enCore Energy’s Dewey Burdock ISR Uranium Project EPA Decision Advances Federal Permitting
enCore Energy’s Dewey Burdock ISR Uranium Project EPA Decision Advances Federal Permitting
Dallas, Texas, Sept. 16, 2025 — enCore Energy Corp. (NASDAQ: EU) (TSXV: EU) announced today that the U.S. Environmental Protection Agency’s Environmental Appeals Board (EAB) has denied in full a petition for review filed by the Oglala Sioux Tribe, Black Hills Clean Water Alliance and NDN Collective challenging the EPA’s issuance of Class III and Class V Underground Injection Control (UIC) permits for enCore’s 100%-owned Dewey Burdock In-Situ Recovery (ISR) Uranium Project in South Dakota. The EAB decision allows the Dewey Burdock Project to advance through federal permitting and positions the Company to commence state permitting activities in 2025. The Dewey Burdock Project was approved for fast-track federal permitting under the Fast-41 Program on August 28, 2025.
Robert Willette, Acting Chief Executive Officer of enCore Energy, said: “This decision by the EAB affirms the validity of the permits and the integrity of the regulatory process following years of administrative and judicial review. The Dewey Burdock Project is part of enCore’s U.S. production pipeline, and today’s decision provides the certainty needed to continue advancing toward development. This outcome not only strengthens enCore’s growth strategy but also underscores our role in delivering secure, domestic uranium supply critical to America’s clean energy and national security future.”
The petitioners alleged that EPA Region 8’s permit decisions violated multiple statutes and procedures, including the Safe Drinking Water Act, the Administrative Procedure Act and the National Historic Preservation Act. After extensive review the EAB concluded that EPA Region 8 acted properly, that the permits are fully supported by the administrative record, and that no errors were made in the regulatory process. The denial of review confirms the validity of enCore’s UIC permits, which are essential for ISR uranium recovery operations at the Dewey Burdock Project.
This decision follows more than a decade of permitting and litigation, during which the Dewey Burdock Project was subject to parallel challenges before both the Nuclear Regulatory Commission (NRC) and the EPA. With the EAB ruling, all major federal authorizations for the project — including the NRC Source and Byproduct Materials License and EPA UIC permits — are final and effective.
About the Dewey Burdock ISR Uranium Project
The Dewey Burdock Project, wholly owned by enCore, is an advanced-stage uranium project located in Custer and Fall River counties in South Dakota. The project will recover uranium from subsurface sandstone ore bodies using ISR technology, which employs a water-based solution in the production wellfield to dissolve uranium minerals in place and then pumps the uranium-bearing solution to a central processing plant for recovery. ISR technology enables minimal surface disturbance compared with conventional open-pit or underground uranium mining. The project comprises wellfield areas, a central processing plant, supporting infrastructure and environmental protection systems.
The Dewey Burdock Project was approved for inclusion in the Fast-41 Program by the U.S. Federal Permitting Improvement Steering Council on August 28, 2025, as part of the implementation of the Executive Order on Immediate Measures to Increase American Mineral Production. This designation supports the development of domestic uranium production in the United States. For more information, see the Federal Permitting Dashboard entry for the Dewey Burdock ISR Uranium Project: Dewey Burdock ISR Uranium Project | Permitting Dashboard.
The Company received its NRC Source and Byproduct Materials License (SUA-1600) on April 8, 2014, covering approximately 10,580 acres. enCore controls the mineral and surface rights for the area covered by the NRC license and will continue to work with the NRC as the lead federal agency for federal permitting as the project advances toward development and operation using ISR extraction methods.
Mineral Resource Summary
| ISR Resources | Measured | Indicated | M&I | Inferred |
|---|---|---|---|---|
| Lbs (U3O8) | 14,285,988 | 2,836,159 | 17,122,147 | 712,624 |
| Tons | 5,419,779 | 1,968,443 | 7,388,222 | 645,546 |
| Avg. GT | 0.73 | 0.41 | 0.66 | 0.32 |
| Avg. Grade (% U3O8) | 0.13 % | 0.07 % | 0.12 % | 0.06 % |
| Avg. Thickness (ft) | 5.56 | 5.74 | 5.65 | 5.87 |
Notes
- Effective date of mineral resource is October 8, 2024.
- enCore reports mineral reserves and mineral resources separately. Reported mineral resources do not include mineral reserves.
- The geological model used is based on geological interpretations on section and plan derived from surface drillhole information.
- Mineral resources have been estimated using a minimum grade-thickness cut-off of 0.20 ft% U3O8.
- Mineral resources are estimated based on the use of ISR for mineral extraction.
- Inferred mineral resources are estimated with a level of sampling sufficient to determine geological continuity but less confidence in grade and geological interpretation such that inferred resources cannot be converted to mineral reserves.
- Mineral resources that are not mineral reserves do not have demonstrated economic viability.
John M. Seeley, Ph.D., P.G., C.P.G., enCore’s Chief Geologist and a Qualified Person under Canadian NI 43-101 and S-K 1300, has reviewed and approved the technical disclosure in this news release on behalf of the Company.
About enCore Energy Corp.
enCore Energy Corp., America’s Clean Energy Company™, is committed to providing clean, reliable and affordable fuel for nuclear energy. enCore is the only United States uranium company with multiple central processing plants in operation and is led by industry experts with extensive experience in ISR uranium operations and the nuclear fuel cycle. enCore solely utilizes ISR for uranium extraction, a proven technology co-developed by leaders within the company.
Following demonstrated success in South Texas, enCore’s planned project pipeline includes the Dewey Burdock Project in South Dakota and the Gas Hills project in Wyoming, along with other assets, non-core holdings and proprietary databases. The Company works with local communities and indigenous governments to create positive impacts from corporate developments. More information is available at www.encoreuranium.com.
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements under the Private Securities Litigation Reform Act of 1995 and Canadian securities laws that are based on management’s current expectations, assumptions and beliefs. Forward-looking statements often include words such as “will”, “expects”, “plans”, “believes”, “intends”, “estimates”, “projects”, “continue”, “potential” and similar expressions, or statements that certain actions, events or results “may”, “could”, or “will” be taken. These statements are not guarantees of future results and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied. Important factors that could affect actual results include exploration and development risks, changes in commodity prices, access to skilled personnel, results of exploration and development activities, extraction and environmental risks, regulatory approvals and litigation, timing and availability of equipment and materials, defects in title, market conditions and other risks described in the Company’s filings with the SEC and SEDAR+. The Company assumes no obligation to update forward-looking information except as required by law. Additional information identifying risks and uncertainties is available at www.sec.gov and www.sedarplus.ca.
Source: enCore Energy Corp.