THE MINE NEXT DOOR: Part 5

Alfred Berry (center) and underground/high country crew members Scott George and Bryan Pace, circa 1995.

The Red Mountains are full of rich deposits of pyrite, or iron sulfide, which contribute to the challenges of remediating Red Mountain Creek. (Photo by Don Paulson)

Idarado General Manager Rick River (in hat and yellow shirt) inspected the progress of Idarado high country crew members as they built a network of diversion channels in Marshall Basin.

The Yankee Girl head frame stands sentry over the Red Mountain Mining District. Historic mine tunnels and shafts driven into the Red Mountains produce hundreds of gallons per minute of extremely degraded, acidic waters that pollute Red Mountain Creek. The Genessee Mine is the worst offender, contributing about a third of all the dissolved zinc in the creek. (Photo by Brett Schreckengost)

Joe Smart stood at the Idarado Mine’s compliance point on Red Mountain Creek on a wintery day last March, where he samples the water once a month, snow or shine.

A perfectly poured high country diversion channel routed stream water around acidic, metal-loaded historic waste rock piles in Marshall Basin above Telluride. Altogether, there are 26 diversion channels in the Savage and Marshall basins, covering some 13,000 feet, and many more on the Red Mountain side of the mine.

A birds-eye-view of Idarado’s settling ponds in Pandora, built during the RAP years. As their name suggests, the settling ponds allow sediments and metals in the mine water emanating from the Mill Level Tunnel to gradually settle out of the water. Throughout this process, the water takes on vivid hues of orange, green and blue from the dominant minerals that are still suspended within it. Eventually the water either evaporates or soaks into the ground. The entire process is mechanical; no chemicals or other additives are used to treat the water.

Contract workers from Nielson Construction built diversion channels around the mining ruins in Savage Basin, circa 1994.

 

 

 

 

 

A Tale of Two Watersheds

by Samantha Tisdel Wright

Deep inside the guts of the San Juan Mountains, thousands of feet beneath the ragged ridge line that parts the mighty San Miguel and Uncompahgre river watersheds, two headlamps bobbed along like buoys in an inky sea – Alfred Berry in front, George Cappis right behind him – on the abandoned 2000 level of the Idarado Mine.

The year was 1991. Idarado was proactively working on mine closure, even before the Redial Action Plan that would ultimately guide that closure was negotiated and signed. A skeleton crew on a shoestring budget did the dirty, dark and dangerous work of re-activating the long-neglected underground workings, to make them safe for future closure activity.

Berry’s skin prickled as they passed the gaping maw of the 2030 ore pass, its black breath rising up from the depths to meet him. It was creepy working alone in this sprawling, empty mine, and he was glad that Cappis had agreed to come along that day to help him rehab a crumbling stretch of tunnel on the Argentine vein.

As they made their way along the tomblike passageway toward their work area, it dawned on Berry that Cappis had been awfully quiet for a while. He turned around, and Cappis was nowhere to be seen. Berry raced back and soon found him, leaning up against the rib of the tunnel beside the ore pass.

Berry thought he’d had a heart attack.

“George!” he yelled. “Are you alright?” Cappis was an old hand, as solid as they come. He’d worked at the Idarado almost forever, and not much could faze him. But when he lifted his head and stared at Berry, his face was as white as a sheet of paper. He looked as if he had seen a ghost. Indeed, he had.

“I can still hear his voice. And see his light down there,” Cappis muttered.

That’s how Berry found out that a young rookie miner had fallen down the 2030 ore pass, years ago. And that Cappis had pulled that miner’s broken, lifeless body out from the bottom of the chute, along with the broken ore, 900 feet below.

People had died over the years in various parts of the Idarado Mine – most of them well before the historic mine workings on the Telluride side were even consolidated into the Idarado in the 1950s – with no one left to remember who they were or how they’d died.

Under the watchful eye of their supervisor Jerry Heldman, Berry and Cappis and the others on the skeleton crew were now slowly, methodically preparing the Idarado itself to die –  tending to the underground workings in anticipation of the extensive mine remediation that would soon take place, when the State of Colorado and Idarado/Newmont finished duking it out in court.

