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Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Dairy Syncline Mine and Reclamation Plan, Caribou County, ID

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Bureau of Land Management, Interior; U.S. Forest Service, Agriculture.


Notice of Intent.


Notice is hereby given that the Department of the Interior, Bureau of Land Management (BLM), Pocatello Field Office and the U.S. Department of Agriculture, Forest Service (FS), Caribou-Targhee National Forest, will jointly prepare an Environmental Impact Statement (EIS) to determine and analyze the effects of a proposed phosphate mine and reclamation plan on people and the environment. The BLM will serve as the lead agency. Plans have been developed and submitted for agency review of proposed open pit mining operations at the Dairy Syncline Phosphate Lease Area in Caribou County, Idaho by the J.R. Simplot Company (Simplot). The Dairy Syncline Phosphate Lease Area is located about 12 miles east of Soda Springs, Idaho.

The proposed new mining operations at the Dairy Syncline Phosphate Lease Area lie within the Caribou-Targhee National Forest on lands where the surface estate is administered by the FS, and the Federal mineral estate is administered by the BLM. In 2000, the BLM completed an EIS to support a decision to lease. The BLM issued Federal mineral lease I-28115 to Simplot by competitive bid in 2000. The Federal mineral lease I-0258 was transferred from P4 Production LLC to Simplot in 2009. These leases grant the lease holder, Simplot in this case, exclusive rights to mine and otherwise dispose of the Federally owned phosphate deposit at the site. Through development of this EIS, the BLM will analyze environmental impacts of the proposed mining operations, land exchanges and reasonable alternatives. Appropriate mitigation measures also will be formulated.


To ensure comments will be considered, the BLM must receive written comments on the scope of the analysis described in this Notice by May 13, 2010. The BLM will announce future meetings or hearings and any other public involvement activities at least 15 days in advance through public notices, media news releases, and/or mailings.


Send written comments to: Dairy Syncline Mine EIS, Bureau of Land Management, Pocatello Field Office, 4350 Cliffs Drive, Pocatello, Idaho 83204. E-mail:

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Barry Myers, Bureau of Land Management, Pocatello Field Office, 4350 Cliffs Drive, Pocatello, Idaho 83204, phone (208) 478-6369. Information is also available at:​id/​st/​en/​fo/​pocatello/​planning/​dairy_​syncline_​mine.html.

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Agency Decisions: 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 acreage lease approvals (enlargement of leased areas), appropriate land use authorizations on leased lands, and an amendment to the current Resource Management Plan (RMP) for the Pocatello Resource Area. 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:

1. Recommendations to the BLM concerning surface management and mitigation on leased lands within the Caribou-Targhee National Forest; and

2. Decisions on mine related activities which occur off-lease.

Special use authorizations from the FS will be necessary for all off-lease support structures 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.

Scoping Procedure: The scoping procedure to be used for this EIS will involve: Notification in the Federal Register; a mailing to interested and potentially affected individuals, groups, Federal, State, and local government entities requesting comments, issues and concerns; news releases or legal notices; and public scoping meetings.

Please note that public comments and information submitted, including names, street addresses, and e-mail addresses of respondents, will be available for public review and disclosure at the address listed below during regular business hours (8 a.m. to 4 p.m.), Monday through Friday, except holidays.

Before including your address, phone number, e-mail address, or other personal identifying information in your comment, you should be aware that your entire comment—including your personal identifying information—may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.

Background: Simplot has operated the existing Smoky Canyon Mine since 1983. Simplot has indicated that they will eventually complete mining of currently permitted reserves, necessitating the proposed expansion to the Dairy Syncline phosphate leases. Because of the significant construction time associated with the infrastructure needed for the proposed mine (i.e. new mill and tailings impoundment), this proposal is being analyzed in advance of depleting the currently permitted reserves at the Smoky Canyon Mine.

