Quesnel Lake. Photo courtesy of Concerned Citizens of Quesnel Lake

Prince George, B.C. – People who live and vacation in the vicinity of Quesnel Lake will be receiving an update at the end of September from researchers studying the environmental effects of the massive breach of the Mount Polley mine tailings pond on BC Day, August 4th, 2014.

The breach of the earthen wall of the pond at the open pit gold and copper mine sent 25 million cubic metres of water and contaminated slurry into Polley Lake, down Hazeltine Creek and into Quesnel Lake which, at the time, was the cleanest deep-water lake in the world.  Subsequent testing showed increased levels of arsenic, copper, selenium and other elements.

Dr. Phil Owens, professor in UNBC’s Environmental Science department who works at the Quesnel River Research Centre at Likely, says staff there continue sampling and monitoring of conditions in the lake and in Quesnel River.  He adds “this summer we’ve also been collecting samples from some of the other big rivers that flow into the lake in order to either discount or incorporate them as sources of contaminants in the lake.”

“We also continue to monitor conditions in the water column.  The important finding there is that, particularly during the winter period we’re finding that the sediment and tailings at the bottom of the lake are getting re-suspended into the water column and some of that material is passing down through the Quesnel River.”

The indigenous peoples and those who reside either individually or in communities surrounding Quesnel Lake have historically taken their drinking water from the lake and, since the spill three years ago, have had concerns about whether it is safe to continue doing so.  Asked about that issue Dr. Owens says “I can’t comment on the quality of the water in the lake in terms of drinking water but I can certainly say that at times of the year some of the material at the bottom of the lake gets re-suspended back into the water column.”  That normally occurs during the period November through February.

“Some of those particles that are likely to be tailings material we have analyzed and there are certainly some very high levels of, for example, copper.  Some of that material does get flushed out of the lake and into the river but a lot of it will stay in suspension for a period of time and then settle back down to the lake bed” in what has pretty much been a continuous cycle.

Quesnel Lake is also part of the migratory route of a number of fish species and Dr. Owens says “in terms of the salmon the next big run is due in 2018 and that will be a very informative year to identify whether the event which occurred in 2014, when there was a peak salmon run of the order of 800,000 sockeye salmon moving into the Quesnel Lake river system during the time of the spill, whether that’s had an effect.  But in terms of the resident fish like trout, that’s something the Department of Fisheries and Oceans is working on to understand whether there is a signal getting into the resident fish.”

He says “some of the work that has been done by DFO and the research team at the QRC has suggested that there was evidence that there was higher levels of copper, for example, in some of the zooplankton which are at the bottom of the food chain immediately after the event.  So there is no reason to think that wouldn’t move up into the higher levels of the food web, such as the fish.”

Research team members are meeting again at the end of September “and will probably have a closer idea of some of the biological impacts.  Unfortunately, because of the wildfires the research centre is closed for three weeks or so and that has had some impact in that we weren’t able to do some of the eco-toxicology work we were hoping to do this summer.  That will now be re-scheduled for another time of the year.”

He says each year the research centre holds an open house in Likely to verbally present all of its findings to the community.  This year it’s the last Saturday in September.  In the past representatives from the Mt Polley mine and some provincial agencies have also been on hand.

Dr. Owens says “we’re also in the process of writing some publications which will contain some of our findings which will be made available to the scientific community.  We do feel there is evidence that the system is still showing sings of the spill and we are very keen that there is ongoing interest in monitoring and research about what the effects are.”

“We certainly don’t feel that it’s a done story.”