most extensive plant cover to tailings on both sides of the mine. Timothy and Kentucky bluegrass also thrived. The mix also included varieties of forbs – broad-leaved flowering non-woody plants – such as cicer milkvetch, Rocky Mountain penstemon, clover, dryland alfalfa and native yarrow.

Species diversity is an important part of Idarado’s tailings remediation. And over the last few years, it has been on the rise – especially in newly amended areas where mulch has been imported to cover up bare patches. These patches have become “diversity islands” that now support intrepid new species. The hope is that these interlopers will venture out onto the rest of the tailings over time.

But the real magic on the tailings has happened through a process called nutrient cycling, in which soil-dwelling critters break down the plant material growing on site. Every year plants die back and drop their litter on the soil surface, dead roots decompose, and the nutrients are released back into the soil so plants can use them the next year.

“That’s how natural systems sustain themselves over time,” Redente said. “And that is definitely occurring on the tailings piles. One of the issues is having that decomposition happen fast enough so nutrients are released at a quick enough rate. It takes time. We started with something inert and we are trying to build a soil that will be self-sustaining.”

Redente’s been watching the grass grow on Idarado’s tailings for 25 years, and it’s been anything but boring. He returns to Idarado each year to check the plant growth for coverage and diversity as required under the RAP.

The project has been hailed as a huge success. Winds that once spun dust-devils of tailings through Telluride now riffle through the grassy meadows that grow on top of the tailings piles. Rainfall and snowmelt get sucked up by the plants, significantly reducing the amount of zinc and other metals that may otherwise seep from the piles into the San Miguel River and Red Mountain Creek.

No earthworms have found their way into the tailings soil yet, but there are plenty of other creepy-crawlies in there – insects, bugs, nematodes, microbes, bacteria and fungi. The former big dead place is now buzzing, swarming, squirming and writhing with life.

“Really what you are seeing is nature in action,” Redente said. “Start with a totally inert material, turn it into a material that can actually sustain plant growth, and watch it change over time. That’s something that has really helped me as an ecologist feel as though I am doing something positive.”

Meadow Muffin

Camille Price came to Idarado at about the same time as Redente.

She, too, spent 25 years of her career monitoring Idarado’s tailings revegetation – as well as other aspects of the RAP – for the Colorado Department of Public Health and Environment. Her task: making sure that Idarado complied with all the terms of the remediation settlement agreed to in 1993 after years of CERCLA litigation.

Price always knew she wanted to help the environment. She went to college at Colorado State University where she fell in love with the emerging field of environmental reclamation.

Cleaning up disturbed lands resonated deeply within her. “I grew up with ‘Give a hoot, don’t pollute,’ and commercials of Native Americans with tears in their eyes as they looked at litter,” she said. “I wanted to do something to improve the world.”

When she arrived at Idarado headquarters in Pandora back in 1992, the RAP was just getting underway, run by an all in-house Idarado crew. She got to know the guys on a nickname basis – Squeaky, Squawky, Finn, Tadpole, Parker, Swanney, and Swede, among others. Price herself was dubbed “Meadow Muffin” – “Muff” for short. “We were all just a bunch of kids,” she said.

The first time Price had to go inside the mine to observe the progress of the underground remediation, she was scared to death. But she relished the other aspects of her job – tracking the water quality in the San Miguel River and Red Mountain Creek, heading up into the high country to inspect the concrete diversion channels, and trekking out onto the tailings piles to monitor how the plant cover was coming along.

Through it all, Price remained vigilant in her oversight role, and held Idarado’s feet to the fire when necessary to make sure the mining company stayed on course in its remediation efforts. But she steered away from taking an adversarial or authoritarian approach.

“We were the first generation of reclamation workers,” Price explained. “I had to rely on people that knew more than me. I was smart enough to know what I didn’t know. I realized from the beginning it was the mine’s responsibility to perform the remediation, and I wasn’t here to micromanage it. I would say what the outcome needed to be, and they’d figure it out.”

But she wasn’t afraid to roll up her sleeves and lend a hand from time to time. She still has a scar on her leg from slinging hay on the tailings piles.

As new life grew out of the amended tailings, seeds of goodwill also began to sprout. Once upon a time, Idarado and the State of Colorado had been courtroom adversaries. Now, as the remediation unfolded on the ground, Redente, Price, Smart, and the others became a team, working together toward a common goal of healing the environment.

The Skeleton Crew Goes to Washington

In 2006, the U.S. Department of the Interior’s Bureau of Land Management recognized this work by presenting the Idarado Mining Company with the Hardrock Mineral Director’s Award for outstanding achievement in sustainable development.

“Through a collaborative effort with local stakeholders, Idarado Mining Company’s adoption of a non-disruptive remediation technique has preserved the historical aspects of the area’s mining legacy and has improved water quality, thereby achieving a balance between historic preservation and environmental protection,” the BLM noted. “We salute the efforts of all employees at the Idarado Mining Company for their outstanding accomplishments and contributions to the community.”

Newmont flew the Idarado skeleton crew to Washington, D.C. to attend an award ceremony hosted by the National Mining Association.  “It was great – they set us up in a top-of-the-line hotel; and they actually let us stay over another day just to tour the mall and stuff,” recalled Idarado’s Red Mountain site manager Eric Schoenebaum. "It was a lot of fun.”

