Tailings Dam Failure Hits Fraser River Watershed, Salmon Spawning Regions

By Margaret Bauman
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
“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
“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
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
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
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.