Dairy Syncline Project Environmental Impact Statement
The United States Department of Interior Bureau of Land Management, Pocatello Field Office (BLM) and the United States Department of Agriculture Forest Service (FS), Caribou-Targhee National Forest (the Agencies) are jointly preparing an Environmental Impact Statement (EIS) for a mine and reclamation plan proposed by J.R. Simplot Company (Simplot) for development of the Dairy Syncline Phosphate Leases I-28115 and I-0258 (Project). Simplot has notified the Agencies of their intent to exercise their mining and development rights that are granted to them in the leases. The BLM is serving as the lead agency. The Idaho Department of Environmental Quality and the United States Army Corps of Engineers are cooperating agencies in the preparation of the EIS. Through the EIS process, the agencies will evaluate the environmental impacts of the Proposed Action and alternatives, as well as formulate mitigation of site-specific environmental consequences related to the proposed mining activities.
The Project is located approximately 12 miles east of Soda Springs, Idaho in Southeastern Caribou County, Idaho (See the Project Location Map under the Maps Tab). Activities associated with the proposed mine and reclamation plan would occur on lands administered by the FS and BLM, as well as on state and private lands, with the mineral estate administered by the BLM and the State of Idaho.
The proposed mining activities consist of six open pits (Northeast Pit, North Pit, West Pit, East Pit, South Pit, and Southeast Pit), topsoil stockpiles, mine equipment parking and service areas, access and haul roads, a mill and tailings facility, an ore stockpile area, a power line extension from Dry Valley, permanent external overburden storage areas, and runoff/sediment control facilities. Proposed access for the Project would be via the either the Georgetown Canyon Road or the Trail Canyon Road (See the Mine Access Routes map under the Maps Tab). A portion of these activities are proposed within portions of the Huckleberry Basin Inventoried Roadless Area (IRA).
Initially, overburden generated from the West Pit would be placed east of the pit in an external overburden disposal area. Mining would continue northward from the West Pit to the North Pit, followed by the Northeast Pit, the East Pit, the South Pit, and finally the Southeast Pit. There will be concurrent mining of pits as the sequencing progresses. Excess overburden not used to backfill and reclaim the pits would be permanently placed in 271 acres of external overburden disposal areas on lease.
Ore would be hauled in trucks from pit areas to the ore stockpile area, and concentrated in the on-lease mill facility. Ore concentrate from the mill would be transported to the Simplot fertilizer plant in Pocatello, Idaho via a new underground slurry pipeline that would connect the proposed mill with the existing slurry pipeline system, located north of the tailings facility. Mill tailings would be deposited in the proposed tailings pond facility.
The proposed tailings pond facility is located approximately 4.4 miles northwest of the Dairy Syncline leases. The proposed tailings pond is located on FS, BLM, and private lands. A land sale with mitigation (BLM) and a land exchange (FS) of federal lands for private holdings are proposed for the proposed tailings pond area. The proposed mitigated land sale would require an amendment to the 2012 Pocatello Resource Management Plan. The proposed configuration of the tailings pond would be large enough to hold all of the tailings expected to be generated during the life of the mine.
Disturbed lands resulting directly from the proposed activities would total approximately 1,796 acres on lease and 337 acres off lease. New pits would disturb approximately 1,389 acres of which approximately 1,274 acres would be backfilled and reclaimed. Highwall and pit bottoms totaling approximately 115 acres would remain after reclamation is complete. The remainder of the disturbed acreage would consist of the following approximate acreage: 34 acres of roads; 271 acres of external overburden disposal areas; 34 acres of a mill and an ore stockpile area; 299 acres of tailings facility; 33 acres of pipelines, access roads, office facilities; and 73 acres of runoff management and topsoil facilities, water monitoring facilities, and topsoil piles, all of which would be reclaimed.
The EIS will analyze the proposed enlargement of the lease(s) to accommodate Simplot’s plans. This includes six areas labeled A – F. Area A is a 330-acre lease modification on the northern edge of the lease, Area B is a 200-acre modification on the northeast edge of the lease, Area C is a 240-acre modification on the east edge of the lease, Area D is a 252-acre modification on the southeast edge of the lease, Area E is a 40-acre modification on the south edge of the lease, and Area F is a 40-acre modification on the southwest edge of the lease. Environmental impacts from mining operations within these areas would be analyzed in this EIS. Based on this analysis, the BLM will issue a leasing decision, with consultation from the FS.
Issues initially identified for the proposed Project include potential effects on the following resources: ground water and surface water quantity and quality; wildlife and their habitats; livestock grazing; wetlands and riparian habitat; recreation; socio-economics; Native American rights, treaties, and land uses; inventoried roadless areas; visual resources; and cumulative effects.
Potential impacts to surface resources and water quality include erosion, sedimentation, and dissolved contaminants such as selenium. Simplot has proposed to implement practices designed to reduce, eliminate, or mitigate these impacts. Suitable topsoil would be salvaged from disturbed areas for use in reclamation. Reclamation of mining disturbances would include the following: removing facilities and equipment, backfilling pits, regrading slopes, restoring drainages, constructing a designed cover over reclaimed seleniferous overburden to limit infiltration of meteoric water, spreading topsoil, stabilizing surfaces, revegetation, and environmental monitoring.
Please see the document "Detailed Proposed Action Description" under the Documents Tab for additional information on the project.
Decisions to be made
The BLM Idaho State Director or delegated official will make a decision regarding approval of the proposed mine and reclamation plan, proposed land sale with mitigation, proposed lease modification and/or fringe lease approvals (enlargement of leased areas), appropriate land use authorizations on leased lands, and an amendment to the 1988 Pocatello Resource Management Plan. Decisions will be based on the EIS and any recommendations the FS may have regarding surface management of leased National Forest System lands.
The Caribou-Targhee National Forest Supervisor makes recommendations to the BLM concerning surface management and mitigation on leased lands within the Caribou-Targhee National Forest, and makes decisions on mine related activities which occur off lease. Special use authorizations (SUA) from the FS will be necessary for all off lease support structures on FS land for the mine. A FS decision regarding the proposed exchange of FS land for private holdings will be issued by the Regional Director of Lands.
The Army Corps of Engineers may also make decisions related to permits under Section 404 of the Clean Water Act.
Additional permits will be required from the Environmental Protection Agency, the Idaho Department of Environmental Quality, the Idaho Department of Water Resources, and the Idaho Department of Lands.