The Dairy Syncline Phosphate Lease Area represents a significant phosphate ore deposit that is economically feasible for prolonged development. In total, approximately 2,133 acres are proposed for disturbance. The proposed project would include an open pit phosphate mine, a new milling facility, installation of underground phosphate slurry, tailings and water lines, a new tailings impoundment, a new power line, and a land sale with mitigation (BLM) and a land exchange (FS) of Federal lands for private holdings. The proposed mitigated land sale would require an amendment to the 1988 Pocatello RMP.

The proposal also includes six lease modification or fringe acreage lease areas that are contiguous with the existing leases that would allow for optimum recovery of the existing phosphate ore body. Disturbance on these proposed lease modification and/or fringe acreage lease areas represent approximately 347 acres of the total Start Printed Page 18876proposed disturbance. The development of the ore deposits would result in six pits representing approximately 1,389 acres of pit disturbance. Proposed sequencing for the Dairy Syncline mine plan would begin with mining a portion of the west pit along with the north pit. Initial overburden from the west pit would be placed directly to the east of the initial disturbance in an external overburden storage facility on-lease. Mining would continue within the north pit, followed by the northeast pit, the east pit, south pit, and finally the southeast pit. There would be some concurrent mining of pits to maintain a consistent grade of ore available for milling purposes as well as maintaining an economic mine pit stripping ratio.

In their mine and reclamation plan, Simplot has proposed management practices to reduce environmental impacts. As mining progresses, reclamation would begin concurrently. Simplot's plan emphasizes total backfill of mine pits and limiting the amount of overburden placed external to the pits. In addition, Simplot's mine plan contains provisions aimed at limiting the amount of time seleniferous overburden is exposed to the elements. To reduce the potential for contaminant release to water or uptake into reclamation vegetation, Simplot is proposing to cover over all seleniferous overburden with non-seleniferous material consisting of approximately 2 feet of chert, overlain by 2 feet of Dinwoody and/or Salt Lake Formation, and finally a topsoil layer estimated at 6 to 12 inches, contingent upon the baseline soil resources study.

Associated new facilities that are proposed include: Main office/security building, mill and shop complex, support facilities, ore stockpile, tailings pond, groundwater supply well(s), and pipelines. The proposed location of the main office/security building is an area southeast of the mouth of Wilde Canyon and west of the Slug Creek Road. This location is on National Forest System lands off-lease and would require a Special Use Authorization from the FS. Approximately 5 acres would be disturbed for the office and parking areas.

The proposed location for the mill/shop complex is in the mining area between the north and south pits. The complex would disturb about 20 acres. The mill would be required to process the ore into concentrated slurry that would be pumped in a proposed 8-mile underground pipeline to a currently existing pipeline that connects to Simplot's Don Fertilizer Plant just outside of Pocatello, Idaho. The proposed mill is assumed to be configured essentially the same as the operating Smoky Canyon Mill. In addition, a shop would be required for repairing and maintaining the mining equipment. The shop area would be included in the mill/shop complex.

An ore stockpile (of 750,000 to 1,000,000 tons) is proposed for supplying ore to the mill. The location of the stock pile would be on-lease near the mill building at the mill/shop complex. The stockpile would be approximately 13 acres in size. The simple milling process would consist of crushing and grinding the phosphate ore to a fine powder. Associated clay would be physically removed from the finely ground ore and would then be mixed with water and pumped into another new underground pipeline to the tailings impoundment. The product and tailings pipelines would be installed next to each other. To facilitate mobile equipment operation and personnel, some small support facilities at the active mining sites would be required. Typically, these facilities would consist of equipment ready lines (cold climate hot starts), electrical power, fuel and grease storage within secondary containment, communication, and safety structures. The location of these facilities would vary during the mining process.

A new tailings pond is proposed for the mining operation. The proposed location would be approximately 4.4 miles northwest of the Dairy Syncline leases. 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. An earthen dam structure on the north end of the pond would be constructed resulting in a design capacity of 20 million cubic yards of material. The proposed configuration would be large enough to hold all of the tailings expected to be generated during the life of the mine.

