The design of the tailings impoundment for the Mt Tolman molybdenum mine involved a 300-ft high rockfill embankment above which would rise a 600-ft high embankment of sands cyclones from the tailings. When this design was proposed in the early 1980s, the resulting embankment, nearly 1,000-ft high would have been one of the largest anywhere. So it was with interest that I came across the following story on the internet:
Voters on the Colville reservation decisively rejected the mining referendum when the votes were officially tallied on March 23, 2006 Votes against numbered 1,254, compared to 847 ''yes'' votes for nearly a 60 percent to 40 percent ratio in opposition to mining. Voters essentially turned down the possibility of huge financial gains in favor of protecting the environment and cultural values. Many considered the financial income as a chancy situation dependent on several factors, most notably the long-term value of molybdenum. Molybdenum is the primary ore at the Mount Tolman site that was being considered in the mining proposal.
Billie Jo Bray, a San Poil, was one of the leaders in getting the word out in opposition to mining. The organization she represents, Visions for Our Future, is a non-profit grass-roots organization concerned about preventing destruction to natural resources and saving sacred sites on the reservation.
''I'm very happy. I'm jumping with glee inside,'' Bray said. ''I want to do a celebration dinner right now to bring people together and enjoy the company - to pray and say 'thank you.' I'm really excited.'' Sonny George, another member of Visions, had similar comments. ''I think it's overwhelming. There's no question that people don't want mining.'' He added: ''It's a great day for our reservation. Everyone should be happy.''
Despite their elation, each expressed some concerns, acknowledging that despite the decisive vote the tribal council could opt to go against the will expressed by the voters. George added that he thought the vote would answer the questions of tribal leaders about the desires of tribal members and hoped this would end the discussion. ''I'm glad it's over,'' commented Harvey Moses Jr., chairman of the Colville Business Council. ''I'm also glad it didn't pass. I'm against mining in and around the reservation for environmental, cultural and traditional purposes.''
Asked about the possibility of the tribal council overturning the vote, he replied, ''Yes, tribal council could have done that; but after the count was certified they [tribal council] passed a resolution saying 'no' to mining.'' That would certainly seem to put to rest the concerns expressed by Bray, George and others opposed to mining.
I have previously written the following about this proposed impoundment: When the Columbia River was dammed by glacial ice, sediments deposited in the deep valleys of northern Washington State. Amax sought to develop a molybdenum mine just off the Columbia in the Colville Tribe reserve. I was brought across to design the tailings impoundment at the selected site. I was brought across because preliminary surveys had revealed up to 30 meters of soft, unconsolidated mud filling the selected valley, and after all, I had just succeeded with a similar soil deposit in South Africa.
To contain the calculated volume of tailings from the proposed mine, the impoundment would have to be 1,000-ft high, an unprecedented height in 1980, but more common now. A quick calculation revealed that the rate of rise was so fast that no amount of expedited drainage of excess pore pressure would yield a fast enough gain of strength to provide the required stability. We had to find another way.
In concert with the mining engineers, we came up with the idea of building a 300-ft high starter dike of waste rock. Stripping overburden would provide the waste rock and if we dumped it in fifty-foot lifts we could have the starter dike ready before the mill came on stream. If we cycloned the tailings, there would be enough coarse material to fill in behind the dike and then go on to raise the embankment above the rock dike. The fine cyclone overflow would be discharge behind the sand embankment. Sketches and drawings were generated, and stability analyses undertaken (a junior colleague got his master thesis completed on the strength of the stability analyses).
We consulted with the experts including a memorable visit to Arthur Cassagrande to discuss piping of tailings through the segregated waste rock. I came across that new American institution, the peer reviewer and I was eviscerated by them for my early mistakes. Finally the local authorities include Roy Soderberg of the Spokane mining department approved the design and we were ready to go to construction. But Carter became president, the economy collapsed, mining projects were shelved in every state, and engineers in the mining industry were thrown out of work. House prices collapsed, the interest rate shot up, and Reagan became president. The mine never opened. Rob Dorey, now an independent consultant in Denver, took the ideas, ran with them, expanded them, improved them, and formulated the design of a great tailings impoundment that was built in Idaho. But that is another story.
So many changes and so little change. I wonder if any from the Colville Tribe went to Thompson Creek
before deciding how to vote?