Restoration: North Empire Creek acid mine drainage mitigation

Graphic via the Clear Creek Watershed Foundation
Graphic via the Clear Creek Watershed Foundation

From the Clear Creek Courant (Ian Neligh):

The Clear Creek Watershed Foundation will spend $536,000 to remove the waste and re-vegetate the area between April and August. David Holm, the foundation’s executive director, hopes the mitigation will begin to make the water less acidic, eventually allowing plants to grow along the creek’s banks and fish to live in its waters.

However, he doesn’t want to mislead people into thinking the creek will be perfect when the work is complete.

“So how will it look afterward?” Holm asked. “We hope the stream corridor is going to look pretty good. There’s not going to be mine waste in it. It is going to look like a natural stream, and it is going to have vegetation on both sides as far out as we can get it.”

Empire Mayor Wendy Koch lauded the effort, saying the stream does not currently support life of any kind.

Koch said an Empire resident once questioned why he could never find deer, elk or any wildlife in that area.

“Well, that’s why,” Koch said of the stream and its acidity level. “(The project) will support our various wildlife, everything from bears to birds and anything in between.”

The project will be paid for by Miller Coors, which gave $394,000; the watershed district; the Colorado Division of Reclamation Mining and Safety; and in-kind donations from the county, the Environmental Protection Agency, U.S. Forest Service and Trout Unlimited.

Holm said the stream has a pH of 3, compared to a neutral pH of 7.
“When you get down to pH 3, you’re into 10,000 times more acidic than what you’re really going for,” Holm said. “So acidity is a real problem in North Empire Creek. There are very high elevations of copper and zinc. Both of those are very toxic to aquatic life.”

Holm said the stream also has toxic levels of iron, aluminum and manganese…

Holm said the area has an interesting history, being one of the earliest mining sites in the state.

“Initially, they did hydraulic mining in this area, which involves high-pressure hoses that are used, essentially, to wash the unconsolidated soil and subsoil … which in this area had disseminated gold deposits,” Holm said. “But it is a brute-force, ugly kind of mining that results in the hill slopes really not having a growth medium when it is said and done.”

More water pollution coverage here.

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