Public Notices

Listed below are the current Public Notices published by the Walla Walla District for proposed projects within the state of Idaho. The Public Notices are sorted by Effective Date and are provided in PDF format. You must have Adobe Acrobat Reader installed on your PC to view these files. 

Viewing Public Notices. To view a Public Notice, left-click on the Permit Application Number (highlighted in blue). To download the file to your PC, right-click on the Permit Application Number, then select "Save Target As" from the menu.

How to Submit Comments. To submit comments via email, cut and paste the email address of the respective Project Manager's from the table below into an email and in the subject line of your email enter: Public Notice Comments for (referencing the specific project).  To submit comments in writing, send them to the respective Project Manager at the U.S. Army Corps of Engineers, Walla Walla District Regulatory Division, 720 E. Park Blvd., Suite 245, Boise, ID 83712. All comments should include the permit application number and project name, your name, address, and phone number.

NWW-2014-00302-I01: P4 Productions, LLC - Caldwell Canyon Mine

Published July 2, 2019
Expiration date: 8/2/2019

Interested parties are hereby notified that the Walla Walla District has received an application for a Department of the Army permit for certain work in Waters of the United States, including wetlands, as described below in the attached documents:

APPLICANT: P4 Production, LLC, PO Box 816, Soda Springs, Idaho 83276, 208-547- 1435, ATTN: Mr. Chris Leatherman.

U.S. ARMY CORPS OF ENGINEERS PROJECT MANAGER: Robert Brochu, Idaho Falls Regulatory Office, 900 North Skyline Drive, Suite A, Idaho Falls, Idaho, 83402- 1718. 208-522-1645.

PURPOSE: To construct a road to transport phosphate ore and mine overburden from the proposed Caldwell Canyon mine to Dry Valley, Idaho.

WATERWAY: Quonset Hut Creek, Stewart Creek, and Dry Valley Creek.

LOCATION: The proposed project is located on the east face of Schmid Ridge and in Dry Valley. Schmid Ridge is north-south trending and is south of the Blackfoot River. It lies between Dry Valley Creek on the east and Slug Creek on the west. Project impacts to Waters of the U.S. would be to Quonset Hut Creek, Stewart Creek and Dry Valley Creek and their adjacent wetlands. The location of the impact sites are within the Boise Meridian, Sections 8 and 16 of Township 8 South, Range 44 East and Section 7, Township 8 South, Range 43 East. All sites are within Caribou County, Idaho. Location maps are provided on Drawing Sheets 1, 2 and 3 of 10.

DRIVING DIRECTIONS: From Soda Springs, drive north on Highway 34 toward Grays Lake for 12 miles to the Blackfoot River Road intersection. Turn east on the Blackfoot River Road and travel approximately 11 miles to the junction with Slug Creek/Dry Valley Road. After crossing the Blackfoot River the Slug Creek and Dry Valley Creek Roads diverge. Schmid Ridge is the mountain range to the south with Dry Valley Road on the east and Slug Creek Road to the west. The middle of the mine site is Caldwell Canyon Creek, approximately 3.7 miles south on Slug Creek Road. Entrance to the rail transfer site is approximately 3.9 miles south of the Blackfoot River on Dry Valley Creek Road.

AUTHORITY: This permit will be issued or denied under the authority of Section 404 of the Clean Water Act (33 U.S.C. 1344). A Department of the Army permit is required for the discharge of dredged or fill material into waters of the United States, including wetlands.

WORK: The purpose of the proposed work in Waters of the U.S. is to construct road crossings of creeks and wetlands, impacting a total footprint of approximately 0.445 acres. A combined total of approximately 13,150 cubic yards of rock and soil would be discharged below the ordinary high water mark of Quonset Hut Creek, Stewart Creek and Dry Valley Creek and into adjacent wetlands to construct road crossings. A total of 855 linear feet of creek channel would be altered by culvert installations. Five distinct areas of Waters of the U.S. in the form of creeks with their adjacent wetlands would be altered for road construction.

ADDITIONAL INFORMATION: An Environmental Impact Statement has been prepared for the proposed Caldwell Canyon Mine by the Bureau of Land Management with the Corps of Engineers and other state agencies cooperating. A Final EIS was completed and made available to the public on May 17, 2019. The BLM is preparing a final Record of Decision on the overall mine project. The Final EIS describes the overall project as well as the proposed work in Waters of the U.S., which is limited to the haul roads. P4 would use the roads move ore and overburden from the proposed Caldwell Canyon Mine to Dry Valley wherein ore would be loaded onto rail cars in Dry Valley and select overburden would be placed into the former Dry Valley Mine D-Pit. Other waterways and wetlands would be impacted by the overall Caldwell Canyon Mine, however, these aquatic features were determined to be isolated waters, with no hydrologic connection to downstream Waters of the U.S. and, therefore, not Waters of the U.S. per Section 404 of the Clean Water Act. P4 looked at other road alignments for haul road construction from the mine to Dry Valley.  Alignment considerations included grade of roads, number and radius of turns in the road, road width and total road landscape disturbance, volume of material associated with cut and fill for road construction, acres of wetland impacted, channel crossings, and cultural resources. P4 is proposing the alternative with the least wetland and channel impacts, least volume of cut and fill, relatively low road grade into Dry Valley, and no impacts to cultural resources.

