The state is allowing a Canadian company to dig deep into the ground to explore for copper near a tributary of the famed Smith River north of White Sulphur Springs.
In a notice released Thursday, the Montana Department of Environmental Quality wrote that after reviewing the proposal by Tintina Alaska Exploration Co. for the Black Butte Copper Project, the state believes the company can mitigate any negative impacts from the exploration work. That mitigation would be through “design, or enforceable controls or stipulations or both” imposed by DEQ or other governmental agencies.
Those requirements include methods for containing soil that may contain metals that contribute to acid mine runoff; having an archaeologist present to protect a prehistoric site that was identified; and weekly surface water and groundwater monitoring, with the results to be submitted monthly to DEQ.
The exploration permit under the Final Mitigated Environmental Assessment doesn’t permit the actual mine; it only allows Tintina to build a “decline,” which will let it get a better look at whether it’s economically feasible to mine for copper there.
The decline is a 5,200-foot-long ramp that goes underground. It will be 18-feet-high and 18-feet-wide on about 12,000 acres of public and private lands along Highway 89.
Tintina will be allowed to pull out 10,000 tons of rock for bulk sampling for metallurgical testing if the permit is issued.
In the 60-page draft document, Tintina had proposed putting the underground materials it hauls out of the decline into two piles lined with a thick, non-permeable barrier. The “PAG” pile is of Potential Acid Generating materials, and is estimated to include about 30 percent of the rock. The remaining materials go into the “NAG” pile, which is the Non-Acid Generating rock.
Water that falls on the rocks will be collected and treated if necessary. The PAG pond would have the capacity to store 1.9 million gallons of water, while the NAG pond would have a 4.1 million gallon capacity.
If Tintina decides that it’s not feasible to develop the copper mine, the company will put the PAG rocks back into the decline, cover it with a concrete barrier, then put the other rocks on top of that and reclaim the site. DEQ believes that by burying the PAG, it no longer will create acid runoff.
About 4,500 people submitted comments on the mine, including Jim Jensen with the Montana Environmental Information Center. The statewide group is opposed to the mine, saying that they believe acid mine runoff from the disturbance could harm both the environment and the Smith River.
“I’m disappointed that the agency is either politically incapable or unwilling to say that there are some places that the risk is too high,” Jensen said. “DEQ says ‘Trust us; we have new special protective measures.’ But they say that every time for every mine, and the agency has failed every time.”
MEIC believes the mine violates Montana’s constitution because it will contaminate water, which will then be treated.