A feasibility study is a detailed assessment of whether a proposed project can be developed and operated successfully. It considers the project’s design, expected production, infrastructure, estimated costs and economic potential.

The updated study forecasts strong financial results for the proposed Sisson Project based on the information and assumptions available when the study was prepared.It estimates that Sisson could operate for about 27 years, require an initial investment of about $1.53 billion, directly employ around 500 people during construction and provide around 300 long-term operating jobs. The study estimates a post-tax net present value of about $6.9 billion, a post-tax internal rate of return of 49.8 per cent and a payback period of 1.6 years.

The original feasibility study was completed in 2013. The updated study, completed in 2026, incorporates more recent engineering, field investigations and testing, along with current information about costs, commodity markets and other factors affecting the project.It also reflects updated guidance and industry practices, additional environmental impact assessment conditions and refinements to the proposed mine, processing facilities, infrastructure, tailings storage facility and water management system.

The proposed mine and processing facility would produce separate tungsten and molybdenum concentrates.Over its proposed 27-year operating life, the project is expected to produce about 16.1 million metric tonne units of tungsten trioxide and 113.5 million pounds of molybdenum. This represents average annual production of about 598,000 metric tonne units of tungsten trioxide and 4.2 million pounds of molybdenum.The mine plan begins in an area with higher tungsten grades. As a result, average annual tungsten production is expected to be higher during the first five years of operations.

Tungsten and molybdenum are recognized as critical minerals by Canada and other international jurisdictions. They are valued for properties such as strength, durability and resistance to heat and corrosion.Tungsten is used in defence and aerospace applications, including military munitions and protective equipment; industrial tools such as drills and machine components; and electronics such as cell phones, television sets and microwaves.Molybdenum is an essential alloy that is used with other elements – such as steel – to increase hardness, strength, electrical conductivity and resistance to wear and corrosion. It is incorporated in stainless steel, automotive grease, electronic devices and medical instruments, such as scalpels.If developed, Sisson could contribute to a more reliable and accessible North American supply of both minerals.

Several elements of the proposed project have changed or been refined since 2013:The updated design focuses on producing tungsten concentrate rather than the ammonium paratungstate, or APT, proposed in 2013. This reduces the proposed processing plant’s cost and complexity. The option of producing APT may continue to be assessed as market conditions evolve.The mine plan incorporates autonomous haul systems to improve safety and hauling efficiency and reduce operating and personnel costs.The tailings storage facility and water management system have been significantly updated to reflect current guidance, industry practices, lessons from tailings incidents and additional environmental impact assessment conditions.Higher forecasted tungsten prices and changes in the Canada-U.S. exchange rate have strengthened the project’s forecasted financial results. Inflation, higher provincial tax rates and design refinements have also increased estimated capital and operating costs.

No, not yet. The updated study is an important project milestone that further advances the project towards a construction decision. The project will now focus on progressing additional regulatory, engineering, engagement, financing and investment activities. A decision is targeted for late 2027.

The estimates are based on the information and assumptions available when the study was prepared, including assumptions about construction and operating costs, mineral prices, exchange rates, mineral recovery, production and project design.Based on the current level of engineering and design, the Feasibility Study capital and operating cost estimates are expected to have an accuracy range of approximately ±15%. This represents an industry-standard level of accuracy for a Feasibility Study and should not be interpreted as a guarantee of the final project costs or financial results.The project’s forecast financial results are particularly sensitive to commodity prices, exchange rates, ore grades and mineral recovery rates. Estimates may change as further engineering and project planning are completed.The complete  Feasibility Study Update Technical Report provides detailed information about the study’s methods, assumptions, sensitivities and risks.

The Sisson Project received provincial environmental impact assessment approval in 2015 and federal approval in 2017. It has also received other key authorizations, including an amendment to Schedule 2 of the Metal and Diamond Mining Effluent Regulations and Fisheries Act authorizations.These approvals include conditions that must be addressed as the project advances, including requirements related to water and air quality monitoring and management, the detailed design and approval of the tailings storage facility, emergency preparedness and other measures intended to protect the environment throughout the project’s life.Further engineering, permitting and regulatory work also remains before construction could begin.

