ASX-listed gold miner Regis Resources has managed to reinstate the reserves of the McPhillamys project, in New South Wales, after a prolonged period of legal uncertainty over a heritage declaration on a certain area of the project made by the federal government in August 2024.

MD and CEO Jim Beyer deems the reinstatement of the project's 56-million-tonne reserve, grading 1.1 g/t gold for 1.89-million ounces, a significant milestone for Regis since the "disappointing" Section 10 Declaration on the project, which particularly impacted the project's envisioned tailings storage facility (TSF).

The company's ore reserve estimate of 1.89-million ounces could no longer be relied upon by investors following the Section 10 Declaration and was therefore withdrawn. Regis also wrote off the $192-million carrying value of the project at the time. The McPhillamys mineral resource estimate was not affected by the Section 10 Declaration.

The company has been developing a dual path strategy to get the McPhillamys project back on track, with a new prefeasibility study (PFS) having reinforced the project's economics using an alternative development pathway, particularly for its land designation for the TSF.

Regis still awaits a final court decision after the company challenged the procedural fairness of the Section 10 Declaration through a judicial review.

The PFS demonstrates that, at a A$4 000 oz gold price, or $2 800/oz, the project can deliver 190 000 oz yearly production on average at an all-in sustaining cost of $1 718/oz, for gross revenue of $7.1-billion over its 9.4-year lifetime.

At this same gold price, the project has a net present value of $1.13-billion and an internal rate of return of 21.8% (after tax).

The project will require $1.08-billion in pre-production capital.

Regis is targeting a final investment decision on the project in the first half of 2028, subject to permitting.

Notably, the PFS does not include consideration of any prospects outside of the McPhillamys deposit such as the Discovery Ridge and Kings Plains targets, which represent upside potential for the project.

TAILINGS REFORM

In respect of a TSF, the PFS envisions an integrated waste landform that is located entirely within land owned by Regis and does not encroach on the Section 10 declared area.

If, however, the court sets aside the Section 10 Declaration, the development approach using the TSF as outlined in the project's 2024 definitive feasibility study will be the preferred pathway.

The alternative tailings strategy identified in the new PFS would replace the conventional value-fill TSF with a filtered tailings solution in which the slurry is mechanically dewatered to a filter cake consistency and co-disposed within the mine waste dump.

Regis reiterates that while the Section 10 Declaration remains in force over a northern portion of the McPhillamys project area, it does not encroach on the deposit, the designed openpit, the mine waste dump or the processing plant.