Hard Rock Mining

Stillwater Mining Company (Stillwater) East Boulder Mine proposes a major amendment to Operating Permit #000149 for the addition of the Lewis Gulch Tailings Storage Facility (LGTSF) and the Dry Fork Waste Rock Storage Area (DFWRSA). Construction of these facilities will provide Stillwater with the tailings and waste rock storage capacity needed to continue to mine the JM Reef in the near term. A summary of the facilities is provided below, and detailed information is in the attached Amendment 004 Plan of Operations (POO). The LGTSF is proposed to be constructed along the west end of the existing East Boulder tailings storage facility in the general area of the current borrow pit. Infrastructure relocation is proposed for 2028 with lining to the basin mid-point in 2030 and lining to the top in 2033. The proposed LGTSF footprint will encompass 87.81 acres an additional 38.9 acres of disturbance associated with roads and infrastructure will be disturbed resulting in a total of 126.71 acres. The LGTSF is expected to provide storage for 5.8 million cubic yards of material which should provide storage at the current mining rate until 2043 to 2045. The DFWRSA is proposed to be constructed to the north of the current mine site. The proposed DFWRSA footprint will encompass 57.02 acres with an additional associated disturbance of 38.53 for a total of 95.55 acres. Of the 95.55 Acres to be disturbed 45.99 are USFS and 49.56 are privately owned by SMC. The DFWRSA will be built in three stages with construction stages proposed to begin in 2025, 2028, 2035. Infrastructure to support construction of the waste rock facility is expected to be constructed in 2024. Total storage will be 5.4 million cubic yards of waste rock which at the current mining rate should provide waste rock storage until 2036 to 2047. Both facilities will have HDPE lined underdrain collection water management systems.

Please contact Craig Jones DEQ MEPA-MFSA Coordinator for a copy of the application. 

Venture Stone LLC (Venture Stone) proposes a major amendment to Hardrock Operating Permit #00189. The proposed amendment would add a new site, Site #14, to the permit. The site is located at Section 10, T05N R21E, approximately 10 miles to the southwest of Lavina in Golden Valley, Montana. After stripping topsoil and overburden, rock would be quarried from the Judith River formation to a maximum depth of 10 feet below current ground surface. Quarrying would be done with an excavator, loader and skidsteer. Approximately 2 to 3 truckloads of product would be hauled offsite during the summer months. 

The proposed amendment would increase the size of Venture Stone’s total permit area by 78 acres from 14,063 acres to 14,141 acres. A portion of the proposed area Venture Stone requested be added to the existing permit was mined under a Small Miner Exclusion Statement, SMES No. 53-015.

Stillwater Mining Company (SMC) filed an application with the Department of Environmental Quality for an amendment (Amendment 014) to Hard Rock Mine Operating Permit No. 00118 under the Metal Mine Reclamation Act. SMC currently operates an underground platinum group metals mine at the Stillwater Mine (SWM). The SWM is located at (Latitude N45°23'20.7", Longitude W109°52'33.2"), on County Road 419/Nye Road, approximately 5 miles southwest of Nye in Stillwater County. The facilities at the SWM include a concentrator, the East Side Waste Rock Storage Facility (ESWRSF), the Nye Tailings Storage Facility (TSF) which is currently being capped, and other ancillary facilities that support the operation. Water management facilities and a second TSF, the Hertzler Stage 3 TSF, are located approximately 7 miles northeast of the mine site at the Hertzler Ranch (Latitude N45°27’30.50”, Longitude W109°47’17.99”) on County Road 420/Stillwater River Road.

Amendment 014 would expand the waste rock and tailings storage capacity of the SWM. The ESWRSF is proposed to be expanded to the north and east of the current footprint and increase the permitted height from an elevation of 5,150 feet to 5,350 ft. There would be 48.2 acres of new disturbance associated with the ESWRSF expansion. SMC proposes to increase the permit area at the SWM site by 4.1 acres, from 2424 acres to 2428.1 acres, and increase the permitted disturbance area by 28.0 acres, from 440.8 acres to 468.8 acres. The expansion would be developed in five stages to provide an additional 16.6 million cubic yards of storage and extend the life of the facility to approximately 2065.

SMC proposes to expand tailings storage for the SWM directly west of the existing Hertzler Stage 3 TSF by the sequential construction of two additional storage cells which have been designated as the Stage 4 TSF and Stage 5 TSF. The Stage 4 TSF would provide an additional 11.8 million cubic yards of storage capacity until approximately 2045 and the Stage 5 TSF would provide an additional 12.8 million cubic yards of storage capacity until approximately 2061. A new, lined 200-million-gallon land application disposal treated water storage pond would be constructed west of the existing Stage 3 TSF to facilitate development of the future Stage 4 and Stage 5 TSF. The total disturbance for the expansion at Hertzler Ranch would be 454.5 acres, which includes 94.3 acres of disturbance outside the current permitted for disturbance boundary and 360.2 acres of disturbance within the current permitted for disturbance boundary.

On July 14, 2020, an application for a Hard Rock Mining Operating Permit was submitted by C3 Limited Liability Company (C3) for a site located in Granite County. C3 filed the application with the Department of Environmental Quality for an operating permit under the Metal Mine Reclamation Act. If approved, the operating permit would authorize a placer mine operation for recovering sapphires. The proposed site is located about 22 miles southwest of Philipsburg, MT in parts of Sections 16, 17, 20, and 21, Township 6 North, Range 16 West, in Granite County for a total permit area of about 412 acres. C3 currently operates in these locations under an Exploration License and Small Mine Exclusion Statement and needs an operating permit due to proposed expansion of the site. C3 proposes to disturb approximately 334 acres over a life of mine of about 66 years. C3 proposes to disturb 20.6 acres in the next 5 years. The site is on private land and would employ up to 4 full and part time employees. C3 sells washed gravel and sapphire concentrate it produces to Cooney’s Sapphire Village Inc. (CSVI). CSVI would employ up to 36 full or part time employees.

Decision Document
Final Environmental Assessment
Draft Environmental Assessment

DEQ received an application for an exploration license from Luke Ployhar on October 4, 2021, to excavate a trench measuring 35 feet long by 10 feet wide by 25 feet deep in order to extract a 125-ton bulk sample for metallurgical testing. The entire proposed project would be located on private land within the former Zortman Mine boundary and disturb about 0.18 acre.

Draft Environmental Assessment

Final Environmental Assessment