Lo Herma’s Future Hinges on Hydrogeological Test Results and Resource Expansion

Hydrogeological Testing Marks a Milestone

American Uranium Limited (ASX – AMU) has taken a significant step forward at its flagship Lo Herma ISR uranium project in Wyoming’s Powder River Basin by commencing hydrogeological testing. This testing, conducted by Petrotek Corporation, a specialist with nearly three decades of experience in injection well and subsurface resource evaluation, aims to validate the aquifer’s performance, a critical factor for the success of in-situ recovery (ISR) mining methods.

The hydrogeological program is running concurrently with Phase 1 of the resource development drilling campaign, which is already more than halfway complete. Together, these efforts are designed to underpin an updated Mineral Resource Estimate (MRE) and a Scoping Study update scheduled for 2026, setting the stage for potential project development and permitting.

Expanding the Resource Base

The current resource at Lo Herma stands at 8.57 million pounds of uranium. The ongoing drilling campaign aims to expand this base, with initial results expected before the end of 2025. The drilling program is critical not only for resource growth but also for refining the understanding of the mineralisation and aquifer characteristics that will influence mine planning.

CEO Bruce Lane highlighted the importance of these programs, noting that Lo Herma is among the few near-term, low-cost ISR projects in the United States. He emphasized that confirming aquifer transmissivity and validating initial observations through hydrogeological testing are essential steps toward advancing the project and capitalizing on supportive US domestic nuclear fuel initiatives.

Technical Details and Next Steps

Earlier in 2025, four groundwater monitoring wells were drilled and completed at Lo Herma to collect hydrogeologic data. These wells demonstrated sufficient submergence of mineralisation within the aquifer, supporting ISR mining feasibility. The current testing involves step-drawdown pumping tests to determine sustainable pumping rates, well efficiency, and hydraulic properties of the aquifer.

Results from these tests will be compared with prior laboratory permeability data to confirm the suitability of the hydrogeologic conditions for ISR mining. Following this confirmation, additional hydrogeological testing is planned to support mine permit applications, including long-term aquifer pumping tests and installation of further monitoring wells.

Strategic Implications

Lo Herma’s progress comes at a time when the US government is actively supporting the domestic nuclear fuel supply chain, making the project strategically significant. The combination of resource expansion and aquifer validation could position American Uranium to move swiftly toward development, potentially benefiting from policy tailwinds aimed at securing uranium supply for national energy security.

While the results of the hydrogeological testing and drilling are still pending, the current momentum and technical groundwork provide a promising outlook for Lo Herma’s advancement in 2026.