Largest Superfund site cleanup to begin in Montana

Cleanup of the Clark Fork River in Montana, which absorbed millions of tons of heavy metals pollution from the mines and smelters of Butte and Anaconda, is about to begin. It will take 10 years to clean up 100 years of damage. Rob Chaney of The Missoulian newspaper today concludes a three-part series on the project, including how wrangling over the Superfund site kept biologists away from the river for 25 years. Now officials are scrambling to assess how much the river's trout and wildlife were damaged by deposits of copper, arsenic and lead that line its shoreline.  The series also looks at the Deer Lodge Valley, hit by the worst of the mine wastes, and examines what the millions of Superfind dollars will buy in rebuilt trout fisheries and wildlife cooridors.

This is the history:

The copper mines and smelters of Butte and Anaconda dumped their mining waste into the Clark Fork's headwaters for nearly a century. Arsenic, cadmium, copper, lead, mercury and 20 other metals sluiced down the river channel, occasionally in catastrophic releases that made the water run orange. One hundred and twenty miles downstream, the former Milltown Dam trapped more than 2 million tons of toxic mining sludge in its reservoir above Missoula.

This is a tour down the river today:

And suddenly, it's paradise lost. A huge slicken (trapped reservoirs of toxic mining sludge) replaces the cottonwoods, covering most of a floodplain with a layer of shiny, blue-gray, crystalline frosting.

It flakes off like rust, revealing a tan muck. It tastes acidic and bitter, with a texture that won't leave the mouth for a long time. Pools of water stranded when the spring runoff receded have turned bright green. Where it is dry, it crumbles like rotten sheetrock. Where it is wet, it clings like gumbo and tries to steal river sandals. Nothing grows in it. Everything that tried has died.

The heavy metals have hurt the fish population of the Upper Clark Fork, but not in ways one might expect. The slickens leach poisons into the water, which cause long-term health problems for the trout.

The bigger worry is flooding, which can rip the slickens apart and literally "unbraid" the river channel. The result is massive spikes in deadly copper salts that kill fish outright, plus the loss of oxbows and other streamside habitat fish need to survive.

-- Rita Hibbard