Tailings pond sediment poses no human health risk, may affect aquatic life
WATCH: The latest test results from water samples taken near a massive tailings pond breach found fish may be at risk. Julia Foy reports.
The ministry of environment says sediment samples taken at the site of the Mount Polley tailings pond breach show it poses no risk to human health, but may have an impact on aquatic life.
“It would be safe to use for agricultural production destined for human consumption and for areas where recreation takes place,” said Dr. Andrew Larder, senior medical health officer for the Interior Health Authority.
However, the sediment samples exceed B.C. guidelines for sediments and contaminated sites regulation standards for copper and iron, and may pose adverse effects on aquatic life.
“Copper in the water can have effects on fish reproduction, behavior and growth,” says Lana Miller, Environmental Impact Assessment Section Head. “However, the results we are talking about today are from the sediment. So the effects that we will see on higher organisms will probably come through the copper moving through the food chain and we need to do a lot more work in conjunction with DFO, independent scientists and the First Nations before we can define those effects.”
There will be no immediate effect on the fish that is currently entering the Quesnel River area, according to Miller.
She says the effect will be of a long-term nature, because it will take time for the copper to be taken up the food chain.
The samples were collected on August 10 from the mouth of Hazeltine Creek and near Raft Creek in Quesnel Lake.
Two samples were from within the impact zone and one sample was from the undisturbed impacted lake bottom.
Minister Mary Polak says the results are not “unexpected” based on the geology of the area and the mine close by.
The ministry says areas where mines are located have elevated levels of metals.
That could mean naturally occurring metal concentrations are often much greater in this region than elsewhere in the province.
The ministry says the metals are not likely to readily move from the sediment into the water, and are not likely to present a risk to future water quality.
The province will conduct the so-called leachability tests in the next few days.
Meanwhile, the “Do Not Use” order in the impact zone involving Polley Lake, Hazeltine Creek and a small part of Quesnel Lake remains in place.
The ministry claims a comprehensive environmental impact assessment and action plan was submitted by the company on Friday.
“The responsibility for the rehabilitation rests with the company,” said Polak. “This would be considered a contaminated site under the regulations, so they would have to present to us a plan for how they would address that.”