US: Costs soar as acidic waters gush freely from 12 of Oregon's abandoned mines

Publisher Name: 
The Register-Guard

This seems more like a scenario in a vulnerable Third World country than a drama playing out near the South Umpqua River.

A foreign, multinational copper mining company tunnels into a mountain south of Roseburg, quits the venture after 2 1/2 years and leaves behind an ecological disaster: Eighteen miles of salmon-rearing stream are dead, killed by acidic waters running from the mine.

The mess is on a Superfund scale of nastiness.

Now, taxpayers must come up with an estimated $15 million for the cleanup, although government experts don't guarantee that their remedy will work.

The metals-caked stream may never recover.

This is a dirty secret from the Oregon backcountry, where hills are pocked with at least 140 abandoned mines. A dozen of them gush fish-killing acidic waters.

This is the legacy of copper, gold, silver and zinc mining. Old mercury mines, meanwhile, create additional problems, rendering fish so contaminated that it's unwise for children to eat them.

In Lane County, the old Champion gold mine in the Bohemia Mining District washes mercury and other heavy metals into Dorena Lake. The Black Butte mine's mercury taints the fish and reputation of the popular Cottage Grove Lake.

Farther south, in Douglas County, the Bonanza mine yielded enough mercury-and-arsenic laden tailings to create railroad beds and driveways in the city of Sutherlin. And that's where the toxic stuff sits today, to the alarm of some residents.

Then there's the Formosa mine, a site so polluted that it impresses even regulators in the big mining states of Montana and Nevada.

No commercial hard-rock metal mining companies are licensed in Oregon today. The industry has no employment to speak of. But there's nothing in federal law to prevent a company from getting a permit, digging in and creating another poison-gusher.

"We have seen this story all too often, even in recent years," said Dusty Horwitt, analyst for the Environmental Working Group in Washington, D.C. "Mining companies leave behind epic disasters, and we have very little money to clean them up."

Withered vines

Such is the story at the Formosa mine, on Silver Butte at the headwaters of an Umpqua River tributary more than 2,000 feet above the valley floor.

In the rainy season, acid waters gurgle out of the old mine entrance at 65 gallons a minute. Annually, 5 million gallons pour out.

The water leaves a yellow residue as it ripples down a hill then falls into a pond, where the state Department of Environmental Quality has made a futile attempt to treat the water before it runs into streams. Acid water also seeps out of springs on the mountain's flanks.

The acid waters carry 30,000 pounds of dissolved copper and zinc out of the mine each year. The metals-laden water is deadly to fish, so the streams that gather waters around the base of Silver Butte are dead. Both Middle Creek and South Fork of Middle Creek are dead.

Ecologically, it's a big loss.

Before the Formosa Exploration Inc. started digging there in 1989, South Fork was a pristine stream rated by the Northwest Forest Plan as vital to spawning coho salmon, rainbow trout and steelhead. Now, it flows with sickly colors, changing as the acidity wanes downstream and the metals fall out in the stream bed.

"You'll see blue-green coating the rocks, and that's a copper precipitate," said Greg Aitken, DEQ cleanup manager. "Higher up you'll start to see white, and that's aluminium or zinc. You'll walk a little higher, and you'll see black. That's manganese."

On the mountaintop, mine workers demolished an 800-foot-long and 200-foot-wide ridge, creating a saddle for the mill and the mine buildings. A dozen years after the operation shut down, nothing can grow on the tainted rock and dirt.

Before Formosa Exploration went out of business, it tried extreme measures to revegetate the 76-acre site. The company spread 42,000 gallons of waste from the Riddle sewage plant. It tried to cultivate blackberry plants.

Nothing took. Not even blackberries. 

AMP Section Name:Natural Resources
  • 183 Environment