Mount Polley mining disaster caused major changes to ecosystem — study

Mount Polley mining disaster cause major changes to ecosystem — study

Aerial view of the Mount Polley mine tailings pond shows the area where the dam wall gave way early on the morning of August 4. (Image from archives)

Nine months after Canada’s Mount Polley copper and gold mine’s tailings pond breach, a new report has found a number of changes in the local ecosystem caused by the massive spill.

Researchers from the University of Northern British Columbia and the University of B.C., who studied the sediment plume of waste and water within Quesnel Lake in the three months following the incident, have concluded the water reservoir’s ecosystem has changed.

Among other anomalies, the report quotes a rise in the lake’s water level of 7.7 centimetres between Aug 4 and Oct 4, 2014, with the temperature at the bottom of the lake climbing from 1 to 2.5 degrees Celsius.

It also found higher levels of sediment — associated with an increase in turbidity in the lake.

Mine tailings were likely flushed from the lake into the Quesnel River, says the document, with huge amounts sinking to the bottom, which could leach over the years, the team said in a statement.

However, they believe it is still too early to determine long-term impacts on fish and drinking water.

Vancouver-based Imperial Metals (TSX:Ill), which operates Mount Polley, has said it could reopen the mine in June if granted a permit.

The company laid off 120 employees this week, according to The Williams Lake Tribune. The figure adds to the 36 who lost their jobs last November, and the 50 people dismissed in February.