Comment Period: March 16, 2023 – April 15, 2023
SUBJECT: Notice of Intent (NOI) to Prepare an Environmental Impact Statement (EIS) and Notice of Public Scoping Meeting for the East Tailings Expansion Project. This notice is to inform interested parties of the opening of scoping and to solicit comments on the proposed project. This public notice may also be viewed at the Corps web site at https://www.spk.usace.army.mil/Media/Regulatory-Public-Notices/. A NOI will be published in the Federal Register. This notice is to inform interested parties of the proposed activity and to solicit comments.
AUTHORITY: This application is being evaluated under Section 404 of the Clean Water Act for the discharge of dredged or fill material in waters of the United States.
Kennecott Utah Copper LLC
Attn: Mr. Doug Stauffer
4700 Daybreak Parkway
South Jordan, UT, 84009
LOCATION: The 539-acre project site is located approximately ten miles west of Salt Lake City, near Magna, Salt Lake County, Utah. The approximate location of the project is Latitude 40.7579º North and Longitude -112.0690º West and can be seen on the Magna USGS Topographic Quadrangle.
The Corps will prepare an EIS for the proposed East Tailings Expansion Project, an expansion of an active commercial open pit copper mining operation near Magna, Salt Lake County, UT. Kennecott Utah Copper, LLC has applied for a Department of the Army permit to discharge fill material in approximately 44.86 acres of waters of the US, including wetlands, to construct the project. The Applicant is developing an updated mine plan for the Bingham Canyon Mine that would extend the open pit life of mine to approximately year 2038 and would generate an additional 1.2 to 1.7 million tons (Mt) of copper equivalent product. To fully implement the updated mine plan, the Applicant has stated that it needs to expand the eastern portion of the historic south impoundment to provide an additional 100 Mt of tailings storage that cannot be met using existing storage capacity. Tailings are created by the mining process in which the ore from the Bingham Canyon Mine is crushed into a fine powder to extract the valuable metals, and the remaining 98 percent of the original ore mass becomes tailings. In addition, studies have shown that the east slope of the historic South Tailings Impoundment is potentially susceptible to earthquake-induced tailing flows resulting from impoundment failure. The Project would buttress the east slope of the historic South Tailings Impoundment to improve seismic stability and reduce the risk of runout caused by a seismic event to a level as low as reasonably practicable. The Project purpose is to increase tailings storage capacity for continued mining operations at the Bingham Canyon mine until approximately 2038 and to improve seismic stability of the east slope of the historic South Tailings Impoundment.
The proposed Project would be located along the eastern edge of the South Tailings Impoundment. The east toe of the historic South Tailings facility would be extended about 1,000 feet to the east to construct the East Tailings impoundment with an elevation of 4,440 feet, which is consistent with the elevation of the historic South Tailings Impoundment. The additional infrastructure required for the East Tailings Expansion would include new access roads; a new drainage system including finger drains; relocation of the clarification canal; a new 50-foot electrical corridor; relocation of Outfall 002 (which discharges to the C-7 ditches); installation of tailings and water piping, pumps, and valve stations required to operate the Project; and a dust control system.
PUBLIC SCOPING MEETINGS. The Corps will hold two public scoping meetings in communities with proximity to the mining operation. The first meeting will be held on, April 4, 2023, from 6:00 to 8:00 pm MT, at the Webster Community Center, 8952 West 2700 South, Magna, Utah. The second meeting will be held on April 5, 2023, from 6:00 to 8:00 pm MT, at the Element Event Center, 5624 South Cougar Lane, Kearns, Utah 84118. Interested parties can provide oral and written comments at the scoping meetings. Interested parties should submit written comments on this notice on or before April 15, 2023, but scoping comments also may be submitted at any time prior to publication of the Draft EIS.
Environmental Setting. Operations at Bingham Canyon Mine, which is located about 12 miles south of the Tailings Storage Facility, began around 1900. The mine’s ore, which contains copper, gold, silver, and molybdenum. The historical footprint of Tailings Storage Facility is referred to as the historic south impoundment. The south impoundment covers an area of approximately 5,200 acres. Tailings deposition at the south impoundment began in the early 1900s, and after nearly a century of operations, deposition on this impoundment ceased in 2002.
In 1996, the Applicant received a Department of the Army Standard Individual permit to expand the Tailings Storage Facility from its historical southern footprint to the north. The 1996 expansion area is referred to as the north impoundment. Tailings deposition started in the north impoundment in 1999. The footprint of the currently active north impoundment covers an area of approximately 4,400 acres with a top elevation of 4,462 feet, which is below the Utah State Engineer’s Office’s approved elevation of 4,500 feet.
The project would impact approximately 539 acres, including 327 acres within the footprint of the existing South Tailings Impoundment, 39 acres of the existing clarification canal and the closed sedimentation pond, and 173 acres on land without previous tailings deposition.
In an approved jurisdictional determination and a preliminary jurisdictional determination dated May 2022, USACE reviewed a 351-acre survey area within and adjacent to the Project along the southeast boundary of the existing tailings impoundment and determined that 38.78 acres are industrial process waters and 9.85 acres are artificial wetlands not subject to regulation under Section 404 of the Clean Water Act or Section 10 of the Rivers and Harbors Act. In addition, USACE determined that 54.93 acres of aquatic resources are potentially subject to Section 404 of the Clean Water Act. The project proposes to impact 44.86 acres of these potentially jurisdictional aquatic resources, including wetlands.
