American Uranium (ASX:AMU) Petrotek engaged for hydrogeological testing at Lo Herma

American Uranium Ltd (ASX:AMU) has marked another key step toward developing its Lo Herma in-situ recovery (ISR) uranium project in Wyoming’s Powder River Basin, appointing the respected Petrotek Corporation to undertake a detailed hydrogeological testing program.
The program coincides with a 50-hole resource-expansion drilling campaign now under way, designed to underpin an updated Mineral Resource Estimate and a revised Scoping Study slated for 2026.

Highlights

• Petrotek Corporation appointed to conduct hydrogeological testing at the Lo Herma ISR Project.

• Testing of previously drilled monitor wells scheduled to begin in November 2025, concurrent with Phase 1 resource-development drilling.

• 50-hole expansion program aims to grow and improve confidence in the current 8.57 Mlb uranium resource.

• Results will inform updates to the Mineral Resource Estimate and Scoping Study next year.

A Technical Step Toward Production Readiness

Petrotek Corporation brings almost three decades of field experience in injection-well engineering and subsurface resource evaluation across the Powder River Basin, the same district that has long hosted some of the United States’ most productive ISR operations.

Its appointment underscores American Uranium’s intent to validate aquifer conditions critical for efficient and environmentally compliant ISR mining.

Phase 1 of the development program combines drilling and hydrogeologic analysis to verify that the Lo Herma mineralisation lies within a sufficiently transmissive aquifer.

This is essential for ISR methods, which rely on circulating leach solutions through permeable sandstone formations to recover uranium without conventional open-cut or underground mining.

As CEO and Executive Director Bruce Lane noted, “Our upcoming hydrogeological testing and resource development drilling programs at Lo Herma represent major steps toward advancing one of America’s most promising ISR uranium projects.”

Testing will be conducted across four previously completed groundwater monitoring wells, each screened through mineralised sand horizons and fitted with five-inch casing suitable for aquifer pumping trials.

The program will include single-well step-drawdown tests to assess sustainable pumping rates, well efficiency and broader hydraulic properties.

The results will be compared with laboratory-scale permeability data gathered earlier in 2025 to confirm field performance and guide the design of future wellfields.

From Data to Development

Should the aquifer behave as anticipated, the data will form the foundation for near-term mine-planning at the Scoping Study level and for the design of additional long-term pumping tests.

These subsequent studies, incorporating extra monitoring wells, will provide large-scale aquifer characterisation required for a future mine-permit application.

American Uranium’s current work builds on earlier confirmation that Lo Herma’s mineralised sands are fully submerged within the local groundwater system, satisfying a key ISR prerequisite.

The company continues to leverage the technical oversight of BRS Engineering’s Principal Engineer Doug Beahm, a veteran of uranium exploration and project evaluation in the western United States for more than five decades.

With hydrogeologic testing about to commence and drilling advancing in tandem, American Uranium is positioning Lo Herma as a credible near-term ISR development within a revitalised U.S. nuclear-fuel landscape.

alidation of aquifer performance will not only strengthen the project’s technical credentials but also provide the data needed for updated resource and economic studies in 2026.

In a sector increasingly focused on secure domestic supply chains and lower-impact extraction, the progress at Lo Herma reinforces the strategic relevance of Wyoming’s Powder River Basin as a cornerstone of America’s next phase of uranium production.

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