It was strange work for miners accustomed to doing everything they could to keep a mine vibrantly alive. A little bit like a doctor caring for a patient on death row.

Boy Boss

In 1992, the State and Idarado finally finished negotiating their Consent Decree and agreed on a Remedial Action Plan, a five-year remedy to help the environment heal from the impacts of a century of mining in the region by Idarado and its predecessors.

Besides revegetating the tailings, the RAP targeted improving surface water quality around the Idarado Mine – specifically, by reducing levels of zinc in the San Miguel River and Red Mountain Creek drainages. Zinc is a stubborn heavy metal to remove from surface water, so if they could reduce zinc concentrations, they’d be reducing other metals as well.

Idarado hoped to achieve this objective through a variety of innovative source control measures to divert water away from mine waste and mineralized areas – both on the surface and underground – in order to prevent it from picking up heavy metals.

Under the direction of Idarado General Manager Rick River, Idarado hired several crews in 1992 to tackle the various elements spelled out in the RAP.

Berry, at 25, was foreman of the high country/underground crew on the Telluride side. Among the men he hired were miners who had been his mentors when he started out at the Camp Bird Mine as a kid fresh out of high school. Now, the tables had turned and Berry was in charge. They called him Boy Boss.

The first task at hand was to finish the work that the pre-RAP skeleton crew had started, bringing Idarado’s underground workings up to MSHA safety standards for the years of remediation work that lay ahead.

Berry and his crew got busy re-timbering raises, guiding new cable through aging WWII-era hoists, putting in new power lines, blasting run-arounds past caved-in workings that were too unstable to rehab, and constructing a network of refuge chambers (bunker-like rooms gouged out of rock that are stocked with oxygen tanks, food and medical supplies) that still exist inside the mine today.

Once they got the mine in shape, they started working on the underground elements of the RAP, building a far-flung network of hydrologic diversions, collection points and pipelines to herd the mine water around metal-laden stopes and ore passes and channel it down and out of the mine.

“We went all over that mine,” Berry said. “Many of the places we saw, nobody will ever see again. They have been abandoned forever.”

High Country Highlife

Berry’s crew had the best of both worlds.

In the winter, they had the run of the underground mine. And in the summer, they re-inhabited the mountain basins high above Telluride that the miners of a century ago had burrowed into like so many jackrabbits, leaving mounds of yellow waste rock and rusty old equipment behind.

Throughout the RAP years, the crew lived together all summer long in a small bunkhouse they dubbed the “Idarado Hilton” perched at 11,000 feet, just above the portal to the Ophir Mine in Marshall Basin.

They spent their days building miles of concrete interceptor channels that still lace the high country today like a bunch of alpine “Slip-n-Slides”, funneling snowmelt and storm water around the old mine dumps and collapsed surface features. It was grueling, filthy physical labor and in between the cussing, they loved it.

They pumped water right out of the creek and mixed their concrete in a continuous mixer. Berry’s friend and long-time mining partner Eric Schoenebaum (now Idarado’s Red Mountain site manager) was the pump-master; he was the only one that could get the cantankerous concrete pump to behave itself.

Just over the hill in Savage Basin, another man camp sprang up during the RAP years from 1993 to 1997, inhabited by a group of contractors from Nielson Construction that had been hired to put in diversion channels around the Tomboy ghost town and mining ruins. While the Idarado crew trucked all of their concrete materials and aggregate into Marshall Basin along the rough and narrow mountain roads, the Nielson contractors had theirs brought up to Savage Basin in an enormous Sikorsky sky crane helicopter.

Tragically, the Idarado high country crew lost one of its own in August 1993 when Berry’s brother-in-law, Thomas Rice, died in a vehicle accident half a mile or so above the old Tomboy town site.

