It could bring many billions of dollars into the Arctic but would also see development of open-pit mines, roads, ports and other facilities in the centre of calving grounds for the fragile Bathurst caribou herd.
"This is going to be the biggest issue," said Sally Fox, a spokesperson for proponent MMG Minerals, a subsidiary of the Chinese state-owned Minmetals Resources Ltd.
It would be hard to exaggerate the proposal's scope. Centred at Izok Lake, about 260 kilometres southeast of Kugluktuk, the project would stretch throughout a vast swath of western Nunavut.
Izok Lake would have five separate underground and open-pit mines producing lead, zinc and copper. Another site at High Lake, 300 kilometres to the northeast, would have another three mines.
MMG also wants a processing plant that could handle 6,000 tonnes of ore a day, tank farms for 35 million litres of diesel, two permanent camps totalling 1,000 beds, airstrips and a 350-kilometre all-weather road with 70 bridges that would stretch from Izok Lake to Grays Bay on the central Arctic coast.
MMG plans a port there that could accommodate ships of up to 50,000 tonnes that would make 16 round trips a year — both east and west — through the Northwest Passage.
Izok Lake would be drained, the water dammed and diverted to a nearby lake. Three smaller lakes at High Lake would also be drained. Grays Bay would be substantially filled in.
The result would be a project producing 180,000 tonnes of zinc and another 50,000 tonnes of copper a year.
The four ministers, of Northern Development, Transport, Natural Resources and Fisheries and Oceans — have three choices. They can send the project back to MMG and ask for changes, they can choose to let the board run hearings itself or they can decide the project's effects would be broad enough to require the involvement of other governments in hearings.