The main project infrastructure components outlined in the 2022 Feasibility Study include the mine and process plant supporting infrastructure, site accommodation facilities, TMF, external and internal access roads, power supply and distribution, freshwater supply and distribution, and the water treatment plant.
The Property is situated on the eastern shore of Nova Scotia, Canada, with the central point of the Property being approximately located at 45° 12’ 2.6” N latitude and 61° 39’ 2.0” W longitude.
The Property will have access to the substantial infrastructure, services, and skilled labour in the area. There will be reduced infrastructure cost requirements due to its location near Route 316 compared to a remote mine site location. The Property is approximately 175 km northeast of the city of Halifax, 60 km southeast of the town of Antigonish, and 1.6 km north of the village of Goldboro, on the eastern shore of Isaac’s Harbour, in Guysborough County, Nova Scotia, Canada. A secondary gravel road (Goldbrook Road), accessed from Route 316, crosses the Property, and passes near the historic Boston Richardson shaft and exploration decline. Smaller logging roads and trails provide good access to most areas of the Property. The elevation is nominally 70 m above sea level. The regional labour force includes experienced equipment operators, mine workers and material and equipment suppliers.
The majority of the earthworks will be realized in the preparation of the mine infrastructure, process plant and TMF infrastructures. Haulage roads on site will be built to withstand frequent heavy traffic between the proposed open pit, ROM stockpile and TMF. They will be wide enough to accommodate two trucks passing between the pits and ROM stockpile at 16.5 m with a grade no greater than 10%. The road to and from the tailing’s management facility will be 11 m wide for one-way traffic by haul trucks.
In total, approximately 5,300 m2 of ancillary buildings (not including the employee accommodations and process plant buildings) have been provided.
These ancillary infrastructure buildings will be pre-engineered steel structures founded on conventional spread footing foundations. Space has been provided for future buildings provided by the mining contractor or in the case of expansion during operations.
Power for the site is anticipated to be provided from a nearby Nova Scotia Power 25 kV distribution line installed along Route 316. A 1.6 km tap line would be installed along a new right of way to the mine site main substation. Nova Scotia Power would upgrade their existing distribution system as necessary to be able to provide the additional power required. Peak power demand for the site is estimated to be 10 MW, with the average demand estimated to be 7.5 MW. A network of 13.8 kV overhead distribution lines would be installed at site to provide power sourced from the main substation for the mine and surface infrastructure.
Water supply infrastructure includes one intake structure, two booster stations, one transmission watermain from Gold Brook Lake to the mill freshwater tank and to the potable water treatment unit; and distribution piping to supply potable water throughout the Project site (mill, emergency response transport (ERT) facility, plant office, general office, mine dry, core storage, truck shop and employee accommodation). A transmission watermain from Gold Brook Lake to the processing plant buildings is to provide a raw water source to support mill process operations and site wide potable water, hence the watermain flowrate was estimated based on the potable and process water demands (22 m3/h).
Gold Brook Lake was considered as the source water, the treatment requirements were established based on the Canadian Drinking Water Guideline, and potable water treatment was sized assuming an equal flowrate for both potable water and wastewater (16 m3/h).
Two separate wastewater treatment units were developed to service employee accommodation (with 350 people) and other buildings/facilities including mill, ERT facility, plant office, general office, mine dry, core storage, truck shop (with 84 people). Sewage flow rates as well as treatment requirements were adopted from the Atlantic Canada Wastewater Guidelines Manual for Collection, Treatment and Disposal, 2006.
The mine water management plan (MWMP) and associated design measures have been developed based on the proposed feasibility level mine site arrangement with inputs from the Company and the Consultants. The MWMP will be implemented during the construction phase and will be adjusted as necessary throughout the mine operations and closure phase.
Site contact water will be managed to meet the following regulatory discharge requirements prior to discharge to the natural environment:
Metal and Diamond Mining Environmental Regulations (MDMER) Objectives
Canadian Council of Ministers of the Environment (CCME) Guidelines for the Protection of Aquatic Life
Tier 1 Nova Scotia Environment Quality Standards (EQS) for Surface Water
Site specific criteria (based on background)
Based on predictive water quality modeling, it is understood that the water quality at some locations may be acceptable for discharge to the environment with total suspended solids (TSS) removal as the only form of treatment (where MDMER objectives are met). Where this is not the case, contingency measures (shutoff valves and pumps etc.) will be put in place to redirect water towards the nearest water treatment system (WTS) in case of exceedances. The primary objectives of the MWMP are as follows:
Provide mechanism to dewater and treat ponded water within the Project Area to allow for development and excavation of mine infrastructure (e.g., pit, waste piles, haul road etc.).
Capture, treat and provide controlled discharge for all site contact water during construction and operations.
Divert all off site clean water away from the mine site infrastructure to reduce the total volume of water entering the settling ponds for treatment.