American Uranium (ASX:AMU) has completed water-well drilling at its Lo Herma in-situ recovery (ISR) uranium project in Wyoming, US, ahead of planned pump testing in August or September 2026.
The company has installed seven additional hydrogeological monitoring wells around the existing LH MW-003 pumping well within the proposed Mine Unit 1.
The newly installed wells are undergoing final development, which is expected to be completed in early August. Pump testing is scheduled for August or September, subject to field conditions and contractor availability, with results expected late in the September quarter.
According to American Uranium, the test design is intended to support groundwater modelling, permitting, and ongoing technical work for the Scoping Study targeted for the same quarter.
The program will assess groundwater flow through the target production sands and the degree of hydraulic connectivity between the target aquifer and the units above and below it.
Four observation wells have been completed in the Middle C Sand at 400–500ft from the pumping well to evaluate directional transmissivity. Three further wells monitor the overlying D Sand and A Coal units and an underlying aquifer.
The company says the layout could also support further testing of the D Sand or underlying sand if additional characterisation is required.
CEO Bruce Lane says the completion of drilling marks the project’s progression towards development and permitting.
“As one of a limited number of US ISR uranium projects advancing along that path, our focus is now on completing the technical, hydrogeological, and environmental workstreams required to support project evaluation, permitting, and future development planning.”
The upcoming work follows hydrogeological testing completed in 2025 across four previously installed monitoring wells. According to American Uranium, those wells maintained sustained flow rates with minimal aquifer drawdown throughout the tests.
Lane says the planned large-scale pump testing is expected to provide key inputs to the company’s targeted Q3 2026 Scoping Study.
“The study will evaluate development across Mine Units 1, 2, and 3, with Mine Unit 1 currently representing the largest and most advanced area and the anticipated starting point of the development sequence under evaluation,” Lane says.
Lo Herma hosts a mineral resource estimate containing 9.45 million pounds of uranium oxide, reported in accordance with the JORC Code 2012.
The project is located in Wyoming’s Powder River Basin.
American Uranium is an Australia-based, US-focused exploration company that also holds projects in Wyoming’s Great Divide Basin and Green Mountain areas, and Utah’s Henry Mountains.
Write to France Pinzon at Mining.com.au
Images: American Uranium
