But government officials acknowledged Wednesday they still didn't know exactly what spilled out or how the breach will affect surrounding lakes and rivers, where salmon spawn, locals get their drinking water and tourism operators take their customers.
A tailings pond dam at Imperial Metals' Mount Polley Mine, about 600 kilometres northeast of Vancouver, failed on Monday, sending 10 million cubic metres of water and 4.5 million cubic metres of toxic silt into Polley Lake and Quesnel Lake.
The breach prompted a ban on drinking or bathing in water from surrounding lakes and river, which was still in effect on Wednesday, though the company has insisted the water in the tailings pond was safe and the solids that spilled out were "relatively benign."
The province's Environment Ministry announced Wednesday that the company received a "pollution abatement order" a day earlier.
Under the terms of the order, Mount Polley Mine was required immediately take steps to prevent more waste from escaping into nearby creeks and lakes. The company was also ordered to conduct an environmental assessment and submit a clean-up action plan by Wednesday, with a more detailed plan due by the end of next week.
The province also ordered the company to provide a detailed assessment of the materials that were released, including the anticipated impact on the environment.
Mines Minister Bill Bennett said it was still too early to assess the potential impact of the spill, though he said that may change Thursday, when the first water-testing results were expected to be released.
"I am hopeful the company is correct in terms of what they say their records show (about what was) in the tailings and that will lead us to positive results, but I don't know that," said Bennett.
The minister promised a thorough investigation that will look at both the actions of the provincial government and the company.
"If the company has made some mistakes and is the cause of what happened, it will have to acknowledge that and it will have to bear the costs and responsibility for that," said Bennett.
A summary of material dumped into the tailings pond filed last year with Environment Canada listed 326 tonnes of nickel, over 400,000 kilograms of arsenic, 177,000 kilograms of lead and 18,400 tonnes of copper and its compounds.
On Monday, the same day as the breach, the company sent the provincial government data about the tailings pond water, B.C.'s Environment Ministry said.
Tests indicated that levels of selenium exceeded drinking-water guidelines by almost three times and organic carbon concentrations exceeded guidelines for chlorinated water. The ministry also said nitrate, cadmium, copper, iron and selenium had exceeded aquatic life guidelines at least sporadically in recent years.
"The ministry would not say that (the water in the tailings pond), based on the characterization, had satisfied drinking water requirements," said Jennifer McGuire of the B.C. Environment Ministry.
Company president Brian Kynoch apologized to local residents on Tuesday and appeared to downplay the potential dangers posed by the spill. He said the water released from the pond was very close to drinking water. He also said mercury had never been detected in the water and arsenic levels were low.
Grand Chief Stewart Phillip of the Union of B.C. Indian Chiefs said the presence of heavy metals in the tailings could be devastating to salmon.
"I don't think there's any question that it's absolutely catastrophic —it has the potential to devastate the wild salmon stock.
Quesnel Lake and the Quesnel River are considered important breeding grounds for wild salmon, as are other nearby creeks. The system eventually reaches the Fraser River.
"It couldn't happen at a worse time: the Quesnel salmon run is expected to pass by in a couple of weeks," said Phillip.
Craig Orr, the executive director of the group Watershed Watch, said he was skeptical of the claims by the company and the province.
"It's a disaster, no question about it," he said in an interview.
"There have been a lot of concerns about human health and drinking water, but a lot of concerns I've heard have been about the fish,"
Orr said debris could impede salmon migration, while heavy metals such as copper could either kill the salmon or harm the fish.
Sharon Borkowski and her husband own Northern Lights Lodge in Likely, offering cabin rentals and fly fishing trips. Last year, they began renting out the cabins to mine workers after officials with the Mount Polley Mine approached them with the offer of steady, year-round rentals.
The miners went home this week and Borkowski isn't sure fishing tourists will return to the site of a major industrial accident to take the workers' place.
"This affects us double," said Borkowski.
Borkowski said she's optimistic with the company's statements that the water is safe, but she's still waiting for the results of water quality testing, expected Thursday.
"When you see those aerial photos, it's pretty devastating," said Borkowski.
"Then (when the results are in) I will feel a little better, but long-term, I just don't know. Until they get those results in, I don't think they can tell you what effect it has."
-- With files from James Keller in Vancouver
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