Mount Polley Mine, the Canadian operation that spilled 4.5 billion gallons of water and 10.3 million cu yd of waste after a massive tailings storage pond breach in 2014, has won government permission to pump treated effluent into nearby Quesnel Lake.
The British Columbia Ministry of Environment approved on April 7 the company’s long-term waste water management plan that allows pumping as much as 13.7 million gal daily into Quesnel Lake, a glacial body that is a salmon spawning area and is the water source for the town of Likely, B.C.
The permit is good through 2022, the projected end of life for the gold and copper mine. The owner, Imperial Metals Corp., Vancouver, must come up with another plan for longer-term use before then, according to the permit signed by Douglas Hill, ministry engineer.
Mount Polley also must halt discharge to Hazeltine Creek – which was severely damaged during the initial spill in August 2014, but has been remediated – by Dec. 31, 2017. It can let a maximum of 7.7 million gal daily into the creek that runs between Polley Lake, near the mine, and Quesnel Lake.
The mine will collect water in small settlement ponds before draining it to an on-site treatment plant for filtration. The water then would be piped to the lake, to a diffuser more than 650 ft offshore and more than 140 ft deep to empty into the lake.
Quesnel Lake, which covers more than 100 sq mi and is more than 600 ft deep, is a major tributary to the Fraser River.
The lake water was too polluted to drink for months after the spill but is now undergoing regular testing and meets government drinking water quality standards.
Environmentalists, however, continue to be concerned about the water quality and the potential impact on fish.
“I’m not at all impressed” with the water treatment plan, said Richard Holmes, president of Cariboo Envirotech Ltd., Likely. “Their ‘treatment’ is a simple one million dollar plant that removes sediment from the site water and therefore lowering the contaminant levels,” he said. “This is simply the cheapest and most basic possible form of treatment by letting the surrounding environment address the contamination.”
Ugo Lapointe, program director for MiningWatch Canada, said the long-term effects of the spill are “unknown at this stage, partly because salmon spawning runs on a four-year cycle.”
Quesnel Lake, he said, is also home to the endangered bull trout and the Fraser River coho salmon, “which has seen sharp decline in recent years.”
An independent study blamed the spill on design flaws and the chief inspector of mines blamed poor water management standards, but neither prosecuted. The breach is still under investigation by the British Columbia Conservation Officer Services, Royal Canadian Mounted Police and other agencies. There is no timetable for completing the investigation.
“The key message to Canadians is this was the biggest mining spill in Canadian history and there have been zero sanctions and zero fines, and certainly that’s not because of lack of evidence of damage to the environment,” Lapointe said.