Accepting comments from July 17, 2025, through August 18, 2025.
BOISE – The Idaho Department of Environmental Quality (DEQ) is seeking public comment on a draft addendum to the Final Section 401 Water Quality Certification for the Stibnite Gold Project.
This draft addendum, published July 17, 2025, supplements—but does not replace—the conditions of the existing certification issued on May 24, 2024.
The draft addendum incorporates updated information from a range of sources, including:
- U.S. Forest Service Final Environmental Impact Statement
- U.S. Forest Service Stibnite Gold Project Biological Assessment
- U.S. Forest Service Final Record of Decision
- Biological Opinions issued by the National Marine Fisheries Service and the U.S. Fish and Wildlife Service
- U.S. Army Corps of Engineers Permit NWW-2013-00321
- Revised technical submissions from Perpetua Resources Idaho, Inc.
These materials provided new or refined pollutant and temperature modeling, updates to the mine plan resulting from interagency coordination, and enhanced mitigation and monitoring measures.
Following review of the federal permit, updated water quality materials, the May 2024 certification, this addendum, and the 2021 modified mine plan, DEQ’s evaluation maintains that if the permittee complies with all applicable environmental protection conditions, then there is reasonable assurance the project will comply with water quality requirements of the Clean Water Act §§ 301, 302, 303, 306, and 307, Idaho’s “Water Quality Standards” (IDAPA 58.01.02), and other appropriate water quality requirements of state law.
The draft addendum and supporting materials are available for public review at DEQ’s State Office (1410 N. Hilton St. Boise, Idaho 83706), DEQ’s Boise Regional Office (1445 N. Orchard St. Boise, Idaho 83706), and on DEQ’s website. Written comments will be accepted through August 18, 2025, at 5 p.m. Pacific Time. Submit comments electronically using the form below or by mail or email to:
Meghan Cline
1445 N. Orchard St.
Boise, Idaho 83706
Meghan.Cline@deq.idaho.gov
Related Documents
Draft addendum
Supporting materials
Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.
Official Government Website
Official Government Website
DEQ seeks public comment on draft addendum to the Final Section 401 Water Quality Certification for the Stibnite Gold Project
Accepting comments from July 17, 2025, through August 18, 2025.
BOISE – The Idaho Department of Environmental Quality (DEQ) is seeking public comment on a draft addendum to the Final Section 401 Water Quality Certification for the Stibnite Gold Project.
This draft addendum, published July 17, 2025, supplements—but does not replace—the conditions of the existing certification issued on May 24, 2024.
The draft addendum incorporates updated information from a range of sources, including:
These materials provided new or refined pollutant and temperature modeling, updates to the mine plan resulting from interagency coordination, and enhanced mitigation and monitoring measures.
Following review of the federal permit, updated water quality materials, the May 2024 certification, this addendum, and the 2021 modified mine plan, DEQ’s evaluation maintains that if the permittee complies with all applicable environmental protection conditions, then there is reasonable assurance the project will comply with water quality requirements of the Clean Water Act §§ 301, 302, 303, 306, and 307, Idaho’s “Water Quality Standards” (IDAPA 58.01.02), and other appropriate water quality requirements of state law.
The draft addendum and supporting materials are available for public review at DEQ’s State Office (1410 N. Hilton St. Boise, Idaho 83706), DEQ’s Boise Regional Office (1445 N. Orchard St. Boise, Idaho 83706), and on DEQ’s website. Written comments will be accepted through August 18, 2025, at 5 p.m. Pacific Time. Submit comments electronically using the form below or by mail or email to:
Meghan Cline
1445 N. Orchard St.
Boise, Idaho 83706
Meghan.Cline@deq.idaho.gov
Related Documents
Draft addendum
Supporting materials
Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.
Public Comment Form