A spokesman for the company said it had submitted a closure plan for the ponds to the government last month and was taking steps to ensure no dust blew from the site and onto residential areas.

He said while most of the water had evaporated from the ponds in hot weather, the company was formalising an agreement to top them up with recycled water to reduce the spread of any dust.

“As the water evaporates, residues are left behind on the floor of the ponds in the form of a salt crust. These residues primarily consist of salt,” he said.

“The recycled water will be used to keep the ponds wet, thus reducing the potential for the generation of dust. The supply of water is imminent and will be at significant cost to the company.”

But community representative on the mine’s Environmental Review Committee, Ian Magee, accused the company of engaging in a “delaying process”, and called on the Department of Economic Development, Jobs, Transport and Resources to release a copy of the plan.

“The closure plan is really just simply anecdotes as to how work would be done and then it requires a work plan and there’s a whole lot of scientific work to be done by consultancies before the physical work starts,” he said.

“We want to see it.”

A spokesman for the department said an assessment of the closure plan was under way and it expected the ponds to be rehabilitated by May 9, 2018.

The community will have a number of opportunities to be consulted about the plans at events and information days organised by [GBM subsidiary] Kralcopic, and through the Environmental Review Committee,” he said.

The spokesman said an expert study into water quality and dust issues had concluded there was no definitive evidence the ponds were significantly affecting surrounding soils.

A public information day has been scheduled for later this month.