CONSTRUCTION PERIOD: The applicant proposes to start construction upon receipt of all federal, state and local permits. It is anticipated that work would begin January 1, 2020. The applicant has requested the permit duration extend for the life of the mine, or approximately 40 years.

PROPOSED MITIGATION: The applicant proposes the following mitigation measures to avoid, minimize, and compensate for impacts to Waters of the United States from activities involving discharges of dredged or fill material. The Caldwell Canyon Mine haul road construction project would result in the loss of 0.445 acres of scrub shrub and emergent wetlands and alteration of 855 feet of creek channels. The duration of these impacts is being evaluated and is discussed in the Aquatic Resources Description section below. The mitigation requirements were prepared assuming impacts to aquatic resources would be permanent. To offset lost functions and values from impacted wetlands and channels, P4 proposes to mitigate at an offsite location owned by the applicant, known as the Fox Hills Ranch. The Fox Hills Ranch is within the same Blackfoot River watershed and is the location of existing wetland and creek compensatory mitigation efforts undertaken by the applicant for a different phosphate mine – Blackfoot Bridge. DA permit NWW 2004-3200012 authorized discharges of dredged and fill material into Waters of the U.S. with a requirement that lost functions and values of those wetlands and creeks must be replaced. The location of the Fox Hills Ranch is provided on Drawing Sheet 4 of 10. Using the Montana Wetland Assessment Method, the applicant has calculated the functional value of the wetlands to be impacted to be approximately 1.94 functional units, which can be replaced by available functional units at the Fox Hill Ranch.

WATER QUALITY CERTIFICATION: This notice will also serve as a Public Notice that the Idaho Department of Environmental Quality (IDEQ) is evaluating whether to certify that the discharge of dredge and/or fill material proposed for this project will not violate existing water quality standards. A Department of the Army permit will not be issued until water quality certification has been issued or waived by the IDEQ as required by Section 401 of the Clean Water Act. If water quality certification is not issued, waived or denied within sixty (60) days of this public notice date, and an extension of this period is not requested by and granted to the IDEQ certification will be considered waived. Additionally, within thirty (30) days of this Public Notice, any person may provide written comments to IDEQ as request in writing that IDEQ provide them notice of their preliminary 401 Certification decision. Comments concerning Water Quality Certification for this project should be mailed to:

Mr. Lynn Van Every

Idaho Department of Environmental Quality Pocatello Regional Office

444 Hospital Way, #300

Pocatello, Idaho 83201

AQUATIC RESOURCE DESCRIPTION: The impacts to Waters of the U.S. is the loss of 0.445 acres of wetlands, including altering 855 linear feet of creek channels. Please note that while road culverts will replace the native creek channels they will not disconnect upstream aquatic resources and Waters of the U.S. Five distinct areas of wetland or creeks determined to be Waters of the U.S. will be filled or piped for road construction. These areas are identified as WET - 24, 26, 27, 31 and 32. Although mitigation requirements assume permanent losses to aquatic resources the proposed fills in wetlands and channels are not to be permanent. The applicant proposes to remove fills in wetlands and channels in the future.

WET – 24 consists of scrub-shrub wetlands and Quonset Hut Creek and 0.17 acres of Waters of the U.S. will be fill for a new road/culvert. This road provides access from the mine site to Dry Valley for ore shipment area and the overburden disposal. The duration of the proposed fill is 40 years.

WET - 26, 31 and 32 consists of emergent wetlands and Dry Valley Creek at three distinct locations. Cumulatively, 0.258 acres of Waters of the U.S. will be filled for new and replacement culverts. WET – 26 fills provide access to the ore shipping area and WET – 31 and 32 to the overburden disposal. WET – 26 fills are anticipated to exist for 40 years, while WET – 31 and 32 for three years.

WET – 27 consists of emergent wetlands and Stewart Creek and 0.017 acres of Waters of the U.S. will be filled to construct a road with a replacement culvert. This road provides access to the ore shipping area and is anticipated to exist for 40 years.

ANTICIPATED IMPACTS ON AQUATIC ENVIRONMENT: The project as proposed would permanently impact 0.445 acres of low to moderate quality wetlands for the duration of the mine and 855 feet of creek channel would be converted to pipe by culvert installation.

