B.C. inspector of mines updated the public Tuesday about the efforts to remediate the Aug. 4 Mount Polley Mine tailings breach.
Speaking to a crowded Likely Community Hall, Al Hoffman said crews have started building a dike upstream of the breach and have completed about 64 per cent of its construction, which is anticipated to be completed by the middle of September.
The dike is a large rock structure and the objective is to prevent any more tailings from flowing out of the breach.
A satellite dam is also being constructed adjacent to the dike, which Imperials Metals vice president of corporate affairs Steve Robertson said is actually a ramp going down into the tailings impoundment.
“We want to go down and dig a sump (pump) down there and intersect that water and get it pumped back into the mine so it’s contained and doesn’t get released into the environment.”
After the tailings breach a plug formed in front of Polley Lake causing the lake level to rise by 1.7 metres.
Water is being pumped out, bringing the level down about one centimetre a day. Several residents sugested the lake should be left alone, however, Robertson said there’s concern because of the heavy rains that the region has been receiving.
“We were pumping at 11,000 gallons a minute and didn’t gain anything because of the rain that came through yesterday,” Robertson said Thursday.
And because crews are working down stream in Hazeltine Creek, there would be a human health hazard if there was a sudden flow of water and debris.
“We have had no life lost through this and we don’t want to lose anybody,” Stevenson added.
The investigation into the tailings pond breach only got underway this week, Hoffman told the crowd.
“We started the process in earnest in the last few days.”
Construction of the tailings storage facility first began more than 20 years ago so staff is looking at old documents, interviewing a number of people on the mine site and externally from the mine site, he explained.
The last geo-technicial inspection of the mine was done in September 2013 and no concerns were noted at the time, Hoffman said.
In the meantime, Hoffman has ordered that all tailings dams be inspected by an independent third party and must be completed by December to try to ensure there are no other dam failures.
While WorkSafeBC looks after other industries, the ministry is responsible for mine health and safety, he added.
The ministry is also responsible for permitting mine sites and part of that responsibility includes the review of tailing dam designs and operations.
“We will be looking into any contraventions of the Mines Act or what’s called the health and safety reclamation code for mines,” he said.