HELENA, Mont. – A draft Environmental Impact Statement (EIS) for a proposed copper mine near White Sulphur Springs and the Smith River has been issued for public review.
The Montana Department of Environmental Quality will take public comment and hold four public meetings in April and May.
“We are looking for feedback on our analysis – this is a very important part of the process,” said DEQ Director Shaun McGrath.
The draft includes an additional component to the project: backfilling additional underground mine workings. The DEQ proposes that at the end of operations, certain voids, like access openings be backfilled with a material consisting of cemented paste tailings from mill processing of stockpiled ore and/or waste rock. The agency said the backfill material has low hydraulic conductivity and would return the bedrock zones to conditions similar to the pre-mining state, eliminating the potential of new groundwater flow paths. The AMA also minimizes the exposure of reactive mineral surfaces that could potentially impact water quality within the mine workings at closure.
DEQ held scoping meetings and accepted public comments in 2017. These comments helped identify key issues for DEQ to examine and address in the EIS.
“One of the main issues we heard during scoping were concerns of impacts to the Smith River. Because of that, we looked at what potential impacts could be, for all resources, to the Smith River,” said McGrath. DEQ’s analysis has not found any potential impacts to the Smith River including water quality, air quality, or aquatic life.
The draft EIS is posted to the DEQ’s website at: http://deq.mt.gov/Land/hardrock/tintinamines
Public Meetings:
- April 29, 2019, 6 – 9 pm, Park High School (102 View Vista Drive, Livingston MT)
- April 30, 2019, 6 – 9 pm, White Sulphur Springs High School (405 S Central Ave, White Sulphur Springs, MT)
- May 1, 2019, and May 2, 2019 webinars, 6 – 9 pm, signup instructions to follow at a later date.
The proposed mine is approximately 20 miles north of White Sulphur Springs. The deposits lie within the Belt Supergroup, an extensive sedimentary formation that extends from central Montana into northern Idaho.
According to the DEQ website, in 2010, Tintina (formerly Mantra Alaska Exploration) applied for an exploration license to conduct core drilling on the Black Butte Project. This work was approved under Exploration License #00710 and bonded accordingly. Since then, several rounds of core drilling have been conducted under amendments to the license and have further defined the extent of the mineralization in the project area. The drill holes have also been used for an aquifer pump test which provided hydrologic information of the Belt Supergroup rocks in which the deposits are hosted.
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