Eagle Gold mine leak entering wetland but water tests clean, inspection report says

Water leaking from a containment pond at the Eagle Gold mine in central Yukon has been seeping into the ground and resurfacing in a nearby wetland, but a newly released report shows that while the same leak has been blamed for a spike in contaminants in a nearby creek, water samples from the wetland appear to be clean.

A Yukon government natural resource officer noted the resurfacing water during a series of inspections of the site in January. However, his report was only published on the Yukon Water Board's website on March 19.

The document, though dated, provides a snapshot of the ongoing efforts to deal with the aftermath of the heap leach failure at the mine. An estimated four million tons of ore being treated with cyanide solution slid off the heap last June, with about half of it spilling out into the environment. 

Storing, treating and monitoring contaminated water at the site has been a major challenge ever since. 

The report indicates that the on-site water treatment plant was already successfully treating contaminated water for cyanide by Jan. 8, though copper, which is being used to treat the cyanide, was present in high concentrations and test fish placed in treated water samples did not survive longer than four days. 

The report also notes an ongoing leak in a water storage pond that was first detected in December. 

Government officials in February announced that contaminated water from that leak had likely reached neighbouring Haggart Creek and was causing spikes of cyanide, cobalt, nickel and chloride that posed a threat to aquatic life. However, the report says that water leaking from the same pond was also soaking into the ground and emerging in a "low lying wetland area" about 200 metres away. 

Department of Energy, Mines and Resources spokesperson John Thompson said in an email that the pond has been used to store both contaminated and treated water and that the movement of groundwater could explain why water leaking into the creek and wetland were of radically different quality.

"Groundwater moves in different directions at different depths. This influences where it surfaces, and why you may see impacts in one area but not another," he wrote. 

Thompson also said officials have increased groundwater monitoring efforts at the site, and that investigations are ongoing, including collecting and analyzing data to understand impacts from the leak.