Aston Bay’s Storm copper study puts capex at $165M

Aston Bay Holdings (TSXV: BAY; US-OTC: ATBHF) estimates developing and expanding its Storm copper project in Nunavut would cost C$164.7 million ($118.5 million), according to a new prefeasibility study that establishes the project’s first mineral reserve.

Discounted at 7%, the prefeasibility study estimates a C$117.1-million after-tax net present value and a 22% internal rate of return, including pre-development spending, the company reported Tuesday. Storm is on Somerset Island, about 1,500 km northwest of Iqaluit.

“The study provides a foundation for further technical work and assessment of potential development, but it does not capture the project’s full exploration upside,” CEO Thomas Ullrich said in a release. “Exploration and resource-expansion work are expected to continue, offering significant potential to create additional value beyond the current mine plan.”

The reserve gives Aston Bay and its majority partner, American West Metals (ASX: AW1), a firmer basis to pursue financing, but the investment case still depends on the cost of building and operating in the Arctic. Aston Bay’s minority stake limits its spending before a mine decision; the project itself still needs funding and approvals.

Shares were unchanged at C6¢ in Toronto late Tuesday morning, giving Aston Bay a market value of about C$15.2 million.

Mine plan

Storm’s 2025 technical report describes a series of copper deposits and prospects around a fault-bounded basin. The property is about 120 km south of Resolute Bay, the nearest community and a staging point for work in the High Arctic.

The study allows C$37.9 million for early development work before an assumed construction decision in September 2029. The valuation is calculated as of September 2028.

The base case assumes $5.30 per lb. copper, $50 per oz. silver and an exchange rate of C$1.39 per US dollar.. The cost estimate excludes sustaining capital, a water-treatment plant and the owner’s mining technical team and grade control.

The initial reserve totals 12.58 million probable tonnes grading 1.2% copper and 3.7 grams silver per tonne, containing 151,400 tonnes of copper and 1.5 million oz. silver, as of Nov. 1. Processing would start in April 2030, recovering 103,000 tonnes of copper over 10 years.

American West owns 80% of Storm and operates the project. Aston Bay holds 20% and doesn’t have to contribute to project spending until a decision to mine following a bankable feasibility study. American West earned its interest under an exploration agreement signed in 2021, according to Aston Bay’s filings.

Funding conditions

Metal trader Ocean Partners signed a purchase agreement in July 2025 covering Storm’s copper, silver and gold products. The arrangement includes a proposed senior secured loan covering up to 80% of initial capital, subject to a bankable feasibility study and formal documentation.

The financing remains conditional, and the partners haven’t approved construction.

The study estimates total funding requirements of C$174.5 million, including working capital and pre-production costs.