Researcher says water management will be 'high priority' as potash mining expands in Sask.

Water usage will increasingly become an issue as Saskatchewan expands its potash mining industry, according to a University of Regina researcher. 

Several mines are in the works in the province. Since 2010, six have been approved through an environmental assessment, according to the provincial government. There are another six in the works or currently under environmental review. 

Yuliya Andreichuk researched water usage of the mines as her master's thesis project for environmental engineering at the University of Regina. 

Andreichuk's estimate is that the amount of water required for the projects, if they move ahead, will be seven times what it was in 2010.

The estimated water usage for nine of the projects is nearly 90 million cubic metres of water per year, according to the Ministry of Economy.  

The Water Security Agency said there is an adequate water supply from Lake Diefenbaker, which is the source of much of the water, for future and current use. 

The agency said one proposed mine by Yancoal would use just 0.15 per cent of the water volume available from it annually.

"That is a drop in the bucket, and not even, of what capacity is there from Lake Diefenbaker," said Patrick Boyle with the WSA.  

While the required amount of water is available now, Andreichuk said the challenging factor for government will be the more extreme variations in precipitation expected due to global warming. 

"Potash was established 60 years ago and it was not really prolonged droughts in that time, but there can be in the future," Andreichuk said. 

"This is something they have to keep in mind, especially when they're trying to manage water for the municipalities and industries to keep everyone happy."

The high water usage is mainly because all but one of the proposed mines would use the solution mining technique, which means they extract potash using a large amount of hot water. 

The main source of Lake Diefenbaker is Alberta's waterways and the Rocky Mountains. 

"Alberta shares with us only 50 per cent of that water, so water management has to be really high priority," Andreichuk said. 

Environment Minister Dustin Duncan said the mines do require an "extraordinary" amount of water, and acknowledged Saskatchewan's water usage affects other jurisdictions. 

Duncan said whenever the ministry is making decisions on approving these projects, they ensure that amount of water is available to use.

"If it does look like in the future that we're going to put more demands on those resources, we need to make sure that we're doing that in concert with our neighbouring jurisdictions, to ensure that they're able to use their water supply and we're able to use ours as well," Duncan said.  

Contaminated water 

One complicating factor for solution mining is the effluent water is "pretty contaminated," said Andreichuk.

That means it can't be returned to its original source and has to be either evaporated through evaporation ponds or deep injected for storage. 

"It's only one-way using water; it never comes back to original source," Andreichuk said. 

"In that case, you have to make sure that you will have enough water for all span of potash mines, and some potash mine projects can be up to 100 years."