“He was making the last trip of the day hauling some material and his truck ran off the road and he was killed. It was a horrible deal,” Schoenebaum said. “When you are working together doing these jobs you get real, real close. So that was just real tough when it happened. But we went on, you know.”

Their hard work paid off, as the San Miguel River gradually recovered from the degrading impacts of a century’s worth of mining. Idarado has now been meeting its compliance standard for zinc concentration in the San Miguel River nearly every year since 2004, and the river supports a healthy fishery.

Seeing Red

Making things better in the upper reaches of the Uncompahgre River watershed, where Idarado’s Treasury Tunnel is located, has turned out to be a more elusive goal. Here, the geology, hydrology and mining history of the Red Mountain District present a Gordian knot of challenges that Idarado has yet to unravel.

The RAP on Red Mountain has two components: direct revegetation of the tailings, and remediating water discharges from various portals on both Idarado and non-Idarado property.

Idarado’s Barstow Mine and Treasury Tunnel on the west side of Red Mountain Creek are not that problematic. The water draining out of them is zinc-loaded, but has a neutral pH. It is either piped into buried weeplines where it slowly seeps into the ground or, from time to time, diverted back through the mine to flow out into a boulder field below the Meldrum Tunnel on the Telluride side. The system works pretty well.

The troubles have come from a dozen mines in the historic Red Mountain Mining District just across Red Mountain Creek. Idarado never owned or operated these mines but accepted responsibility, under the Consent Decree and RAP, for cleaning up their mess.

The mining properties include a who’s who of Red Mountain’s leaky, acidic problem-children – the Joker, the Rouville, the Guston, and the biggest, baddest metal loader in the ‘hood – the Genessee Adit – which today contributes around a third of all the zinc in Red Mountain Creek depending on the time of year.

The RAP calls for Idarado to reduce zinc in the creek by 50 percent from pre-remediation levels – as measured at a compliance point just downstream of Idarado’s Tailings Pile #4 in Ironton Park.

The third-party mining properties named in the RAP are all upstream of this compliance point, and leak far more zinc into the creek than Idarado’s own properties. Thus, the most expedient way for Idarado to meet its zinc compliance standard for Red Mountain Creek is by dealing with these other draining mines.

By and large, Idarado’s remediation work on the Red Mountain side looks similar to what was done in the high country of the San Miguel River Basin – some portal collection systems, a few weep lines here and there, and lots of concrete diversion channels to route storm water and mine water discharge around waste rock to minimize the dissolution of metals into the water.

The systems were built well and did what they were supposed to do. But they have only gotten Idarado half-way to its remediation goal. To date, zinc loading in Red Mountain Creek has been reduced by just 25 percent from pre-remediation levels, rather than the 50 percent reduction the RAP calls for.

A quick peak into the geologic history of the region helps explain why the source control systems that worked so well on the Telluride side failed to achieve the same results for Red Mountain Creek.

In the Beginning

Before the mine, there were the mountains. Before the mountains, 35 million years ago, a cluster of supervolcanoes blew their lids in cataclysmic explosions, hurling out chunks of rock and spewing thick layers of magma and ash across present-day southwestern Colorado.

Spent at last, the volcanoes collapsed, leaving behind a rash of calderas that pockmarked the region like bad acne. The Silverton Caldera was among them.

Another surge of volcanism swelled the Silverton Caldera’s collapsed crater, shattering its western rim with radial and concentric fissures that shot through the surrounding rock, and injecting them with hot, mineralized juices that formed rich veins of sulfide ore. Inside the caldera, meanwhile, fierce hydrothermal activity leached the volcanic rock, enriching it with iron pyrite that weathered a rusty-red.

Glaciers and streams came along, sculpting the San Juan Mountains that we see today.

These mountains are essentially giant water towers, whose cracks and faults fill up with and store storm water and melting snow. When mine workings penetrate the mountains, they hijack the natural underground hydrology, offering new conduits that expose groundwater to oxygen, heavily mineralized rock, and – particularly in mines inside the Silverton Caldera – rich deposits of pyrite, or iron sulfide.