Environmental protection and water management are central to the project’s planning and regulatory requirements.The proposed design would collect and treat water that comes into contact with project facilities. Water that does not come into contact with project facilities would be diverted around them where practical. Process water would be recycled, and treated water would be reused or discharged, as appropriate, in accordance with applicable requirements and where practical.A centralized water treatment plant would treat collected water to applicable federal and provincial requirements. The plant is expected to operate throughout the mine’s life and, as required, during post-closure care. Groundwater monitoring wells would also be installed around the tailings storage facility to monitor seepage and water quality.Monitoring and compliance would continue through construction, operations, closure and after mining operations have ended.More information is available on the Environmental Responsibility page, and Protecting the Nashwaak Watershed and Reclamation and Closure sections.

Tailings safety is a legitimate and important public concern. Since the 2013 feasibility study, the proposed tailings storage facility has undergone a significant design update to the design to reflect updated guidance, industry practices, lessons from tailings incidents and additional environmental impact assessment conditions.Under the current Canadian Dam Association guidance, the proposed dam has been reclassified to the highest consequence classification. The updated design responds to this classification through a full centreline dam design and consideration of a larger potential flood event.The updated water management design also includes:A tailings thickener to reduce the amount of water transported to the facility;Operational spillways to provide additional water management protection;Collection and treatment of contact water;Diversion of non-contact water around mine facilities where practical; andGroundwater monitoring wells to monitor seepage and water quality.The facility would be constructed in stages and would be subject to regulatory requirements related to design, construction, water management, inspections, monitoring and emergency planning. Further engineering and regulatory work remain.

Following mining, the project would undergo decommissioning, reclamation and closure to support the site’s long-term physical, chemical and biological stability and meet regulatory requirements and agreed future land uses.Buildings and infrastructure that are no longer required would be removed, and disturbed areas would be restored back to their previous ecological state. The tailings storage facility’s embankments and beaches would be capped and revegetated, and the water management system would be reconfigured to support the site’s long-term stability.Water would continue to be monitored and treated after closure, as necessary, to meet regulatory requirements.The provincial government requires financial security to help ensure the project can be properly closed and reclaimed. The study estimates that this security would increase over the mine’s operating life to about $210 million at closure, in today’s dollars. It is intended to fund closure and reclamation activities, as well as post-closure water treatment costs.

The project is expected to directly employ at least 500 people during construction and at least 300 people while operational. The operating workforce would be drawn from surrounding towns and cities, and no permanent work camp is currently proposed.Construction and operations would also require a wide range of goods and services, creating potential opportunities for local and New Brunswick businesses. Northcliff plans to engage further with businesses and communities about the capabilities needed from a supply chain perspective, as well as a strategy for specialized training to build on existing skills and services.Based on the assumptions in the study, the project is forecast to generate about $14.5 billion in taxes and royalties over its forecast mine life of  27 years. Northcliff also intends to commission a separate economic impact study to provide more detailed information about the project’s potential local, provincial and national economic impacts.

Northcliff has continued to engage with the Wolastoqey in New Brunswick since receiving environmental approvals and has had a Co-Operation Agreement with Wostak (Woodstock) First Nation since 2017. The company also shares project information with the Wolastoqey Nation in New Brunswick and has sought its participation in relevant field programs.The company’s engagement scope has also expanded, based on communication protocols issued by the provincial government in December 2025, to include the consultative bodies for Mi’mawe’l Tplu’tagnn Incorporated (MTI), Kopit Lodge and the Peskotomukhati Nation, as well as First Nation communities throughout New Brunswick.Northcliff will continue to meet and share information with First Nations, local communities and other stakeholders as engineering, environmental, regulatory and project-planning work advances.

The Sisson Partnership will use the study to inform further engineering, regulatory, commercial and financing work. This includes basic engineering to optimize equipment selection, site layouts and design criteria, as well as continued work to address environmental approval conditions and other requirements. Meetings with First Nations, local communities and other stakeholders will also continue.An anticipated construction and investment decision is targeted for late 2027, after the necessary work has advanced and project financing has been secured. Should construction proceed, it is expected to take around two years, with mine operations targeted to begin in 2030.

The following is available on this page:Feasibility study news releaseTechnical report news releaseThe complete NI 43-101 Technical Report is available from Northcliff Resources SEDAR+ profile.