Three pipelines are proposed for the project; one each for delivery of tailings, ore concentrate, and a water return line. The pipelines would be buried in one earth covered trench. The ore concentrate pipeline would transport ore in slurry form from the proposed mill site to the existing pipeline. The buried 8-inch diameter steel pipe would be about 8 miles long. The proposed pipeline route would originate at the mill/shop complex, follow the access road on the north side of Wilde Canyon, and then follow the western side of the Slug Creek Valley where it would tie into the existing ore concentrate pipeline from Smoky Canyon to the Conda Pump Station. This pipeline route represents approximately 14 acres of off-lease disturbance.

The tailings pipeline would transport tailings from the mill/shop complex to the proposed tailings pond. The pipeline would be approximately 5 miles long. The proposed pipeline route would originate at the mill/shop complex and be placed in the same trench as the ore concentrate pipeline. At a location near the tailings pond, the tailings line would go east to the southern end of the pond. A number of pipeline branches would be installed around the pond to ensure even distribution of tailings in the pond.

The water return line would transport water from the tailings pond back to the mill and would be approximately 5 miles long. As noted above, this line would be in the same trench as the tailings and concentrate pipeline.

Off-lease facilities would include the main office/security building, tailings pond, and portions of access roads, pipelines, a power line, and storm water control features. The proposed power line would run northeast to connect with an existing power line and existing corridor in Upper Dry Valley. It is estimated that off-lease activities would total about 337 acres of disturbance, which would include the assumed disturbance for the power line.

Truck haulage would transport both ore to the proposed on-lease ore stockpile and overburden to its permanent disposal site. Several external pit roads would be required throughout the life of the mine for both overburden and ore transportation. All of these roads are located on-lease and would be constructed of chert or limestone with cut side ditches, culverts as appropriate, and fill side berms where necessary for safety. Access to the mine site for employees, equipment, and supplies is proposed through Georgetown Canyon and along Slug Creek via the existing FS road. Upgrades to this road will be necessary for safe passage of two-way traffic.

Potential impacts to surface resources and water quality include erosion, sediment, 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: removal of facilities and equipment, backfilling pits, regrading slopes, restoring drainages, spreading topsoil, stabilizing surfaces, revegetation, testing and treatment for remaining hydrocarbon contaminants, and environmental monitoring.Start Printed Page 18877

Issues initially identified for the proposed mining of the Dairy Syncline phosphate leases include potential effects on: Groundwater 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.

The EIS will analyze the Proposed Action and the No Action Alternative. Other alternatives may consider: Alternative access road(s); alternative tailings pond locations; alternatives to the land sale with mitigation and land exchange; use of conveyors to transport ore to the existing mill; revising the layout or sequencing of the proposed mining facilities; different methods for reducing potential impacts from overburden handling; and other alternatives that could provide mitigation for potential impacts.

The tentative EIS project schedule is as follows:

  • Begin Public Scoping Period and Meetings: Winter/Spring 2010.
  • Estimated date for Draft EIS and associated comment period: Fall 2011.
  • Final EIS Publication: June 2013.
  • Record of Decision: August 2013.

At least four “open-house” style public scoping meetings will be held which will include displays explaining the project and providing a forum for commenting on the project. Meetings are currently planned for Pocatello, Fort Hall, Georgetown, and Soda Springs, Idaho. The dates, times, and locations of the public scoping meetings will be announced in mailings and public notices issued by the BLM (see contact information above). The BLM and FS are seeking information and written comments from Federal, State, and local agencies as well as Tribal entities, individuals and organizations interested in, or affected by, the Proposed Action or Alternatives. To assist the BLM and FS in identifying issues and concerns related to the Proposed Action or Alternatives, comments for scoping, and later for the Draft EIS, should be as specific as possible.

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Joe Kraayenbrink,

District Manager, Idaho Falls District, Bureau of Land Management.

Brent Larson,

Forest Supervisor, Caribou-Targhee National Forest.

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[FR Doc. 2010-8391 Filed 4-12-10; 8:45 am]