Yankee Doodle Tailings Pond: Another Mine Waste Site near Butte
Below Butte's Moulton Reservoir and above the Berkeley Pit/Continental Pit area lies the Yankee Doodle Tailings Pond. It is formed by a tailings dam more than six hundred feet high. I am not certain when this area was first used for tailings disposal, but the Anaconda Copper Mining Company concentrator built in 1964 was a significant contributor. Today, Dennis Washington's Montana Resources. (MR) operation discharges its slurry waste onto the Yankee Doodle pond.
Here's a map of the roughly one thousand acre (nearly two square miles) tailings pond:

And here's a Continental Divide view of the Berkeley Pit (left) and tailings pond (right); (photo by Todd Trigsted):

You can visit the Yankee Doodle Tailings Pond by driving north on the Moulton Road from Walkerville. Watch for a user-created ATV troad after you pass Butte's municipal water treatment plant, about a mile north of town.
When MRI shutdown in July 2000 due to high electricity prices brought on by deregulation (interestingly, MR/Washington had lobbied for deregulation, believing it would lower prices), the tailings pond went dry. When wind conditions were right, Butte suffered from duststorms like this (photo by Derek Pruitt, Montana Standard newspaper):

Citizen complaints and a $121,200 fine forced MR to treat the dry pond surface (beginning with pumping water over them and ending with capping) to prevent blowing dust. To help poor Dennis Washington resume mining operations, Butte gave MR a $2 million loan and reduced taxes. By December 2003, MR was once again pumping its 25 cfs slurry onto the Yankee Doodle Tailings Pond (photo by Stephen Jennings, Montana State University):

The upper end of the tailings pond, where water rushes down from Yankee Doodle Creek, is an unearthly blue color:

Like many people, I had assumed this color was from copper sulfate and other heavy metals salts. My colleage, Chris Gammons, in Geological Engineering has done some testing, however, and he tells me the color is primarily from suspended clay sediments. You can see the color nicely in this shoreline view:
The mine waste slurry discharged by MR is very high in lime (which MR uses to precipitate and recover metals). The lime, and resulting high pH, causes the water in the Yankee Doodle pond to be low in metals (Chris did point out that it might be high in metalloids such as arsenic or selenium). The non-toxic nature of the water in Yankee Doodle Tailings Pond explains why it is used so heavily by waterfowl, and why one doesn't find dead ducks floating on the surface:
Still, there is a million yards or more of mine waste stored behind the Yankee Doodle tailings dam. Though it will probably end up being capped and vegetated if and when mining ceases, that is a decision that will have to be made in the future--perhaps as yet another Superfund site is added to the Upper Clark Fork River complex.
Labels: America's largest Superfund site, anaconda copper mining company, Butte




