Tailings Dam Failure Hits Fraser River Watershed, Salmon Spawning Regions
Canadian mining officials in British Columbia are investigating a tailings pond dam rupture that released an estimated 14.5 million cubic meters of mine wastes into the Fraser River watershed, including salmon spawning regions.
British Columbia's minister of Energy and Mines Bill Bennett announced at a news teleconference in Williams Lake, BC on Aug. 6 that the operator of the Mount Polley mine was ordered to immediately halt the pollution and immediately submit an environmental impact report. A more detailed cleanup plan is due by Aug. 15, provincial authorities said.
Imperial Metals Corp., of Vancouver, BC, was also told to submit weekly plans on its cleanup plan. The provincial government plans to post those reports on its website. Bennett also said some 20 other mines operating in the province with similar tailings pond dams are now going to be watched more closely, based on what happened at Mount Polley.
It was also disclosed during the news conference that the province had warned mine officials on May 24 about excessive water levels in the tailings pond, and that water levels returned to those authorized on June 30. Bennett said that was the only such incident on record and that there "was no warning that we should be concerned about this tailings dam."
A day earlier, Bennett issued a statement calling the Aug. 4 breach of the tailing pond dam at the Mount Polley copper and gold mine site in central British Columbia "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 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.
Gerald MacBurney, who was foreman of the mine for more than seven years before he quit in June, said in interviews with Canadian broadcasters that the tailings dam was not designed to hold the amount of tailings put into it.
MacBurney said he had warned the company that they needed to reinforce the dam, but they wouldn't do it, so he quit.
Knight Piesold Consulting, an international consulting group, with offices in Vancouver, BC is the former engineer of record of the breached tailings storage facility at Mount Polley.
In a statement issued Aug. 8, Knight Piesold said that their company had ceased to perform that role for the mine on Feb. 10, 2011.
"The original engineering done by Knight Piesold Ltd. accommodated a significantly lower water volume than the tailings storage facility reportedly held at the time of the breach," the company said. "Significant engineering and design changes were made subsequent to our involvement, such that the tailings storage facility can no longer be considered a Knight Piesold Ltd. design," the company said.
Upon completing all assignments as the engineer of record in 2010, Knight Piesold wrote to the mining company and the chief inspector of mines for British Columbia, stating that "the embankments and the overall tailings impoundment are getting large and it is extremely important that they be monitored, constructed and operated properly to prevent problems in the future.
"A formal handover of design, construction and monitoring responsibilities was conducted on March 8, 2011 when AMEC Earth and Environmental was acknowledged as the new engineer of record for all future work" at Mount Polley, the statement said.
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 habitat, but the Department of Fisheries and Oceans has already banned salmon fishing in the Cariboo and Quesnel rivers because of the mine wastes. Continuous testing of the water and sediment is planned.
The CBC said hundreds of thousands of salmon were making their way up the Fraser River in what had been billed as a banner year for sockeyes. Sockeye salmon migrate up the Fraser River, then into Quesnel River and into Quesnel Lake. They also would have headed up into Hazeltine Creek to spawn, a waterway decimated by the spill.
Ernie Crey, fisheries advisor for eight First Nations along the Fraser, told the CBC, "Right now there is a lot of anxiety throughout the entire watershed among First Nations fishermen about contaminants they hear are in those suspended materials."
Craig Orr, executive director of the Watershed Watch Salmon Society, told CBC News that the Quesnel Lake is a major summer sockeye producer in the Fraser River. Orr noted that heavy metals pose a huge risk to fish.
Copper, even in lower concentrations, can impair the sockeyes' ability to smell and this is important for returning salmon using olfactory cues to return to their natal streams. There is also fear that the fish will die as a result of toxics from the debris or silt in their gills.
In a report filed last year with Environment Canada, mine owners said 326 tons of nickel, more than 400 tons of arsenic, 177 tons of lead and 18,400 tons of copper and its compounds were put into the tailings pond in 2013.
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 rivers 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 dedicated 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."
"Pebble's claims that the Fraser River watershed is the ideal example of where mining and fish coexist are completely unfounded," said Kim Williams, of Dillingham, Alaska director of Nunamta Aulkestai, an association of Alaska Native tribes and corporations opposed to the Pebble mine. "Our hearts go out to those in BC who live downstream from this devastating mine failure."
The failure of the BC tailings dam also prompted comment from commercial fisheries and environmental organizations in Southeast Alaska, who are concerned about the proposed Kerr-Sulphurets-Mitchell mine and other mines proposed on the Taku and Stikine rivers.
The KSM mine is one of a dozen large open pit mine proposals currently under review on the B.C. side of the transboundary region. If developed, the KSM mine would be among the largest open pit mines in the world.
Brian Lynch of the Petersburg Vessel Owners Association drew parallels between the Mount Polley mine, and the proposed KSM mine. "This is exactly the type of disaster we are trying to avoid on the Unuk and Nass rivers by seeking a higher standard of environmental review for the KSM project," Lynch said. "We urge that Canada issue no new mine permits in the transboundary river region until there is a full investigation of this accident and guarantees that similar accidents won't occur at larger mines proposed in the Unuk, Stikine and Taku watersheds."
"The destructive impacts of the Mount Polley breach are both tragic and ironic, especially as we prepare comments on a massive mine proposed for the Unuk River, home to one of Southeast's biggest king salmon runs," said Dale Kelley, executive director of the Alaska Trollers Association. "Mount Polley's tailings pond is miniscule when compared to the holding facilities proposed for KSM mine, which spans two watersheds that produce important runs of wild salmon.
On July 29, the government of British Columbia granted Seabridge Gold Inc. an environmental assessment certificate for the proposed KSM mine. It is now under review by the federal Canadian Environmental Assessment Agency at the mid-level "comprehensive review" with a public comment period open through Aug. 20.