Exploring the Hydrological Impact of Abandoned Mines in Colorado
In 2015, three million gallons of water escaped the abandoned Gold King Mine near Silverton, Colorado, turning the Animas River orange and drawing national headlines as the contamination passed through Durango. Over time, the polluted water traveled nearly 400 miles to Lake Powell, with the EPA ultimately designating the mine a Superfund site.
An environmental disaster? Yes. An isolated risk? Not by a long shot.
To understand the threat posed by abandoned mines in Colorado, we interviewed Rory Cowie, Ph.D., owner of Silverton-based Alpine Water Resources. His consultancy works with the EPA to monitor water quality and flow in the area, using a combination of backcountry and scientific expertise to inform ongoing cleanup activities.
During the interview, Cowie explains how legacy mines affect Western communities, his team’s work to mitigate that impact and why high-resolution data is critical to their efforts.
Get the full episode and more stories from the field on Aquapod, our water monitoring podcast.
Why the Gold King Mine Spill Matters
Mining began in Silverton in 1860, with the search for gold. It picked up steam in the 1870s, when prospectors discovered rich silver deposits in the area. Today, hundreds of miles of abandoned mine workings sit beneath the San Juan Mountains encircling Silverton and Telluride, conveying groundwater through a complex network of interconnected pathways.
“When mines are abandoned, their entrances tend to collapse over time,” says Cowie, adding that most of these entrances or adits are covered with piles of rock and rubble.
“Collapsed mine tunnels can build up water behind them and eventually have a blowout because the earthen dam at the entrance to the mine isn’t a permanent structure.”
Mine water from the San Juan Mountains carries a wide range of metals, from iron oxide that causes sludging and discoloration to lead and cadmium that are toxic to humans and wildlife. The Animas River, where the 2015 spill occurred, is part of the Colorado River watershed, which supports drinking water, farming and recreation activities for more than 40 million Americans.
“These mines are all at the headwaters of pretty major rivers leaving the Southwest,” says Cowie. “We’re trying to understand the sources and locations of contamination and pollutants in the area, monitoring the quality and quantity of water arriving at rivers through different sources.”
Protecting Communities with High-Resolution Data
Following the Gold King Mine spill and increased federal funding to address the problem, Cowie’s team has set up over...