Alternatives. The EIS will include an evaluation of a reasonable range of alternatives. Currently, the following alternatives are expected to be analyzed in detail: (1) the no action alternative (no permit issued) and (2) the applicant’s preferred project (proposed action). The no action alternative assumes that the Applicant would continue to operate the mine in its existing footprint; no changes to existing infrastructure would occur with all potential waters of the United States avoided. In addition to the Proposed Action, the Corps anticipates evaluating additional on-site and off-site alternatives for potential detailed analysis. However, in addition to the proposed action, the Corps anticipates evaluating additional on-site and off-site alternatives for potential detailed analysis. All reasonable project alternatives, in particular those which may be less damaging to the aquatic environment, will be considered.
Mitigation. The Corps requires that applicants consider and use all reasonable and practical measures to avoid and minimize impacts to aquatic resources. If the applicant is unable to avoid or minimize all impacts, the Corps may require compensatory mitigation. The applicant has proposed to use existing wetland mitigation bank credits at the Inland Sea Shorebird Reserve to provide for compensatory mitigation for impacts to waters of the United States.
Scoping. The scoping process for the development of an EIS is intended to be an early and open process for determining the scope of issues to be addressed and for identifying the significant issues related to the proposed action. The Corps' scoping process for the EIS includes a public involvement program with several opportunities for interested parties to provide oral and written comments. In addition to public meetings and notifications in the Federal Register, the Corps will issue public notices when the draft and final EISs are available. Affected federal, state, and local agencies, Native American tribes, and other interested private organizations and parties are invited to participate.
The Corps is soliciting scoping comments from the public, Federal, State, and local agencies and officials, Indian tribes, and other interested parties in order to consider and evaluate the impacts of this proposed activity. All factors which may be relevant to the described activity will be considered, including the cumulative effects. The benefit, which reasonably may be expected to accrue from the described activity, must be balanced against its reasonably foreseeable detriments. The EIS will evaluate all significant impacts of the proposed activities. Potentially significant issues to be analyzed in the EIS include, but are not limited to impacts to waters, hydrology, water supply, water quality, cultural resources, biological resources, traffic and transportation, and air quality.
OTHER GOVERNMENTAL AUTHORIZATIONS: Water quality certification or a waiver, as required under Section 401 of the Clean Water Act from the Utah Department of Environmental Quality is required for this project. The applicant has not indicated they have applied for certification.
HISTORIC PROPERTIES: The Corps will initiate consultation with the State Historic Preservation Officer under Section 106 of the National Historic Preservation Act, as appropriate.
ENDANGERED SPECIES: The project would not affect any Federally listed threatened or endangered species or their critical habitat that are protected by the Endangered Species Act.
ESSENTIAL FISH HABITAT: The proposed project would not adversely affect Essential Fish Habitat (EFH) as defined in the Magnuson-Stevens Fishery Conservation and Management Act.
The above determinations are based on information provided by the applicant and our preliminary review.
EVALUATION FACTORS: The decision whether to issue a permit will be based on an evaluation of the probable impacts, including cumulative impacts, of the described activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefit, which reasonably may be expected to accrue from the described activity, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the described activity will be considered, including the cumulative effects thereof; among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, consideration of property ownership and, in general, the needs and welfare of the people. The activity's impact on the public interest will include application of the Section 404(b)(1) guidelines promulgated by the Administrator, Environmental Protection Agency (40 CFR Part 230).
The Corps is soliciting comments from the public, Federal, State, and local agencies and officials, Indian tribes, and other interested parties in order to consider and evaluate the impacts of this proposed activity. Any comments received will be considered by the Corps to determine whether to issue, modify, condition, or deny a permit for this proposal. To make this decision, comments are used to assess impacts on endangered species, historic properties, water quality, general environmental effects, and other public interest factors listed above. Comments are used in the preparation of an Environmental Assessment and/or an Environmental Impact Statement pursuant to the National Environmental Policy Act. Comments are also used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.
SUBMITTING COMMENTS: Written comments, referencing Public Notice SPK-2009-01213-UO must be submitted to the office listed below on or before April 16, 2023, but scoping comments may be submitted any time prior to publication of the Draft EIS.
Nicole Fresard, Project Manager
US Army Corps of Engineers, Sacramento District
533 West 2600 South, Suite 150
Bountiful, Utah 84010
The Corps is particularly interested in receiving comments related to the proposal's probable impacts on the affected aquatic environment and the secondary and cumulative effects. Anyone may request, in writing, that a public hearing be held to consider this application. Requests shall specifically state, with particularity, the reason(s) for holding a public hearing. If the Corps determines that the information received in response to this notice is inadequate for thorough evaluation, a public hearing may be warranted. If a public hearing is warranted, interested parties will be notified of the time, date, and location. Please note that all comment letters received are subject to release to the public through the Freedom of Information Act. If you have questions or need additional information, please contact the applicant or the Corps' project manager Nicole Fresard, (801) 295-8380 ext. 8321, Nicole.D.Fresard@usace.army.mil.