Should the Old Eugenia Mine Be Cleaned Up? The Answer Was No

The sign on the remains of the miners' cabin near the Eugenia Mine. NPS.

The question

In the nineteenth century, prospectors searched what is now Rocky Mountain National Park for valuable minerals. The Eugenia Mine, on the slopes of Longs Peak, worked in the 1800s but never paid off. Its shaft has been sealed since the 1960s, but mine tailings still lie near the entrance — and might be leaching harmful heavy metals into groundwater. Should they be cleaned up?

The study

David Rathke and Richard Graham of the U.S. Environmental Protection Agency (Region 8), with John Burghardt of the National Park Service's Geologic Resources Division, examined the mine and the drainages below it.

• They sieved samples of waste rock and tailings and measured their elements with x-ray fluorescence.
• They sampled water and soil downslope to see whether metals were moving out of the tailings.

What remains of the Eugenia Mine: the former adit. NPS.

The answer: leave it

• The local bedrock is not high in heavy metals, and it is not leaching significant metals into streams.
• Removing the tailings would likely flush soil and sediment into local streams — and would probably increase the metals reaching park waters.
• So a cleanup would do more harm to the ecosystem than leaving the site alone. The recommendation: leave it as it is.

Sources

Based on "Cleaning Up the Eugenia Mine," Rocky Mountain National Park, National Park Service; a work of the United States government in the public domain.