With regards to the Williams Lake Tribune article submitted by Lynn Anglin of Imperial Metals dated May 10 titled “Progress Made on Remediation at Mount Polley.”
I find that her comment “The tailings in Quesnel Lake, which is a very deep lake, are sitting at depths of greater than 100 metres and there is no evidence that they are re-suspending” is not supported by other research undertaken on Quesnel Lake as a result of the disaster that occurred in 2014.
The UNBC research by Dr. Ellen Petticrew and Dr. Phil Owens and other researchers from various universities finds that the resuspension of the tailings may be occurring.
In a related communication that I recently received from the UNBC research team the following was stated:
“Results of post-spill water column monitoring indicate elevated turbidities in the bottom waters of the West Basin in the fall and winter, when the lake circulation is most active.
This was observed in fall 2015, 2016, and 2017 with decreasing intensity each year.
Suspended sediment delivered to the Quesnel River from the lake exhibits copper levels exceeding both local background sediment concentrations (60-100 mg/kg) and the probable effects level for aquatic organisms (197 mg/kg) in mid-October 2014 through to late-May 2015, again from November 2015 through to mid-May 2016 and in January of 2017.
The timing of these high river sediment copper concentrations corresponds with the elevated turbidity in the West Basin.
These observations suggest the copper-elevated suspended sediment in the Quesnel River is coming from the bottom waters of the West Basin.
The original source of these sediments could be natural or mine-related material, or a combination of both. Research is continuing to determine the source of this sediment.”
Further to this I understand that Lynn Anglin and other Imperial Metals staff have been present for presentations by UNBC and other universities that discuss the summary of West Basin Turbidity and Quesnel River Suspended Sediment Copper Concentrations provided above by UNBC.
I and many of your readers would be pleased to know why this research on suspended sediment is not being recognized by Lynn Anglin and Imperial Metals in her May 10 article.