Water (H2O) plus pyrite (FeS2) yields iron oxides and sulfuric acid, also known as acid rock drainage. The acid leaches other heavy metals out of the surrounding rock and into the watershed.
 
The Telluride region doesn’t have an acid rock drainage problem. Way back when the supervolcano near Silverton went kablooie, a bonanza of carbonate rock blasted up into the air, and splatted down near present-day Telluride. That carbonate goodness remains in the environment, buffering the water issuing from the Idarado Mine above Telluride, and easing remediation efforts in the San Miguel River basin.

But the red acidic rim of the Silverton Caldera at the headwaters of the Uncompahgre River has no pH-buffering carbonate material at all. Indeed, if there was ever a geologic lottery for acid rock drainage, the Silverton Caldera stood in line twice waving its hands in the air screaming “Me, me, me!”

Mining has made the problem worse, but Mother Nature is complicit too; natural springs as acidic as lemon juice have been found well above historic mine workings in the Red Mountains.

Long story short, if there’s one thing to know about the geochemistry of the San Juan Mountains, it is this: “You are either in the caldera or you’re not, and it’s very different mineralization depending on where you are at,” said Ouray geologist Bob Larson.

The Idarado Mine is not in the caldera; its workings plunge into the gray-colored mountains across the highway to the west. But the third-party mines Idarado agreed to remediate through the RAP are well inside the caldera’s sour belly, and taint Red Mountain Creek with their acidic, metal-loaded drainage.

Up Red Mountain Creek Without a Paddle

After years of remediation efforts in the Red Mountain District, Idarado found out in 2012 that it still wasn’t meeting its zinc objective on Red Mountain Creek. This discovery triggered a contingency plan in the RAP that Idarado is now following to try to get into compliance.

First came yet another round of water sampling throughout the basin, which Idarado completed in 2012.

“And we found what we found 30 years ago – the major sources were basically the same,” said Idarado consulting environmental engineer Sherm Worthington. “Most of the zinc-loading in Red Mountain Creek comes from non-Idarado sources such as the Genessee Mine, the Red Mountain Adit and the Rouville Mine.”

To more effectively remediate the water seeping out of these mines (as well as its own), Idarado has looked at doubling down on tried-and-true source control remedial measures. It has also been evaluating different experimental processes for in-situ passive treatment, using its own Treasury Tunnel as a guinea pig.

Newmont’s Senior Engineer for Legacy Compliance, Devon Horntvedt, heads up this effort. He has evaluated two alternative treatment methods so far and has a third treatment study in progress this summer, but still hasn’t found the magic bullet. (We’ll take a closer look at Horntvedt’s ongoing work in the last story in this series.)

In the meantime, Idarado dances an awkward tango with the State over the next steps that are required to move forward with the remediation of Red Mountain Creek.

“The State is very open to alternative treatment systems,” Worthington said. “But they have to have a comfort level that what would be implemented has a likelihood of success – that it would work in terms of reducing zinc concentrations.”

“Idarado has done a lot of studies in quantifying how much zinc-loading is coming out of each adit. They know what the major contributors are. It’s Idarado’s responsibility now to come up with a plan to meet its performance objective,” said Ross Davis, Idarado Project Manager for the Colorado Department of Public Health and Environment, who keeps tabs on the Idarado’s RAP compliance. “We recognize it will take a fair bit of effort to get there, but it’s attainable.”

Idarado is up for the challenge.

“We want to come to a sustainable solution,” Horntvedt said. “I think there are definitely opportunities to make strides, and we are looking forward to making them.”

In the meantime, Idarado’s water quality compliance officer, Joe Smart, will continue to make the trip up Red Mountain Pass in his pickup truck once a month, park at the toe of the giant remediated tailings pile in Ironton Park, scoop some water out of Red Mountain Creek with his dipper stick, and pour it into bottles to send off to the lab.

One of these days, with any luck, the lab results might come back with a nice surprise.

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Next week: Green Grass Grows on Gray Mountain – Adventures in Tailings Pile Remediation