Tailings Dam Failure Hits Fraser River Watershed

Canadian mining officials in British Columbia are investigating a tailings dam rupture that released an estimated 10 million cubic meters of water and 4.5 million cubic meters of fine sand into the Fraser River watershed.

British Columbia’s minister of Energy and Mines, Bill Bennett, issued a statement Aug. 5 calling the Aug. 4 breach of the tailing pond dam at the Mt. Polley copper and gold mine site “a serious incident that should not have happened. We are devoting every appropriate resource working with local officials to clean up the site, mitigate any impacts to communities and the environment, and investigate the cause of the breach,” Bennett said.

Imperial Metals Corp., in Vancouver, BC, meanwhile issued a statement saying that the breach had been stabilized, although the cause of the breach is unknown at this time. Monitoring instruments and onsite personnel had no indication of an impending breach, the company said. Imperial is an exploration, mine development and operating company based in Vancouver.

The tailings dam rupture on Aug. 4 followed by two days the opening of the first gillnet commercial fisheries targeting Fraser River sockeye salmon. The forecast issued by Fisheries and Oceans Canada calls for returns within a wide range between 7.3 million and 72.5 million fish. The median return is 23 million fish.

It was not immediately known what effect the tailing dam rupture would have on the fishery.

Michelle Imbeau, a spokeswoman for Fisheries and Oceans Canada said “the possible impacts on the Fraser River sockeye salmon as a result of tailings deposit into Quesnel Lake are not known at this time. Sockeye are currently migrating toward the Quesnel Lake system.  Fisheries and Oceans Canada will be closely monitoring the salmon run as it approaches the Quesnel system over the coming days to assess the potential effects of these pollutants and other factors including water temperature on salmon returns,” she said.

Bennett said that BC’s Cariboo Regional District has issued a precautionary water ban advisory not to drink or bathe in the water, not to allow pets or livestock to drink the water. The ban includes Quesnel and Polley lakes, Hazeltine and Cariboo creeks, as well as the Quesnel and Cariboo river systems up to the Fraser River.

Carol Ann Woody, an Anchorage-based fisheries scientist who has done extensive research in the Bristol Bay watershed, said a tailings dam disaster like this “is Bristol Bay’s worst nightmare.”

The Fraser River, said Woody, “is Canada’s number one salmon producing system, and to see this happen here is a travesty.”

The incident comes on the eve of public hearings in Anchorage and Southwest Alaska on a proposal from the Environmental Protection Agency to use the Clean Water Act to restrict mining activity in the salmon-rich Bristol Bay watershed, where a subsidiary of a Canadian global mining group wants to build the massive copper, gold and molybdenum Pebble Mine.

“Our research shows that these tailings dam failures are far more common than the industry wants to admit,” said Bonnie Gestring of Earthworks, a nonprofit organization dedicating to protecting communities and the environment from adverse impacts of mineral and energy development. “In the US more than a quarter of the currently operating copper porphyry mines have experienced partial or total tailings pond failures.

“That’s why the EPA’s plan to restrict mine waste in the Bristol Bay watershed is so critical to the future of our nation’s most valuable wild salmon fishery.”