MINTURN — Nothing about the Eagle Mine is simple — from who’s responsible for the property to the miles of plumbing associated with the cleanup. Changes to the cleanup are complicated, too, but those responsible for the process are starting to work to alter the way contaminated water from the mine is kept out of the Eagle River.
The mine was the subject of a recent meeting hosted by the Eagle River Watershed Council. That meeting brought together representatives from the companies that are running the cleanup, as well the state and federal agencies that are overseeing the project.
While much of the meeting was taken up with a great deal of history about the mine and the cleanup, the short version is this: A new owner took over the mine in 1983, then abandoned the project the next year. After that, the pumps failed that kept snowmelt and groundwater out of the underground mine. The maze of tunnels quickly flooded, and the water, contaminated by zinc, copper and other minerals, leaked into the Eagle River, turning the water a rusty orange. Old tailings piles from decades of processing zinc ore at the site also contributed to the contamination.
After years of work, state and federal environmental officials, along with the corporation ultimately responsible for the property — now CBS — signed an agreement for a plan to clean up the mine property and a way to keep contaminated mine water out of the river.
The tailings piles — more than 65,000 cubic yards — were removed and transported to an area in Maloit Park, near Minturn. Those tailings were put into a large pile, then capped with clay and other material that doesn’t allow snow to seep in, or out, of the pile.
CLEANING THE WATER
Next to the pile is a water treatment plant. That plant treats contaminated water from the flooded mine works, returning cleaned water to the river after the minerals have been taken out and turned into something with the rough consistency of modeling clay.
PROBLEMS WITH THE SYSTEM
The system works well, most of the time. But there are problems.
The system is hard to keep clean, due mostly to the presence of lots of iron in the water and the fact there aren’t enough cleaning ports in the roughly three miles of pipeline between the mine and treatment plant.
Watershed council researcher Seth Mason told the group of about 35 people at the meeting that there have been several discharges of contaminated water into the river. The biggest of those in recent years was a 2012 discharge of more than 400,000 gallons of untreated water into the river.
Geologist Dave Hinrichs, whose company, NewFields, is one of the specialists involved with the continuing cleanup. He said a combination of the pipeline’s design and materials in the water make it tricky to keep the system in top working order.
A POSSIBLE SOLUTION
A solution may be on the horizon. Dave Heinze is a senior manager for Environ, the company overseeing the project for CBS. He told the group at the meeting that those in charge of the project are looking at new technology and techniques to make the treatment system more reliable and less expensive to run.
The key part of the current ideas is moving the treatment plant closer to the mine’s entrance, above Belden. That’s a tricky proposition, given that the tight canyon between Maloit Park and Belden is susceptible to landslides and avalanches.
Heinze said there could be enough room inside the mine, which once contained ore processing equipment. That’s going to require a couple of things.
The biggest hurdle is regulatory. Moving the water treatment plant will require redoing the legal agreement between CBS, the federal Environmental Protection Agency and the Colorado Department of Public Health and Environment.
Wendy Naugle, an engineer with the state health department, said opening up the existing agreement will take a lot of study and, ultimately, must be approved by all parties. That could take up to two years, she said.
LIBERTY WELL A KEY STEP
In the meantime, another key step is already in the works.
Heinze said a new well between the mine and Red Cliff, called the Liberty Well, is one source of water going into the mine. It’s now pumping “pristine water” at a rate of about 65 gallons per minute into Turkey Creek near Red Cliff, then into the Eagle River.
The well could ultimately pump 200 gallons per minute. That’s water that won’t go into the mine, Heinze said.
After the meeting, Red Cliff resident Bob Will said he’d learned a lot.
“It sounds like they’re staying on it,” Will said. “Everybody’s trying to make it better.”
Vail Daily Business Editor Scott Miller can be reached at 970-748-2930, firstname.lastname@example.org and @scottnmiller.