The framed award and a letter of commendation from the BLM hang side by side in a backroom at the Idarado office in Ouray, gathering dust, as the work of caring for the aging mine and remediating the environment goes on.

Pile Patrol

Today, the tailings are Mark Parker’s big sandy babies. As Idarado’s Pandora site manager, Parker is responsible for watching over the tailings on the Telluride side. Before that, during the RAP years, he worked on the tailings remediation crew, so he knows all about the tailings on both sides of the mountains.

“Our most perfect one is Red Mountain Number One, a little baby one below the Treasury Tunnel,” Parker says. “Number One is a sweetheart, tucked into a corner. It’s always beautiful.”

You can’t really say the same about Idarado’s biggest tailings pile, the massive loaf-shaped mound looming over Telluride Town Park.

Some years, the vegetation here is so lush and tall and green that the deer play hide and seek in it. “All you can see is their ears,” Parker says. This year, though, in late July, the Number 6 tailings pile is having kind of a tough time. It’s been a dry summer, on top of a dry winter, and the grassy growth on the flat expanse up top is pretty stubby, pretty dry.

So dry in fact, that Parker decided not to fertilize this year. The less messing with the tailings, the better, in a year like this. Back in the early years when the vegetation was still getting established, they watered regularly, but the powerful old pump that sucked water out of the San Miguel River and delivered it up to the top of the tailings pile has been taken offline.

Now the tailings piles are left to their own devices – and the voles. Cute little mouse-like critters with rounded ears and stubby tails that burrow into the sand, leaving shallow snakelike tunnels near the surface so they can eat their favorite food, grass stems and blades. The voles are especially manic in the springtime and early summer.

“One year it got so bad, the voles would burrow on top of the tailings, and pop out the sides,” Parker says.

Coyotes like the tailings too. Parker, who comes from a sheep ranching family, has a natural aversion to coyotes. But he makes an exception for the coyotes that come up on the tailings piles. “They like to come out here and hunt,” he says approvingly.

As tough a summer as it’s been, Number 6 still looks a lot better now than it did back when locals called it the Toxic Twinkie or Gray Mountain. Parker remembers how it used to look – “like an ugly waste dump. There was a pond up here. And a lot of bare yellow tailings. The side slope was pretty gnarly and steep.”

After the remediation, it took a while to fine-tune things to where they are today. That first year, the tailings unintentionally made a lake on top that spilled over the edge toward Town Park, “like Hawaii Five-0. Like a tidal wave,” Parker recalls. He figured out how to fix the design flaw, and that doesn’t happen anymore.

Truth be told, though, it’s still pretty gnarly up here. The hot sun spanks the tailings all day long. “It’s just so big. It takes a beating,” Parker acknowledges, squinting out across the hot, flat, 64-acre expanse. Here and there, little bare patches of sand expose themselves, but even in this difficult year, the tailings are mostly covered with tenacious grassy green vegetation.

The majority of the plants growing here now came from the original seed mix. But on a closer look, new species are moving into this plant neighborhood from the surrounding wilderness and human-influenced landscapes, elbowing out a place for themselves, and putting down roots.

The ultimate goal, when the Idarado reclamation got started all those years ago, was that Idarado would someday be able to walk away from these tailings piles altogether. Parker can’t imagine what they were thinking. “You can’t walk away from something like this,” he says. “Mother Nature will throw you a curve ball.”

Who knows what it will be. A flood. A fire. An exultation of voles. Whatever it is, Parker – or his successor down the road – will be here to deal with it.

Done with his pile patrol, Parker climbs back in his pickup truck, and cruises along the utility road that skirts the bottom of the tailings, past a stretch of reclaimed land between the tailings and the river where his granddaughter helped him scatter seed when she was a toddler. She’s 20 now, and the area has grown into a lush, grassy wildflower meadow.

Then Parker slows to a stop. Stares out the window at the contoured slope of Number 6.

“Is that a raspberry bush?” he asks.

Sure enough. A wild raspberry bush is growing right out of the tailings – its tight young berry buds balled up like tiny fists; its light-green, serrated, spade-shaped leaves quietly photosynthesizing in the summer sunshine.

A yellow butterfly flutters by.

Parker smiles a bemused smile. “I’ll be damned,” he says.

Buried Treasure

Voles aren’t the only critters that like to dig in the tailings. Just last summer, Schoenebaum was making his rounds of the Red Mountain tailings piles when he spotted two suspicious-looking characters messing around on Number 4 (the big tailings pile in Ironton Park).

Schoenebaum drove up on the tailings to investigate. “And there they are with shovels, digging giant holes, all gooey and muddy and yellow,” he said.

Turns out, the intruders were digging for “Fenn’s Treasure”, a million-dollar treasure chest supposedly filled with gold nuggets, gold coins, pre-Columbian gold figures, rubies, sapphires, emeralds, diamonds, and cash, that an elderly, eccentric New Mexico millionaire named Forrest Fenn says he hid somewhere in the Rocky Mountains in 2009.

Schoenebaum sent the gold-diggers packing. All they got for their troubles was some barren yellow sand. Some men are just born to dig.

They missed out on the real treasure though – the wealth of green plants that have taken root amidst those tailings, the wild beauty of the mountains, and the rich history that twines its way throughout the ghost towns and mining ruins of the high country.


Next week: “Windows in Time – Historic Preservation at the Idarado Mine”