The tiny town of Sherridon is sounding big alarm bells over mine waste, but the provincial government says there’s no true cause for concern.
In a recent letter to the province and media, Sherridon Mayor Nick Benyk warned that “highly acidic mine tailings water” was slated for release into Kississing Lake last week.
“Kississing Lake is one of the main sources of income for numerous businesses and residents of Sherridon,” wrote Benyk. “This includes fishing lodges and outfitters who provide employment to local residents as well as commercial fishermen, wild rice growers, and trappers. The lake is also utilized for swimming, boating and other recreational water activities in the summer.”
In his sharply worded letter, Benyk said he and his council do not trust Mineral Resources Minister Dave Chomiak, who has overseen the ongoing mine-waste remediation project in Sherridon.
His letter came as provincial contractors were scheduled to potentially discharge some water from Camp Lake, where the mine waste in question is stored, into Kississing Lake.
Dr. Chris Beaumont-Smith, director of mines for the provincial government, said it was made clear to Sherridon that water would be discharged only if it met federal guidelines for pH levels and metal content.
“We were very explicit about that,” he said.
In 2009, the province launched a project to remediate decades-old mine waste in Sherridon, a town of about 85 people situated 60 km northeast of Flin Flon.
Beaumont-Smith said the project involved relocating the waste, known as tailings, into Camp Lake and submerging it in water. The last of the tailings were moved in 2013.
The project included the construction of a water treatment plant and an accompanying access road across Camp Lake.
The plant was ineffective in treating the water in Camp Lake, Beaumont-Smith said, so further research was conducted.
It was discovered that the access road itself, built with tailings, was producing acid, he said.
The plan now is to decommission the plant this spring and summer and submerge the access road by excavating it.
In the interim, 1,500 tonnes of lime were spread on the frozen surface of Camp Lake in an effort to neutralize the pH level when the ice melts.
Unacceptable level
In his letter, Benyk worried about the lime producing a false-positive reading. When lime was used on Camp Lake last year, he wrote, the pH returned to an unacceptable level within two weeks.
Beaumont-Smith confirmed lime was used last year and that while this initially led to neutral pH levels, that neutrality could not be maintained because there was more acid-generating capacity than expected.
But after additional testing, he said the province now has a much better estimate as to how much acidity must be neutralized.
Discharging some of the water would lower the depth of Camp Lake, Beaumont-Smith said, so the access road, now partially submerged, can be used.
Without a discharge, Camp Lake will eventually overflow, he said.
Beaumont-Smith said that before the remediation project began in 2009, 17 million cubic metres of acidic water drained into Kississing Lake each year.
“Now it’s zero,” he said.
In his letter, Benyk also referenced an incident involving lime on Camp Lake, saying there was “lime dust everywhere,” including the community’s school, hotel and skating rink.
Beaumont-Smith said some lime dust did become airborne during a particularly windy day last winter.
The same thing happened again after contractors sprayed the lime with water in hopes of preventing a recurrence, he said, admitting his disappointment.
Asked about potential health concerns – sufficient exposure to lime can cause problems – Beaumont-Smith said, “I don’t think it’s at the level of testing [people].”
He said contractors on site found only “minor traces” of lime in the school area and made sure to wipe down all of the playground equipment.
Asked why tailings were used to build the Camp Lake access road, Beaumont-Smith said the material was available and that at the time consultants did not believe it would become a significant source of acid.
The road was also intended to be underwater in 2011, he said, meaning it has had four additional years to generate acid.
Overall the remediation project carried an initial budget of $34.5 million. Beaumont-Smith said the work remains on budget.
