Three months ago, the Mount Polley mine experienced a small, but notable, breach that was quickly corrected when the gold and copper operation "got itself into compliance," according to the province's mines minister.
But environmental advocates say the incident should have served as a warning to avert the massive tailings-pond failure this week that has spewed millions of cubic metres of potentially contaminated waste into central British Columbia's waterways, a disaster believed to be the largest of its kind in Canadian history.
The Mount Polley tailings pond damn burst early Monday morning, spewing enough mining waste water into the Cariboo district's waterways to fill 2,000 Olympic-sized swimming pools. The Cariboo Regional District declared a local state of emergency; up to 300 residents in the rural community of Likely remain without clean water for drinking or bathing.
On Wednesday, the B.C. government ordered Imperial Metals Corporation, which owns the mine, to undertake an environmental impact assessment and submit cleanup plans to the Ministry of Environment.
The exact cause of Monday's rupture is under investigation. There are three inspectors on site and two consulting companies are working with the Ministry of Energy and Mines, Minister Bill Bennett said.
Mr. Bennett played down the significance of the May breach, noting that a routine, annual geotechnical inspection of the site that same month found "no evidence to indicate" there was cause for concern.
"We don't have indication, certainly that I'm aware of yet, in our files, that any inspectors since [the mine opened in] 1997 had a concern about the tailings dam," he said.
In May, water in the Mount Polley tailings pond – into which mining waste is dumped – had climbed too high, in contravention of B.C.'s Environmental Management Act, which requires at least half a metre between the waterline and the top of the pond. The Ministry of Energy and Mines issued an advisory to the company, which then pumped some water into an empty pit and "got itself into compliance."
Calvin Sandborn is legal director at the University of Victoria's Environmental Law Centre, which has long called for stricter regulation of the mining industry. He viewed the ministry's May advisory to Mount Polley – which Mr. Bennett said was the only warning the mine has ever received – as hardly a slap on the wrist.
"The minister's comment that the company 'got itself into compliance' is all too common with the B.C. government, which shrugs off non-compliances and tries to coax and cajole companies to stop breaking the rules," Mr. Sandborn said. "It's not just up to the company to 'get itself into compliance'; that's the government's job, and they failed miserably here."
A 2011 report by the law centre found that, of six Ministry of Environment enforcement actions taken against B.C. coal and metal mines from 2006 to 2010, the fines for five were less than $600 – "little incentive to comply with the law," Mr. Sandborn said.
Mr. Bennett sought to discredit the public comments of Brian Olding, president of environmental planning company Brian Olding & Associates Ltd., who was hired as an independent consultant in 2011 to review a technical report from the Mount Polley mine, which at the time was seeking an effluent discharge permit. Mr. Olding had told media his firm found discrepancies in the company's report and provided recommendations, most of which the company ignored.
"He didn't deal with any geotechnical aspects, he didn't deal with the construction or the design of the tailings pond," Mr. Bennett said. "He was not hired, nor did he look into, the geotechnical aspects of this dam. So there was no warning from him or anybody else that we should be concerned about this tailings dam."
In 2012, the Ministry of Environment granted that permit, which allowed Mount Polley to discharge up to 1.4-million cubic metres of dam seepage effluent from the tailings pond to nearby Hazeltine Creek each year. Last month, it applied for another permit, which would allow it to discharge up to three million cubic metres of treated effluent to Polley Lake, which overflows to Hazeltine Creek.
The ministry had been considering the request when the dam burst.
Mr. Bennett also refuted claims that cuts in environmental staff at the B.C. government may have contributed to the disaster. The Environmental Law Centre report claimed deep budget cuts resulted in an inadequate number of government staff to carry out enforcement actions, and noted the human resource challenges that arise from the perceived low pay of environmental enforcement officers.
"The inspections that are done on mine sites are no different today than they were five years ago," Mr. Bennett said. "I know that between 2001 and 2003 a lot of people were laid off in the B.C. government. … I also know that resources in this ministry came back up to 2001 levels by 2009. The inspections of tailings ponds are as frequent as they were five years ago."
Imperial Metals did not make president Brian Kynoch available for an interview on Wednesday.