Name of the Project
Waihi gold project.

Location
The project is located in the Waihi district on North Island, New Zealand.

Project Owner/s
OceanaGold.

Project Description
A preliminary economic assessment (PEA) has shown the potential for a robust project, with an initial mine life until 2036 from multiple sources of mill feed.

Total indicated resources are estimated at 12.2-million tonnes grading 4 g/t gold and 18.2 g/t silver. Inferred resources are estimated at 11-million tonnes grading 4.4 g/t gold and 17 g/t silver.

The projects included in the PEA comprise Martha underground (MUG), Wharekirauponga underground (WKP), Martha openpit Phase 5 cutback (MOP5) and the Gladstone openpit.

MUG is expected to produce from 35 000 oz to 45 000 oz of gold in 2021, with production beginning in the second quarter using modified Avoca and remnant mining methods.

The WKP will be mined using a decline from private land, with several access locations under consideration. The material mined will be transported underground through a decline to a portal, then to the surface to the existing Waihi process plant. A modified Avoca mining method will be used.

Openpit mining at Gladstone will provide early mill feed and rock for underground mine backfill over the life-of-mine and construction of the tailings storage facilities (TSFs).

Mining of MOP5 envisages an additional cutback to the previously permitted Phase 4 cutback and will require some relocation/replacement of surface infrastructure, acquisition of a mining fleet and prestripping of overburden.

The PEA includes the use of the existing Waihi process plant, which has a throughput capacity of 1-million to 1.3-million tonnes a year and envisions modest-growth capital investment to increase the plant’s capacity to 1.6-million tonnes a year. The throughput of the plant will be achieved through upgrades to the crushing, milling and carbon-in-pulp circuits. Options are available to further increase the capacity of the plant to accommodate the potential expansion of existing resources and production levels over the life-of-mine.

Options for future TSFs include two upper lifts on the existing TSFs, the construction of a third TSF and the potential conversion of Gladstone openpit to a TSF when mining is completed there.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at a 5% discount rate, of $931-million and an internal rate of return of 61% using $1 500/oz as a base case.

Capital Expenditure
The project is estimated at $447-million.

Planned Start/End Date
Production at MUG is expected to start in 2021; openpit mining from Gladstone is expected to start in 2024; and first production from WKP and MOP5 is expected to start in 2026 and 2027 respectively.

Latest Developments
OceanaGold expects to complete a feasibility study for MUG in the first quarter of 2021 and complete a prefeasibility study for WKP in the second half of 2021 to convert existing resources to reserves.

The company also expects to complete a feasibility study for Gladstone, MOP5 and the additional TSF in 2022.

It also plans to complete the consenting process for all the projects as soon as possible to facilitate the development of the Waihi district, prioritising the development of WKP.

The consenting process includes extensive technical, environmental and cultural assessments, as well as significant social engagement beyond the initial geological work that established the mineral resource. The consenting process is expected to start in the second half of 2020.

For the remainder of 2020, OceanaGold expects to drill an additional 5 000 m at WKP on the high-grade East Graben structures.

At MUG, the company completed about 10 000 m of drilling in the first half of 2020 and expects to complete an additional 15 000 m of drilling in the remainder of the year, with a focus on resource conversion to the indicated category.

In addition to the current reported resource at MUG, the company has an identified exploration target with the potential of six-million to eight-million tonnes grading 4 g/t gold to 6 g/t gold, which represents a future opportunity for resource addition.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
OceanaGold VP investor relations Sam Pazuki, tel +1 720 602 4880 or email
IR@oceanagold.com; or corporate communications manager Melissa Bowerman, tel +61 407 783 270 or email melissa.bowerman@oceanagold.com.