OTHER AUTHORIZATIONS: Approvals for the proposed road construction activities are required by the Idaho Departments of Water Resources and Environmental Quality as well as the Bureau of Land Management. The Final EIS provides a list of other authorizations required for the Caldwell Canyon Mine Project.

CULTURAL RESOURCES:  P4 has provided cultural resource surveys for the proposed Caldwell Canyon Mine Project. These surveys were conducted by Desert West Environmental. Five Class II cultural resources inventories (phases 1, 2, 3, 4, and 5) were conducted for the Caldwell Canyon Mine Project in 2014, 2015, 2017 and 2018. The surveys were coordinated with the Bureau of Land Management’s archaeologist and provided to the Idaho State Historic Preservation Office. The results are discussed in detail in the FEIS. Coordination is currently being conducted with the office of the Idaho State Historic Preservation Office to determine if this activity will affect sites: one that is listed on the National Register of Historic Places, and one that may be eligible for listing on the Register. We are also coordinating with the appropriate Tribal entity or the Tribal Historic Preservation Offices for the Shoshone-Bannock Tribes, to determine if there are any tribal historic or cultural interests within the project area.

TRIBAL TREATY RIGHTS and INTERESTS: Federal agencies acknowledge the federal trust responsibility arising from treaties, statues, executive orders and the historical relations between the United States and American Indian Tribes. The federal government has a unique trust relationship with federally recognized American Indian Tribes, including the Shoshone-Bannock Tribes. The Corps has a responsibility and obligation to consider and consult on potential effects to Tribal rights, uses and interests. The Corps further recognizes there may be a need for additional and on- going consultation.

ENDANGERED SPECIES: No listed threatened or endangered species or designated critical habitats are known to exist in the project area. Coordination was currently being conducted with the U.S. Fish and Wildlife Service (USFWS) to determine if the activity will have any effect on species designated as endangered or threatened under the Endangered Species Act, or their critical habitat, under the Endangered Species Act of 1973 (87 Stat. 844; 16 U.S.C. 1531 et. seq.).

ESSENTIAL FISH HABITAT: The Magnuson-Stevens Fishery Conservation and Management Act, as amended by the Sustainable Fisheries Act of 1996, requires all Federal agencies to consult with the National Marine Fisheries Service on all actions or proposed actions, permitted, funded or undertaken by the agency that may adversely affect Essential Fish Habitat (EFH). No EFH species are known to use the project area. Preliminarily, we have determined the described activity would have no effect on EFH.

ENVIRONMENTAL IMPACT STATEMENT: The Bureau of Land Management has lead an interagency team in the preparation of an EIS. The team included the Idaho Departments of Lands and Environmental Quality, the Idaho Governor’s Office of Energy and Mineral Resources, and the Walla Walla District, Corps of Engineers. A notification of the Final EIS was released in the Federal Register on May 17, 2019 (FR Vol 84, No 96, pages 22512 to 22513). The EIS included a much larger project, of which the proposed action is a smaller but integral action. The only impacts to Waters of the U.S. would be authorized by this permit.

EVALUATION: The decision whether to issue a permit will be based on an evaluation of the probable impact, including cumulative impacts, of the proposed activity on the public interest. This 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 proposal must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal 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. In addition, our evaluation will include application of the EPA Guidelines (40 CFR 230) as required by Section 404(b)(1) of the Clean Water Act.

CONSIDERATION OF PUBLIC COMMENTS: The Corps of Engineers is soliciting comments from the general public; Federal, State and local agencies and officials, Tribal entities and other interested parties in order to consider and evaluate the impacts of this proposed project. Any comments received will be considered by the Corps of Engineers 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 the other public interest factors listed above. The BLM EIS process included solicitation of public comments on the overall mine project in several phases. Comments were solicited on scoping for the mine plan, the Draft EIS and the Final EIS. Comments received in response to this Public Notice will be used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.

PUBLIC HEARING: Any person may request in writing, within the comment period specified in this notice, that a public hearing be held to consider this proposed activity. Requests for a public hearing shall state specific reasons for holding a public hearing. A request may be denied if substantive reasons for holding a hearing are not provided or if there is otherwise no valid interest to be served.

COMMENT & REVIEW PERIOD: Interested parties are invited to provide comments on the proposed activity, which will become a part of the record and will be considered in the final decision.

Please mail all comments to:

U.S. Army Corps of Engineers Walla Walla District

Robert A. Brochu

Idaho Falls Regulatory Office 900 N Skyline Drive, Suite A Idaho Falls, Idaho 83402-1700


Comments should be received no later than the comment due date of August 02, 2019, as indicated on this notice, to receive consideration.


Kelly J. Urbanek

Chief, Regulatory Division

Walla Walla District



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