Sunday, March 18, 2018

Benbow Portal project up for public comment

The Stillwater Mining Company’s proposed Benbow Exploration Portal project is up for a second round of public comments.
The proposed project site near Dean would allow for mineral exploration along the eastern edge of the JM Reef. It would also serve as a secondary escape-way and connect the tunnel currently being dug by the SMC’s Tunnel Boring Machine (TBM) that began at the Nye site.
SMC submitted its inch-thick proposal to the Custer-Gallatin National Forest Service (FS) and the Montana Department of Environmental Quality (DEQ) in September 2014. A public informational hearing and comment period was held that same month, during which public concerns were brought forth.
Those concerns included economics, water quality, noxious weed spread, wildlife, scenery and recreation issues.
The Forest Service and DEQ then went back to the SMC to work on resolving those issues and then reissued its Environmental Assessment (EA). That adjusted EA is now what public comments are being sought on until April 22.
“We are here to listen,” said Custer Gallatin Assistant Forest Service Geologist Dan Seifert.

In the long term, assuming “economic mineralized resources are found,” the portal would be used as mine ventilation, a secondary underground escape-way and on a small scale, to re-supply the Nye mine, according to the SMC proposal.
The proposed portal would consist of a 20-foot-by-20-foot horizontal portal connected to an underground exploratory mine decline. There would be an adjacent flat 8.5 acre cleared pad around the portal and 0.8 miles of new access road construction.
The Benbow Portal would run 24 hours a day, seven days a week and be staffed by approximately 25 people, according to the proposal. The total permit area is 920 acres on the far eastern edge of the JM Reef, which is under SMC claim package.
Other facilities proposed on National Forest System lands include water monitoring wells, a water treatment plant and a waste rock storage area, according to the Forest Service. Excess groundwater from the decline would be treated to meet state water quality standards prior to disposal.
The proposal details plans on how the company will make the smallest possible impact on the environment and any existing roads, as well as specific plans on what is the expected impact on land, wildlife, air, ground water, surface water and more during construction and once in operation.

EA Adjustments
Seibert said adjustments were made to the EA through the joint work of the Forest Service, DEQ and SMC as a result of the first public comment period. Those adjustments include the following:
-Scenery resources (regarding things like a less-visible waste rock pile and surfaces made to look more natural).
-Coloring of buildings to make them appear less visible.
-Signage at a trailhead regarding restrictions.
-Wildland fire mitigation around proposed buildings.

-A more aggressive noxious week mitigation plan
-Proposed road construction to include culverts for proper draining at every intersection.
-A road maintenance construction plan.
-Increased attention on cutthroat trout located in Little Rocky.
Seibert said EA adjustments are normal during the scoping process and depending on the second public comment period, SMC could receive the green light to proceed as early as August 2015.

Stillwater Protective Association
The Stillwater Protective Association (SPA) has been meeting with SMC managers for the past few years regarding some of the same areas of concern regarding the proposed Benbow Exploration Portal project.
Last December, those meetings culminated in the signing of the Benbow Mitigation Plan, which addressed the major concern of the disposal of water produced in the portal, according to SPA Representative Charles Sangmeister.
“Under the auspices of the GNA (Good Neighbor Agreement) we (SPA, SMC, & USFS) came to an agreement that SMC would use an injection well rather than Land Application Disposal (LAD) pond and dispersal system (pivots), has a large surface impact such as can be seen at SMC’s Hertzler facilities,” said Sangmeister in an email. “Successful testing of the injection well has been taking place for some time and is expected to be completed in the near future. We were also able to establish an area in which, if there were water impacts on individuals living in proximity to the portal area, SMC would replace domestic water if any is lost to mining activities.”

Part of the Blitz Project
The Benbow Portal is part of the present Blitz Project, which is using a custom-built underground tunnel boring machine (TBM) to cut through 23,000 feet of rock to eventually connect the East Portal at the Stillwater Mine to the Benbow Portal, allowing for lateral development of the JM Reef. To date, the TBM has cut through 7,300 feet. A second TBM crew was added in October of 2014 with the addition of a third crew expected in the second quarter, according to SMC’s Public Affairs Manager John Beaudry.
The TBM tunnel, as well as a parallel tunnel being dug roughly 600 feet about the TBM tunnel, will eventually be intersected by the Benbow Portal, providing ventilation and an emergency egress for the Blitz work area.
SMC expects the Blitz Project is expected to extend the life of the mine by decades and increase overall production by a net 25,000 ounces of PGMs (platinum group metals) yearly. Most critically, it will enable SMC to “more than offset depletion in other parts of the mine and sustain our future production level at the increased level to which the Far West and Blitz projects will take us,” according to the company.
For more information on the proposal or to download project documents visit online at: For questions or to provide public comment, please contact Dan Seifert at the Beartooth Ranger District: by telephone at 406-446-2103; or by email at:
Comments or input addressing the exploration portal should be submitted by April 22, 2015 to Beartooth R.D. (6811 US Highway 212 South, Red Lodge, MT, 59068). All comments received, including names and addresses of those who comment, will be part of the public record. For general information about the Custer Gallatin National Forest follow us at: @CusterNF or on facebook: Custer Gallatin National Forests. For general information about Montana DEQ, go to

The Blitz Project
The Blitz Project consists of driving two parallel underground development drifts eastward from the Stillwater Mine on different levels that ultimately will each extend about 23,400 feet, according to the company. A new surface portal for ventilation and emergency egress will be constructed at the far end of these two drifts. While much of Blitz will provide access to areas along the J-M Reef that are not yet well delineated geologically, there is evidence from the surface of ore continuity in this area.
As the development progresses, SCN will have the opportunity to drill and evaluate the mineralization from underground to confirm the surface delineation results. Although it is difficult to provide specific guidance as to future production rates from the Blitz area, SCN expects that production from Blitz in the future will replace declining production from depleted mining areas within the Stillwater Mine, and may provide some growth in annual production rates as well.