Mount Polley mine: sediment near spill may harm fish

The latest test results from a tailings pond that spilled waste from the Mount Polley mine in the Cariboo show that while the discharged sediment is still not toxic for humans, it may harm aquatic life.

The province says sediment samples collected Aug. 10 from the mouth of Hazeltine Creek and near Raft Creek in Quesnel Lake exceed guidelines and contaminated sites regulation standards for copper and iron.

• MORE | Initial water quality test results within drinking guidelines
• MORE | Mount Polley mine spill: Drinking-water ban partially lifted

Two samples were from within the impact zone and one was from the undisturbed lake bottom, the province said in a news release.

However, the government says other areas where mines are located have naturally occurring elevated levels of metals. 

It also says scientific evidence indicates the metals are not likely to leach from the sediment into the water. However, it says it will be conducting more tests in the next few days to determine if that is, in fact, the case.

Results not unexpected

Environment Minister Mary Polak says the results are not unexpected and are similar to what is found in the tailings.

She says long-term monitoring and remediation will continue in the affected areas.

"All the raw data from the tests has been shared with First Nations and Interior Health," said Polak.

"The results were tested at an independent lab in Vancouver and show that the sediment poses no human health risk. However, it may pose adverse effects on aquatic life and it exceeds B.C. guidelines for sediments and contaminated sites regulation standards for copper and iron."

Polak said Imperial Metals, the company that owns the breached pond, must show the government how it will address the situation.

"They will have to present to us a plan for how they would address that," said Polak. "In terms of the specifics, that will all unfold as the plans are put in place and reviewed by our staff and with First Nations."

The Ministry of Environment said it is still too early to determine what kind of harmful effects the sediment could have on aquatic life.

Lana Miller, an official with the ministry, said copper could affect the reproduction, growth and behaviour of fish.

"The effects that we will see on higher organisms will probably come through the copper moving through the food chain," she said.

Miller said more tests need to be done before authorities can understand what exactly will happen to fish and other wildlife in the area.

'Huge impact' on First Nations groups

The tailings dam at the Mount Polley gold and copper mine failed last week, sending millions of cubic metres of water and silt spilling into lakes and rivers in a remote area about 600 kilometres northeast of Vancouver.

Hundreds of people were ordered not to drink or bathe in their water as Imperial Metals started cleaning up.

Initial test results came back within drinking-water and aquatic-life guidelines, prompting the local health authority to partially lift the water ban.

• MORE | Controlled release of Polley Lake water in mine tailings breach underway
• IN DEPTH | What happens to tailings pond effluent over time
• FAQ | Tailings ponds: What's in them and what risks do they pose?​

But there has been concern about the impact on fish that live in or pass through the affected lakes and rivers.

People will be going hungry because of this problem.—Chief Joe Alphonse, Tsilhqot'in National Government

Chief Joe Alphonse of the Tsilhqot'in National Government said First Nations leaders had previously ordered people to stop fishing from the area since the spill because of health concerns, but the test results have confirmed their fears.

"The findings are just proving what we've always believed," he said.

Alphonse said this time of year is critical for First Nations anglers, who would normally be catching salmon in the Fraser and Quesnel River areas to stock up for the winter. Fishermen will not be able to stock up this year and may not be able to feed their families, he said.

"It's a huge impact — a giant impact," he said. "People will be going hungry because of this problem."