Some people living north of Fredericton want to know who will pay for the future clean-up of a proposed tungsten mine in the Nashwaak Valley area.

The Sisson Project is being led by Northcliff Resources and, if approved, could turn into one of the world’s largest open-pit mines.

Gary Spencer said he wants to know who is going to foot the bill for cleaning up after the mine closes.

"Somebody's going to have to treat the water and, I start sounding silly when I say this, but, forever," he said.

"Somebody's going to have to maintain the roads, provide electricity to the pumps that are going to pump the water back, and so on and so forth."

The mining project is still in the environmental impact assessment stage.

However, Northcliff Resources is expected to release its environmental impact assessment on the Sisson project in the near future.

The company has estimated the construction of the mine could start in 2014 and operations could start in 2016.

The mine’s footprint will likely be 14.5 square kilometres and the company expects to hire 300 people to work in the mine.

'Best advice: make a reasonable estimate and maybe double it or so. Otherwise taxpayers will be on the hook.'— Jamie Kneen, MiningWatch Canada

A national mining watchdog said it's hard to know how much money is enough to set aside for the future cleanup of the large mine site.

Jamie Kneen, the communications and outreach co-ordinator of MiningWatch Canada, said mine remediation costs are often higher than expected.

"Best advice: make a reasonable estimate and maybe double it or so. Otherwise taxpayers will be on the hook," Kneen said.

The provincial government is still paying to clean up the Caribou mine near Bathurst.

The Department of Energy and Mines recently agreed to spend up to $15 million to address historical problems around the northern mine.

Spencer will be looking for how much money the company will set aside for cleaning up the area after the mine closes.

Meanwhile, a potential designation of the Nashwaak River Valley as a protected natural area has been stalled since December.